development proposal & environmental management … city council... · 2015-11-27 · 6.3.15...

BURNIE WASTE MANAGEMENT CENTRE

STAGE 1 LANDFILL LEACHATE TREATMENT WETLAND

DEVELOPMENT PROPOSAL &

ENVIRONMENTAL MANAGEMENT PLAN

NOVEMBER 2015

Perth

12 Monger Street

PerthWA,Australia 6000

t +61[0]8 9227 9355

f +61[0]9 9227 5033

ABN : 39 092 638 410

Melbourne

2/26-36 High Street

Northcote VIC,Australia 3070

t +61[0]3 9481 6288

f +61[0]3 9481 6299

www.syrinx.net.au

BURNIE LEACHATE TREATMENT WETLAND

DPEMP

This Development Proposal and Environmental Management Plan was prepared by:

Syrinx Environmental Pty Ltd

Head Office:

12 Monger Street, Perth 6000, WA

Contact Person: Dr Kathy Meney

Company Director | Principal Scientist

Telephone: 08 9227 9355

Email: [email protected]

For:

Burnie City Council

Registered office

PO Box 973, Burnie 7320

Contact Person: Mr Rowan Sharman

Manager Engineering Services

Telephone: 03 6430 5752

Email: [email protected]

Significant input regarding the landfill stability and potential associated risks was provided by

Tasman Geotechnics.

The DPEMP will be submitted to:

The Chairperson

Board of the Environment Protection Authority

GPO Box 1550, Hobart TAS 7001

mailto:[email protected]


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PURPOSE OF REPORT

Syrinx Environmental Pty Ltd (‘Syrinx’) has prepared this document titled ‘Burnie Waste

Management Centre Stage 1 Landfill Leachate Treatment Wetland - Development Proposal &

Environmental Management Plan ’ (the ‘Report’) for the use of Burnie City Council (the

‘Client’).

LIMITATIONS OF REPORT

Syrinx Environmental PL has prepared this report as an environmental consultant provider. No

other warranty, expressed or implied, is made as to the professional advice included in this

report. This report has not been prepared for the use, perusal or otherwise, by parties other

than the Client, and their nominated consulting advisors without the consent of the Owner. No

further information can be added without the consent of the Client, nor does the report contain

sufficient information for purposes of other parties or for other uses. The information contained

in this report has been prepared in good faith, and accuracy of data at date of issue has been

compiled to the best of our knowledge. However, Syrinx Environmental PL is not responsible

for changes in conditions that may affect or alter information contained in this report before,

during or after the date of issue.

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TABLE OF CONTENTS

1.0 INTRODUCTION 1

1.1 TITLE OF THE PROPOSAL 1

1.2 PROPONENT DETAILS 1

1.2.1 Proponent Background 1

1.3 PROPOSAL SUMMARY 3

1.3.1 Proposal Background 3

1.3.2 Regional Context 6

1.4 LEGISLATIVE CONTEXT 7

1.4.1 Relevant Legislation, Regulations, Codes and Policies 7

1.4.2 Commonwealth Assessment Process 7

1.4.3 State Legislation & Assessment Process 8

1.4.4 Management Plan 10

1.4.5 Existing Permits & Manuals 10

2.0 PROPOSAL DESCRIPTION 11

2.1 PROJECT NEED 11

2.2 DETAILED PROJECT DESCRIPTION 12

2.2.1 General 12

2.2.2 Current Stage 1 Leachate Management 16

2.2.3 Proposed System Summary 19

2.2.4 System Components & Processes 20

2.2.5 Wetland Capacity and Performance 35

2.2.6 System Operation 38

2.2.7 Proposed Stormwater & Creek Enhancement Works 39

2.2.8 Construction 41

2.2.9 Commissioning 42

2.2.10 Precedent Projects 44

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3.0 PROJECT ALTERNATIVES 47

3.1 ON‐SITE TREATMENT VS DECOMMISSIONING & REMEDIATION VS

TRADE WASTE DISCHARGE 47

3.2 EVALUATION OF REUSE VS DISPOSAL OPTIONS 48

3.2.1 Reuse 48

3.2.2 Disposal 49

3.3 EVALUATION OF TREATMENT APPROACHES & TECHNOLOGIES 50

3.3.1 Evaluation of Leachate Management Approaches 50

3.3.2 Detailed Evaluation of Shortlisted Treatment Technologies 52

3.4 ASSESSMENT OF TREATMENT WETLAND LOCATIONS 53

4.0 PUBLIC CONSULTATION 56

4.1 STAKEHOLDER CONSULTATION 56

4.1.1 Community Consultation 56

4.1.2 Consultation with TasWater 59

4.2 REGULATORY CONSULTATION 60

5.0 THE EXISTING ENVIRONMENT 61

5.1 PLANNING ASPECTS 61

5.1.1 Land Tenure 61

5.1.2 Land Use & Planning History 62

5.1.3 Neighbouring Properties 62

5.2 ENVIRONMENTAL ASPECTS 63

5.2.1 Topography 63

5.2.2 Climate 63

5.2.3 Geology & Soils 64

5.2.4 Leachate (Current) 65

5.2.5 Leachate Seepage 78

5.2.6 Groundwater 81

5.2.7 Stormwater 88

5.2.8 Cooee Creek and its Tributary 92

5.2.9 Biodiversity & Conservation Significance 106

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5.2.10 Natural Events & Hazards 109

5.2.11 History of Waste Management 110

5.3 SOCIO-ECONOMIC ASPECTS 112

5.3.1 Project Socio-Economic Benefits 112

5.3.2 Heritage 113

6.0 POTENTIAL IMPACTS & THEIR MANAGEMENT 114

6.1 KEY ISSUES SPECIFIC TO THIS PROPOSAL 114

6.1.1 Potential Surface Water Quality and Hydrological Impacts 116

6.1.2 Summary of Potential Impacts to the Creek 125

6.1.3 Potential Groundwater and Geotechnical Impacts 127

6.2 HAZARD AND RISK ASSESSMENT OF KEY ISSUES 128

6.2.1 Risk Assessment Approach 128

6.2.2 Risk Identification 129

6.2.3 Risk Analysis 133

6.2.4 Proposed Management Measures 137

6.3 OTHER POTENTIAL IMPACTS AND MANAGEMENT RESPONSES 141

6.3.1 Air Quality 141

6.3.2 Noise Emissions 142

6.3.3 Waste Management 143

6.3.4 Dangerous Goods and Environmentally Hazardous Materials 143

6.3.5 Biodiversity and Natural Values 144

6.3.6 Pests, Weeds and Diseases 146

6.3.7 Dust 146

6.3.8 Sediment 147

6.3.9 Marine and Coastal 147

6.3.10 Greenhouse Gases and Ozone Depleting Substances 147

6.3.11 Heritage 148

6.3.12 Land Use & Development 149

6.3.13 Visual Impacts 149

6.3.14 Socio-Economic Issues 149

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6.3.15 Health & Safety Issues 149

6.3.16 Fire Risk 149

6.3.17 Infrastructure and Off-Site Ancillary Facilities 150

6.3.18 Environmental Management Systems 151

6.3.19 Cumulative and Interactive Impacts 151

6.3.20 Traffic Impacts 152

7.0 MONITORING & REVIEW 152

7.1 MONITORING PROGRAM 152

7.1.1 Sample Collection, Handling and Analysis 153

7.1.2 Sampling Locations 153

7.1.3 Sampling Frequency and Parameters 155

7.2 MANAGEMENT TRIGGERS 156

7.3 GEOTECHNICAL MONITORING 161

7.3.1 Construction Monitoring - Pre, During and Post Construction 161

7.3.2 Ongoing Settlement Monitoring 161

7.3.3 Wetland Liner Leakage Monitoring 161

7.4 MAINTENANCE & SYSTEM HEALTH MONITORING 162

7.4.1 Ongoing Maintenance Tasks 162

7.4.2 Scheduled Maintenance Tasks 163

7.5 REPORTING 164

8.0 DECOMMISSIONING & REHABILITATION 164

9.0 COMMITMENTS 164

10.0 CONCLUSION 164

REFERENCES 173

APPENDICES 176

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LIST OF TABLES

Table 1. Wetland components and design details 36

Table 2. Estimated Performance of the Proposed Stage 1 Leachate Treatment System 37

Table 3. Preliminary construction timetable 41

Table 4. Estimates of raw materials and sources 42

Table 5. Wetland commissioning tasks and timing 44

Table 6. Broad leachate management approaches 50

Table 7. Outcomes of preliminary stage 1 leachate treatment options screening 51

Table 8. Summary of assessment of alternative wetland locations 54

Table 9. Frequency distribution of Stage 1 leachate flows 67

Table 10. Stage 1 leachate WQ – physical parameters 70

Table 11. Concentrations of nutrients in Stage 1 leachate 71

Table 12. Stage 1 leachate WQ – metals (total) 74

Table 13. Stage 1 leachate WQ – detected organics 77

Table 14. Mass loading of key pollutants to sewer 78

Table 15. Leachate seepage chemistry for the 3 sampling events in 2013 80

Table 16. Soil data from within the leachate seepage area (northern embankment of

Stage 1 landfill) 81

Table 17. Summary of groundwater quality data – pH, nutrients and dissolved metals 87

Table 18. Stormwater quality 91

Table 19. Estimated mass loading of key stormwater pollutants to the Creek from

Stage 2A stormwater flows 92

Table 20. Cooee Creek monitoring data - water quality results (April 2014) and

comparison with the Stage 1 leachate and site stormwater 97

Table 21. Sediment quality within Cooee Creek and unnamed tributary – April 2014 97

Table 22. EPA proposed water quality objectives for Cooee Creek 100

Table 23. Proposed water quality protection levels for discharge to the Cooee Creek

unnamed tributary 105

Table 24. Threatened species recorded (in bold) within 500m of stream reach and

those potentially present, by habitat type or survey evidence (NEST 2014) 107

Table 25. Pollutant concentrations in the Infiltration Wetland effluent 120

Table 26. Volumes estimated to be discharged directly to the Infiltration Wet Forest –

mean daily 120

Table 27. Annual discharge and mass loadings to the Infiltration Wet Forest 120

Table 28. Volumes estimated to be discharged directly to the Creek – mean daily 121

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Table 29. Mass pollutant load to creek based on daily rainfall and flows 122

Table 30. Annual discharge and mass loadings to creek. 123

Table 31. Peak day mass load discharge to creek based on > 90% flows 124

Table 32. Summary of possible receptor/pathways interactions 132

Table 33. Proposed monitoring schedule for the treatment wetland 157

Table 34. Commitments table for the Burnie Treatment Wetlands proposal 165

Table 35. Summary of compliance with specific guidelines 167

LIST OF FIGURES

Figure 1. Location of the Burnie Waste Management Centre and the Stage 1 landfill 13

Figure 2. Land boundary, site layout and location points 14

Figure 3. Site Plan showing landfill stages 15

Figure 4. Burnie Waste Management Centre Site Plan 17

Figure 5. Process sketch showing existing leachate management (from BCC) 18

Figure 6. General site layout showing location of major components & access

points for construction and maintenance. 22

Figure 7. Process diagram showing proposed collection & conveyance

infrastructure works 23

Figure 8. Proposed modifications to the leachate collection and conveyance

infrastructure, and construction of emergency control infrastructure 26

Figure 9. Proposed alterations to MH1 (leachate) and MH3 (stormwater) 27

Figure 10. Typical section through surface flow wetland. 30

Figure 11. Long section showing proposed infiltration wet forest, stormwater swale

for treatment of low flows and modified creek discharge 32

Figure 12. Cross section showing proposed infiltration wet forest, stormwater swale

for treatment of low flows and modified creek discharge 33

Figure 13. Proposed nature & extent of creek enhancement works, and location of

new stormwater swale 40

Figure 14. Explanatory diagram of Lorong Halus Leachate Treatment Wetland 46

Figure 15. Rory Shaw Wetlands Park currently being constructed at a former landfill

site in California.. 46

Figure 16. Summary of leachate treatment technology evaluation 52

Figure 17. Mean climate data for Round Hill, Burnie 64

Figure 18. Average stage 1 leachate flows (March 2010-December 2014) 66

Figure 19. Frequency distribution graph of Stage 1 leachate flows 67

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Figure 20. Site current sampling locations 69

Figure 21. Seasonal changes in nutrients levels in Stage 1 leachate 72

Figure 22. Seasonal changes in Fe and Mn levels in Stage 1 leachate (median values) 75

Figure 23. Seasonal changes in Al concentrations in LO1 and SW1 (median values) 76

Figure 24. Seasonal changes in Zn levels in LO1 & stormwater (median values) 76

Figure 25. Seepage area showing ponding & low ‘sheen’ indicating metal precipitation 79

Figure 26. Extent of leachate seepage in August 2013 79

Figure 27. Standing water level data and cumulative deviation from mean annual

rainfall recorded for GW1 over the period 1991 to 2000. 83

Figure 28. Standing water level data and cumulative deviation from mean annual

rainfall recorded for GW2 over the period 1991 to 2006. 84

Figure 29. Conceptual site model – existing scenario 85

Figure 30. Stormwater network at BWM 89

Figure 31. Average (Stage 2) stormwater point discharge flows to Cooee Creek tributary 90

Figure 32. Cooee Creek catchment area. Burnie landfill site is up-gradient of CT-1 93

Figure 33. Conservation of Freshwater Ecosystem Values (CFEV) for the site. 94

Figure 34. Location of Water and Sediment samples undertaken as part of Cooee Creek

and Cooee Creek tributary background sampling 96

Figure 35. The outline of the 1000 year floodplain (blue hatched areas) 110

Figure 36. Conceptual site model – PROPOSED DEVELOPMENT SCENARIO 115

Figure 37. Proposed water circuit and water balance for normal (median) and high flows 118

Figure 38. Site layout showing borehole locations 119

Figure 39. Annual mass loading to the Infiltration Wet Forest 121

Figure 40. Annual mass loading to the Creek (based on daily rainfall and flows) 122

Figure 41. Proposed sampling locations. 154

LIST OF APPENDICES

APPENDIX 1. Burnie Waste Management Centre (BWMC) Stage 1 Landfill Leachate

Treatment Study – Option Development and Evaluation and Preferred

Option Concept Design (Syrinx Environmental PL, July 2014) 177

APPENDIX 2. Natural Values Assessment Report (NEST July 2014) 178

APPENDIX 3. EPBC Referral Decision 179

APPENDIX 4. Addendum to Stage 1 Landfill Leachate Treatment Study – Design Changes &

Alternative Wetland Option Assessment

(Syrinx Environmental PL May 2015) 180

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APPENDIX 5. Assessment of Alternative Leachate Management Options

(BCC May 2015) 181

APPENDIX 6. Hydro‐geotechnical Investigation and Risk Assessment Version 2,

August 2015 (Tasman Geotechnics August 2015) 182

APPENDIX 7. Preliminary Treatment System And Associated Infrastructure Layout 183

APPENDIX 8. EPA Class Assessment Of The Project Proposal 184

APPENDIX 9. Proposed Wetland Species List 185

APPENDIX 10. Letters to Stakeholders 187

APPENDIX 11. Certificate of Title 188

APPENDIX 12. Chronology of the Waste Management Activities On Site 189

APPENDIX 13. CFEV Assessment Component Report. 190

APPENDIX 14. Risk Assessment Descriptors 191

APPENDIX 15. Risk Assessment Evaluation 193

LIST OF ABBREVIATIONS

Al Aluminium

ANZECCAustralian and New Zealand Environment and Conservation Council and Agriculture

and Resource Management Council of Australia and New Zealand

ARI Average Recurrence Interval

BCC Burnie City Council

bgl / m bgl Below ground level / meters below ground level

BOD Biochemical Oxygen Demand/Biological Oxygen Demand

BOM Bureau of Meteorology

BWMC Burnie Waste Management Centre

C Carbon

Chl-a Chlorophyll-a

CFEV Conservation of Freshwater Ecosystem Values

cfu Colony forming unit

COD Chemical Oxygen Demand

Cr Chromium

Cu Copper

d Day

dia Diameter

DO Dissolved Oxygen

DOC Dissolved Organic Carbon

DPEMP Development Proposal & Environmental Management Plan

DPIWE Department of Primary Industries, Parks, Water and Environment

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EC Electrical Conductivity

E. coli Escherichia coli

EH&S Environmental Health & Safety

EMPC Environmental Management and Pollution Control

EPA Environmental Protection Authority

EPBC Environmental Protection and Biodiversity Conservation

EPN Environmental Protection Notice

EPP Environment Protection Policy

ET Evapotranspiration

EWR Environmental Water Requirement

Fe Iron

ha Hectare

GCL Geosynthetic Clay Liner

GHG Green House Gas

GIL Groundwater Investigation Level

GW Groundwater

HLR Hydraulic Loading Rate

HDPE High Density Polyethylene

Hr Hours

HRT Hydraulic Retention Time

kg Kilogram

kL Kiloliter

kW Kilowatt

kWhr Kilowatt hour

LLDPE Linear Low Density Polyethylene

LOD Limit of Detection

LOR Limit of Reporting

L/sec Litre per second

m Metre

MAH Monocyclic Aromatic Hydrocarbons

MBR Membrane Bioreactor

MH Manhole

MF Microfiltration

ML Megalitre

mm Millimetre

Mn Manganese

MRT Mineral Resources Tasmania

NEPM National Environment Protection Measure

NH4-N Ammonium Nitrogen

Ni Nickel

NOI Notice of Intent

NOx Oxidised Nitrogen (Nitrate & Nitrite)

NRM Natural Resources Management

NTU Nephelometric Turbidity Units



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OC Organic Carbon

OC/OP Organochlorine / Organophosphate (pesticides)

Org N Organic Nitrogen

ORP Oxidation Reduction Potential

PAHs Polycyclic Aromatic Hydrocarbons

Pb Lead

PCB Polychlorinated biphenyl

PEVs Protected Environmental Values

pH Hydrogen Ion Concentration [Potential of Hydrogen]

Redox Reduction Oxidation Potential

RO Reverse Osmosis

SBR Sequencing Batch Reactor

SFW Surface Flow Wetland

SIDP Stormwater Infrastructure Development Project

SMD Slightly to Moderately Disturbed

SSFW Subsurface Flow Wetland

SW Stormwater

TDS Total Dissolved Solids

TEC Threatened Ecological Communities

TN Total Nitrogen

TP Total Phosphorus

UF Ultrafiltration

UTAS University of Tasmania

UV Ultraviolet

TALC Tasmanian Aboriginal Land Council

TSS Total Suspended Solids

WQ Water Quality

WQGs Water Quality Guidelines

WQO Water Quality Objective

WWTP Wastewater Treatment Plant

Zn Zinc



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1.0 INTRODUCTION

1.1 TITLE OF THE PROPOSAL

Burnie Waste Management Centre Stage 1 Landfill Leachate Treatment Wetland.

1.2 PROPONENT DETAILS

The proponent of the landfill leachate treatment wetland is Burnie City Council.

Registered address: 80 Wilson Street, Burnie 7320, Tasmania

Postal address: PO Box 973, Burnie 7320, Tasmania

ABN number: 29 846 979 690

The relevant council contact officer and contact details are:

Mr Rowan Sharman

Manager Engineering Services

Burnie City Council

Ph. (03) 6430 5752

F: 1300 287 643

[email protected]

1.2.1 Proponent Background

Burnie City Council has a strong and successful record of delivering capital works projects and

has a strong engineering team in its Technical Services Department to provide support to the

project. Some recent large projects are provided below.



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Project Project Cost Project Description

Coastal Pathway

and Waterfront

Boardwalk

$3,925,474 Completed in October 2010.

Three major elements were constructed to create a 5.5 km shared

walking and cycling pathway around Burnie’s foreshore as part of

the greater Cradle Coast Regional’s coastal pathways project. The

project comprises a concrete pathway, an elevated timber

boardwalk along West Beach and a rail overpass structure.

Waterfront

Development

$6,358,051 Completed in February 2012.

Comprises the redevelopment of the Burnie Waterfront Precinct

to include a new 280 m long terraced sea wall including lawn

events area, BBQ shelters, wet and dry play elements, lighting and

a pedestrian friendly street and parking arrangements that brings

the city to the sea. Many elements design and managed by

Council Technical Services.

Stormwater

Infrastructure

Development

Project

$4,250,000 Commenced in June 2012 – Ongoing.

The objective of this project is to reduce stormwater infiltrations

to the waste water network to provide capacity for economic

expansion opportunities in the region. Works include; identifying

sources of infiltration, installing stormwater mains and property

plumbing. The Stage 1 Leachate Treatment proposal is an element

of this project.

Waste Transfer

Facility

$1,461,005 Completed in November 2012.

This project included the construction of a waste transfer and

resource recovery facility at the Burnie Waste Management

Centre to offer a long term sustainable solution for the

management of waste, by maximising the recovery of resources

from the waste stream and avoiding their disposal to landfill.

Managed by Council Technical Services.

Stage 1 Landfill

Rehabilitation &

Stage 2A Landfill

$1,700,000 Completed July 2006.

This project comprised capping and rehabilitation of Stage 1

Landfill and development of Stage 2A landfill cell at the Burnie

Waste Management Centre. Managed by Council Technical

Services.



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1.3 PROPOSAL SUMMARY

1.3.1 Proposal Background

Project Overview

Burnie City Council is proposing to construct and operate an on-site wetland treatment and

disposal system for management of Stage 1 landfill leachate generated at the Burnie Waste

Management Centre (BWMC), Burnie, Tasmania (Figure 1).

The project is part of a federally funded Stormwater Infrastructure Development Project

(SIDP). The goal of this SIDP Project is to deliver a stormwater improvement program across

the Burnie City that will reduce discharge and infiltration to TasWater’s waste water network

by at least 1.9ML per day, within a total cost of $4.25 million. This project was due to be

completed by the end of June 2015. However, an extension of time has been granted to

complete the leachate treatment project by the end of June 2016.

The SIDP carries environmental and efficiency benefits, and ultimately it is a critical

investment in infrastructure-readiness to realise economic expansion opportunity for the

region. The leachate management project is critical to achieving the objectives of the SIDP

program, since it accounts for almost a third of the stormwater diversion target.

This proposal involves the design and construction of a treatment wetland system and

associated hydraulic and civil infrastructure at the BWMC to manage the Stage 1 Landfill

leachate. It also includes decommissioning of the current (Stage 1) leachate discharge system

to TasWater’s sewage network, and replacement of this with site infiltration (median flows) and

point discharge (large flows) of highly treated leachate into the un-named tributary of Cooee

Creek.

Unlike typical landfill leachate, the Stage 1 landfill leachate is low strength predominantly

comprising groundwater (>80-90%) due to compromises in the original construction and

landfilling practices resulting in the ingress of groundwater into the leachate collection system.

As such, the characteristics of the leachate stream are more akin to groundwater or

stormwater, than to leachate. The only contaminants exceeding the EPA Draf t Water Quality

targets for Cooee Creek are ammonium nitrogen and total nitrogen. There are occasional

exceedances of aluminium, chromium, copper, nickel and zinc.

Studies Completed and Current Project Status

A wide range of technical studies and reports have been completed as part of this project to

date, which form the basis of this DPEMP:



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Surface Water & Preliminary Soil and Sediment Investigation (and supporting sampling

quality plan) (an appendix in Syrinx Environmental PL, July 2014) – contained in

APPENDIX 1.

Burnie Waste Management Centre (BWMC) Stage 1 Landfill Leachate Treatment

Study – Option Development and Evaluation and Preferred Option Concept Design

(Syrinx Environmental PL, July 2014) – APPENDIX 1.

Natural Values Assessment Report (NEST July 2014) - APPENDIX 2.

EPBC Referral documentation (BCC Nov 2014) and EPBC assessment. The EPBC

assessment is contained in - APPENDIX 3.

Addendum to Stage 1 Landfill Leachate Treatment Study – Design Changes &

Alternative Wetland Option Assessment (Syrinx Environmental PL May 2015) –

APPENDIX 4.

Assessment of Alternative Leachate Management Options (BCC May 2015) -

APPENDIX 5.

Hydro‐geotechnical Investigation and Risk Assessment Version 2, August 2015

(Tasman Geotechnics August 2015) - APPENDIX 6.

BCC Mooreville Road Hydrological Runoff Assessment (Tasmanian Consulting

Service, April 2015, provided as an appendix in Tasman Geotechnics August 2015) –

APPENDIX 6.

These studies were provided to the EPA as part of the NOI submission in Sept 2015.

The proposal is currently in the design phase, with a view to construction in Feb – Jun 2016.

The project timelines are driven by the SIDP, which will require this project to be substantially

delivered by end June 2016, otherwise the funding will need to be returned or re -appropriated,

and this project will not proceed.

Physical Components of the Proposal

The key physical elements of the proposal are as follows:

Refurbishment of the main Stage 1 leachate pumping station to separate leachate from

site stormwater flows and incorporate a sedimentation trap. NOTE: stormwater is being

managed as a parallel project on site. This will incorporate capacity and treatment

improvements across the site.

Installation of new pumps, rising mains to the wetland and sediment traps to ensure

efficient and sufficient duty and standby capacity to convey large flow events (>50

year) and to ensure appropriate sediment controls are in place to prevent pump wear

and protect the capacity of the chamber.



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Construction of an emergency leachate overflow storage tank to enable gravity

conveyance and storage of overflows due to pump failure, from the leachate manhole

chamber and gravity return to the leachate manhole chamber as levels subside.

Decommissioning of the existing TasWater sewer discharge point and construction of a

new gravity connection downgradient of the emergency storage tank, as a final

contingency against non‐compliant flows.

Construction of the treatment wetland itself on the Stage 1 landfill cap, comprised of

the following components:

o Inlet sedimentation/precipitation pond – for removal of iron, manganese and

other metals to prevent clogging of wetland. Limestone or limesand will be

incorporated in this pond to elevate pH.

o Surface flow (horizontal) wetland – multiple cells in parallel to allow draining,

maintenance and operation of each cell depending on flows.

o Subsurface flow (horizontal) biofilters (2 in parallel) to promote denitrification

primarily.

o Polishing wetland with adsorption media to allow further treatment and a

recirculation system to return water to the head of the system if non‐compliant.

Construction of an infiltration wetland within the northern boundary of the site to

enable infiltration of compliant treated water.

Construction of an overflow pipe and swale to discharge to the existing unnamed

tributary of Cooee Creek in large flow periods.

A preliminary site layout plan showing the major components is provided in APPENDIX 7.

Best Practice Management

The perceived best practice management of municipal solid waste and landfill leachate has

altered significantly over the past 50 years, moving from unlined landfills with leachate

discharge to surface waters and/or aquifers, to fully contained ‘dry’ landfills and disposal of

leachate predominantly to sewer, to ‘wet cell’ (bioreactor) landfills and on‐site treatment and

discharge of leachate. There is a growing number of projects globally that look to redevelop

existing landfills and post‐closure landfill redevelopment is becoming recognised as part of the

sustainable landfill management process.

These shifts reflect better controls on waste management and recycling, better understanding

of landfill processes, concerns around the long‐time scale required for management of dry

containment landfills since degradation processes are extremely slow, and an appreciation of

issues associated with discharging leachate to wastewater treatment plants. Hence,

enhancing the rate of degradation of landfill waste (wet landfills) and enabling leachate



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treatment and discharge to the environment using ‘state‐of‐the‐art’ technologies and risk

assessment methods is becoming the new standard globally (see review in ARRPET 2007).

Discharge of landfill leachate to sewers is not considered best management practice due to

compromises in the WWTP associated with leachate composition and/or hydraulic loading,

and because this does not concur with sustainability principles and guidelines within Australia

and overseas that promote on‐site leachate management. Sewer discharge is discouraged in

some countries (e.g. Sweden) via legislative measures and stringent requirements of

wastewater treatment plants for acceptance of incoming industrial wastewater. Most Australian

mainland states (e.g. Queensland, WA) do not permit disposal of leachate to sewer unless a

strong case can be mounted to justify this approach. On‐site treatment and discharge of

leachate to the environment is becoming a preferred global approach. Treated leachate

discharge to fresh water ecosystems is currently practiced in South Africa (e.g. the

Buffelsdraai and Mariannhill landfill sites in Durban), Scandinavia, the US, UK and Australia.

The BWMC scenario is interesting in that the cell, while designed as a dry containment cell,

operates as a ‘wet’ cell in reverse; that is, whilst there is little infiltration of rainwater due to a

competent surface cap, there is upward migration of groundwater into the landfill cell due to

compromised groundwater drainage pipes. Hence, the Stage 1 landfill has operated

(unintentionally) as a modern upflow bioreactor cell. This accounts for the low strength ‘raw’

leachate quality (as indicated from leachate seepage data, Section 5.2.5).

Costs & Benefits

The capital cost of this project is approximately $2 mill. The proposal will not generate a direct

product however will provide important 1. environmental benefits - including reinstating

environmental flows to the Cooee Creek tributary (approximately 400 m3 day on average of

clean groundwater is currently mixed with leachate and diverted away from the catchment to

sewer); 2. community benefits - the wetland system is a community asset providing

educational and research values; 3. economic benefits – the system will free up capacity in

the TasWater sewer system which will enable expansion of key economic growth projects.

1.3.2 Regional Context

As described above, this project is part of a federally funded Stormwater Infrastructure

Development Project (SIDP) intended to deliver a stormwater improvement program across

the Burnie urban area. The direct result of this Stage 1 Landfill Leachate Treatment Project

will be to release significant capacity (up to 600kL/day) at the waste water treatment plant at

Round Hill and its associated pipe network and pump stations, to handle the forecast waste

water flows from the new Lion cheese processing plant, a lead enterprise for the expansion of

the dairy industry on the north-west coast of Tasmania and other similar enterprises.



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This project is being undertaken along with stormwater treatment and creek enhancement

works within the site (see Section 2.2.7). It is expected these works will occur concurrently

with this leachate treatment project.

1.4 LEGISLATIVE CONTEXT

1.4.1 Relevant Legislation, Regulations, Codes and Policies

Legislation, regulations, policies and guidelines that are relevant to the Burnie project include

the following:

Commonwealth

Environment Protection and Biodiversity Conservation Act 1999.

State

Environmental Management and Pollution Control Act 1994 (EMPCA) and associated

policies and Regulations.

State Policy on Water Quality Management (EPA 1997).

Water Management Act 1999 and associated Regulations.

Workplace Health and Safety Act 2012 and the Work Health and Safety Regulations

2012.

Environment Protection Policy (Air Quality) 2004.

Threatened Species Protection Act 1995.

Weed Management Act 1999 and the Weed Management Regulations 2000.

1.4.2 Commonwealth Assessment Process

Under the Commonwealth’s Environmental Protection and Biodiversity Conservat ion Act 1999

(EPBC Act) the proposed actions (‘the project’) cannot proceed if they have or a re likely to

have a significant impact on any of the matters of environmental significance without referral

to the Department of Sustainability, Environment, Water, Population and Communities, and

approval from the Australian Government environment minister.

A referral of the Burnie project was made under the EPBC Act on 12th November 2014. The

outcome of this referral was that the proposed project is not a controlled action. The EPBC

referral decision is included in APPENDIX 3.

http://epa.tas.gov.au/policy/Pages/Document.aspx?docid=576



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1.4.3 State Legislation & Assessment Process

The Environmental Management and Pollution Control Act 1994 (EMPC Act)

This is the primary environment protection and pollution control legislation in Tasmania.

Section 27B(2) of the EMPC Act states that a Notice of Intent (NOI) document may be

prepared and submitted the Board of the Environment Protection Authority (the Board) to

enable the Board to determine the class of assessment and to develop project-specific

guidelines for the case assessment.

In line with this, BCC submitted a NOI document (Notice of Intent – Construction of a Leachate

Treatment Wetland and Infiltration/Discharge of Treated Leachate to an Unnamed Tributary of

Cooee Creek, North West Tasmania) and all supporting documentation on the 7th

of

September 2015 .

The EPA undertook an assessment of the provided information and determined the proposal is

a ‘level 2 activity’, as defined in the EMPC Act, being a Wastewater Treatment Works (clause

3(a), schedule 2 of the EMPC). The class of assessment was determined to be 2B as the

project is not considered to be a small-scale project with minor, localised environmental

impacts that can be readily mitigated through appropriate management (EPA September

2015).

Project Specific Guidelines were prepared by the Board identifying the key issues that have

been considered and addressed in the preparation of this DPEMP document (shown in Section

10.0).

State Policy on Water Quality Management (EPA 1997)

Any discharges to Cooee Creek or its tributaries is regulated by the State Policy on Water

Quality Management and will require EPA Board approval. This states the following key

principles for setting emission limits for discharge to surface waters (Division 2B, Section

16.2):

(a) The discharge limits must be set at levels which will not prejudice the achievement of water

quality objectives; and

(b) Pollutant discharges to the environment should be reduced to the maximum extent that is

reasonable and practical having regard to best practice environmental management, and in

accordance with the following hierarchy of waste management, arranged in decreasing order

of desirability:

(1) waste avoidance;

(2) recycling/reclamation;

(3) waste re-use;



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(4) waste treatment to reduce potentially degrading impacts; and

(5) waste disposal.

The approach taken in developing the discharge strategy for this project followed this

hierarchy.

Environment Protection Policy (Air Quality) 2004.

The Environment Protection Policy (Air Quality) 2004 (the Air Quality EPP), provides a

framework for the management and regulation of point and diffuse sources of emissions to air

for pollutants with the potential to cause environmental harm.

The key environmental values of relevance to Burnie project that require protection under this

Act are:

The life, health and well-being of humans (on-site workers, neighbours and general

public) at present and in the future; and

The integrity of ecosystems and ecological processes within the key receiving

environment, which is the unnamed tributary to Cooee Creek.

Potential impacts on these values arising from the proposed project are discussed in Section

6.

Threatened Species Protection Act 1995

This Act provides the statute relating to conservation of flora and fauna. The aim of the Act is

to provide for the protection and management of threatened native flora and fauna and to

enable and promote the conservation of native flora and fauna. The Threatened Species

Protection Act 1995 is administered by the Department of Primary Industries and Water

(DPIW) and operates within the Resource Management and Planning System for Tasmania.

Under the Act, threatened species are given a listing category (endangered, vulnerable or

rare) depending on the extinction risks the species face.

Potential impacts of the project on the threatened flora and/or fauna species are discussed in

Section 6.3.5.

Weed Management Act 1999

The Weed Management Act 1999 is the principal legislation concerned with the management

of declared weeds in Tasmania. The Act provides for the control and eradication of weeds

focusing on:

(a) minimising negative effects of weeds on the sustainability of Tasmania's productive

capacity and natural ecosystems; and

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(b) promoting a strategic and sustainable approach to weed management; and

(c) encouraging community involvement in weed management; and

(d) promoting the sharing of responsibility for weed management between government,

natural resource managers, the community and industry in Tasmania.

Appropriate, sustainable management of weeds underpins the proposed wetland treatment

system design (Section 2.2) and the Environmental Risk Assessment (Section 6.3.6).

Numerous management actions are proposed and will be implemented during the system’s

construction and operation which focus on weed management (Section 6.2.4). These will

contribute to the overall enhancement of the creek and surrounding environment.

1.4.4 Management Plan

The following will be developed to ensure good environmental practices on site and to

minimise any risks associated with the system construction, commissioning and operations, as

delineated in the environmental risks assessment undertaken for the project (see Section ):

1. Operation and Maintenance Plans will be developed and will detail the required

maintenance activities and frequencies.

2. Existing risk management plans will be updated regularly, to include responses to

incidences potentially connected with the treatment system.

3. Appropriate training of staff responsible for system maintenance will be undertaken,

including preparation of user-friendly management and maintenance plans.

1.4.5 Existing Permits & Manuals

BCC has operated the Stage 1 landfill under a Permit to Operate Scheduled Premises

Conditions issued by Department of Primary Industries, Parks, Water and Environment

(DPIWE, formerly Department of Environmental and Land Management). In 2004 DPIWE

issued a new Environmental Protection Notice (EPN) for the site, and since then the Stage 2A

landfill has been operating in accordance with this EPN and two additional update EPNs as

follows:

EPN 7007/1 (issued on the 18th

November 2004), is the current main EPN for the site,

issued after the DPEMP for the Stage 2 landfil l area was approved.

EPN 7007/2 (issued on 7th

October 2005) amended the reporting cycle from a calendar

year arrangement to a financial year arrangement, as per the request of BCC.

EPN 7007/3 (issued on 20th

April 2006) stipulates that waste data must be reported

against processing routes, the primary source and secondary source (where possible).



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The BMWC landfill operations are managed in accordance with an environmental management

manual titled, Mooreville Road Landfill – Environmental Operations Manual (prepared by

Mienhardt Infrastructure and Environment, April 2005). BCC undertakes regular water quality

monitoring and reporting in accordance with EPN monitoring requirements. The monitoring

program includes sampling, testing and reporting of groundwater bore holes, surface water

locations and leachate flows. Sampling is undertaken on a quarterly basis and quarterly

monitoring reports as well as the annual reports are submitted to the EPA for review.

2.0 PROPOSAL DESCRIPTION

2.1 PROJECT NEED

Treatment and diversion of the mixed groundwater-leachate stream at the Burnie Waste

Management Centre is a critical component of the federally funded Stormwater Infrastructure

Development Project (SIDP) as described previously. This project accounts for almost a third

of the stormwater diversion target.

The core project drivers for this project and the SIDP program more broadly are:

1. Recurring environmental issues associated with the current leachate management,

including:

a. Occasional leachate overflows to the adjacent creek/stormwater system

(Cooee Creek unnamed tributary) in high rainfall events.

b. Leachate seepage episodes in very large rainfall events or extended rainfall

periods.

c. Groundwater incursion into the leachate collection system significantly

increasing the overall leachate volumes requiring treatment and management,

and causing a reduction in environmental flows to the receiving Cooee creek

unnamed tributary.

d. Capacity limitation of the existing sewer network, which currently results in raw

sewage and raw leachate overflows in events greater than the 1:10 year ARI

directly into Cooee Creek (TasWater pers. comm.).

e. Capacity limitation of the existing WWTP network. TasWater are strongly

supportive of the proposal to remove leachate from the daily Round Hill WWTP

load due to issues with hydraulic loading and other well established issues

associated with its composition. TasWater has advised they are working toward

strongly dis-incentivising disposal of landfill leachate and other trade waste to

sewer over the coming years.



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2. Economic issues including:

a. Long-term cost to maintain discharge to the TasWater sewer system

particularly in context of recent and anticipated future escalation of trade waste

charges implemented across Tasmania that will most certainly make leachate

disposal to sewer cost-prohibitive.

b. Issue of limiting TasWater from being able to take additional waste from the

Lion cheese factory and other enterprises due to capacity constraints of the

sewer and WWTP.

3. Potential community issues given that escalation in charges for sewer disposal will

flow on to the community via rates and also due to potential exposure to leachate (and

sewage) along the creek during storm events.

2.2 DETAILED PROJECT DESCRIPTION

2.2.1 General

The project essentially involves the use of constructed wetland technology to remove the low

level contaminants from the Stage 1 leachate, the use of an extensive infiltration ‘wet forest’

area for indirect discharge of treated water within the BWMC land, and the construction of an

overflow discharge point to the unnamed tributary of Cooee Creek, at the northern boundary of

the site, adjacent private land. Improvement works to the creek are also included.

This proposal is associated with an existing activity on site, which is the Burnie Waste

Management Centre (and former landfill site). It is currently regulated via existing

Environmental Protection Notices (EPNs) (see Section 1.4.5). This project is part of the overall

landfill closure planning for the site, focussed on leachate management for the Stage 1 landfill

cell, which was decommissioned in 2004/5.

Location Map & Site Plan

A general location map with site images is shown in Figure 1. The land boundary is shown in

Figure 2. Note the middle red line in Figure 2 indicates two separate titles. The land boundary

is the outer red line.



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Figure 1. Location of the Burnie Waste Management Centre and the Stage 1 landfill

Top of Stage 1 landfill looking east. Trees

mark property boundary/buffer

Stage 1 leachate pump station looking

north toward Cooee Creek tributary.



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Figure 2. Land boundary, site layout and location points

Site boundary

point Latitude Longitude

1 41° 04'51.26"S 145°52'35.89"E

2 41° 04'51.59"S 145°52'39.26"E

3 41° 04'49.61"S 145°52'39.73"E

4 41° 04'51.29"S 145°52'55.07"E

5 41° 05'00.91"S 145°52'52.94"E

6 41° 05'10.56"S 145°52'50.85"E

7 41° 05'08.78"S 145°52'36.36"E

8 41° 05'09.88"S 145°52'32.60"E

9 41° 05'07.99"S 145°52'29.82"E

10 41° 05'05.48"S 145°52'27.52"E

11 41° 05'01.37"S 145°52'32.58"E

12 41° 04'58.77"S 145°52'34.31"E



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Figure 3. Site Plan showing landfill stages



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2.2.2 Current Stage 1 Leachate Management

The existing layout of the site showing the current leachate collection and conveyance network

is shown in Figure 4, and leachate process sketch in Figure 5. Leachate generated in Stage 1

of the landfill is currently collected in the northern pump well (MH1) down gradient of the

landfill area and pumped into TasWater’s sewer reticulation system for treatment at the

Roundhill WWTP. This stream is a combined leachate and groundwater stream (refer Section

5.2.4).

During dry and moderate rainfall periods (low flows), leachate collected in the northern pump

station (MH1) is directed (pumped) into the adjacent 150 dia. gravity sewer pipe. The capacity

of the pump at MH1 from Stage 1 is around 17 L/sec. High level alarms are fitted to the pump

stations which are connected to Council’s telemetry alarm. However, during extended or

intense periods of wet weather when the combined leachate-groundwater flow is high, the 150

dia. gravity sewer pipe does not have sufficient capacity to convey the flow. To overcome the

150 dia. sewer pipe capacity limitations, flow is pumped from the northern pump well via an

overland 100 dia. PE rising main to the leachate pond located near Stage 2A cell. From there,

it is pumped via an 80 dia. uPVC rising main along Mooreville Road to discharge into

TasWater gravity system beyond the zone of pipe capacity limitation. The pump capacity of

the leachate pond is also 17 L/sec.

On two occasions in the last few years, leachate has almost overflowed from the leachate

pond into the adjacent creek/stormwater system.

There is a weir in the northern pump well to separate leachate from stormwater. If the power

fails or pump problems occur, leachate will overflow the weir and enter the stormwater/creek

system. If the 150 dia. gravity sewer pipe is overloaded, leachate (comb ined with sewage from

site amenities) may enter the stormwater system and flow into the creek.



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Figure 4. Burnie Waste Management Centre Site Plan

Stage 1 leachate pump station and

MH1 cover.

Stage 1 leachate/stormwater manhole

chamber (MH1) showing baffle

separator.



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Figure 5. Process sketch showing existing leachate management (from BCC)



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2.2.3 Proposed System Summary

Design Objectives

The following have been set as design objectives for the proposed wetland and associated

infrastructure/works:

Separation of individual water streams generated within the landfill site (leachate,

stormwater and leachate seepages) to manage peak flows and minimise risks of direct

discharge of untreated flows to Cooee Creek tributary.

Incorporation of a gravity overflow pipe and emergency storage tank from the raw

leachate chamber that prevents raw leachate flows overflowing to Cooee Creek

tributary.

Provision of a multi-stage treatment system with excess capacity, operational flexibility

and multiple contingencies to optimise treatment performance and risk management.

Incorporation of design features that enable progressive adaption and responses to

changing water quality and volumes, resulting from climate change and changes in

landfill leachate characteristics.

Restoration of biodiversity values within the landfill site and the immediate discharge

environment.

Creation of a wetland attraction/feature within the site that could eventually be opened

to the public with educational, research and interpretative opportunities.

Design Criteria

The following criteria apply to the design of the proposed wetland, which reflect the

environmental, hydrological and geotechnical constraints associated with the project setting.

These are discussed in detail in Section 5.0.

Treatment of contaminants to the set Water Quality Targets for discharge to Cooee

Creek tributary, which are in line with the EPA Draft Water Quality Objectives for

Cooee Creek and ANZECC Water Quality Guidelines (2000) and incorporate findings

of the creek-specific water quality monitoring undertaken for this project (refer to

Section 5.2.7).

A requirement to use plant species endemic to the area and local to Tasmania to

prevent weed issues, species appropriate to the hydrological regime and water quality,

species that will enhance the biodiversity values of the site and wider area.



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Ability to appropriately treat (i.e. to the set water quality standards) up to the 90

percentile flows (note, 90 percentile flows calculated on present flow data as 600

m3/day).

Provision of back-up contingencies in case of power failure, maintenance outages and

storm events, including emergency storage tank.

Ability to detain and treat the leachate flows generated in >50-year storm events by

providing sufficient capacity within the wetland and pump system to deliver and contain

3500 m3 for 24-hours of flows (>80-year event).

Capacity to intercept and treat leachate seepages generated in extreme rainfall events

to prevent direct discharge of untreated leachate to the creek.

Provision of sufficient contingencies to enable recycling of leachate if treatment

standard is non-compliant with discharge standards, and/or for leachate volumes

beyond the pump capacity of the main system (i.e. extreme events).

Sizing of the wetland freeboard and pipework infrastructure to contain the direct

volumes generated in a 1000 year ARI rainfall event to avoid overflows. Hydrological

modelling indicates that direct rainfall volumes generated in a 1000 year rain event

could be accommodated within the wetland system with a freeboard of 182 mm, hence

a minimum freeboard is set at 200 mm.

Height of wetland bunds to be no greater than 2 m to prevent potential excessive

settlement on the landfill cap.

For all wetland cells, allowance of a setback buffer of a minimum 10 m from the landfill

bund wall and central stormwater swale on top of the landfill cap, and 10 m from the

toe of the northern embankment, to ensure no compromise to landfill stability.

Design should accommodate settlement of the wetland over time in line with predicted

landfill settlement rates (see Section 6.1.2 and APPENDIX 6).

2.2.4 System Components & Processes

The proposed treatment wetland will be a combination of parallel components in series to

enable single operation in low flows and/or maintenance events. The components are as

follows:

1. Modified manhole and pump station for conveyance of flows to the wetland.

2. Pre-filter – iron/manganese drop out pond.

3. Vegetated surface flow wetland- aerobic system for promotion of nitrification and

precipitation of any residual metals.



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4. Vegetated subsurface flow wetland – anaerobic media filled beds, operating

intermittently to promote denitrification.

5. Polishing wetland (aerobic) with outlet monitoring point and recirculation pipe for non-

compliant water.

6. Infiltration ‘Wet Forest’ – to enable highly treated water to further attenuate residual

nutrients/contaminants through the soil profile and promote diffuse subsurface release

to the unnamed tributary to Cooee Creek.

7. Phytoremediation swale – to intercept and divert for treatment leachate seepage flows

that can occur at the bench on the northern embankment during extreme rain events.

The following physico-chemical and biological processes dominate the treatment sequence:

Aeration – reduces the COD/BOD demand, promoting oxidation of organics and

reduced forms of metals, metalloids.

Volatilisation – removes simple organics from the water matrix to the atmosphere.

Filtration (entrainment & settlement) – physically removes suspended solids and

pathogens from the leachate stream.

Passive chemical oxidation and precipitation – converts dissolved metals/metalloids

into particulate forms, which are then removed by filtration and precipitation. Metals

precipitate in the form of insoluble carbonates and hydroxides (in aerobic and

anaerobic conditions).

Attachment & adsorption – metals/metalloids, organics, pathogens and colloids adsorb

to media, biofilms and plant roots/rhizomes.

Ion exchange – the sediments of wetlands and high cation exchange media such as

volcanic and organic media act as ion exchange sites for metals.

Solar disinfection – destroys pathogens via UV radiation.

Biodegradation – converts organics and nutrients to inert forms, including to gaseous

phases or carbon sources for plants. Occurs on biofilms attached to media and plant

root/rhizomes. These processes are mediated by bacteria, fungi, yeast and algae.

Phytoremediation – reduces contaminants in the leachate stream via plant uptake and

accumulation of metals, nutrients, hydrocarbons and salts.

A general site arrangement is shown in Figure 6. A process schematic is provided in Figure 7.



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Figure 6. General site layout showing location of major components & access points

for construction and maintenance.



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Figure 7. Process diagram showing proposed collection & conveyance infrastructure works



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Construction Material Details

The general construction material components are as follows:

1. Liner: Existing landfill clay cap levelled and stripped of topsoil; 2 mm LLDPE (linear

low density polyethylene) liner.

2. External Bunds: Clay won on site 2 mm LLDPE liner.

3. Internal Bunds: Clay won on site. Note seepage through internal bunds is not an issue

since leachate is contained by the base liner and external bunds.

4. Media: The pre-treatment cell will contain 0.4m depth of limestone spalls (~10mm dia)

in the first half of the cell to increase alkalinity. The surface flow wetlands will only

contain topsoil over the liner (mainly won from site but some additional material may

need to be imported). The subsurface flow wetland is to contain 0.6m depth of clean

washed lightweight volcanic media (scoria or local alternative material). The polishing

wetland contains a small area of zeolite (0.2 m depth) and topsoil in the remainder.

5. Wetland Hydraulic Infrastructure: All major conveyance pipework will be constructed of

HDPE of appropriate size and class. Internal distribution pipework within cells will be

slotted PE or uPVC. Outlet controls will include adjustable weirs to allow variable

operating depths and siphon pipes to facilitate full drainage and control detention

periods. Adjustable weirs will be concrete with timber birdsmouth sheeting. Sufficient

grades will be provided for all pipe connections to allow for settlement of the landfill.

6. Plant Species: Species selection has been based on those species which have been

successfully used previously in constructed wetlands with similar hydraulic regimes

and compositions, and which occur locally in the area and hence are well adapted to

local conditions and do not pose weed issues to the surrounding creek and other

remnant vegetation areas. The species list includes rushes and sedges

(predominantly from the families Cyperaceae and Juncaceae) within the wetlands, a

range of local shrubs and herbs on the bunds, and a range of trees, shrubs,

sedges/rushes and trees within the infiltration area to maximise ET losses and

biodiversity benefits.

The infiltration ‘wet forest’ will use species typical of the Wet Sclerophyll Forest type

on lower slopes (dominated by stringybark eucalypts, Eucalyptus obliqua). This is

present as remnants within the local region and was present historically. Note, no trees

species will be used on top of the landfill cap.

The indicative species list has been derived from the Burnie Planting Guide, local

nursery lists, Tasmania Flora census lists and previous species lists used by Syrinx for

projects within Tasmania, and is contained in APPENDIX 9.



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Detailed Components

A summary process description for each component provided below. Preliminary design

drawings are provided in APPENDIX 7.

Manhole Pump Station, Rising Main and Stormwater Modifications

This project will involve modifications and refurbishment to the existing raw leachate collection

and conveyance infrastructure as follows and as shown in Figure 7, Figure 8 and Figure 9:

Retain and refurbish the existing leachate pump station (MH1). Install a new sediment

chamber ahead of the manhole to facilitate sediment collection and removal.

Decommission the stormwater line between MH2 and MH1 and seal the pipe inlet to

the MH1 chamber.

Repurpose and modify the existing stormwater outlet pipe from MH1 to connect raw

leachate to the emergency leachate storage tank (activated at a set water level)

(Figure 9).

Install a new rising main (possibly two lines, one for average flows and one for peak

flows) from MH1 to the wetland inlet. The inlet will be a splitter box arrangement to

enable separation of high flows and average flows within the wetland feed system.

Install a new high efficiency duty duty pump optimised for average flow delivery (~5-

7L/sec) with peak pump capacity of 18L/sec, and maintain the existing pump (23L/sec)

as duty standby (in case of pump failure and for peak flows). The combined capacity

will be 43L/sec, or 3,542 kL/day.

Construct a new stormwater pipe connection from MH2 to MH3 (Figure 8, Figure 9).

Construct new pipe from MH3 to head of new stormwater treatment swale. Retain

existing 1050 dia pipe outlet to creek for high flow discharges. Stormwater

swale/wetland to extend between MH1 and the creek for treatment of average

stormwater flows (1 in 1 year).

Construct new MH4 with sediment capture and connect new 150 dia leachate line into

this chamber (Figure 8).



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Figure 8. Proposed modifications to the leachate collection and conveyance infrastructure, and construction of emergency control infrastructure



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Figure 9. Proposed alterations to MH1 (leachate) and MH3 (stormwater)

The conveyance pumps are serviced by site power, however a back-up generator will be

installed to ensure continuous pumping during power outages. The variable speed

submersible pumps are 3.4 kW capacity with an estimated power draw of ~12,000 to 20,000

kWhrs per annum, inclusive of peaks. The recirculation pump to return non-compliant flows

from the polishing wetland back through the treatment circuit is a solar operated pump, hence

has no grid power draw and no emissions.

The operational life of the pumps is estimated at 15 years. The life of all other associated

infrastructure (pipes, manhole chambers etc) is 50 years or longer.

The rising main will be a single 200 mm HDPE line or dual 150 mm lines. This will be

determined based on the most efficient arrangement for the selected pumps (duty duty

20L/sec (average 8L/sec daily cycle) and duty standby 23 L/sec).



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Pre-filter (Inlet) (Cell 1)

The Constructed Wetland comprises a range of different cells performing different functions in

a treatment train arrangement.

The Prefilter is the inlet pond to the wetland system designed to assist in the precipitation and

settling of low level metals (principally iron and manganese), as well as to dissipate flows and

equalise volumes to enable steady and distributed flows to the main wetland system. To

facilitate metal drop-out, the first part of the pond is to be filled to 0.3 – 0.5 m depth with local

limestone stones (10mm dia); the last half of the pond is to be kept clear of rocks to enable

sludge removal in time. This is not expected to occur more frequently than every 5-10 years

since the TSS of the leachate is low.

The inlet to the Pre-filter will receive pumped water from the manhole chamber (MH1), which

is to be distributed in a deep rock-lined distribution channel along the length of the pond and

approximately 1m wide, to dissipate flows. The deeper open water areas of the Pre -filter are to

allow for settling, flow equalisation and aeration, while the shallow thick vegetated areas

encourage plant and microbial filtration and pollutant uptake.

The pre-filter discharges to the surface flow wetland via a series of adjustable weirs, spaced

evenly to ensure even flow distribution.

Surface Flow Wetland (10 cells)

This component is designed to maximise the removal of ammonium nitrogen and is to be

aerobic. The surface flow wetland is configured so as to distribute flows into four pairs of cells

in series, with the system operable in four separate streams to facilitate flow control and

maintenance. Flow is horizontal in all cells, and is controlled by manual operated valves that

will be adjusted twice yearly as follows:

From June/July to Oct of each year – all cells on maximum flow. This corresponds with

the largest inflows to the system since groundwater contributions are highest during

this period.

From Nov to May of each year - cells cycled off in series to enable drawdown and

reoxygenation of sediments, any other maintenance, and then returned to low flow

conditions.

During very low flow periods (150 kL/day or less), only some cells will operate to prevent

stagnation and generation of organics. Other cells will receive intermittent flows to avoid

drying of sediments.

The total area of the 10 cells is approximately 1.1 ha and this component has an average

residence time of 10 days.



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The outlets of the surface flow wetland cells discharge to the subsurface flow wetland, with

sufficient hydraulic grade between weirs to facilitate gravity flow. A typical section through the

surface flow wetlands is shown in Figure 10.

Subsurface Flow Wetlands (3 cells)

This component is designed to maximise the removal of nitrate and is to be anaerobic. The

inlet to the subsurface flow wetlands (SSFW) is via four perforated distribution pipes set just

below the surface of the wetland. Flow is downward vertical. Multiple cells are required to

allow intermittent operation of each cell, to maximise nitrification-denitrification and facilitate

maintenance. The cells are to be 600mm depth and filled with scoria or similar volcanic media

with high cation exchange capacity and high surface area. The combined system is to be

approximately 2500 m2, 0.6m depth, fully vegetated, and allow an average detention of 2 days

to optimise denitrification. Beds would operate intermittently to optimise anaerobic conditions.

Treated leachate from these cells discharges into the polishing cell.

Polishing Surface Flow Wetland

This cell provides additional polishing of the leachate prior to discharge to the infiltration ‘Wet

Forest’. This cell would act as the performance monitoring point. The cell would be vegetated

except at the outlet weir which would be constructed as a deep open water zone to avoid

incursion of vegetation. This cell would incorporate zeolite and possibly other amendments to

polish residual ammonium via adsorption.

The discharge outlet structure for this cell would have a slow release pipe for average

treatment flows, while outflows above the normal discharge level/pipe capacity would rise and

be detained. Treated flows would then either discharge over a weir structure if water quality

compliance is maintained, or be recirculated back to the surface flow wetland if not complian t

(i.e. installed monitoring sensor triggers this requirement for indicator parameters (i.e. NH 4-N,

pH, conductivity). A recirculation pipe and pump will be installed to enable return of flows to

the treatment network if they are non-compliant.



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Figure 10. Typical section through surface flow wetland.



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Infiltration ‘Wet Forest’

The northern area of the landfill site down-gradient of the Stage 1 landfill has been reserved

for infiltration/evapotranspiration, and would be revegetated as a ‘Wet Forest’, or infiltration

wetland (Figure 11 and Figure 12). This enables the recharge of treated leachate to the

aquifer and eventual discharge of these waters to the unnamed creek via subs urface flows.

There is approximately 6m separation distance between the base of the wetland and the

superficial aquifer, which is under artesian pressure at this location. Hence, further

attenuation of residual nutrients would occur through this process.

Using a conservative infiltration rate of 1*10^-6

(typical permeability point recorded in Coffey

shallow bores for sandy clay/silty clays, Coffey 2007) shows that >90% of summer‐autumn

flows and >75% of winter‐spring flows will be infiltrated within this zone and report as

subsurface discharge to the creek (which mimics the normal hydrological regime for this creek

and others in this region) (see also Section 5.2.6).

This wet forest area allows for further attenuation of contaminants through the soil and via

plant root activity, as well as a more natural subsurface recharge regime to the creek for the

majority of the time. To accommodate the grade changes, this area would be bunded and

terraced to reduce the slope and optimise vertical infiltration/ET losses. Flows in excess of the

infiltration capacity would discharge via a weir/cascade outflow to the creek.

Emergency Storage

Given the leachate will need to be pumped to the inlet of any treatment system (due to depth

of leachate collection pipes and height of available treatment area), some provision for peak

flows in excess of pump capacity is required. An emergency storage tank is therefore

incorporated downgradient of the raw leachate chamber to enable gravity overflow from the

manhole to this storage tank.

Raw leachate overflows from the MH1 which occur as a result of either extended duration non-

compliant flow, or dual pump failure (i.e. both duty and duty standby pump outage) are

proposed to be managed via a 150 kL partially buried emergency storage tank. Leachate

would rise within the current manhole and overflow to the tank. This tank provides 6 hrs

storage for the 90 percentile flows and ~10 hrs storage for average daily flows. This is

considered sufficient time to repair pumps or reinstate power or back-up power to the pumps

(if these have failed).

Flows from this tank would drain (via gravity) back to the MH1 pump station when the system

is repaired (see Figure 8).



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Figure 11. Long section showing proposed infiltration wet forest, stormwater swale for treatment of low flows and modified creek discharge



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Figure 12. Cross section showing proposed infiltration wet forest, stormwater swale for treatment of low flows and modified creek discha rge



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Leachate Seepage Phytoremediation Swale

An interception swale planted with medium and deep rooted vegetation is proposed along the

northern containment bund where seepage events have occurred in very high, extended

rainfall events. This is intended to intercept subsurface flows continually, and to enable

capture and remediation of seepage expressions as they occur. This swale would be pervious

but part filled with limestone stones to provide an alkalinity buffer to seepage waters, and

prevent acidification of soils. Plant species with metal tolerant and uptake capabilities would

be preferenced as shallow rooted vegetation. Flows in excess of infiltration treatment capacity

will be discharged to the MH1 chamber. Species selected will be locally native and members

of Cyperaceae (sedges), Juncaceae (rushes) and Restionaceae (Southern Rushes) , proven in

phytoremediation.

Creek Discharge

Flows in excess of infiltration capacity will discharge via a new pipe discharge, embedded

within a rock cascade, to the unnamed creek tributary (Figure 11 and Figure 12). The

discharge works will be tied into the proposed creek restoration works, and will be positioned

within the BCC site boundary. An on-line ultrasonic clamp on flow meter (or similar) will be

installed to automatically monitor discharge flows and activate and alarm to trigger manual

sampling. The creek discharge will be the final compliance monitoring point.

Connection Infrastructure to Existing Taswater Sewer Network.

Currently, the Stage 1 leachate is discharged to the TasWater sewer network via a pump

located within the MH1 chamber, to an existing sewer manhole (MH) (Figure 5). A minor

leachate pipe (Ø150) discharges directly to the sewer MH. In large events, leachate is pumped

via a rising main to the main Stage 2 leachate storage pond, and is discharged to sewer from

this point.

This proposal will decommission the two existing Stage 1 discharge points (the leachate pond

and sewer connection will be maintained for Stage 2 leachate flows). A new gravity connection

point (new manhole) will be constructed immediately downgradient of the emergency storage

tank, which will be activated when levels within the emergency storage rise. The proposed

location of the new manhole MH5 is shown in Figure 8.

The requirements for discharge to sewer are as shown in Figure 8, and are limited to pump

failure, and wetland non-compliance. The pump and pipe network along with excess capacity

within the wetland and emergency storage can effectively detain leachate flows generated in a

>80 year peak event (the wetland has 3,600 - 5,500 m3 of freeboard capacity within the

system depending on seasonal adjustments to operating water levels). The 24 hr 100 year

storm event leachate flows have been estimated at ~3,600 m3/day (Syrinx 2014, APPENDIX



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1). However the wetland may not effectively treat the leachate flows during a 24 hour >80 year

event, hence slow release discharge may occur on the days following the storm event.

Off-site infrastructure

No new off-site infrastructure or ancillary facilities are required to support this proposal.

2.2.5 Wetland Capacity and Performance

To size the wetland, detailed modelling was undertaken using average and median daily and

monthly flows for the period 2010-2014, mean monthly concentrations of leachate pollutants,

and temperature and rate constant factors adjusted for the climatic setting and from previous

relevant Syrinx performance data. Capacity sizing was undertaken also using the 90 percentile

wet year to ensure adequate storage and treatment in wet years. The model used was a

modified first-order kinetic, sequential model based on Kadlec and Wallace (2008). The model

was run for the limiting parameter (ammonium nitrogen) for initial sizing, and included all

nitrogen species, phosphorus, TSS, metals and COD for detailed sizing.

A specific daily water balance model was built to determine daily flows and to determine the

spill over of flows from cell to cell, using rainfall and run-off data for the period 1968-2010 for

the Burnie BOM station. The required treatment area, operating depth/volumes, hydraulic

loading rates and hydraulic retention times are shown for each component in Table 1.

The expected performance of the system for the key contaminants is shown in Table 2.

Modelled performance data is presented for the three wettest months of the year (August to

October), which are characterised by the highest loads of key pollutants (nutrients) in a typical

year (see Section 5.2.4).

Note, while progressive pollutant removal through the treatment system and performance

efficiency of each system component was modelled using the approach outlined in Section

6.1.1, a conservative approach was taken such that once the set target concentrations are

achieved in the system, no further reduction was considered (although in reality pollutants will

be further removed in subsequent components as demonstrated by specific modelling outputs

for individual cells). Consequently, in Table 2 specific modelled data was presented only for

those system components where levels are above the set targets; once these targets are met

it is assumed that pollutant concentration will stay below these target levels.



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Table 1. Wetland components and design details

OFF

LANDFILL

CELL

CELL 1

CELL 2 - MAIN

SURFACE FLOW

WETLAND

CELL 3 - SUBSURFACE

FLOW BIOFILTER

CELL 4 -

POLISHING

WETLAND

CELL 5

Pretreatment for

metal removalCell SF2A Cell 3 SSFA Cell 4

Infiltration

wetland

Cell area (m2) 500 11,000 2,500 500 4,000

Total depth (substrate & water) (m) 0.9 0.6 - 0.8 0.6 0.8 0.1

Substrate typelocal limestone

(10 - 50 mm dia)sandy clay scoria sandy clay

sandy clays /

silty clays

Substrate depth (m) 0.3 0.3 0.6 0 - 0.3 -

e (void space as %) 0.0 0.0 0.45 0.0

Operating water depth (above

substrate) (m)0.6 0.3 -0.5 0.0 0.5 0 - 0.1

Operating volumetric capacity (kL) 300 3,300 675 250 400

Min freeboard height (to

accommodate 1:1000 yr event) (m)0.2 0.2 0.2 0.2 0.1

Freeboard capacity 100 2200 - 4400 500 100 400

Peak volumetric capacity (extreme

event) (kL)395 7,590 1,150 350 800

HLR (q) (M/yr) 1.07 - 0.54 0.05 - 0.02 0.22-0.1 1.1 - 0.5 0.1 - 0

Theoretical detention time (d) 1 - 0.5 11.21 - 7.6 2.61 - 1.22 0.9 - 0.4 4.4 - 0.9

WHOLE SYSTEM Area (m2) 18,500

Detention time (d) 11 - 20

ON LANDFILL STAGE 1 CELL



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Table 2. Estimated performance of the proposed Stage 1 leachate treatment system (median for wet months August to October)

OFF LANDFILL

CELL

RAW

LEACHATE

CELL 1 -

PREFILTER

CELL 2 - MAIN

SURFACE

FLOW

WETLAND

CELL 3 -

SUBSURFACE

FLOW

BIOFILTER

CELL 4 -

POLISHING

WETLAND

CELL 5 -

INFILTRATION 'WET

FOREST'

SET

TARGETS

FUNCTION

▪ Inlet pond to the

system; flow

dissipation &

volume

equalisation

▪ removal of

ammonium

nitrogen via

oxidation (& TN

removal)

▪ removal of nitrate

- dinitrification (&

TN removal)

▪ further polishing of

treated leachate

▪ precipitation &

settling of low level

metals (mainly Fe

& Mn)

▪ removal of TP

& BOD

▪ removal of TP ▪ attenuation of

contaminants through

the soil & via plant

root activity

▪ removal of

suspended solids

▪ metal

precipitation

▪ removal of

coliforms

▪ provision of

subsurface recharge

regime to the creek

▪ aeration ▪ removal of

coliforms

Total Suspended Solids (TSS) mg/L 18.9 5.66 <5 <5 <5 <5 -

Biochemical Oxygen Demand

(BOD)mg/L 10 9.07 <5 <5 <5 <5 -

Total Nitrogen (TN) mg/L 7.9 7.5 2.22 1.6 <1.45 <1.45 1.45

Ammonium Nitrogen mg/L 7.9 7.1 1.70 <1.6 <1.6 <1.6 1.61

Total Phosphorus (TP) mg/L 0.036 0.035 <0.03 <0.03 <0.03 <0.03 0.03

Total Iron (Fe) mg/L 9.36 2.3 0.5 0.4 <0.3 <0.3 0.30

Total Manganese (Mn) mg/L 2.043 1.9 <1.9 <1.9 <1.9 <1.9 1.90

Faecal coliformsCFU/

100 ml260 202 <100 <100 <100 <100 100

ON LANDFILL STAGE 1 CELL

▪ polishing of

nutrients & metals

prior to discharge

to the infiltration

‘Wet Forest'.

Pollutant Removal (effluent conc. - cell outlet) - median for August to October



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2.2.6 System Operation

Hours of operation – System Life

The system will operate 24 hrs a day, every day for the forecast life of the leachate treatment

system (minimum 20-30 years). The pumps will operate between 8-24 hrs per day. This is

equivalent to the current leachate pump operation cycle.

Vehicle movements - Construction

All materials will be supplied locally and will be transported to site via trucks. Most topsoil and

clay for bund construction will be sourced from site.

Truck movements into the site will be required for the delivery of:

1. LLDPE liner materials – 2 container loads (est), ex Melbourne by ship.

2. Topsoil (max 1500 m3) – 95 truck loads at 22 m

3 per load.

3. Machinery for construction works (mobilisation and demobilisation) – approx 15

machines (including 4 heavy load vehicles) and light vehicles (3 excavators, 4 site

trucks, 2 bobcats, 1 trencher, 1 grader, 4 utes), ex Burnie, by road.

4. Pumps and pipework – 10 loads: flat tray truck. Pipe, local manufacture (ex Burnie or

Launceston), by road. Pumps Italian manufacture by road, ex Launceston. Pipe fittings

ex Melbourne by sea.

5. Volcanic rock media – 1 truck, ex Hobart by road.

6. Plants local – by road.

Hours of operation – Construction

Works will be completed according to the Hours of Use specified in the Environmental

Management and Pollution Control (Miscellaneous Noise) Regulations 2004 - SCHEDULE 7 -

Hours of Use:

Monday to Friday: 7.30am to 6pm inclusive.

Saturday: 8am to 6pm inclusive.

Sundays and Public Holidays: 10am to 6pm inclusive.

Vehicle movements - Commissioning

Only light vehicles (Council vehicles) will be used for commissioning and ongoing operations.

A sludge truck will be required infrequently (~5-10 yearly) to remove sediment in the pre-filter,

and annually to biannually to remove sediment from manhole chambers.



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Operational Regime

The entire wetland system has individual inlet/outlet flow control valves to cells, which allows

for flexibility in operation design features to allow for draining, maintenance and variations in

flow. Cells will have siphon drainage pipes installed to provide a full drain option for re -

aeration of sediments and to prevent excessive detention of flows that could lead to stagnation

and mosquito/odour issues.

2.2.7 Proposed Stormwater & Creek Enhancement Works

Currently, the stormwater from the site discharges into the same manhole chamber as the

leachate, separated by a baffle (see Figure 5).

The current condition of the creek at the discharge point is degraded. There is limited

overstorey cover and the understorey is predominantly weeds (APPENDIX 2), including

glyceria, blackberry and hawthorn. The weeds, particularly glyceria (Glyceria maxima), are

choking the stream, reducing water quality and also reducing potential habitat for the

threatened Burnie burrowing crayfish and giant freshwater lobster.

BCC intends rehabilitating the creek within their site boundary (predominantly south of the

Stage 1 landfill as part of a parallel project. This will involve the clearing of weeds and

replanting with local native species. The works will involve battering some of the banks in

places to reduce erosion and improve the site for planting.

In addition to the site based works, BCC will undertake tie in works at the discharge point for

these current works, which similarly will include weed control, erosion control and revegetation

works. The extent of works will extend into the neighbouring downstream property, subject to

landholder permission/interest. The nominal extent of works is shown in Figure 13.



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Figure 13. Proposed nature & extent of creek enhancement works, and location of new stormwater swale



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2.2.8 Construction

A preliminary timetable for major construction activities is shown in Table 3.

Table 3. Preliminary construction timetable

Note, measures for managing construction risks, including weed controls, pests and diseases,

sediment, dust etc are outlined in Section 6.0.

An estimate of the raw materials that will be required for the proposal is provided in Table 4.



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Table 4. Estimates of raw materials and sources

2.2.9 Commissioning

For the correct function and operation of the passive leachate treatment system the correct

sequence and timing of events must be adhered to during wetland commissioning. Factors

such as water levels, plant height and health and leachate loading must be carefully managed

to ensure that the wetland design and plants are not compromised by initial and subsequent

water level increases.

Key commissioning items include:

Pumps, pipework and valves (as part of civil contract)

Telemetry system and flow/water quality meters (as part of civil contract)

Treatment wetland planting (as part of landscape contract)

Treatment wetland validation monitoring (separate specialist contract) .

The key wetland commissioning items are shown in Table 5, with the major items described

below. Note, discharge to TasWater is proposed to be maintained during the commissioning

phase, until such time that validation monitoring has demonstrated acceptable performance of

the system.

Water Levels

The water levels in the wetland cells must rise gradually (by no more than 100 mm per week)

to avoid plant stress and fully inundating plants. It is critical that the water level does not

exceed more than two thirds the heights of the plants. If this depth should be exceeded the

commissioning process should be halted until the plants have grown to above this nominal

level.



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The system should be commissioned using the minimum operating water depth until the

system is ‘full’. At this point, the weir boards should be raised in concert with plant growth to

the seasonal operating depth.

Leachate Loading

The wetland should be commissioned with the Stage 1 leachate, after planting is completed to

avoid human contact with the leachate and potential health risks during planting works.

Planting should occur after sufficient rain has fallen to ensure moist soil conditions. The

design of the wetland, including the type of species planted, and the diluted nature of the

leachate means that the leachate loading during the commissioning phase has an extremely

low risk of impacting on the wetland plants and is suitable without diluting with a clean water

source.

Timing of Commissioning

Commissioning of the wetland should occur over a period of three months after wetland plants

are established and after the wetland is sufficiently ‘full’ and discharging . Validation monitoring

should be undertaken over a six month period, after the completion of commissioning.

End of Commissioning

Commissioning will be considered completed after six months of validation monitoring has

demonstrated acceptable performance of the system. Acceptable performance will be defined

as the meeting of the water quality compliance targets (Table 23) and as outlined in the

expected performance targets provided in Table 2.

Table 5 below details the sequence of actions to be followed during commissioning of the

system.



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Table 5. Wetland commissioning tasks and timing

2.2.10 Precedent Projects

Whilst the intended wetland system on top of the landfill does not represent a post -closure

land use, the intent is that the wetlands and infiltration ‘wet forest’ will be retai ned in the long

term as a biodiversity and educational area abutting the agricultural and nearby residential

areas.

There is a growing number of projects globally that look to redevelop existing landfills and

post-closure landfill redevelopment is becoming recognised as part of the sustainable landfill

management process. Bouzza and Kavazanjian (2001) discuss various aspects of

redevelopment associated with hard and soft uses. Hard uses include commercial/industrial

developments, shopping centres and highways, while soft uses include golf courses, leachate

storage and treatment infrastructure, public parks and recreational facilities.

Sequence

of EventsTask Timing Location Notes

Time

frame

1Check all pipew ork and pipe

connections.Pre leachate release.

Entire Wetland

System.

Visually inspect all pipew ork and pipe connections for

debris, blockages and cracks or other defects. Repair as

required.

1 day

2Check all manholes, pits and

headw alls.Pre leachate release.

Entire Wetland

System.

Visually inspect all pits and headw alls for debris,

blockages and cracks or other defects. Repair as

required.

1 day

3

Wet commission pumps and test all

electrical componenets (f low

meters, WQ probes)

Pre leachate release.Entire Wetland

System.Use clean w ater for commission testing. 1 day

4

Ensure w eirs w ithin the system are

set at the low est level, and that the

outlet to the leachate chamber is

active to prevent any leachate and

w ater release to infiltration

w etland/ creek.

Pre leachate release. Polishing WetlandWill be opened one system is commissioned and w ater

quality is monitored and performance is proven.1 day

5 Check inlet valves. Pre leachate release. Pre f ilter. Visually inspect. Repair and adjust as required. 1 day

6

Progressively f ill pre f ilter w ith

leachate until design w ater level is

reached.

At leachate release. Pre f ilter. Fill using leachate and let w ater overflow into SF1. 1 w eek

7

Progressively allow w etland cells

to f ill until all areas reach minimum

design w ater levels.

At leachate release.Entire Wetland

System.

* Fill using leachate.

* Ensure that at least one third of the average plant foliage

is above the top w ater level at all times.

2 w eeks

8

Check integrity of all liners and

inspect pipe connections and

headw alls for leaks.


System.

Monitor w ater levels w eekly to see if any leaks through

the liner or at pipe/headw all joints are occurring.

ongoing

for 4

w eeks

9

After checking leachate quality for

compliance, close outlet connection

to the leachate chamber and allow

leachate to discharge into

infiltration basins.

After monitoring of

leachate qualityInfiltration basins.

If leachate quality is non-complinant, maintain discharge to

leachate chamber.Week 3

10

As w ater levels are raised check

for plant health, short circuiting and

preferential f low paths.


System.

If plant health is poor contact Syrinx for plant trouble

shooting. If short-circuiting or preferential f low paths are

developing, monitor frequently. If problem still exists after

more w ater is released reduce f low s and undertake

remedial bio-engineering w orks to correct the problem.

2 months

11

Monitor the w etland w eekly for the

f irst month to ensure plant health is

acceptable, short-circuiting and

preferential f low paths do not

occur.

At design f lowEntire Wetland

System.

It is imperative that during the f irst month the w etland is

checked daily to ensure correct function and

performance.

1 month

12

It is essential that regular

maintenance checks are

undertaken.

Post leachate release.Entire Wetland

System.

A detailed maintenance checklist w ill be provided in the

O&M Manual, (pending)Ongoing

Leachate Treatment Wetland, BCC

Commissioning Schedule



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Waste settlement is an important factor in both hard and soft post-closure uses of landfills.

Both total and differential settlements are of engineering concern. For soft uses, settlement

may affect drainage grades and grade-sensitive uses.

Whilst many landfills are remediated and/or geotechnically engineered in order to support the

proposed end use, many ‘soft’ uses with re latively lightweight loads are constructed with

minimal or no geotechnical improvements. These include:

Woodland habitat restoration projects, wetlands and major landscape, sports field (e.g.

Sydney Olympic Park, and Churchill Park in Launceston);

Golf course developments (e.g. Burswood in Perth developed in the 1980s, and

Cannon Hill Community Links which is about to start in Brisbane). Golf courses

typically incorporate ponds, bunkers and vegetation screening, all of which apply

different loads to the landfill.

A directly similar project to the one proposed for Burnie was constructed for the City of

Lancaster in Ohio at the Stonewall Cemetery Road Landfill in 2006 (Burgess and

Niple, 2015). A series of leachate treatment wetland cells were constructed o n top of

the covered waste and down gradient of the landfill to maximise the available space,

and were lined with a double LLDPE synthetic liner.

Another similar project is the Lorong Halus landfill in Singapore which was closed in

1999. Part of the Lorong Halus landfill nearest the river was then turned into a

wetlands preserve (Eco Water Treatment Park) so that the leachate could be pumped

into the wetlands for treatment (Figure 14). The Lorong Halus Eco Water Treatment

Park was completed in 2010 and is not only a functioning organic water treatment

system and a test bed for new bio-engineering water treatments, but also serves as an

education centre and a nature park.

The Rory Shaw Wetland Park in LA, California has used a former landfill site and is

repurposing it to feature a green, native-habitat-rich treatment approach to stormwater

management (shown below). Environmental benefits of the project include stormwater

capture and pretreatment; stormwater detention; constructed t reatment wetlands; and

groundwater replenishment (Figure 15) (http://www.psomas.com/wetlands-park-

transforms-former-landfill-site-rory-shaw-wetland/#sthash.J0KqIUkp.dpuf).

Hence, the proposed concept for the Burnie treatment wetlands on top of the landfill cap is not

without precedent.



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Figure 14. Explanatory diagram of Lorong Halus Leachate Treatment Wetland (from

Singapore Public Utilities Board)

Figure 15. Rory Shaw Wetlands Park currently being constructed at a former landfill

site in California. Image sourced from Los Angeles County Department of Public

Works.



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3.0 PROJECT ALTERNATIVES

The project involved several levels of investigation regarding the feasibility of various options

for the Stage 1 leachate management, including:

Evaluation of an on‐site treatment system vs full decommissioning and remediation of

the Stage 1 landfill vs continuing with the trade waste discharge to sewer arrangement.

Evaluation of various on-site and off-site reuse and disposal options.

Evaluation of on-site treatment approaches and technologies, including risk and cost

analysis.

Alternative assessment of treatment wetland locations.

3.1 ON‐SITE TREATMENT VS DECOMMISSIONING & REMEDIATION VS TRADE WASTE

DISCHARGE

An assessment of alternate leachate management options was undertaken by BCC and Syrinx

in May 2015 in order to investigate and evaluate the potential risks associated with different

leachate management approaches, and to determine the best option in terms of environmental

outcomes and financial feasibility. The evaluation criteria used to access each option included:

Environmental Benefit/Impact, Risk, Economic Impact, and Community Impact/Sustainability.

The assessment process and final recommendations are contained within APPENDIX 5.

As a initial step, this assessment process evaluated the suitability of the following options:

Do nothing and continue to discharge to TasWater Sewerage System under a Trade

Waste Agreement (TWA) with TasWater (Base Case).

Remove waste from Stage 1 Landfill and develop and dispose to new waste cell on

site (Stage 2B/C).

Remove waste from Stage 1 Landfill, transport and dispose to an alternate landfill (e.g.

Port Latta or Dulverton).

On-site treatment.

The two options that considered site decommissioning and remediation of the Stage 1 landfill

with waste removal and disposal were found not to be environmentally or financially viable.

The costs to remove the waste body and dispose it to an alternate location were determined to

be extreme and prohibitive. The evaluation process also identified high risks associated with

both of these options in terms of environmental impacts during the construction and

rehabilitation phase.



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The option that considered the Do Nothing approach based on continuing with a Trade Waste

Agreement was also found to be cost prohibitive (especially in light of the highly likely increase

in disposal charges), with very poor environmental and community outcomes. This option was

not seen by Burnie City Council as feasible as it does not deal with the key pressing

environmental issues on site and does not represent a long-term sustainable solution for the

Council.

Furthermore, in dialogue with TasWater it became obvious that a “do nothing’ option would not

be seen favourably as there are continuous issues with regard to acceptance of trade waste to

the sewer system, given that the leachate stream is highly dilute and at times causes

biological performance issues for the WWTP. Also, the TasWater WWTP and sewer network

currently operates near capacity, and removing trade waste flows from the sewer would

reduce the number of non-compliant discharge events and is seen as critical to freeing up

capacity to accommodate the Lion development and other future waste streams. Furthermore,

the objectives of Council’s Stormwater Infrastructure Development Project would not be met

without a solution that removes leachate from the TasWater sewerage system.

On‐site treatment was assessed as the best sustainable economic, environmental and

social outcome in the long run.

3.2 EVALUATION OF REUSE vs DISPOSAL OPTIONS

In line with the State Water Policy, and in acknowledgment of the local receiving environme nt,

treated leachate reuse was considered ahead of a discharge consideration. The evaluation

process was undertaken in discussion with relevant stakeholders, e.g. TasWater, EPA and

adjacent landowners.

The approach and summary key findings arising from this evaluation process are out lined in

sections below. More details regarding this process can be found in APPENDIX 1 and

APPENDIX 4.

3.2.1 Reuse

Limited treated effluent reuse options were identified, namely reuse for off-site irrigation of

pasture.

On-site reuse opportunities identified included irrigation of capped landfill areas and

surrounding grassed buffers for which demand is very low (calculated to be <4 ML/annum) and

seasonal. Hence, given the high annual volumes of treated leachate (90% of daily volumes are

at or below 600 kL/day meaning that annually more than 20 ML of leachate is generated), on

site reuse was found to be unfeasible as it would require a major winter storage (>90 ML,



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assuming 6 months storage) which is prohibitive in terms of the space requirement within the

landfill site boundary. Hence, on-site reuse was determined not to be a realistic reuse option

on its own, as it cannot deal with full volume of treated leachate over a full ye ar.

Off-site reuse opportunities were also found to be limited and unfeasible because of good

rainfall and the availability of high quality groundwater in the region, and absence of industrial

or other high volume users within feasible proximity. Furthermore, immediate reuse demands

from surrounding neighbours for dam storages would require major pumping and infrastructure

and would only address a small portion of the excess supply.

3.2.2 Disposal

In addition to the discharge to the TasWater sewer option (Do Nothing) considered in Section

3.1 above, two other discharge options were considered and evaluated:

Discharge within the site or above the landfill site.

Off site discharge to the downstream unnamed tributary of Cooee Creek.

Infiltration of leachate into the landfill body was not found to be feasible given the high rainfall

in the area, as it would create a re-circulation loop for leachate with only minimal potential for

a reduction in the quantity of leachate requiring disposal. Similarly, infiltration in areas located

above the landfill site were also found to be unfeasible given this scenario would require

significant pumping costs, has high groundwater tables within a recharge area, and therefore

could result in a localised recharge of the groundwater with contaminated water which adds to

the leachate/groundwater volumes reporting to the Stage 1 collection system.

Infiltration within the site was found to be feasible along the northern site boundary (area

approximately 0.4 ha with optimal soil infiltration characteristics. Using a conservative

infiltration rate of 1*10^-6

m/s(typical permeability for this part of the site) shows that most of

the treated leachate will infiltrate in this zone and report as subsurface discharge to the creek

(which mimics the normal hydrological regime for this creek and others in this region).

Consequently, the optimal strategy was determined to be:

1. Indirect discharge of the treated leachate onsite via infiltration in a ‘wet forest’

wetland zone,

2. Direct discharge of large treated leachate flows that exceed the infiltration capacity to

the unnamed tributary of the Cooee Creek.

Further evaluation of the potential impacts to groundwater and the creek is covere d in Section

6.0.



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3.3 EVALUATION OF TREATMENT APPROACHES & TECHNOLOGIES

A range of leachate management approaches and technologies commonly applied on landfill

sites was assessed in terms of their appropriateness for the Stage 1 landfill leachate in the

Syrinx Options Study (APPENDIX 1).

3.3.1 Evaluation of Leachate Management Approaches

The broad methods commonly applied to leachate management are summarised in Table 6.

Table 6. Broad leachate management approaches

These methods were assessed against a range of preliminary screening criteria developed

specifically for the project. These criteria, as well as the outcomes of the preliminary

evaluation of possible treatment technologies for the Stage 1 leachate, are shown in Table 7.

Based on the requirement that the standard of treatment of the leachate is met consistently,

as well as on other environmental impacts and site suitability, the best performing

technologies were found to be: reverse osmosis (RO), membrane bioreactor (MBR), and

constructed wetlands. These three shortlisted technologies were further subjected to detailed

evaluation in order to determine a preferred treatment solution for the Stage 1 leachate.



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Table 7. Outcomes of preliminary stage 1 leachate treatment options screening

+ Meets criterion

± Partially meets criterion or meets criterion but

requires more effort / investment.

- Does not meet criterion



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3.3.2 Detailed Evaluation of Shortlisted Treatment Technologies

The three shortlisted technologies were evaluated against each other and against the “do

nothing” (Base Case) option (continuation of discharge to sewer). The evaluation was done

using a custom built Sustainable Infrastructure Decision Model (SIDM©) which contains a

number of criteria grouped in the following risk-based evaluation categories:

Local environment & Public health protection;

Design;

Costs; and

Planning & Management

The overall performance of the shortlisted technologies against the evaluation criteria can be

seen in Figure 16.

Figure 16. Summary of leachate treatment technology evaluation



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In summary, the constructed wetland system scored the highest and outperformed MBR

and RO technologies across all evaluation categories, primarily due to the following

characteristics:

▪ passive sustainable nature;

▪ low reliance on energy & low/no chemical requirements;

▪ built resilience to deal with changes in flows and leachate quality;

▪ simplicity of operation and a significantly lower operating cost; and

▪ a range of value adds, such as biodiversity enhancement.

Consequently, the treatment wetland system was found to be the preferred

technological solution for dealing with the Stage 1 landfill leachate, and was further

progressed in terms of design and risk management.

3.4 ASSESSMENT OF TREATMENT WETLAND LOCATIONS

The following assessment step investigated the feasibility of alternative locations for the

construction of the proposed the on-site treatment wetland system. This process is outlined in

further detail in APPENDIX 4.

The following alternative wetland locations were evaluated:

1. Treatment wetland located south of Stage 1 adjacent to the creek system.

2. Treatment wetland located down gradient of the pump station (on Bartlett’s property).

3. Treatment wetland located north of the Stage 1 Landfill, within the existing Council

boundary.

These options were then compared with the “preferred option” of locating the treatment

wetland on top of the Stage 1 Landfill as proposed in the original system design (APPENDIX

1) and as proposed in this current Development Proposal. The landfill cap has a large

relatively flat land area available, meaning the full treatment system can be constructed within

the site boundaries with adequate buffer zones. The system involves pumping leachate to the

head of the wetland and gravity flow of treated effluent to an Infiltration Wet Forest; flows in

excess of infiltration capacity discharge to the creek.

All of the above described location options (the three alternative and the preferred options)

were assessed against five (5) criteria (Table 8):

Available area and compliance with discharge criteria.



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Availability and timely acquisition of land (including rezoning).

Clearance of established vegetation buffers.

Proximity to residential areas.

Avoidance of 1:1000 year flood plain.

Cost.

Table 8. Summary of assessment of alternative wetland locations

Of the three alternative locations, Option 3C (located north of the Stage 1 Landfill) was found

to be the most favourable alternate site option to compare with the preferred location for a

wetlands development (Table 8). This option would be fully contained within the site and no

additional purchase of land would be required. Similar to locating the treatment system on the

Stage 1 Landfill, this option involves pumping leachate to the head of the wetland and gravity

flow of the treated effluent to the infiltration wetland and the creek. The terrain available for

this option is very steep and would require significant earthworks, estimated to cost

approximately $1.5M more than the preferred location.

Locating the wetland to the north of the Stage 1 Landfill would involve a much greater

pumping head compared with locating the wetland on top of Stage 1 Landfill (preferred

option). Furthermore, there would be very limited potential for infiltration of treated leachate

within the site boundary due to less available land, hence the majority of treated leachate

would be discharged directly to the creek.

In contrast, a wetland located on top of the Stage 1 Landfill requires only minor top soil

stripping / earthworks as the terrain is ideally suited to a wetland, and has a lower pumping

head which enables recirculation between system components with minor grade changes.



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Further, this option allows for the majority of the land along the northern boundary to be used

for infiltration of treated leachate (Wet Forest), minimising direct discharge to the creek and

providing further water treatment.

The geotechnical report (Tasman Geotechnics August 2015) which evaluated the potential

hydrogeotechnical risks of each location concluded that the hazards associated with loc ating

and operating a wetland on top of the Stage 1 Landfill presents a Low to Very Low risk,

provided the following aspects are incorporated into the design and operation of the wetland

as follows:

Regular maintenance checks on pump and equipment are undertaken to minimise

blockages and overtopping.

Wetland is designed for sufficient freeboard to cope with anticipated rainfall events.

Wetland is located at least 10m from the crest of the landfill containment bund.

Incorporating a geosynthetic or LLDPE liner in the floor of the wetland is not essential;

however it would reduce the risk profile associated with seepage into the landfill to Very Low.

Based on the above evaluation, a wetland system constructed on top of the Stage 1

Landfill scored highest against the assessment criteria and remains Council’s preferred

option for the management of the Stage 1 Landfill leachate.



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4.0 PUBLIC CONSULTATION

In order to develop an appropriate treatment and disposal/reuse option, a collaborative

engagement process was undertaken with the stakeholders and the EPA, as key regulators.

This consultation and engagement process that has been undertaken thus far and is being

developed for the next project stages is in line with the aims, principles and approaches

outlined in A Tasmanian Government Framework for Community Engagement (Tasmania

Government, December 2013). The overall objective of the consultation process is to provide

an engagement continuum (i.e. a continuum of engagement practices, coordination and

information sharing) that facilitates decision-making and provides positive and mutually agreed

outcomes for the community, the Government and the Council.

4.1 STAKEHOLDER CONSULTATION

Key stakeholders in this project include Burnie City Council, TasWater, the general Burnie

community, adjacent neighbours, downstream landowners (residents living along the Creek),

TAFE Farm, Schools, UTAS, and Cradle Coast Authority NRM.

4.1.1 Community Consultation

Initial Engagement

BCC and Syrinx met initially with the immediate neighbours (adjacent landowners)

downstream of the landfill site in late April 2014 to brief them on the project, hear any

concerns and gauge interest in potential reuse of treated wastewater.

Downstream landowner’s permission was also sought for the background Cooee Creek

sampling program undertaken as part of this study (April 2014), and these downstream users

were briefed on the sampling project by Syrinx staff. A letter regarding the overall project and

sampling program was distributed by the BCC to seven immediate landowners in March 2014

(see APPENDIX 10 for the letter and list of contacted landowners).

Additional communication (via phone and in person) was held with relevant neighbours and

downstream landowners.

A summary of the information provided by Syrinx and BCC to private stakeholders included

the following:

Overview of leachate treatment study.

Scope of works for sampling event.



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Brief summary of environmental issues and reasoning for undertaking this sampling

project.

Environmental, social and economic considerations associated with the project, project

approach, timelines and likely preferred approach.

During this initial public consultation, no objections to the proposed project were received.

Feedback from conversations with landowners was generally positive and indicated their

desire to be kept progressively informed during the project.

Follow On Consultation

Stakeholder consultation was again undertaken in July 2015. A letter advising all landholders

downstream and adjacent to the unnamed tributary and Cooee Creek (original landowners

contacted plus additional seven landowners) was issued, advising them of the NOI submission

and providing an update regarding the project status, additional stud ies undertaken in 2015

and the status of the approvals process. This letter also included a plan showing the location

of the proposed system, and a concept layout of the treatment cells.

From this correspondence, three landowners, which are also creek water users, requested

further project information. These stakeholders were individually visited in early September

2015 by BCC and Syrinx, and briefed in detail. In summary, the main initial concerns were

primarily related to the potential impact of leachate discharge (both treated lea chate and non-

treated in peak storm events or events of system failure) on the creek water quality and

subsequently on crops/vegetable irrigation and livestock drinking.

However, after Syrinx /BCC provided additional information regarding the additional studies

undertaken to ‘proof up’ the proposed system, the ‘safety nets’ put in place for the project, and

in particular after communicating and explaining the current sewer capacity issues and the re-

occurring spillage incidents, the landholders appeared reassured that the system would be

safe and that it provides an overall beneficial outcome for the environment and the local

community. One landholder stated his philosophical opposition to the removal of leachate from

sewer since he saw this as a breach of an agreement.

This landholder meeting also clearly demonstrated the absolute need for continuity of

community consultation that would be responsive to differences between the key landholders

and perceived key issues. The concern that all of the landholders expressed for the ecosystem

health of the Creek system also paralleled their willingness for more meaningful engagement

in next project stages, especially in those restorative elements related to

protection/enhancement of the creek.



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Consultation Alignment with Framework for Community Engagement

As stated in the Tasmanian Government Framework for Community Engagement , a successful

community engagement process should include the following steps:

Inform – this is a one-way communication process mostly based on the information

provision to public.

Consult – this is a two-way communication and sharing process.

Involve, collaborate/ partner - working with communities through partnerships.

Empower - community empowerment.

The public consultation process undertaken thus far for the Burnie project follows this staged

engagement approach, and up to this point in the project it has successfully delivered the two

first steps, information sharing and a two-way communication which was used to gather

feedback on the key public issues associated with the proposed works and to ‘test’ the

proposed system in terms of public acceptance.

This engagement process was undertaken in a timely and honest fashion, with straightforward

account of all project benefits, risks and risk management measures. The consultation process

was also respectful of different people’s agendas and views, and was done with an aim to

enable community inputs.

In terms of future public engagement, the focus will be on continuing with the progressive

information sharing and on meaningful community involvement and collaboration .

BCC will continue to communicate with stakeholders through the following mechanisms:

Provision of copies of this DPEMP to, and discussion with, key stakeholders.

Provision of additional information that would increase community awareness

regarding the creek’s values, key existing threats, and positive impacts of the project

on the creek’s ecosystem health and visual values.

A special community information session days will be scheduled in the Council building and

at the waste centre site, with Council and Syrinx representatives that will enable all

interested community members to seek additional information regarding the project and

express (voice) their concerns, opinions and suggestions. To facilitate this process, visual

panels containing the most relevant project information presented in an appropriate (user-

friendly) form will be prepared for this community session and displayed in the Council

building foyer. Open day panels will remain displayed in the Council building and comments

will be sought for any further inputs. This will allow residents to have a progressive input into

the project (post information sessions) and will also enable those residents that couldn’t

attend the information sessions to ‘have their say’. Panels accompanied with the key project



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information will also be uploaded on the Council’ website and residents will be able to leave

on-line comments and inputs specific to the project.

Provision of opportunities for community and other stakeholders to be directly involved in the

project.

The project includes intensive creek restoration efforts and wetland planting. These actions

are planned to be undertaken in close collaboration with the community, school and NRM.

This involvement is expected to assist in raising community understanding of the project

drivers and benefits leading to a greater project appreciation and ownership.

Maintaining a line of communication with the key stakeholders.

Regular updates will be provided to all stakeholders regarding the project’s progress,

environmental achievements (including water monitoring data) and creek rehabilitation plans.

This will be done through written communication (newsletters to community), on-line

information (on Council’s website) and via annual reports.

Provision of additional opportunities for community education, engagement and

ownership through interaction with improved visual amenities of the project area.

The project will significantly improve aesthetic values of the site via creek restoration

efforts, an appropriate landscape design of the wetland system and provision of

educational/recreational opportunities and interpretative signage. Together, this will

make the site ‘appealing’ to community. Due to its educational and research values it

is expected that the site will be also frequently visited by school students. Schools and

the NRM will be involved in the wetland planting works.

Providing opportunities for community to comment on and provide inputs regarding the

project after the system commissioning.

Post commissioning residents will be able to express their opinions (positive and

negative) and raise any concerns regarding the system performance, site aesthetics or

any other issues. This will be facilitated on-line (comments on the dedicated forums on

Council’s website) and via comment forms collected in the Council building.

4.1.2 Consultation with TasWater

The engagement process with TasWater included progressive information sharing and regular

meetings aimed at understanding the key issues with regard to acceptance of trade waste to

the sewer system and potential barriers for continual discharge of Stage 1 leachate to sewer.

The initial meeting with TasWater was held on 23rd

of April 2014. During this meeting

TasWater stressed that the current WWTP is at capacity, and removing trade waste flows from

the sewer would reduce the number of non‐compliance events and free up capacity to deal



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with other waste streams not currently serviced by the WWTP. In terms of the Stage 1

leachate specifically, this stream is dilute and causes issues in terms of the biological

performance of the WWTP, and overflows along the existing creek in peak storm events.

Therefore, TasWater was of an opinion that there was a broader environmental benefit of on-

site leachate management and disposal. During this initial engagement, they acknowledged

that this BCC Stage 1 leachate project could be a demonstration site that would demonstrate

sustainable management of industrial wastewater, and would encourage research into onsite

treatment options for other landfill areas across the State that would potentially result in a

reduction in industrial waste disposal to their sewer systems more broadly.

A follow up meeting was held with TasWater on September 4th

2015, which focused on

discussions regarding the formal approval for maintaining an emergency connection to sewer.

TasWater advised that this was acceptable and will issue a letter of agreement, following

receipt of design flow requirements from BCC. TasWater has provided preliminary comments

to the EPA, which indicate they are supportive of the project.

Syrinx and BCC are in the process of collating and providing additional information to

TasWater regarding the frequency and volumes of leachate expected to be discharged to

sewer. The two scenarios where sewer discharge is expected are in the unlikely event of

pump failure, and in periods of non-compliant treated water discharge (see Figure 8). There is

a lag in peak flows into the leachate collection system after rain events since flows must first

recharge and then discharge from the aquifer (see Section 5.2.4 and APPENDIX 1), and there

is significant buffering and storage capacity within the wetland system. However, some

volumes may be subsequently released to sewer if the wetland cannot treat these flows

adequately. This means any discharge to sewer, if required at all, will be activated on the

second or third day following the storm event after the peak capacity of the sewer is restored.

4.2 REGULATORY CONSULTATION

BCC and Syrinx have maintained an ongoing consultative relationship wi th the EPA on this

project. Engagement with the EPA began immediately on project inception (March 2014) and

has included comprehensive and ongoing communication with both the local regulatory officer

and various experts in the Hobart office. The EPA have progressively provided advice and

informal review of studies/reports undertaken and have assisted in guiding the approvals

process thus far.



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5.0 THE EXISTING ENVIRONMENT

5.1 PLANNING ASPECTS

5.1.1 Land Tenure

The Burnie Waste Management Centre (BWMC) is located within the Burnie City Council Local

Government area and is operated by Burnie City Council. The subject site includes two lots:

Lot description

City of Burnie

Lot 1 on Plan 145841

Derivation: Part of 50,000 acres granted to the Van Diemans Land Company

Derived from A19301

City of Burnie

Lot 2 on Sealed plan 27996

Derivation: Part of Section 133, 50,000 acres granted to the Van Diemans Land Company

Prior CT 4261/55

The existing site Certificate of Title, is shown in APPENDIX 11.

The tenure is freehold and is owned by Burnie City Council. Under the Town Planning

Scheme, the site is included in “Community Purposes”. The planning scheme specifies the

zone is primarily intended to ensure that locations are available for specific public uses such

as disposal areas, cemeteries, crematoria, schools and council depose. Within the

“Community Purpose” zone, the landfill site is zoned “Utilities” which is primarily intended: i)

“To provide land for major utilities installations and corridors ”and ii) “To provide for other

compatible uses where they do not adversely impact on the utility”.

The proposed project site is located within the BWMC boundary, as shown in Figure 2.

The land surrounding the BWMC to the west and south of the site is mainly agricultural (zoned

Rural Resource), while the area to the north and east is zoned as General Residential.

The proposed leachate wetland treatment project does not conflict with any other known

developments within the BWMC site or surrounding land.

There are no easements on the property.



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5.1.2 Land Use & Planning History

The BWMC includes a landfill site (Stage 1 and Stage 2A), new Waste Transfer and Resource

Recovery Facility (WTRRF), Recycle/Recovery Loops and associated infrastructure (toll booth,

amenities building, tip shop, leachate ponds and pump stations) (see Figure 4). The total area

of the BWMC site is ~ 28 ha. The total landfill area is ~14 ha, comprising of ~8.3 ha for the

Stage 1 and ~5.8 ha for the Stage 2A.

The entire BWMC site has been used for waste management since it was opened as a formal

landfill site in 1987. Prior to this the land was used solely for agricultural purposes (livestock

grazing) and comprised of open pasture with remnant bush along the creeks.

A brief chronology of the landfill site is given in APPENDIX 12.

Currently the BMWC landfill site operates as a Waste Transfer and Resource Recovery

Facility, with putrescible waste being transferred to another landfill site (Dulverton Landfill).

The resource recovery facility includes a recycle loop, and tip shop, while concrete, masonry

and timber is stockpiled for reuse processing.

Green waste is handled on a green waste hardstand area, located on part of the old Stage 1B

landfill area.

5.1.3 Neighbouring Properties

There are three neighbouring properties located mainly adjacent to the north -east and

northern boundary of the site (visible on Figure 1). These are:

Land immediately downstream land (incorporating the unnamed tributary which is the

current BCC discharge point).

Land to the south of the landfill site.

Land adjacent to the waste centre eastern boundary (upgradient of Stage 1).

The nearest residential subdivision is currently on Three Mile Lane Road, approximately 200m

away (visible on Figure 1).

The TAFE agricultural farm site is located > 1 km north-west of the project site. Farmland

occurs to the west of Mooreville Rd.

There are no other land uses within the 500 m of the proposal site.



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5.2 ENVIRONMENTAL ASPECTS

A detailed description of the physical environment within project site and its immediate

surrounding is provided in various sections of APPENDIX 1 and APPENDIX 6.

Below is the synthesis of key characteristics of the physical environment.

5.2.1 Topography

The BWMC site comprises about 28 ha of moderate sloping ground. The natural ground

elevation is approximately 165 mAHD at the southern end of the site to 139 mAHD at the

outlet to Cooee Creek tributary. The location of the proposed leachate treatment system is on

top of the Stage 1 landfill (see Figure 6) to take advantage of the available space and to

maximise gravity flow of treated leachate through the treatment cells (note, the leachate will

be pumped to the head of the wetland system). The top of the Stage 1 landfill cap is at ~162

mAHD at the peak, as surveyed in April 2013.

5.2.2 Climate

The Bureau of Meteorology (BOM) station closest to the project site is at Round Hill Burnie

(operational since 1944), and data from this station has been used to determine the local

climatic conditions. The key characteristics are as follows:

Burnie exhibits a temperate, maritime climate with mild summers and relatively cold

winters.

The warmest months are January (21.1°C) and February (21.3°C), while July is the

coldest (12.8°C).

Significant temperature variations exist on site - In summer temperatures can rise to

35C° while from March to November they fall below zero. Significant temperature shifts

are also recorded for individual months where temperature can vary by up to ~20-

30°C.

The average annual rainfall is 945.9 mm with a low of 402.5 mm/year and high of

1488.4 mm/year. For the seven months during the year (April to October), average

daily rainfall exceeds evaporation.

Analysis of leachate flow data (APPENDIX 1) revealed that the leachate flows were

found not to show a correlation with individual rainfall events (although do with

seasonal rainfall) however these high rainfall events greatly impact on the overall

water behaviour on site (stormwater generation, groundwater levels, seepage) and

contribute to the overall leachate-associated issues on site.



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Wind is predominantly westerly or southwesterly (especially during the afternoon). The

months with the highest wind speed are October, November and December (14.1-14.9

km/hr at 9 am and 18.4-19.1 km/hr at 3 pm).

Mean rainfall, evaporation and temperature data is summarised in Figure 17.

Figure 17. Mean climate data for Round Hill, Burnie

5.2.3 Geology & Soils

The natural geology of the site and region generally are Tertiary volcanic basalts, which are

highly weathered (Mineral Resources Tasmania (MRT) Digital Geological Atlas, 1:25,000

Series, Burnie sheet). Although grouped as basalt soils, they typically comprise a sequence of

layers or flows. Creeklines and valleys within the region also contain Quaternary quartz

sediments and river silts and gravels, with Precambrian dolerites underlying the basalts or

outcropping in some areas.

The Stage 1 landfill pre-development site lies within a valley tract, and was constructed over

two spring-fed gullies and a swamp which together with two other spring-fed gullies on the site

form the head of the unnamed tributary to Cooee Creek.

There are no features of geoconservation significance within the project area.

Soils for the area are classed as Tertiary basalt ferrosols within the Lapoinya Association.

Within the site, the landfill overlays the semi confined basalt aquifer, with riverine creek fill

0

5

10

15

20

25

0

20

40

60

80

100

120

140

160

Tem

pe

ratu

re (°

C)

Rai

nfa

ll /

Evap

ora

tio

n (

mm

)

Mean rainfall (mm) for years 1944 to 2015

Mean monthly evaporation (mm) for years 1965 to 1982 (calculated from daily)

Mean maximum temperature (Degrees C) for years 1944 to 2015

Mean minimum temperature (Degrees C) for years 1944 to 2015



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materials and swampy deposits associated with now piped/drained spring expressions. Soils

are indicated as mainly brown to orange clays and silts of low to medium plasticity, associated

with weathering of the basalts (APPENDIX 6).

The site is not within an acid sulphate soil risk area (LIST Tasmania).

5.2.4 Leachate (Current)

Quantity (Flows)

Detailed analysis of leachate flows (current and historic) and flow distributions & patterns was

undertaken as a part of the initial Syrinx study (APPENDIX 1). This section summarises the

key points.

Analysis Approach

Currently, leachate flows are not directly monitored and are derived from pump data from the

MH1 chamber. The ‘capture rate’ of leachate flows is limited by the pumping capacity of the

system, which is ~ 40L/sec, or 3,456 kL/day, which can accommodate at least the 80 year ARI

event.

Because the leachate stream is around 80-90% groundwater, Stage 1 leachate flows

historically have been highly variable, influenced by seasonal rainfall patterns and

consequently variable groundwater inflows to the leachate drainage system. Further, annual

variations are or have been influenced by direct rainfall infiltration (in years prior t o capping in

2005), as well as a range of site works in more recent years associated with the development

and recent capping of the Stage 2 landfill and improvements to stormwater collection and

diversion on-site (which has reduced the incidence of mixing with leachate in MH1).

Due to these effects, the dataset used to characterise the existing leachate conditions on -site

is for the period March 2010 to December 2014 (current BCC dataset). This appears to be the

earliest stable trending dataset, and mainly reflects the completion of stormwater collection

and diversion works within Stage 2 and the waste facility area. Data points that reflected no

pumping or maintenance days were removed from the dataset.



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Current Flows

Stage 1 flows for the period March 2010 to December 2014, are given in Figure 18.

This dataset shows an average flow of 350 kL/day and a median value of 311 kL/day. Peak

pumped flow for this period was 1,449 kL/day recorded in August 2012, which appears from

the data to be due to a result of groundwater level rise after continuous rainfall, rather than a

singular rain event. The highest overall flows were recorded in spring 2013 .

Figure 18. Average stage 1 leachate flows (March 2010-December 2014)

0

100

200

300

400

500

600

700

800

900

Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec

2010 2011

2012 2013

2014

AVERAGE STAGE 1 FLOWS (kL/day)

kL/day 2010 2011 2012 2013 2014

OVERALL

AVERAGE

2010-2014

(kL/day)

se

Jan 456.0 287.6 272.4 339.8 339.0 8.22

Feb 448.1 251.2 265.3 306.0 310.3 8.80

Mar 207.3 365.1 250.7 230.5 278.4 265.3 5.54

Apr 214.2 347.5 297.3 204.7 279.8 268.2 7.73

May 194.4 282.3 471.9 203.3 266.5 283.7 8.82

June 206.1 267.2 477.4 198.4 265.2 282.9 9.36

July 242.8 288.4 280.3 258.6 284.3 271.1 4.33

Aug 286.3 338.3 763.3 502.8 343.8 446.9 20.10

Sep 395.8 383.5 806.1 661.1 340.2 517.3 17.33

Oct 390.9 381.6 585.5 675.2 332.0 473.0 15.36

Nov 361.1 364.7 379.4 538.6 306.0 389.9 7.40

Dec 377.4 344.8 341.9 424.4 285.6 354.9 7.55

350.2TOTAL AVERAGE



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Flow Distribution

A frequency graph was generated in order to assess the distribution of Stage 1 discharge

flows that will require treatment in the proposed system (Figure 19). Table 9 shows the

percentile rankings, which indicate that around 70% of flows are below 400 kL/day, 80% below

500 kL/day, 90% at or below 600 kL/day, and 95% 700 kL/day or below.

Figure 19. Frequency distribution graph of Stage 1 leachate flows

Table 9. Frequency distribution of Stage 1 leachate flows

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

30.0%

35.0%

40.0%

45.0%

100 200 300 400 500 600 700 800 900 1100 1200 1300 1400 1500

Fre

qu

en

cy

Range (daily flows kL/day)

Stage 1 Daily Flow Distribution for Feb 2010 - May 2014

95 percentile90 percentile

Flow Range

(kL/day)

Number of

Occurrences

Percentage

Frequency

Cumulative

Frequency %

100 3 0.2% 0.2%

200 193 12.6% 12.7%

300 357 23.2% 35.9%

400 587 38.2% 74.0%

500 208 13.5% 87.5%

600 44 2.9% 90.4%

700 75 4.9% 95.3%

800 36 2.3% 97.6%

900 10 0.7% 98.2%

1100 16 1.0% 99.3%

1200 4 0.3% 99.5%

1300 3 0.2% 99.7%

1400 3 0.2% 99.9%

1500 1 0.1% 100.0%



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Quality

As with leachate flow, a detailed analysis of leachate quality in terms of contaminant

composition, concentration and variability was done as a part of the initial Syrinx study

(APPENDIX 1). The section below summarises the key points.

Analysis Approach

The BCC have been undertaking monthly, quarterly and annual monitoring of various leachate

parameters to meet EPN compliance requirements. This comprehensive data set (from

January 2005 to November 2013) was used as the basis of Stage 1 leachate (LO1) quality

assessment. In line with the monitoring requirements, four LO1 samples are collected each

year from the MH1 chamber (except for the first monitoring year when only two samples were

collected), meaning that data from 33 sampling events was used in this analysis (Figure 20).

Stage 1 leachate (LO1) samples were analysed for a range of physico-chemical characteristic

as follows:

Physical characteristics, nutrients, most metals, and major anions/cations (quarterly).

Organic pollutants (insecticides/ pesticides and petroleum hydrocarbons) (tested

annually as they are generally found to be below the Level of Reporting (i.e. are not

detected in LO1 samples).

Under the existing scenario, leachate does not discharge to the Creek. However, the proposal

will result in highly treated leachate discharges in high rainfall events. As such, and in line with

the existing monitoring & reporting program and the Landfill Sustainability Guide (DPIWE

2004), the leachate water quality (WQ) data was assessed against the Australian Water

Quality Guideline for Aquatic Ecosystems (ANZECC, 2000) trigger values.

Trigger values are pollutant concentrations that, if exceeded, would indicate a potential

environmental problem, and would hence ‘trigger’ a management response, e.g. further

investigation and subsequent refinement of the guidelines according to local conditions. If the

trigger value is not exceeded, the risk of an impact is low and no further action is required.

Note, the aquatic ecosystem guideline trigger values for toxicants (e.g. metals) are risk-based

in the sense that they are calculated to protect a predetermined percentage of species with a

specified level of confidence (i.e. 99%, 95%, 90% and 80% protection level signifies the

percentage of particular species expected to be protected).

The WQ trigger values considered appropriate for the site are for the Ecosystem Condition 2

(level of protection 95% species) trigger values applying to lowland streams. This reflects the

agricultural land use surrounding the landfill site and the activities associated with landfill

operations and development within the site.



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Note, the ANZECC trigger value used for ammonia is corrected for the pH of the leachate, in

accordance with Table 8.3.7 of the guidelines - a trigger value specific for pH 7.5 (1.61 mg/L)

was used to analyse ammonia data and establish ammonia-specific treatment requirements.

Figure 20. Site current sampling locations



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Physical Characteristics

A summary of the Stage 1 leachate physical characteristics is given in Table 10. The key

findings are as follows:

pH is within the circum-neutral range, averaging 6.8. pH values were found to be

slightly below the lower limit set by ANZECC guidelines on five occasions since

monitoring began (16% trigger breach).

Table 10. Stage 1 leachate WQ – physical parameters

Redox potential is positive indicating well oxygenated conditions . Note, a positive

oxidation-reduction potential and the presence of oxygen are common for mature

leachates, which have undergone the final maturation stage of waste degradation

(ARRPET, 2004), hence even disregarding the influence of groundwater incursion, the

leachate itself is expected to be well oxygenated.

Most solids are being reported as dissolved (TDS, soluble fraction) while only a small

fraction is present in particulate suspended form (TSS).

Commonly, under positive redox (oxidising conditions) and with a neutral pH (pH

greater than 5.5), redox-sensitive metals (Cu, Cr, Mn and Fe) react with water to form

relatively insoluble hydroxides and oxides. However, most of the Stage 1 leachate

contaminants are in soluble form and no correlation was found between either pH or

redox values with TSS and TDS. This indicates the leachate chemistry is complex and

simple patterns are overprinted by other factors that impact on these metal

concentrations (and probably concentrations of other pollutants). The key factor is

clearly the ingression of groundwater and the consequent dilution effect.

The conductivity of the leachate is primarily influenced by alkalinity which, for the pH

range, is dominated by bicarbonate ions. The balance of salts is comprised of sodium,

chloride and sulphate, which are at low levels within the leachate, with median values

recorded as follows: chloride – 53.5 mg/L; sodium - 36.6 mg/L; magnesium - 20.6

Physical Characteristics Range Average MedianANZECC (2000)

Aquatic ecosystem

pH 6.1 - 8 6.8 6.8 6.5 - 8.0

Alkalinity total mg CaCO3/L 30 - 271 172.9 179.6

Total Suspended Solids (TSS) mg/L 7 - 72.8 25.4 18.9

Total Dissolved Solids (TDS) mg/L 92.8 - 373 272.3 276.4

ORP (redox potential) Eh mV 276 - 663 470.2 434.0

Conductivity µS/cm 157 - 795 540.3 557.0



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mg/L; sulfate - 11.3 mg/L; and potassium - 6.9 mg/L. Metals and ammonia comprise

the balance of electrical conductivity.

Nutrients

Nutrients (nitrogen species and phosphorus) are the key contaminants of concern for the

Stage 1 leachate, with a very high frequency of trigger exceedances (Table 11), meaning

these will need to be reduced within the proposed treatment system prior to any discharge to

creek.

Table 11. Concentrations of nutrients in Stage 1 leachate

Total nitrogen (TN) concentrations have exceeded trigger values at every sampling

event since the start of the monitoring program, with a median value of 7.9 mg/L. Most

of the total nitrogen reports as ammonia, while NOx species (nitrate and nitrite)

represent only a small portion of TN (6%).

Concentrations of ammonia in Stage 1 leachate exceed the set trigger value almost all

of the time (95% exceedances). Whilst elevated, ammonia concentrations in the

leachate are significantly lower compared to typical leachate, where ammonia often

exceeds 400 mg/L. This possibly reflects the significant dilution of leachate stream

with groundwater/stormwater, but also the waste composition.

Most of NOx species are present as nitrate (97%), typical of streams with positive

redox.

Phosphorus levels are low, with both average and median values well below ANZECC

trigger values. Detected TP values exceeded trigger values 25% of the time. Only

>20% of total P is in dissolved form.

Note, although phosphorus levels are relatively low in the Stage 1 leachate, they are

within the range that enables effective growth of wetland vegetation. Generally,

phosphorus is considered to be inefficient to support biological processes in

constructed wetlands if the N to P ratio is greater than 500 (Maehlum, T. 1999) , which

Nutrients Range Average Median

ANZECC (2000)

Aquatic

ecosystem

% exceed.

TN mg/L 1.1 - 15 8.1 7.9 0.5 100%

Ammonia total mg/L 0.07 - 14 7.8 7.9 1.61 97%

Nitrate mg/L 0.034 - 1.71 0.48 0.39 0.7 9%

Nitrite mg/L 0.004 - 0.03 0.01 0.01

TP mg/L 0.002 - 0.093 0.036 0.025 0.1 26%

Dissolved reactive P mg/L 0.002 - 0.044 0.006 0.004 0.02 0%



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is not the case; the proposed wetland system has an N:P ratio of ~300. In terms of the

potential effect of low phosphorus concentrations on the efficiency of nitrogen removal

in the wetland treatment system, the key biological processes involved in removal of N

species (ammonification and nitrification) are primarily influenced by the N:C ratio, and

less so by the N:P ratio. Consequently, despite the relatively low TP levels in the

Stage 1 leachate, no addition of fertilisers is expected to be required either during

periods of wetland establishment nor during the normal system operation.

The existing data indicates seasonal patterns in terms of nutrient levels. As seen in Figure 21,

concentrations of TN, ammonia and TP appear to be the lowest in winter months (May to Aug),

with relative peaks in March and September. March peaks probably reflect a typical ‘first flush’

response at the onset of rainfall and initial recharge of the groundwater from agricultural

areas. The winter lows coincide with dilution as a result of higher rainfall and flows. Spring

peaks coincide with the highest leachate-groundwater flows in a typical year. It is unclear why

these presumably more dilute rain-dominated flows also have the highest nutrient

concentrations, however it may be associated with the rising leachate levels within the landfill

cell causing ‘scouring’ of higher layers within the leachate landfill in a rise and fall fashion

(APPENDIX 6), that means more concentrated nutrients become entrained in the discharge

flows. Pastures in the region are fertilised in winter and spring and it is also possible that low

uptake of N-fertilisers in winter when temperatures are low may increase this load to

groundwater and surface waters, however there is no evidence of similar spring peaks in

stormwater concentration up-gradient of the landfill (SW2).

Figure 21. Seasonal changes in nutrients levels in Stage 1 leachate (median values)

(data set 2005 – 2013)

0.00

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0.07

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Jan Feb Mar Apr May Jul Aug Sep Oct Nov Dec

TN ammonia TP

TP (

mg/

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Nit

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It should be noted that the ANZECC trigger value used for ammonia is corrected for the pH of

the leachate, in accordance with Table 8.3.7 of the ANZECC guide lines.

The freshwater high reliability trigger value for ammonia is 0.9 mg/L in Table 8.3.7 of the

ANZECC guidelines, and BCC has used this trigger value in their WQ monitoring and reporting

program. This trigger value has been derived from figures corrected as total ammonia at a

fixed pH of 8.0, which is not the pH characteristic of the leachate and results in an

overconservative trigger value.

Importantly, the toxicity of ammonia is primarily attributed to the un-ionised NH3 (not total

ammonia), and is highly influenced by pH (as well as temperature and ionic composition of

water). In general, at higher pH values (>8) ammonia predominantly exists in a more un -

ionised (more toxic) form, while at lower pH values, the un-ionised (ammonium) form is

dominant; hence the overall toxicity is greater at a higher pH. As outlined in the ANZECC

guidelines, trigger values for ammonia at pH conditions other than 8 should be calculated

using equations provided in these guidelines, or adopting pH-corrected values provided in

table 8.3.7 of the guidelines.

The average and median pH values of the Stage 1 leachate are 6.8 (Table 10), and since the

start of the monitoring program a pH greater than 7.5 was recorded only once while most of

the time (~65%) the pH was below 7. Furthermore, recent monitoring of water quality of the

unnamed tributary to Cooee Creek (March 2014), which is the key sensitive receiving

environment showed that the average pH is 7.4 with the maximum recorded value 7.5.

Therefore, to appropriately reflect the reduced ammonia toxicity at reported pH values

(leachate and creek), a trigger value specific for pH 7.5 (1.61 mg/L) was used to analyse

ammonia data and establish ammonia-specific treatment requirements.

Metals

In general, concentrations of heavy metals in Stage 1 leachate can be characterised as low to

very low, which is a characteristic of mature leachate that has undergone the fermentation

stage of waste degradation during which soluble metals are mostly bound in a metal sulphides

form. In terms of the total concentrations, two dominant metals are iron and manganese.

Other key metals that were found to at least one occasion during the monitoring period exceed

relevant ANZECC trigger values (95% protection) are aluminium, chromium, copper, nickel

and zinc (Table 12).

All of these metals are typical of municipal landfills and reflect the mixed nature of the waste

being disposed at the landfill (municipal, commercial and mixed indust rial waste). Other

monitored metals (As, Cd, Hg, Pb) were never found to exceed trigger values and were

predominantly below the level of detection, and hence were not included in Table 12.



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Table 12. Stage 1 leachate WQ – metals (total)

In terms of individual metals, the Stage 1 leachate is characterised by the following:

Manganese (Mn) - is the key metal of concern in terms of compliance with the

ANZECC protection levels, as both the average and median values exceed 95% trigger

values. While frequent (64% of time), these exceedances are relatively minor (~7%

above trigger values). Manganese (and iron) are also signatures of the basalt geology,

hence elevated Mn could reflect the groundwater intrusion into the leachate system as

well as landfill chemistry. This is difficult to verify since there is no total metal data

available for groundwater. Mn levels in stormwater samples (SW1) are much lower

compared to leachate (see Section 5.2.7).

Reported Mn levels in leachate reflect total metal concentrations which includes the

concentration of metals in both dissolved and particular form. Dissolved metals are

generally considered more mobile, biologically available and potentially toxic. Under

aerobic conditions typical of the Stage 1 leachate stream, the solubility of Mn is

generally low as it forms a stable oxidized form (generally as MnO 2), which is highly

insoluble. Thus, most of the Mn reported in the Stage 1 leachate is expected to be in

particulate form.

Iron (Fe) - Higher Mn concentrations co-occur with elevated levels of iron (Fe) in the

leachate, as a result of their similar chemistry and responses to redox and pH (i.e. for

Mn to precipitate, the water must be well oxygenated to the extent that essentially all

Fe is insoluble, and pH should be near neutral or above). Given the local geology is

dominated by iron-rich volcanic basalt, high concentrations of iron are expected in the

local soils which were also used in landfill construction materials. This may have

added to the Fe load within the landfill waste and relatively high Fe levels in the

leachate stream. While not causing significant negative environmental impacts, high

Fe concentrations together with Mn do pose practical challenges for leachate

Range Average Median

ANZECC (2000)

Aquatic

ecosystem - 95%

protection

% exceed.

Al µg/L 2.5 - 705 44.8 13.4 55.0 16%

Cr µg/L 0.5 - 3 0.74 0.5 1.0 12%

Cu µg/L 0.4 - 2.98 0.71 0.50 1.4 6%

Fe µg/L 1,887 - 34,500 12,930 9,358

Mn µg/L 142 - 3,960 2,159 2,043 1,900 64%

Ni µg/L 2.4 - 15.8 10.2 10.1 11 30%

Se µg/L 5 - 26 8.5 5.0 5 3%

Zn µg/L 0.5 - 39 7.3 6 8 27%

denotes trigger value exceedances

Metals (total)



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collection and treatment. They contribute to the hardness of the leachate, and can

precipitate within the leachate distribution systems causing a reduction of pipe

diameters and eventually clogging, as well as the loss of pressure in pumps and pipes.

Seasonal variations in Fe and Mn concentrations in the leachate show a strong

correlation (Figure 22), and are similar to seasonal patterns observed for nutrients

(nitrogen, ammonia, phosphorus, Figure 21). Furthermore, they show reasonable

similarity with the seasonal patterns in Fe and Mn concentrations in stormwater (see

Section 5.2.7). As with nutrients, concentrations are at a peak in spring when

groundwater has recharged and the interaction between groundwater and leachate

waste materials are at their highest.

Figure 22. Seasonal changes in Fe and Mn levels in Stage 1 leachate (median values)

Aluminium (Al) - At times Al concentrations in the Stage 1 leachate were found to

significantly exceed ANZECC 95% trigger values, the average and median

concentrations are below this trigger values.

Seasonal variations in Al concentrations in the Stage 1 leachate and SW1 stormwater

showed very similar patterns, indicating interaction and mixing between these two

streams (Figure 23). Al levels in SW1 stormwater are higher compared to LO1

leachate (as well as the SW2 stormwater entering the landfill site) suggesting that

these high Al levels may originate from other activities beyond the Stage 1 landfill.

High natural background levels of aluminium (Sharman 2002) could also be one of the

contributors.

0

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1,000

1,500

2,000

2,500

3,000

3,500

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10,000

15,000

20,000

25,000

30,000

Jan Feb Mar Apr May Jul Aug Sep Oct Nov Dec

Fe Mn

Fe (

ug/m

l)

Mn (ug/m

l)



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Figure 23. Seasonal changes in Al concentrations in LO1 and SW1 (median values)

Zinc (Zn) & Nickel (Ni) - Both Zn and Ni exceed relevant ANZECC guidelines ~30% of

the time, although their median and average concentrations are below relevant trigger

values.

Relative similarity in seasonal patterns in Zn levels in leachate and SW1 stormwater

indicate mixing of these streams. Similarly to Al, during certain months Zn levels were

higher in the SW1 stormwater samples compared to the leachate stream, indicating

that other activities other than the Stage 1 landfill contribute to stormwater

contamination with Zn (Figure 24). As for aluminium, high background levels of zinc

(Sharman 2002) could also be contributing to this observed Zn levels in stormwater.

Figure 24. Seasonal changes in Zn levels in LO1 & stormwater (median values)

0

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Jan Feb Mar Apr May Aug Sep Oct Nov Dec

SW2 LO1 SW1

Zn

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(µg/

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Organics & Other Chemicals

The Stage 1 leachate is characterised by a very low presence of organics as demonstrated by

i) the low COD which is found to be below LOR throughout the sampling events, and ii)

absence (concentrations below LOD) of most organic pollutants tested as a part of the regular

monitoring program. Out of more than 50 different organic contaminants tested on an annual

basis only four polycyclic aromatic hydrocarbons (PAHs) have been detected in the Stage 1

leachate stream (Table 13). These four PAHs were found to be only occasionally present in

LO1 (≤50% of time), and at very low levels. The ANZECC trigger values are set for

naphthalene only, and this PAH is well below the 95% protection level.

Such a low level of organics in leachate is typical of mature landfill sites that have undergone

degradation and volatilization of aromatic hydrocarbons which are the most organic

compounds reported in landfill leachate. As a result, only small amounts of refractory organic

carbon usually remain in old landfilled wastes, and report to their leachate streams.

Table 13. Stage 1 leachate WQ – detected organics

Cyanide was detected in the Stage 1 leachate during a single monitoring event only

(14/02/2006) when it was above the guideline limits, and hence is not considered to be a

major contaminant of concern.

Thus, based on the available leachate data, organics are not considered to be major

contaminants of concern in terms of environmental impacts associated with the discharge of

treated leachate to the creek. If anything, the very low presence of organics may slow down

biological treatment processes within the wetland system, most notably dentitrification

processes in the subsurface (anaerobic) system component. Further data is being gathered to

assess the BOD:COD ratio and determine if supplementary carbon will be required. Carbon

additions can be accommodated within ether the Cell 1 pre-treatment cell (e.g. by adding

slowly degrading carbon materials such as woodchips), or as liquid or granular humates within

any system component. When the system reaches maturation, the wetland cycle of plant and

microbe growth, death, atmospheric fixation and partial decomposition etc will likely provide a

sufficient carbon source.

Organics Range Average Median % detected

ANZECC (2000)

Aquatic

ecosystem

Acenaphthene µg/L <0.5 - 1.39 0.82 0.62 50% -

Naphthalene µg/L <0.5 - 0.54 0.51 0.50 17% 16

Benzo(k)fluoranthene µg/L <0.5 - 0.6 0.52 0.50 17% -

Fluorene µg/L <0.5 - 0.7 0.55 0.50 33% -



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Pathogens

The presence of pathogens (E. coli) in Stage 1 leachate is monitored annually. Since the

beginning of the monitoring program, E. coli was always found to be below the level of

detection in the leachate stream.

Discharge (Mass Loads) to Sewer

Mass loadings (average daily and average annual) of key contaminants present in Stage 1

leachate to TasWater sewer were calculated using the median pollutant concentrations

available for the period 2005-2013 and average annual leachate flows calculated using

available leachate flow data for the period 2010-2014. This data is presented in Table 14.

Table 14. Mass loading of key pollutants to sewer

5.2.5 Leachate Seepage

There have only been two seepage events on site which occurred in 2007 and 2013 along the

northern containment bund, both after extreme (>80 year ARI) or extended rainfall periods. In

both cases, leachate seepages expressed as localised ponding which eventually infiltrated

(Figure 25), and there was no discharge to the creek, however in both cases flows were within

20 m of the creek discharge point (Figure 26).

Leachate seepages caused localised mineral salt scalding and plant death.

Throughout the record August/September 2013 rainfall, small volumes of landfill leachate

seeped from Stage 1 landfill containment bund over a length of approximately 20 m. This

AVERAGE

ANNUAL FLOWS

(2010-2014)

(kL/annum)

127,890

ANNUAL MASS

LOADING TO SEWER

(kg per annum)

TSS 2,417

TN 1,010

Ammonia 1,009

TP 3.2

Al 1.7

Cr 0.06

Cu 0.06

Fe 1197

Mn 261

Ni 1.3

Se 0.6

Zn 0.7



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seepage ponded in an area adjacent to the northern boundary (Figure 26). The issue was

identified on 13/9/13 and the EPA was advised the same day, who requested BCC to

undertake sampling. Two samples were taken at Site 1 and 2 on the 17/9/13 down gradient of

the seepage source, and two further sampling events were conducted in December 2013.

Flows were too small to estimate volumes, however given the area impacted it is estimated to

be <50 m3.

Figure 25. Seepage area showing ponding & low ‘sheen’ indicating metal precipitation

Figure 26. Extent of leachate seepage in August 2013



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The composition of leachate water sampled within ponded areas of the site over the three

sample periods indicated a highly diluted flow (Table 15), supporting the view that this

seepage is most likely to have come from lateral flow out of the landfill cap intermediate batter

into the drainage trench that is around the east and north sides of the scrap metal storage

compound area. It is likely that this flow has seeped through the landfill containment bund to

present as ponds on the mid level bench of the containment bund. A similar seepage along

the west side of the scrap metal area in 2007 was controlled by the installation of a drainage

blanket and subsoil drain directed to the leachate pond.

Table 15. Leachate seepage chemistry for the 3 sampling events in 2013

The chemistry of the seepage is more or less the same as in the LO1 (Stage 1 leachate) for

Mn, Fe, Ni and Zn sampled at a similar time (Sept 2013). However, Al concentrations are

extremely elevated – 4,210 ug/L compared with 54 ug/L in the LO1 leachate flows - this may

indicate a point source within the landfill itself. Cu and Cr are also elevated compared with

LO1 leachate.

Interestingly, organics (COD) are detectable, and within the typical mature leachate range.

COD is always below the level of reporting in the Stage 1 leachate samples, since it is highly

diluted by groundwater mixing.

In April 2014, Syrinx undertook additional investigations of soils within the leachate seepage

area, to assess the extent of contamination, if any, and possible requirements as part of the

overall leachate treatment design options. Soil data (Table 16) indicates that there is no

contamination of soils (using NEPM guidelines for industrial sites). While this is not therefore

of immediate concern (since contaminants did not discharge off-site), given seepage events



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have occurred more than once on-site at this location, the seepage zone as such has been

incorporated into the overall treatment system by creating a phytoremediation swale to collect

the seepage and direct it to the leachate treatment system. Furthermore, soils, while below

the relevant guidelines, still contain elevated metals (copper, chromium III, nickel and zinc) .

Hence, these soils will be stripped and disposed of or only used within embankment fill

material or for site levelling material under liners.

Table 16. Soil data from within the leachate seepage area (northern embankment of

Stage 1 landfill)

5.2.6 Groundwater

Hydrogeological Context

The regional catchment hydrogeology has been well characterised (Martin and Currie 2008 ‐

Conceptual model report for Cam‐Emu‐Blyth), the subregional (Cooee Creek) catchment

hydrology modelled as part of flood risk assessments (Entura 2011), and the local site

catchment hydrogeology (including the installation and monitoring of a large number of bores)

studied as part of baseline land capability assessments and specific landfill design studies

(Sloane 2000, Coffey 2004, 2007, 2008, SKM 2007, Tasman Geotechnics 2015).

A continuous water level record exists for the Burnie wells for the period December 2003 to

March 2006 and is reported on in the state (Mineral Resources Tasmania) groundwater data

collection program. Manual water level readings have been recorded since 1991.

These studies and investigations demonstrate that the entire landfill operation is confined

within a natural Tertiary basalt valley. The site acts as a significant groundwater discharge



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zone with spring expressions along the valley slopes and floor and discharge of all

groundwater to the two creeks on‐site.

The Stage 1 subcatchment discharges to the northern ‘unnamed tributary’. The long term

hydrographs for the site (Figure 27 and Figure 28) and the groundwater contour levels (which

are above the creek invert level) support a “fill and spill’ groundwater model for the shallower

sub‐regional flow systems; i.e. rapid infiltration of rainfall recharge occurs to a maximum level

(sustained through capillary rise) at which point any subsequent infiltration is lost as discharge

to the surrounding rivers and streams.

The unnamed creek is a minor part of the overall Cooee Creek catchment (<5% of the

catchment area), and constitutes less than 1.5% of the total Cooee Creek flows (Entura 2011).

A conceptual site model illustrating the interactions between groundwater with leachate and

surface flows is shown in Figure 29.



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Figure 27. Standing water level data and cumulative deviation from mean annual rainfall recorded for GW1 (Burnie Tip site 1, ID 17778) o ver

the period 1991 to 2000. From Martin and Currie 2008



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Figure 28. Standing water level data and cumulative deviation from mean annual rainfall recorded for GW2 (Burnie Tip site 4, ID (ID 1778 0)

over the period 1991 to 2006. From Martin and Currie 2008



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Figure 29. Conceptual site model – existing scenario



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Groundwater Quality

Groundwater quality monitoring has been undertaken across the site since 1991 as part of the

original site permit conditions and subsequently as part of the s tate (Mineral Resources

Tasmania) groundwater data collection program. Quarterly groundwater monitoring of one

upstream (GW3) and two downstream bores (GW2, GW 1) is undertaken by the BCC.

Historical data for GW1 and GW2 is contained in periodic MRT reports.

Groundwater monitoring bores (located on Figure 20) are as follows:

GW3 – located upgradient of the landfill along the southern boundary of the site.

GW2 - located near the entrance at the northwestern end of site down gradient of the

Stage 2A landfill, and the western section of the Stage 1 landfill.

GW1 - located along the northern boundary downstream of the Stage 1 landfill.

The key water quality data for the three monitoring bores (Table 17) shows groundwater is

characterised by a slightly acidic to neutral pH, with elevated nutrients (mainly nitrogen) and

some metals. Similar to stormwater, the dominating nitrogen form is nitrate while ammonia

represents only a small fraction of TN. Total N and nitrate values appear to be higher in the

bore up-gradient of the landfill (GW3), compared to the downstream bores, suggesting that

agricultural activities may be the dominant source of nutrients in GW. Dissolved metals

including Cr, Ni and Zn are present in GW3 and GW2, but are low in GW1. It is difficult to

determine the source of these low level metals, since they are typical of both agricultural

fertilisers and herbicides, and of the leachate waste. Organic pollutants, which are monitored

annually, were not detected in any of the GW samples.

The springhead dam on private land above the GW3 bore and SW2 stormwater monitoring

point has been filled with unapproved materials in the past, including tyres, which may have

contributed to elevated chromium and metals in groundwater.

In comparing the long term water quality data for groundwater bores with other regional bores

from the MRT program indicates there is no difference between the Burnie bores and other

regional rural bores in terms of quality. Importantly, groundwater recharge zones are located

above the Stage 1 and Stage 2 landfill operations, with these and the majority of the site

within a groundwater discharge zone, hence all site runoff reports to Cooee Creek as surface

or subsurface discharge and the potential for groundwater contamination is remote. All bores

are similar in chemistry and contaminants measured all are within groundwater drinking level

criteria (NEPM GIL criteria).



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Table 17. Summary of groundwater quality data – pH, nutrients and dissolved metals



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5.2.7 Stormwater

Stormwater Flows

Stormwater at the BWMC site is managed by a network of open channel, cut-off swale drains

and pipe conveyance infrastructure. The stormwater network is indicated in Figure 5 , Figure 8

and Figure 30.

The capacity of the stormwater network was assessed as part of this proposal by Tasmanian

Consulting Service (2015) using a DRAINS model, which in particular focussed on the risk of

flooding to the proposed wetland under extreme rain events (APPENDIX 6). This study

concluded that the site stormwater infrastructure can adequately handle flows from rainfall

events to up and including 20 Year ARI without any overland flows or upwelling. During 100

year ARI events, some overspilling was modelled to occur adjacent the 900 DIA RCP culvert

under 3 Mile Line Road, however this does not result in overland flow over the roadway since

the Northern Waterway/Creek (Cooee Creek unnamed tributary) would simply swell and flood

the adjacent grass paddocks. Detailed flood modelling undertaken by Entura (2011) showed

the same result. The addition of treated leachate flows to the creek is minor and therefore

highly unlikely to increase the risk of flooding along this section of the creek.

Direct (point source) stormwater discharge to Cooee Creek tributary occurs via a pipe and

pump connection that links Stage 2A stormwater flows to the MH1 chamber. Flow data is

estimated using pump records (period 2010-2014, Figure 31). Stormwater from Stage 2A is

pumped to MH1 at a maximum 10L/sec flow rate and this flow reports to the MH1 chamber

and from here discharges via a pipe to the creek.

The dataset indicates there is a constant baseflow of ~ 2.5 -3 L/sec, and in winter/spring flows

are ~4-5L/sec. These average flows are used below to estimate the current mass load to the

creek from point stormwater discharges from Stage 2A only. Note, this is clearly an

underestimation of total site stormwater flows.



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Figure 30. Stormwater network at BWMC (from Tasmanian Consulting Service 2015 report)



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Figure 31. Average (Stage 2) stormwater point discharge flows to Cooee Creek tributary

Stormwater Quality

Stormwater quality is monitored quarterly by the BCC as part of the EPN conditions. Similar to

groundwater, there are upstream (SW2) and downstream monitoring points (SW3 is in the

Stage 2 landfill area and SW1 downgradient of the Stage 1 landfill, Figure 20).

Stormwater quality data is shown in Table 18.

Stormwater entering the site (SW2) contains elevated levels of nutrients with both median TN

and TP values exceeding ANZECC standards, most likely as a result of fertiliser use on the

upstream farm properties. In contrast to the leachate stream, stormwater TN is dominated by

inorganic forms, with nitrate dominating and ammonia representing only a small fraction of the

total nitrogen (up to 10%).

Metal characteristics are similar to Stage 1 leachate, with stormwater entering the site (SW2)

containing notable levels of metals which occasionally exceed ANZECC guidelines for the

protection of aquatic ecosystems. This most likely reflects an agricultural source.

When comparing the water quality at SW1 (downstream) with the two monitoring points

upstream of the site (SW3 and SW2), it can be noted that most of the detected metals are

0

100

200

300

400

500

600

700

Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec

AVERAGE STORMWATER DISCHARGE TO CREEK kL/day (2010-2014)

2010-2014 kL/day

median 252.00

average 286.49

max 5040.00

min 0.00



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present in higher concentrations and are characterised by a higher frequency of guideline

exceedances. This is particularly the case for Al, Fe, Mn, Ni and Zn (Table 18), which

suggests interaction/mixing between these streams.

While the higher concentrations of Fe, Mn and Ni in SW1 may originate from the ingression of

leachate into the stormwater system, the same is not the case for some other metals including

Al, Zn, Cr and Cu. As discussed previously in the leachate WQ section, levels of Al and Zn in

SW1 are higher compared to LO1 samples, suggesting the influence of some other activities

on stormwater quality.

Stormwater flows across the landfill site generally do not show organic contamination as

indicated by the very low COD (below LOR), relatively low DOC and general absence of

analysed organic pollutants in SW samples.

A key risk response included in the proposed project includes the separation of the current

stormwater discharge infrastructure from the leachate collection and treatment system to avoid

untreated leachate discharge via the stormwater system.

Table 18. Stormwater quality



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Estimated Current Stormwater Mass Loads to Creek

There is insufficient flow data to generate a mass load balance for the site. As an estimate,

the pump flow data from Stage 2 that reports to MH1 and directly discharges as point source

to the creek, is shown in Table 19. This is clearly only a portion of the total flows.

Table 19. Estimated mass loading of key stormwater pollutants to the Creek from

Stage 2A stormwater flows

5.2.8 Cooee Creek and its Tributary

The Burnie Landfill operations are within the immediate water catchment of Cooee Creek. The

Stage 1 landfill pre-development site lies within a valley tract, and was constructed over two

spring-fed gullies, and a sumpland (swamp) along a major creekline (Cooee Creek unnamed

tributary). These were infilled and drained as part of the development works, and the majority

of the creek tributary infilled, diverted and/or modified for both Stage 1 and Stage 2 landfill

activities.

Under the current landfill operational regime, this creek receives all flows from the site not

managed within the leachate recovery and disposal system (i.e. stormwater plus groundwater

flows that bypass the leachate collection system). This means that this unnamed tributary is

the immediate off-site receiving environment. In addition to this site discharge, this tributary

receives groundwater discharge and surface runoff from neighbouring farms (this includes

agricultural pollutants).

The unnamed tributary has its origin 100 m upstream of the landfill area, and rises as springs

mostly within the landfill site and connects to the Cooee Creek watercourse approximately 3.0

km north-west of the landfill site. The Cooee Creek catchment starts near West Ridgley and



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flows into the Bass Strait, dropping around 300 m over its 13 km length. The total catchment

area is 102 km2, and the catchment area of the unnamed tributary is 5.2 km

2 or 5% of the

catchment (Entura, 2011). Martin and Currie (2008) analysed data (stream heights, DEM,

groundwater elevations) for the catchment and concluded that rivers and creeks in the vicinity

of the site are gaining creeks (i.e. groundwater discharge zones), and do not recharge the

groundwater except at local higher catchment creeks where the invert of the creek bed may be

seasonally at least above the groundwater level. This latter pattern was shown for the creek in

the Stage 2 Development Approvals reporting for the site (Coffey, 2004).

Cooee Creek is within the broader Cam River Surface Water Catchment (DPIPWE, 2014),

although functions within its own hydrological boundary (Cooee Creek Catchment). The Cam

River is very well protected in terms of its Protected Environmental Values (PEVs) as it is very

intensively used for recreation, and the EPA have used the Cam River data in developing Draft

Water Quality objectives for Cooee Creek. PEV’s have not been formally identified for the

Cooee Creek catchment or the unnamed tributary on the landfill site.

Figure 32. Cooee Creek catchment area. Burnie landfill site is up-gradient of CT-1

Creek Ecology

The two natural values assessments undertaken for the project site (NEST 2013 & APPENDIX

2) concluded that the Cooee Creek unnamed tributary is already significantly impacted as it

flows through a highly modified environment. The section of the unnamed tributary close to the



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BWMC and neighbouring agricultural land were found to be generally degraded and in poor

condition, infested with weeds (APPENDIX 2). Visual assessment of Creek’s condition

undertaken by Syrinx in April 2014 (APPENDIX 1) also confirmed that the unnamed tributary is

fairly degraded, with evidence of erosion, high weed extent, stock impacts and limited riparian

vegetation. Parts of the creek have been piped (through the residential area downstream of

Three Mile Rd) and dammed in some sections ( the TAFE property is the first main dam

feature).

Approximately 3 km downstream of the BWMC (APPENDIX 2) the unnamed tributary passes

through remnant vegetation, with steep forested gullies of mixed eucalypt over a wet

understorey that provides high quality habitat for creek fauna.

According to the Conservation of Freshwater Ecosystem Values (CFEV) database (WIST,

DPIWE), the creek above the Stage 1 landfill site is identified as of moderate conservation

management priority, however the tributary downstream of the Stage 1 landfill (within and off -

site including piped sections) is shown as having high conservation management priority

(APPENDIX 13).

Figure 33. Conservation of Freshwater Ecosystem Values (CFEV) for the site.



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While not mapped formally on the Groundwater Dependent Ecosystems Atlas (Bureau of

Meteorology, Australian Government), Cooee Creek is known to be groundwater recharged

and hence should be classed as a groundwater dependent creek system. As such the

vegetation and fauna supported by the creek system relies on groundwater discharge to

maintain environmental flows and permanent pool habitats.

Water Abstraction

There are fifteen known water licence holders (21 water licence numbers and 65 abstraction

points) along Cooee Creek and its tributary with this water used for irrigation purposes (Water

Information System of Tasmania, accessed November 2015). Water use is primarily during

summer months for irrigation of vegetable crops and pasture. Water is stored in dams over the

winter period and then used in summer. Direct take allocation allow a water user to take water

directly from the flow of the creek during the summer months.

Properties that are riparian to a stream have an automatic water right for stock and domestic

purposes, such as watering livestock, home gardens and even dwellings.

Water Quality

Water quality and sediment sampling and analysis of Cooee Creek and its unnamed tributary

were undertaken as part of this leachate treatment project (APPENDIX 1) to determine

baseline conditions of these key surface water receiving environments.

Water samples were collected during two sampling events at four locations along the tributary

and four locations (upstream and downstream from the unnamed tributary) (Figure 34).

Sediment samples were collected from four locations across the creek system. All samples

were analysed for a broad range of physico-chemical stressors and toxicants (Table 20 and

Table 21).

The water quality data of Cooee Creek and its tributary indicates that this creek system is

already impacted upon and receives discharge from the landfill site, as a result of groundwater

and stormwater discharge (which is to be expected given the local hydrology and the loc ation

of the landfill in a valley). Consequently, the system can be classified as slightly or moderately

disturbed (condition 2 ecosystems) based on the ANZECC (2000). This classification has been

adopted by the EPA in the Draft Proposed Water Quality Objectives for Cooee Creek.

The key concerns in terms of creek water quality are nutrients (total nitrogen, nitrate and total

phosphorus) and some metals (aluminium, copper, lead and manganese).



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Figure 34. Location of Water and Sediment samples undertaken as part of Cooee Creek and Cooee Creek tributary background sampling (Syrinx,

APPENDIX 1)

Cooee Creek

Cooee Creek

Cooee Creek

Unnamed tributary

Unnamed tributary

BWMC



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Table 20. Cooee Creek monitoring data - water quality results (April 2014) and

comparison with the Stage 1 leachate and site stormwater

Table 21. Sediment quality within Cooee Creek and unnamed tributary – April 2014



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Importantly, levels of key pollutants (nutrients and metals) and their distribution both upstream

and downstream of the landfill site suggest that groundwater/surface water discharge from the

landfill site is not the only source impacting on creek health. Rather, this creek system

receives inputs from other sources such surface runoff or groundwater discharge from nearby

properties (with a strong signature of fertiliser practices) as well as downstream properties.

For example, the presence of copper at very high concentrations along the length of the

tributary and Cooee Creek, is a strong signature of fertiliser use. Furthermore, a dominance of

organic N in sediment suggests other inputs apart from landfill leachate, given leachate is

dominated by ammonia.

Protected Environmental Values (PEVs)

PEVs have not been specified for Cooee Creek however the Environmental Management

Goals for the North-Central Coast Catchments do recommend suitable PEVs based on the

origin of the creek and the nature of the landscape through which it flows. For this project the

following PEVs were proposed as a minimum to ensure protection of Cooee Creek and its

unammed tributary:

Protection of aquatic ecosystems - (ANZECC Water Quality Guidelines (2000))

Recreational water use; and

Agricultural water use.

Given the current degraded nature the unnamed tributary (i.e. erosion, relatively poor water

quality, highly impacted by the extensive urban and agricultural land use in the catchment, it is

anticipated that the unnamed tributary would be rarely (if ever) used for recreational purposes

and most likely this would include secondary recreational activities only (e.g. less body contact

such as fishing). The recreational (primary and/or secondary) users of Cooee Creek were not

considered to be a key human receptor group given that any flows discharged to the unnamed

tributary would be significantly diluted before they reach Cooee Creek. Hence, protection levels for

secondary recreational contact were adopted.

EPA Draft Water Quality Objectives for Cooee Creek

A snap shot water quality monitoring event undertaken in Cooee Creek and its tributary in

April 2014 (APPENDIX 1), together with visual assessments of ecosystem health (APPENDIX

1 and APPENDIX 2), suggests that this system is already impacted upon and hence can be

classified as slightly or moderately disturbed (condition 2 ecosystems) based on the ANZECC

(2000).

In line with this, the Tasmanian EPA has prepared Draft Water Quality Objectives for Cooee

Creek as part of the Water Quality Guidelines (WQGs) for Cam Catchment in which Cooee

Creek is classified as a Slightly to Moderately disturbed (SMD) ecosystem. The 80th

and/or



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20th

percentile trigger values were determined using the creek-specific data obtained during

the 30/11/2004 to 04/10/2007 monitoring period (Table 22). For physical parameters, triggers

were derived from 30-31 analysed samples, while for nutrients only 4 samples were used in

determining the trigger values. There is no ammonia specific data for Cooee Creek, and hence

the use of SMD WQOs for the Cam catchment is recommended.

Given the relatively small number of samples (especially for nutrients), this EPA Draft Water

Quality Objectives report is an evolving document, and the EPA have indicated they are

interested in obtaining creek-specific data to finalise the draft.

To this end, the Cooee Creek water quality data gathered in April 2014 by Syrinx as a part of

this BCC project could be included in the overall data set for refinement of the 20th

/80th

percentile trigger values. When this data (i.e. for Cooee Creek and its unnamed tributary) is

compared with the data used to derive the EPA trigger values, the following can be observed:

Median values for DO and the conductivity are very similar to the EPA median levels.

pH levels of Cooee Creek and its tributary measured in April 2014, while within circum -

neutral range, appear to be somewhat higher (more alkaline) compared to the previous

results.

Nutrients (and in particular TN) were found to be elevated compared to the EPA data.

TN concentrations in the six (6) analysed Cooee Creek samples from the three

sampling locations were in the range 0.5 – 2 mg/L, with a median of 1.3 mg/L which is

significantly higher compared to the EPA median of 0.68 mg/L. While nitrate levels are

comparable between the EPA and Syrinx data, this difference in the TN concentrations

is most likely due to the relatively high ammonia levels in the Syrinx April 20014 data.

However, as the EPA data set does not include ammonia levels, this cannot be

confirmed.

Ammonia levels in the Syrinx 2014 sampling of the Cooee Creek and its tributary were

similar to the Cam Catchment WQGs.

TP levels in the Cooee Creek and in particular the unnamed tributary were found to be

higher compared to the EPA data.

Turbidity, temperature and Chlorophyll-a were not included in the April 2014

monitoring program, so no comparison can be made with the EPA data set.

Note, the EPA data does not cover the limits for metals and other chemical contaminants (e.g.

organics, cyanide). Hence, the WQ protection trigger values adopted here for these chemical

toxicants are the default values (95% level of protection) provided in the ANZECC Guidelines.



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Table 22. EPA proposed water quality objectives for Cooee Creek

EPA - Proposed Annual Water Quality Objectives (Shaded)

Percentile 5th 10th 20th Median 80th 90th 95thSample

Number

ANZECC

(2000)#

Unnamed

tributary

(median

values )

Cooee

Creek

(median

values)

Dissolved Oxygen mg/L 8.3 8.7 9 9.8 11.2 11.5 11.6 30 9.85 10.2

Dissolved Oxygen %

SaturationND ND

Field Cond @ TRef25 µS/cm 94 100.6 115.1 151.4 205 215.8 276.5 31 150.5 143.5

pH field - sensor TC 6.7 6.7 6.9 7.2 7.3 7.5 7.7 31 6.5-8.0 7.4 7.6

Turbidity NTU 2.6 3.9 4.3 5.1 7.8 12.8 18 31

Temperature (Celsius) 7.3 8.1 10.1 13 16.7 17.6 18.5 31

Ammonia as N mg/l ND 1.61* 0.05 0.03

Nitrate as N mg/l~ 0.427 0.432 0.441 0.47 0.498 0.508 0.512 2 0.7 0.625 0.435

Nitrite as N mg/l ND

Total Nitrogen as N mg/l ~ 0.155 0.17 0.2 0.438 0.681 0.715 0.732 4 0.5 1.8 1.25

Phosphorus, Dissolved

Reactive as P mg/lND

Total Phosphorus as P mg/l ~ 0.011 0.012 0.015 0.021 0.025 0.028 0.029 4 0.05 0.045 0.030

Total Suspended Solids

(1.5µm)mg/lND <5 <5

Total Suspended Solids

(0.45µm) mg/LND

ND= No data, ~ = Insufficient data for generation of WQOs (va lues included for information purposes only)

* ANZECC 2000 guidel ines - Trigger va lues for toxicants . 95% protection level adjusted for pH

Syrinx data (April

2014)

# ANZECC water qual i ty guidel ines (2000) - Default trigger va lues for phys ica l and chemical s tressors for south-east Austra l ia for s l ightly dis turbed ecosystems

total

ammonia

nitrogen

as N^

(mg/L)

Annual 0.051

Summer 0.048~

Autumn 0.070~

Winter 0.055~

Spring 0.043~

CAM CATCHMENT

WQGs



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While the EPA data and the derived protection limits provide an important understanding of

the ecosystem health of the Cooee Creek, using these values as the water quality protection

trigger values for discharging treated leachate (and stormwater) into the creek system, poses

the following concerns, especially in terms of nutrient targets:

None of the nutrient data collected by the EPA included the unnamed tributary of

Cooee Creek, which is the proposed receiving environment for the treated leachate.

This is particularly the case for ammonia for which the data was adopted from the Cam

Catchment data set. As discussed above, the Cooee Creek unnamed tributary is

already a highly disturbed system. This relatively high level of disturbance is evident in

the recent (April 2014) WQ and sediment data for this tributary, compared to the

Cooee Creek itself (see section above) In contrast, Cooee Creek and the Cam

Catchment as larger scale systems, are far less disturbed, and predominantly limited

to agricultural influences. Such a marked difference between the ecosystem conditions

questions the appropriateness of using the Cam Catchment / Cooee Creek data for

setting the discharge levels for the unnamed tributary.

Nutrient protection levels (TN, TP, nitrate) were derived from only 2 to 4 sampling

events, the last one being in 2007. Such a small number of samples is generally not

sufficient to derive a statistically significant local reference system (as acknowledged

by the EPA in this project). The April 2014 sampling events, if included in the overall

data set would inevitably increase the median, and hence the 80th

percentile trigger

values for TN and TP.

The ammonia trigger values set by EPA (for the Cam Catchment) reflect the levels of

ammonia as a chemical stressor, not as a toxicant.

Based on the ANZECC 2000 Guidelines, nutrients (TN and TP) are generally

considered to be non-toxic direct-effect stressors, meaning that they do not have a

toxic effect but rather that elevated levels result in adverse changes to the ecosystem

as a result of nuisance growth of aquatic plants (eutrophication), excessive algal

growth and cyanobacterial blooms. Ammonia and nitrate, on the other hand, are also

toxicants; that is stressors that are directly toxic to biota.

Protection levels for the key stressors such as TN and TP are derived from relevant

reference systems, either from the same or local ecosystems, or from regional

reference ecosystems. The trigger values of toxic stressors such as ammonia and

nitrate are generally determined from laboratory ecotoxicity tests conducted on a range

of sensitive aquatic plant and animal species. These trigger values are outlined in

Table 3.4.1 of the ANZECC Guidelines. In other words, the non-toxic effect of

ammonia is generally ‘managed’ via setting TN protection levels, while its toxicity is

regulated by the set default values outlined in the ANZECC Guidelines.



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Therefore, in terms of appropriate ammonia and nitrate protection levels for discharge to the

unnamed tributary, both ammonia and nitrate should be considered as toxicants and the 95%

protection levels outlined in the ANZECC Guidelines applied (Table 3.4.1 in Guidelines). Given

the pH-dependence of ammonia toxicity, this ammonia protection value should be pH

corrected, resulting in a trigger value of 1.6 mg/L (see Table 23).

Proposed Water Quality Targets for Discharge to Cooee Creek Tributary

As discussed above, the EPA proposed water quality objectives for Cooee Creek were derived

from a relatively small data set which mostly did not include samples from the unnamed

tributary of Cooee Creek and are considered a draft set intended to be progressively updated

as more specific data becomes available. These values are based on the least impacted sites

within the SMD (Slightly to Moderately disturbed ecosystem) and are considered to represent

aspirational Water Quality Targets. If the Creek-specific water quality data gathered as a part

of this project (April 2014) is included in the overall data set this would alter the 20th

/80th

percentile trigger values, especially for nutrients and pH.

Hence, for the purpose of setting up specific creek water quality protection levels that would

adequately reflect both the specific creek data and the objectives set by the EPA, two types of

targets were developed:

1. Interim targets – that fully reflect creek-specific conditions; they were derived using the

monitoring data from April 2014. These targets are intended to be immediately adopted

and implemented.

2. Aspirational targets – derived by inclusion of creek-specific data into the EPA data set.

These targets are intended to replace the interim targets when the EPA dataset is

statistically robust and trigger values set as final, and after the performance of the

treatment system has been validated over several years .

These two target types apply for nutrients and pH only; the targets for other stressors

(physical) adopt the EPA set values, while targets for toxicants and other pollutants were

derived from relevant ANZECC guidelines.

Therefore, the following water quality protection levels are proposed to be used to manage

discharge of the treated leachate into the Cooee Creek unnamed tributary (Table 23):



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Temperature, conductivity, turbidity & Chlorophyll-a – targets as outlined by EPA.

pH and DO

a) Aspirational Targets: Targets determined by including the most recent April

2014 WQ data into the EPA data set and recalculating the 20th

/80th

percentile

trigger value.

b) Interim Target: Target derived as the median values from Cooee Creek and the

unnamed tributary from April 2014 monitoring data (current baseline).

TN & TP

a) Aspirational Targets: Targets determined by including the most recent April

2014 WQ data into the EPA data set and recalculating the 80th

percentile

trigger value.

b) Interim Target: Target derived as the median values from Cooee Creek and the

unnamed tributary from April 2014 monitoring data (current baseline) .

Ammonia – ANZECC 95% trigger values for freshwater ecosystems corrected for pH

(toxicants, Table 3.4.1).

Nitrate and Metals - ANZECC 95% trigger values for freshwater ecosystems

(toxicants).

Fe – EPA advice on soluble iron (target 0.3 mg/L) was adopted together with the

relevant trigger values for total metals as outlined in the ANZECC Primary Industry

Guidelines (2000).

Other chemical pollutants - ANZECC 95% trigger values for freshwater ecosystems.

Faecal coliforms / E. coli – Currently, the creek water is primarily used for irrigation

of pasture and fodder for dairy animals and as a drinking supply for dairy animals. The

use of this water for garden irrigation cannot be excluded although the exact type of

vegetables being irrigated (e.g. salad vegetables or vegetables requiring peeling or

cooking), the extent of any garden areas and frequency of irrigation, as well as the

irrigation methods (via spray or trickle irrigation) is not known.

In terms of potential recreational use, given the current degraded nature of the

unnamed tributary (i.e. erosion, relatively poor water quality, highly impacted by the

extensive urban and agricultural land use in the catchment) this creek is rarely if ever

used for recreational purposes and is most likely used for secondary recreational

activities only, which include activities with less body contact such as fishing.



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In light of this, the following guidelines and trigger values were considered appropriate

for setting the protection levels for coliforms:

o The ANZECC Guidelines for recreational water quality and aesthetics (2000):

the secondary level recreational contact - the median value in fresh and marine

waters not to exceed 1,000 faecal coliform organisms/100 mL or 230

enterococci organisms/100 mL.

o The ANZECC Guidelines for Primary Industry (2000): drinking water for

livestock – the median value not to exceed 100 faecal (thermotolerant)

coliforms per 100 mL (median value).

o The ANZECC Guidelines for Primary Industry (2000): irrigation waters for

pasture and fodder (for grazing animals except pigs and dairy animals) - the

median value not to exceed 100 faecal (thermotolerant) coliforms per 1,000 mL

(median value).

Escherichia coli is a more sensitive indicator of faecal pollution of source water than

thermotolerant coliforms, and are already monitored as part of the routine BCC

leachate monitoring program. Consequently, E.coli and enterococci have been

adopted as the key indicators of microbiological contamination of creek water with

human (and to a lesser degree, animal) faeces. In line with the ANZECC guidelines

outlined above, the protection levels were set to be <230 organisms/100 mL for

enterococci and <100 cfu/100 ml for E.coli.

Note, this protection level is above the trigger values set for irrigation of vegetable

crops that are directly eaten (e.g. lettuce) which is <10 cfu/100 ml. Given the

uncertainties regarding the use of creek water for this particular purpose, and more

importantly, considering the multiple inputs to the creek from nearby residential

properties and farms which include pathogen contaminated agricultural surface run off,

it is questionable if such a pristine water quality (in terms of pathogen) can be

achieved at all.

Surface run-off from agricultural land or irrigated pasture runoff is known to contain a

major numbers of faecal organisms with levels being as high as 40,000 cfu /100 ml

(Carey et al, 2004). Furthermore, the levels of E.coli in Shorewell Creek passing

through the residential areas of Burnie were detected to be ~2,000 cfu/100 ml

(Sharman, R (2002). Consequently, setting up a very stringent pathogen protection

level of <10 cfu/100 mL was considered impracticable and not critical for the protection

of public and animal health, and a more appropriate, less stringent value of <100

cfu/100 ml was hence adopted.



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Table 23. Proposed water quality protection levels for discharge to the Cooee Creek

unnamed tributary



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5.2.9 Biodiversity & Conservation Significance

There are no national parks, nature reserves or wetlands of national significance (RAMSAR) in

the vicinity of the project site (10 km). The site also does not contain outstanding natural

features.

This proposal was referred to the EPBC in November 2014, and was determined as not a

controlled action (APPENDIX 3).

Listed threatened species and ecological communities

Two natural values assessments of the landfill site for BCC have been undertaken in recent

years – one as part of the Stage 2 landfill rehabilitation planning (NEST 2013) and most

recently one as part of the Landfill Stage 1 leachate management project ( APPENDIX 2).

These studies found that there are several species listed under the Environment Protection

and Biodiversity Conservation Act 1999 (EPBC Act) recorded within 500m of the Burnie Waste

Management Centre and along the un-named tributary flowing from the Centre. Several

species are also listed under the Tasmanian Threatened Species Protection Act 1995.

The threatened species listed under the EPBC Act and recorded within 500 m and 1 km of the

un-named tributary or are likely to occur here, based on habitat, are listed in Table 24. The

section of the creek that flows through the BWMC and the unnamed creek itself were found to

be a suitable habitat for the Burnie burrowing crayfish. This was the only species confirmed

within 1 km of the project site. The Green and gold frog and Eastern barred bandicoot could

potentially inhabit this zone (APPENDIX 2), however the survey did not identify individuals or

evidence of their activity. The only evidence of activity for these two species was found in the

creek section 4 kms downstream of the project site. No impacts to the Eastern barred

bandicoot are likely given the key threats to this species are feral animals and remnant

vegetation disturbance.

The nearest State listed Threatened ecological community is an undefined wetland, which is

listed as vulnerable under State legislation (Nature Conservation Act 2002), and occurs ~2

kms downstream of the project site (LIST Database). It is not listed as being of National

significance.

This community was not identified within the NEST (2014) report, however it was noted that

this area is highly impacted from weeds and cattle impacts. Eucalyptus viminalis wet forest,

which is listed as endangered occurs in uplands around the forested Cam River catchment,

however is not within the area of impact.



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Table 24. Threatened species recorded (in bold) within 500m of stream reach and

those potentially present, by habitat type or survey evidence (NEST 2014)

Listed migratory species

Field surveys conducted in July 2014 (NEST 2014) observed only one migratory species with

the potential to inhabit the area is, Lathamus discolour (Swift Parrot) which is an endangered

species.

Vegetation & Flora

Native vegetation of the areas surrounding the project site is reflective of the diverse

topography of the region, as well as localised hydrological and geological influences. Much of

the privately-owned land in the region has been cleared for agriculture, which has impacted on

the water quality of the creeks and groundwater.

The natural vegetation of the region is Eucalyptus obliqua wet forest with broad leaf shrubs

growing on the lower slopes, with white gum wet forest (Eucalyptus viminalis wet forest)

occurring on the upper slopes and outside of the project area of influence. The wet obliqua

forest dominates the Cooee Creek environment. This community is dominated by stringybark

eucalypts (Eucalyptus obliqua) with a mixture of broadleaf species such as blackwood (Acacia

melanoxylon), dogwood (Pomaderris apetela), and an understorey including forest daisybush



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(Olearia lirata), stinkwood, (Zieria arborescens), satinwood (Nematolepis squamea) and

treeferns (Dicksonia antarctica) (APPENDIX 2).

A total of 29 plant species were identified during the site survey in 2014 over a distance of

approximately 4 km, including the project site. None of the identified species are threatened

flora, i.e. they are not present on the list of Ihreatened plants within the Burnie Local

Government Area (Department of Primary Industries, Parks, Water and Environment,

Threatened Species Section (DPIPWE), site accessed November 2015).

Seventeen weeds/exotic species were also identified. Of these, four species (gorse,

blackberry, Cortaderia species and Elisha's tears) are on the list of Declared Agricultural and

Environmental Weeds in Tasmania (DPIPWE Tasmania, site accessed November 2015).

These declared weeds were primarily identified in creek sections surrounded by agricultural

land.

The section of the creek that flows through the BWMC was found to be highly impacted, with

heavy weed infestations. The dominant weed species in areas close to the BWMC is the

invasive riparian weed, Glyceria, which is classified as a Non-declared Agricultural and

Environmental Weeds in Tasmania (DPIPWE). This weed was considered to be the highest

risk weed to the natural values of the creek (APPENDIX 2).

Fauna

The NEST (2014) assessment of natural values of the Cooee Creek un-named tributary

included an assessment of fauna (APPENDIX 2). This survey was done over the entire 4 kms

from the Waste Management Centre to the confluence with Cooee Creek.

This study found that the section of the creek that flows through the BWMC is suitable habita t

for the Burnie burrowing crayfish. The Spotted tailed quoll, Green and gold frog and Eastern

barred bandicoot could potentially also inhabit this zone.

Downstream of the BWMC, creek sections either passing through areas of native vegetation or

areas that have had work undertaken to improve the riparian zones showed evidence of

burrowing crayfish activity consistent with the presence of the Burnie burrowing crayfish.

Cooee Creek approximately 3 kms from the BWMC provides a well-shaded stream with pools

suitable for presence of the Giant freshwater crayfish.

The green and gold frog was considered potentially occurring in the creek areas in the vicinity

of the project site (unnamed tributary). Signs of habitation by pademelons (Thylogale

billardierii) and Tasmanian Native-hen (Tribonyx mortierii) were also noted.



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Riparian areas in proximity of the project site that are well connected to larger patches of

bushland, are expected to be used as hunting territories by the Tasmanian devil and spotted -

tailed quoll.

A Masked owl (Tyto novaehollandiae) was also sighted during the survey. Signs of bandicoot

activity were also found but it could not be determined whether it was from the Southern brown

bandicoot (Isoodon obesulus) or Eastern barred bandicoot (Perameles gunnii).

As expected, sighting of fauna was dependent on the level of creek degradation and

vegetation cover.

5.2.10 Natural Events & Hazards

Fire

Currently, the risk of fire at the BWMC is relatively low due to the operations being now limited

to waste recovery, and due to existing procedures covered by the existing EPN and

management plan for the site (Mooreville Rd Landfill Environmental Operations Manual,

Meinhardt Infrastructure and Environment Pty Ltd, April 2005). Strict management procedures

apply that include the following:

Strict control of accepted waste types (no explosives).

Site supervision during hours of operations and presence of a Caretakers’ residence

on the site perimeter.

No permission for open fires on the site; only regulated gas flames are us ed.

Appropriate training of operators for fire fighting.

Provision of fire breaks.

Provision of vehicular access on site to all fire fighting equipment.

Provision of appropriate signage.

Appropriate and regular maintenance of all fire fighting equipment.

Restricted site access.

Flooding

The 1000 year ARI flood line is assumed to be up to ~1.0 to 1.5 m above existing surface

above the current creek waterway (top of bank). The outline of the 1000 year floodplain is

shown in Figure 35. The treatment wetland will be located well above this line. The pump

station, emergency storages and infiltration swale will be located within this zone (since this is

the current status).



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Figure 35. The outline of the 1000 year floodplain (blue hatched areas)

Natural Hazards

No active or recent landslides have occurred on the site or have been mapped historically

(MRT Burnie Landslide Inventory Map, Stevenson et al 2010).

5.2.11 History of Waste Management

A summary of historical waste management activities on site that may affect the proposal is

summarised below. In the main, this information is relevant to understanding the nature of the

leachate chemistry (due to mixing with groundwater as discussed in Section 5.2.4), and the

geotechnical assessment of locating a wetland treatment system on top of the landfill cap (see

6.1.2).

Prior to development, the site contained springheads and shallow gullies and a large

swamp at the confluence of the creeks. “Stormwater” pipes were installed in the base



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of the landfill cell to collect the spring flow and surrounding groundwater seepage. The

pipes were rubber ring joined concrete pipe. Strictly speaking, the pipes form a

groundwater drainage system.

The groundwater drainage system under Stage 1 Landfill was compromised many

years ago during landfill operations. Recent (August 2015) photographic evidence

confirms that:

o For some of the manholes, holes were punched into the concrete manhole

sections to allow surface runoff to drain from the operating landfill surface,

o Some manhole shaft joints were not properly sealed, allowing leachate to seep

into the manholes.

o Manhole E shows that the liners are mis-aligned allowing seepage into the

manhole. There are also several holes in the liners.

Stage 1 Landfill was filled between 1987 and 2004, and capped in 2004/2005. Survey

data confirms the base of the manholes is about 10 m below the landfill cap. Anecdotal

commentary from the BCC Waste Team Leader at the time was that filling started

against the northern containment bund wall and progressed in a southerly and easterly

direction. When filled, a temporary cap was put on the landfill. Approval was then

obtained from the licensing authority to place a 2nd lift (3 m of waste) on Stage 1. The

2nd lift was achieved by constructing a bund wall along the northern edge of Stage 1

and filling in the same manner as the first lift: in a southerly and easterly direction

(verified by the cross section presented in Figure 4 of the Tasman Geotechnical report,

APPENDIX 6). There was no separation of waste during filling of Stage 1 (eg greens,

paper and metals) and car bodies were squashed and included in the waste.

Spreading and compaction of the waste was achieved with a 14t drott, an earthmoving

machine similar to a bulldozer, but with a front bucket. However, the degree of

compaction of the waste was minimal. The use of a compactor at the site did not

commence until close to the end of Stage 1. Hence, compaction of the waste is likely

to be poor.

Assuming poor compaction of the waste, the bulk density may be as low as 0.6 t/m3.

However, considering the inclusion of day and intermediate cover, some compaction

from the drott and the fact that Stage 1 was capped at least 10 years ago, it can be

argued that the waste density is higher. A value of 0.8 t/m3 is deemed appropriate to

assess the long term stability of the landfill.

The Stage 1 Landfill comprises two capping designs – the northern part has a rock

aggregate drainage layer while the southern part contains a Geosynthetic Clay Liner

(GCL) (visible on Figure 35 and APPENDIX 7).



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Between 2007 and 2015, the site was accepting select clay material, which was

progressively placed and stockpiled on the western side of the Stage 1 cap. Stage 2A

landfill was capped in March 2015 with the clay stockpiled on Stage 1.

5.3 SOCIO-ECONOMIC ASPECTS

As previously discussed under the Public Consultation Section (Section 4.0), the key

stakeholders that will potentially be impacted by or have an interest in the proposed project

include immediate neighbours, downstream landowners, the broader Burnie Community, the

TAFE Farm, Schools, UTAS, Cradle Coast Authority, NRM and Burnie City Council.

5.3.1 Project Socio-Economic Benefits

In addition to environmental gains, the project is expected to provide a range of social as well

as economic benefits to these key stakeholder groups.

Social Benefits

At the present, the landfill site has no broader social benefits to the local and regional

community, outside of the waste management function. The Stage 1 site is fully fenced and is

not accessible to the public. The site has a very limited biodiversity and aesthetic values, and

is not visually connected to its surroundings.

The proposed wetland system is expected to greatly enhance the aesthetic and biodiversity

values of the landfill and enable better integration of the site with its surrounding environment.

The constructed wetland system will provide an opportunity for installation of boardwalks and

other interpretative signage, and for ongoing teaching and research opportunities with lnks to

the UTAS Cradle Coast Campus and schools. This is expected to increase community

appreciation of the site and site usage, and it is anticipated that over the time (especially after

the wetland system achieves maturation) the site will be frequently utilised by the local

community.

Planting of the wetland will be undertaken with community involvement including local schools,

interested local community members and the NRM group.

Economic Benefits

The project is expected to provide several direct and indirect economic benefits on both a

local and regional scale. These include:

Freeing up capacity in the Round Hill WWTP via removal of leachate from the sewage

system for other industries. A key immediate development demand in this regard is



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expansion of the cheese processing plant by Lion, which is a lead enterprise for the

expansion of the dairy industry in the north-west coast of Tasmania.

The proposal will not have a negative effect on surrounding land values. On the

contrary, the planned the wetland and associated creek restoration and stormwater

works will enhance the values of the site and surrounding land.

Increases in environmental flows will potentially increase the irrigation capacity of the

creek system further benefiting downstream agricultural users.

Provision of employment opportunities during the system construction for the local and

wider regional community.

5.3.2 Heritage

Aboriginal Heritage

Aboriginal people are known to have lived in the region. It is recognised that all registered and

unregistered Tasmanian Aboriginal sites are protected by the State Aboriginal Relics Act 1975

and the Commonwealth Aboriginal and Torres Strait Islander Heritage Protection Act 1984.

A review of the Tasmanian Aboriginal Land Council (TALC) site register indicated an absence

of Aboriginal sites and/or artefact areas within a 2.5 km radius of the landfill site. An aboriginal

cultural heritage assessment of the area confirmed there are no aboriginal artefacts on the

landfill site (SEMF, 2002).

The landscape of the landfill site has been significantly modified by the historic agricultural

and grazing activities and more recently activities associated with landfill operations. As such

there are no Aboriginal landscape values remaining within the project area, in the form of

significant native vegetation with traditional cultural associations. The project area is assessed

as being of low archaeological sensitivity (SEMF, 2002).

European Heritage

The project must comply with the Historic Cultural Heritage Act 1995.

However, there are no listed heritage properties and/or values as no places or sites exist in

the project area that are listed on the National Heritage List, Register of the National Estate,

Tasmanian Heritage Register or the Tasmanian Historic Places Inventory.



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6.0 POTENTIAL IMPACTS & THEIR MANAGEMENT

6.1 KEY ISSUES SPECIFIC TO THIS PROPOSAL

The key issues identified as specific to this proposal are:

Potential surface water hydrology and water quality impacts.

Potential groundwater impacts and geotechnical issues.

The background to these issues is covered in Section 5.0. This section uses a risk based

assessment method to identify the potential impacts, receptors, pathways and

mitigation/management measures required (or already incorporated into the design), to

manage these risks. To assist in the assessment of surface water quality impacts, the mass

pollutant loads expected to be discharged to the infiltration Wet Forest (on site) and to the

unnamed Cooee Creek tributary, is provided, as well as a summary of geotechnical issues

pertinent to the risk profile. The hydrogeotechnical report is provided as APPENDIX 6.

The proposal is not expected to have any impacts on the groundwater aquifer, since the

proposal sits within a groundwater discharge zone with all groundwater within Stage 1

discharging via surface flows or subsurface seepage to the unnamed Cooee Creek tributary.

This has been discussed throughout the document and in detail in Section 5.2.6, and is

illustrated in the current conceptual site model (Figure 29) and the conceptual model showing

the proposed development (Figure 36).



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Figure 36. Conceptual site model – PROPOSED DEVELOPMENT SCENARIO



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6.1.1 Potential Surface Water Quality and Hydrological Impacts

The proposed design of the leachate wetland system aims to minimise direct discharge of the

treated leachate to the unnamed tributary of Cooee Creek by maximising on-site infiltration

within the last component of the system (Infiltration Wet Forest). Hence, most of the treated

leachate will discharge indirectly via subsurface infiltration to the Creek , with only flows in

excess of the infiltration capacity of the Wet Forest overflowing directly to the Creek via a

weir/cascade (i.e. during high or prolonged seasonal rainfall events).

This proposal will result in three key changes:

1. Treatment of the Stage 1 leachate to ANZECC aquatic ecosystem protection standards

prior to discharge.

2. Indirect discharge on site of highly treated leachate via infiltration in low and average

flows (<360 m3/day).

3. Direct discharge to the creek in high seasonal flows, prolonged rainfall periods which

generate above average leachate flows, and peak flows), rather than to sewer.

The proposed routing of flows and water balance is indicated in Figure 37.

Of note, the Stage 1 leachate chemistry is below the EU Landfill Directive Annex II criteria for

inert waste, meaning this would be allowable for direct release to the environment in EU

countries (see discussion in regard to this in Valencia et al 2009). This is not obviously

proposed here however provides some context as to the highly risk averse approach taken to

the treatment and discharge design.

To inform the risk assessment, an assessment of treated leachate flows and pollutant mass

loads to the infiltration forest and to the creek is provided below. Note, actual daily rainfall and

leachate data for the period 2010 – 2014 was used to generate the daily mass balance. This

dataset includes peak rainfall events. The daily mass balance assumes that once the soil

profile is saturated, all further inputs will report via overland flow to the discharge point, and

via the stormwater swale to the Cooee Creek discharge point as shown in Figure 11 and

Figure 12.

Mass load calculations were undertaken using the following inputs and assumptions:

Area of the Infiltration Wet Forest of 4,000 m2, with a 100 mm operating water depth

and additional 100 mm freeboard activated in large flow periods.

Actual (empirical) daily rainfall data and daily leachate flows for the period 2010-2014.

It is important to note that these flow data incorporate peak rainfall events that



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occurred within the 2010-2014 period, including the extreme (>80 year) 2011 summer

rain events and includes both wet years (2012, 2013) and a dry year (2014).

A conservative infiltration rate of 1*10^-6

m/s. Previous borelogs around the site (Coffey

2004, 2007 and APPENDIX 6) indicates the soils in the proposed infiltration area are

sandy clays and silty clays. The recent bore (BH26, Figure 38, drilled as part of the

geotechnical risk assessment indicated soils were silty clays near the toe of the Stage

1 northern embankment (APPENDIX 6). Weathered basalt in BH26 was encountered

at 2.5m bgl. Previous descriptions of a bore near to the Stage 1 pump station (MH1)

indicate deeper profiles with groundwater observed at ~4.5m bgl (Coffey 2007).

For nutrients, iron, manganese and zinc - concentration in the Infiltration Wetland

effluent were modelled based on the approach outlined in Kadlec & Wallace 2008 and

using mean monthly concentrations, temperature adjustments and pollutant specific

removal rate coefficients (Table 25).

For other contaminants of concern, final effluent concentrations were ass umed to have

met the set WQ targets at the outlet of the polishing wetland as outlined in Table 23

(Table 25).

Indirect Discharge Occurrences - Estimated Mass Loadings to Wet Forest

The infiltration ‘Wet Forest’ is designed as a large riparian buffer which will further attenuate

the volume of treated leachate and mass of residual nutrients and trace metals on -site, via the

following processes:

1. Infiltration and storage of water within the soil pore spaces (infiltration rate assumed at

1*10^-6,

which was recorded in bores within the proposed area).

2. Complexation of minerals with clay particles and organics .

3. Plant uptake of water and nutrients.

Treated leachate infiltrated within the site not taken up in soil storage and evapotranspiration,

will eventually join the groundwater throughflow at the contact zone of the basalt, and migrate

via subsurface flows to the creek. The model indicates that subsurface flows will be minimal

(limited to spring/winter). Due to the attenuation within the vertical soil profile (~2.5 – 4.5 m

depth) and the long lateral flow path (>100 m), the concentration of pollutants is expected to

be >90% attenuated (typical of riparian buffers), hence any subsurface discharges will be very

minor in terms of mass load.

For the purpose of this mass balance, all water in excess of ET and soil storages is assumed

to discharge via surface flows to the creek, with indirect discharges ignored at this stage. The

mass loads to the infiltration wetland are shown in Table 26, Table 27 and Figure 39.



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Figure 37. Proposed water circuit and water balance for normal (median) and high flows

MH1

ORANGE: All internal flows through wetland

YELLOW: High flows, 23L/sec max flow rate engaged when median flows exceed 20L/sec. Max 1989 m3/day

HIGH FLOW SPLITTER

BOX & SEDIMENT

DROP OUT CHAMBER

HEADER TANK/SPLITTER

LIGHT BLUE: Median flows, 20L/sec max flow rate max 1728 m3/day

DARK BLUE: All raw leachate flows to max 3600 m3/day or 43 L/sec

RED: All dilute flood flows >3600 m3/day (>80 year event) from emergency storage to swale and creek (>43 L/sec) – flows will be mixed & diluted with on-site stormwater and creek flood flows.

MH1

EMERGENCY STORAGE

GREEN: All treated flows plus rainfall via outlet pipe to infiltration wetland - max 5500 m3/day . Flows in excess of infiltration capacity overflow to max swale and creek - ~35 ML per year .INFLUENT

SAMPLE LOCATION (INF)

EFFLUENT

SAMPLE

LOCATION (EFF 1)

PURPLE: Recirculation of non-compliant flows (max 4 L/sec 350 m3/day.



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Figure 38. Site layout showing borehole locations (from Tasman Geotechnics report,

August 2015). Note BH26 is within natural ground. MW bores are monitoring

wells



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Table 25. Pollutant concentrations in the Infiltration Wetland effluent

Table 26. Volumes estimated to be discharged directly to the Infiltration Wet Forest –

mean daily

Table 27. Annual discharge and mass loadings to the Infiltration Wet Forest

Pollutant

concentrations

(mg/L)

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

TSS 0.31 0.31 0.31 0.31 0.31 0.31 0.31 0.31 0.31 0.31 0.31 0.31

TN 0.3296 0.2625 0.2072 0.2113 0.4015 0.4064 0.4338 0.8906 1.0028 0.7631 0.4307 0.3626

Ammonium N 0.2707 0.2102 0.1584 0.1626 0.3295 0.3341 0.3543 0.7789 0.8877 0.6712 0.3671 0.3030

Organic N 0.0418 0.0416 0.0403 0.0408 0.0398 0.0397 0.0390 0.0391 0.0390 0.0403 0.0418 0.0418

Nitrate N 0.0170 0.0108 0.0085 0.0078 0.0323 0.0326 0.0405 0.0726 0.0762 0.0516 0.0217 0.0178

TP 0.0107 0.0098 0.0082 0.0083 0.0088 0.0088 0.0082 0.0134 0.0151 0.0142 0.0121 0.0111

Fe 0.0368 0.0277 0.0164 0.0243 0.0357 0.0387 0.0345 0.0790 0.1044 0.0776 0.0685 0.0339

Mn 0.1156 0.0906 0.0547 0.0647 0.0829 0.0848 0.0721 0.2714 0.3431 0.2848 0.1752 0.1355

Zn 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0004 0.0006 0.0005 0.0002 0.0002

Al 0.0550

Cr 0.0010

Cu 0.0014

Ni 0.0110

Sn 0.0050

modelled pollutant concentrations

assumed requred conc target will be achieved for these pollutants as outlined in WQ Target table

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

discharge

(m3/day)255.4 225.3 264.5 264.5 312.6 322.7 327.3 526.2 556.8 482.1 383.9 314.5

VOLUMES DISCHARGED TO INFILTRATION WET FOREST (average daily for period March 10-Dec 14)

Pollutants Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecANNUAL

(kg)

TSS 2.45 1.96 2.54 2.46 3.00 3.00 3.15 5.06 5.18 4.63 3.57 3.02 40.02

TN 2.61 1.66 1.70 1.68 3.89 3.93 4.40 14.53 16.75 11.40 4.96 3.54 71.05

NH4- N 2.14 1.33 1.30 1.29 3.19 3.23 3.59 12.71 14.83 10.03 4.23 2.95 60.83

Org N 0.33 0.26 0.33 0.32 0.39 0.38 0.40 0.64 0.65 0.60 0.48 0.41 5.20

Nitrate N 0.13 0.07 0.07 0.06 0.31 0.32 0.41 1.18 1.27 0.77 0.25 0.17 5.03

TP 0.06 0.04 0.05 0.05 0.06 0.06 0.06 0.15 0.18 0.15 0.10 0.08 1.02

Fe 1.28 0.75 0.55 0.79 1.45 1.57 1.44 6.07 8.42 5.51 3.59 1.47 32.90

Mn 0.92 0.57 0.45 0.51 0.80 0.82 0.73 4.43 5.73 4.26 2.02 1.32 22.56

Zn 0.0012 0.0007 0.0005 0.0006 0.0009 0.0010 0.0008 0.0071 0.0098 0.0069 0.0029 0.0017 0.03

Al 0.436 0.347 0.451 0.436 0.533 0.533 0.558 0.897 0.919 0.822 0.633 0.536 7.10

Cr 0.0079 0.0063 0.0082 0.0079 0.0097 0.0097 0.0101 0.0163 0.0167 0.0149 0.0115 0.0098 0.13

Cu 0.0111 0.0088 0.0115 0.0111 0.0136 0.0136 0.0142 0.0228 0.0234 0.0209 0.0161 0.0137 0.18

Ni 0.087 0.069 0.090 0.087 0.107 0.107 0.112 0.179 0.184 0.164 0.127 0.107 1.42

Sn 0.040 0.032 0.041 0.040 0.048 0.048 0.051 0.082 0.084 0.075 0.058 0.049 0.65

MONTHLY MASS LOAD TO CREEK (kg)



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Figure 39. Annual mass loading to the Infiltration Wet Forest (based on actual daily

rainfall and leachate flows)

Direct Discharge Occurrences - Estimated Mass Loadings to Creek

The creek volumetric discharges and mass load discharges in each month and annual mass

load discharges for select pollutants, are shown in Table 28, Table 29 and Figure 40.

Table 28. Volumes estimated to be discharged directly to the Creek – mean daily

0

10

20

30

40

50

60

70

80

TSS TN NH4-N

Org N Nitrate N

TP Fe Mn Zn Al Cr Cu Ni Sn

pollutants 40.02 71.05 60.83 5.20 5.03 1.02 32.90 22.56 0.03 7.10 0.13 0.18 1.42 0.65

kg

annual mass loading (kg)



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Table 29. Mass pollutant load to creek based on daily rainfall and flows

Figure 40. Annual mass loading to the Creek (based on daily rainfall and flows)

Pollutants Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecANNUAL

(kg)

TSS 0.34 0.14 0.23 0.16 0.35 0.38 0.37 1.71 1.74 1.19 0.46 0.24 7.3

TN 0.36 0.12 0.16 0.11 0.45 0.50 0.51 4.90 5.63 2.92 0.64 0.28 16.6

NH4- N 0.30 0.09 0.12 0.09 0.37 0.41 0.42 4.29 4.98 2.57 0.55 0.23 14.4

Org N 0.05 0.02 0.03 0.02 0.04 0.05 0.05 0.22 0.22 0.15 0.06 0.03 0.9

Nitrate N 0.02 0.00 0.01 0.00 0.04 0.04 0.05 0.40 0.43 0.20 0.03 0.01 1.2

TP 0.01 0.00 0.00 0.00 0.01 0.01 0.01 0.05 0.06 0.04 0.01 0.01 0.2

Fe 0.18 0.05 0.05 0.05 0.17 0.20 0.17 2.05 2.83 1.41 0.47 0.11 7.7

Mn 0.13 0.04 0.04 0.03 0.09 0.10 0.09 1.49 1.93 1.09 0.26 0.10 5.4

Zn 0.0002 0.0000 0.0000 0.0000 0.0001 0.0001 0.0001 0.0024 0.0033 0.0018 0.0004 0.0001 0.0

Al 0.060 0.024 0.042 0.029 0.062 0.068 0.065 0.303 0.309 0.210 0.082 0.042 1.3

Cr 0.0011 0.0004 0.0008 0.0005 0.0011 0.0012 0.0012 0.0055 0.0056 0.0038 0.0015 0.0008 0.0

Cu 0.0015 0.0006 0.0011 0.0007 0.0016 0.0017 0.0017 0.0077 0.0079 0.0054 0.0021 0.0011 0.0

Ni 0.012 0.005 0.008 0.006 0.012 0.014 0.013 0.061 0.062 0.042 0.016 0.008 0.3

Sn 0.005 0.002 0.004 0.003 0.006 0.006 0.006 0.028 0.028 0.019 0.007 0.004 0.1

MONTHLY MASS LOAD TO CREEK (kg)



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The comparison of total annual discharge to the Creek in a dry year (2014) and wet years

(2012, 2013) and corresponding mass loadings of key pollutants is presented in Table 30.

Table 30. Annual discharge and mass loadings to creek.

In a dry year the discharge to the Creek and the mass loads of key pollutants is 70 -80% lower

compared to the average discharge. In wet years (such as 2012), discharge and mass loading

is approximately 1.5x higher compared to the average scenario.

Peak per day mass loading of key pollutants for 90% rainfall and flows through the system

(peak loading) was calculated using the average daily flows for the top 10% of monthly flows

for the period 2010-2014, and concentrations of pollutants as discussed above.

These peak per day mass loads to the Creek are presented in Table 31. On those peak days

loads to the Creek are ~4 times higher compared to average daily flows. However, it is

important to note that these peak loading days occur on average 2-3 times per month, or only

7-10% of the time within the year.



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Table 31. Peak day mass load discharge to creek based on > 90% flows



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6.1.2 Summary of Potential Impacts to the Creek

Based on the empirical rainfall and leachate data analysed for the period 2010 to 2014, >90%

of summer‐autumn flows and >75% of winter‐spring flows will be infiltrated within the

‘Infiltration Wet Forest’ along the northern boundary of the site, with only flows in excess of the

infiltration capacity directly discharged to the creek. Hence, on most days there will be no

direct discharges to the creek, and infiltrated flows will be expressed as subsurface seepages

along the banks and base of the unnamed creek tributary. These flows will help to restore the

riparian vegetation and muddy creek conditions favourable to the Burnie burrowing crayfish

and other fauna.

In terms of mass pollutant loads, this proposal will divert minor (predominantly nutrient) loads

to the creek which otherwise would have reported to the sewer system. However, the current

pollutant loads which discharge to the creek via untreated stormwater flows (Table 19) is

significantly higher (more than 11 times the mass of nitrogen for example) than what will be

contributed via treated leachate flows. Since part of the Stage 1 leachate project is to

undertake stormwater improvement works, a percentage of the annual (1 year ARI and less)

mass loads will be retained and treated within the proposed stormwater swale and will no

longer discharge to the creek. The modelling and sizing of the stormwater system is currently

underway, however it is expected that the stormwater swale will remove as a minimum 30% of

the total nitrogen and total phosphorus loads to the creek, and more than 80% of the metal

load. If this is achieved, total nitrogen (key nutrient of concern), would reduce from 178

kg/annum minimum mass load to 124 kg/annum, which means 53.4 kg would no longer report

to the creek. Hence, whilst the treated leachate discharge will result in on average 16

kg/TN/annum being discharged to the creek, more than 3 times this amount will be removed

as a result of stormwater treatment, hence the net effect will be a reduction in pollutant loads

discharged to the creek.

During large storm events, stormwater will discharge as normal to the creek hence there will

be little change to mass loads, however high flows will be conveyed via a rock cascade

structure which will remove sediment even in these larger events. There will be a higher

discharge of treated leachate to the creek in these events since the infiltration capacity of the

Wet Forest will be exceeded. This results in a higher mass load discharge as indicated in

Table 31, however the affect is small on an annual basis (less than 1.5 times average mass

loads) since these are short term events. Furthermore, during these events the broader

catchment effects of dilution and peak run-off will dominate and largely mask these events, as

now typically occurs for this creek. Further, during peak storm events, the tributary upgradient

of Three Mile Road is expected to cause flows to back up and spread broadly within the

floodplain (Tasmanian Consulting Services (appendix report within APPENDIX 6), hence

depositing most of the sediment and pollutant loads as a result along this localised section of



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the creek. The hydrological modelling undertaken by Tasmanian Consulting Services indicated

that the tributary (referred to as the Northern Waterway/Creek in their report) would flood the

adjacent grass paddocks as follows:

In a 50 Year ARI the flooding is relatively minor and is localised to the area

immediately adjacent the road culvert at Three Mile Road,

For a 100 Year event the flooding extends to approximately half of its chainage.

During a 1000 Year event flooding extends to the entire chainage (with flooding at the

landfill boundary relatively minor).

In summary, the mass pollutant loads expected to be discharged to the creek in higher

seasonal rainfall periods and/or in prolonged rainfall events that result in the infiltration

capacity of the system being exceeded, are considered small considering the current

discharges to the Creek from the landfill site and neighbouring agricultural and residential

properties. They are significantly lower than what occurs typically at the site, both as a result

of discharges directly to the Creek when flows exceed the 20 year ARI capacity of the pipe,

pump and pit infrastructure, and in average stormwater discharge events.

On an annual basis, the nitrogen load exiting the site from treated leachate for example is

<10% of that discharge from the Stage 2A stormwater system through the existing piped

network (Table 19) (16 kg/annum, compared with 178 kg/annum).

As a part of this project, at least 30% of the annual mass pollutant loads due to stormwater will

be removed within swales and sediment drop out structures. In peak storm events, the creek is

expected to back up and engage the wider floodplain such that any sediment and entrained

pollutants (from either leachate or stormwater) are likely to be deposited within the floodplain,

rather than being conveyed further downstream. Hence, the overall Stage 1 leachate project

and associated stormwater improvement works combined will lead to a reduction in the overall

mass pollutant loads discharged to the creek.



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6.1.3 Potential Groundwater and Geotechnical Impacts

A hydrogeotechnical investigation and geotechnical model has been undertaken as part of this

project and is contained in APPENDIX 6.

The following potential hazards were identified and addressed in this study:

Wetland leakage – potential to saturate the landfill cell and resultant impact on the

containment bund.

Wetland mass load – potential for landfill cap settlement and risk to overall stability as

a result of the added mass load on the cell.

Water table rise/flood – potential for the inflowing groundwater table to rise within the

waste cell and/or flood from an extreme rainfall event.

Ahead of undertaking the hydrogeotechnical risk assessment a geotechnical model was

developed to provide a robust basis for the assessment. The model was informed by both

previous investigations, additional investigations undertaken as part of this study and revi ew

of published data.

A summary of the hydro-geotechnical model is as follows:

The Stage 1 Landfill is constructed on natural clay that forms the base of the landfill.

The landfill containment bund comprises the northern face of the Stage 1 landfill, and

includes both an excavated portion and constructed embankment.

The landfill is capped with 1 m to 2 m of compacted clay and a growing medium (at

least 0.5 m thick). The cap in the southern section of the landfill contains a GCL layer,

while the cap in the northern section of the landfill contains an aggregate rock layer for

lateral drainage. The cap effectively prevents seepage of runoff into the landfill cell.

The landfill cap is currently experiencing settlement of less than 2 mm/yr.

A section of the cap was surcharged by stockpiling soil. The settlement at the base of

that stockpile was measured to be 50 to 600 mm over a 7 year period. Removal of the

stockpile means that the waste has been pre-consolidated in this area.

Based on review of typical parameters, consolidation, or long-term, settlement is likely

to be completed within 2 years of placing a structure, such as the proposed wetland

cells.

The regional groundwater is recharged upstream of the landfill from rainfall and seeps

into the landfill cell through springs that were present before development of the site.

Groundwater collection pipes were installed on the floor of the landfill, however at least

one of the inspection manholes allows leachate into the groundwater collection pipes



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and the pipes themselves were compromised, allowing leachate to enter. Excavation of

natural clay for construction purposes may have created new seepage zones.

There are several types of openings through which the leachate is drained from the

landfill: broken pipes and holes in manhole shafts. There are fewer openings near the

landfill containment bund than below the centre of the landfill. Therefore, the rate of

outflow near the containment bund may not be sufficient to discharge the groundwater

inflows after an intense rain period. Thus, the leachate level behind the landfill

containment bund increased in early August 2015, as the leachate is temporarily

“stored”.

6.2 HAZARD AND RISK ASSESSMENT OF KEY ISSUES

6.2.1 Risk Assessment Approach

A detailed risk assessment was undertaken using the approach outlined in the Principles and

Guidelines (Standards Australia, 2009), and the supporting document HB 203:2006

Environmental Risk Management – Principles and Process (Standards Australia, 2006). This

approach is based on the consideration of the likelihood and consequences of a hazard event

occurring, in the context of the environment and proposed design (i.e. key environmental

sensitivities and receptors, existing site conditions, design measures etc). It distinguishes the

inherent and residual risk of hazard incidents. Inherent risk represents the risk of

environmental harm occurring from a hazard if there were no mitigation controls in place.

Residual risk measures the likelihood and consequences of environmental harm taking

account of controls.

The inherent risk was analysed under two scenarios:

After acute problems such as significant incidences on site .

During chronic problems such as when a treatment system is performing poorly (e.g.

due to lack of maintenance).

Note, for this risk assessment it has been assumed that all the elements and contingency

measures included in the treatment system design are fully implemented, so the risks

assessed are those that can potentially arise from hazardous events / incidents outside of

normal system operation. In addition, the normal operation of the proposed Burnie leachate

treatment system, under which highly treated effluent is discharged to the unnamed tributary,

was also analysed in terms of any negative/positive impacts on the receiving environment and

any other relevant receptors (environmental and human).



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6.2.2 Risk Identification

The first step of the Burnie Risk Assessment process was the identification of potential risks.

This step included:

Identification of source of risk.

Identification of potential impacts.

Source of risk identification involved recognition of key hazards relevant to the site and

project, key hazardous events and environmental aspects (i.e. receptors and pathways). In

other words this first step is about developing a hazard−pathway−receptor model which

identifies and describes the nature of a risk and how environmental harm may result from it.

This is critical for undertaking risk analysis and developing an effective risk treatment.

To guide the risk assessment, a conceptual site model of the proposed development scenario

(Figure 36) was developed to identify the relevant receptors and pathways.

Identification of Receptors

A receptor is a specific ‘component’ of the environmental that could potentially be impacted by

the hazardous events associated with the project. A receptor could be biological (e.g. flora,

fauna species, habitats or entire ecosystems, biodiversity) or physical (e.g. groundwater,

surface water, land form, etc).

The receptor analysis for the Burnie project site (landfill), was done in the context of its

immediate and broader environmental setting, and using the findings from two natural values

assessments of the landfill site that have been undertaken in recent years (NEST 2013,

APPENDIX 2). Also, water quality and creek sediment baseline investigations undertaken for

this study were used to inform this process (Section 5.2.8).

Groundwater is not considered a receptor on site since the underlying hydrogeology confines

the aquifers with all superficial groundwater flows discharging directly to the creek (Section

5.2.6). Downstream groundwater users are also, by extens ion, not considered to be receptors

since there is no pathway. Groundwater springs that are collected in the groundwater drainage

system that was compromised during construction, does mix with leachate however is

collected within the leachate system and reports to the treatment system.

The following key receptors have been identified with summary descriptions provided.



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Ecological Receptors

1. Unnamed tributary to Cooee Creek

o The unnamed tributary is a very minor part of the Cooee Creek system (5% of

catchment).

o There are no significant flora or fauna receptors within this creek tributary.

o The ecological and landscape values are low due to the extent of degradation and

reduced flows

o Restoring environmental flows to the creek is considered a positive environmental

benefit in terms of ecological values and recovery of significant species habitat.

Detailed information on this receptor is provided in Section 5.2.8.

2. Cooee Creek

o Cooee Creek receives a range of discharges from the surrounding agricultural and

residential land uses, and is not pristine. The Syrinx baseline studies indicate the

Creek system is equivalent to ANZECC Ecosystem Condition 2: Slightly to

moderately disturbed systems

o The key concerns are nutrients (total nitrogen, nitrate and total phosphorus) and

some metals (aluminium, copper, lead and manganese).

o Threatened and listed migratory species - the only potential matter of

environmental significance identified in the proximity of the landfill site is the

Burnie burrowing crayfish (listed as 'Vulnerable' under Schedule 4 of the

Tasmanian Threatened Species Protection Act (1995) and is listed as Vulnerable

under the EPBC Act 1999.).

Detailed information on this receptor is provided in Section 5.2.8.

3. Livestock

o The unnamed tributary and Cooee Creek are used for livestock drinking/stock

watering on properties along these creeks. Consequently, creek contamination as

a result of hazardous events occurring on the landfill site would potentially impact

on livestock.

4. Irrigation pasture

o Creek water is used primarily during summer months for irrigation of vegetable

crops and pasture, and this use could be jeopardised in the event of creek water

contamination.



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Human receptors

1. Recreational users

o Humans could potentially be impacted by contamination originating from the landfill

site and leachate treatment system through recreational use of the unnamed

tributary and/or Cooee Creek.

o Considering the current degraded nature of the unnamed tributary (i.e. erosion,

relatively poor water quality, highly impacted by the extensive urban and

agricultural land use in the catchment) this creek is rarely if ever used for

recreational purposes and is most likely used for secondary recreational activities

only, which include activities with less body contact such as fishing.

2. On site workers & general public

o This group of human receptors include BCC employees and contractors that work

at the landfill site and the general public (mainly immediate neighbours) who can

potentially be exposed to hazardous events occurring within the site. The landfill

has been non-operational since 2012 (stopped taking waste) and is currently

operating as a Waste Transfer and Resource Recovery Facility. Hence, on site

personnel are limited. The site does not permit unauthorised access.

Possible Pathways

The pathway is the route via which a hazard can impact on the identified receptor(s) (note that

for one hazard there may be multiple pathways, receptors and mechanisms of harm). For

exposure to occur, a complete pathway must exist between the source of contamination and

the receptor. Where the exposure pathway is incomplete, there is no exposure and hence no

risk via that pathway.

Considering that the main identified receptors for the Burnie project site include two key

surface water features in the vicinity of the project site (unnamed tributary to Cooee Creek and

Cooee Creek itself) especially in terms of the possible impacts on the Burnie burrowing

crayfish, the main pathway identified for the project is via discharge of pollutants to the

unnamed tributary (Table 32). This can occur as a result of: i) direct discharge of untreated

leachate, and ii) direct discharge of partially treated leachate.

For human receptors, the main exposure pathway is direct contact with contaminants and

intake via solid waste and / or leachate ingestion and dermal contact with waste and/or

leachate (Table 32).

Contaminant pathway via atmospheric depositions (air-borne dust) has not been included in

the exposure pathways, as it can be expected that any air -borne contamination will present a



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minimal risk to the human and surface waters compared with the risk of harm posed by direct

discharge and direct contact. Noise emission was also not considered to be a significant

exposure pathway. Both of these are addressed in later sections however.

Table 32. Summary of possible receptor/pathways interactions

Hazard / Hazardous Event Identification

A hazard is a source of potential harm or adverse impacts to the receptor; a hazardous event

is an event that results in the occurrence of negative impacts associated with the hazard.

The hazard/hazardous event identification process was based on an analysis of all activities

and processes associated with the operation and maintenance of the proposed leachate

treatment system, in the context of the local setting and current and future landfill activities.

This process resulted in short listing of the following hazardous events (incidences), which are

grouped based on their potential consequences:

Hazardous event/incidents resulting in the release of raw leachate and/or solid waste to

creek, and/or ponding of raw leachate on site

1. Sliding failure of landfill containment bund caused by:

a. Wetland mass/location compromises structural integrity of landfill bund.

b. Rising leachate levels within landfill causing saturation and weakening of

containment bund.



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2. Pump / electrical failure – caused by:

a. Power outage (weather, fire, explosion etc)

b. Pump clogging due to lack of / poor maintenance

Hazardous event/incidents resulting in the release of partially treated leachate to creek,

or ponding on site

1. Leakage of the proposed wetland treatment system leading to either seepage of

leachate through the clay liner base into the existing clay capping and lateral seepage

of leachate through the landfill containment bund. This could be caused by differential

settlement of the landfill cap potentially impacting liner integrity.

2. Failure of wetland embankment caused by differential settlement of landfill

leading to localised subsidence of wetland cell bunds, overtopping of leachate from

wetland bunds and exposure of partially treated leachate to receptors.

3. Failure or impeded performance of wetland cell(s) caused by:

a. Compromised system construction (system not built to design).

b. Cold weather that compromises biological system performance.

c. Change in leachate chemistry beyond design ranges for prolonged per iod of

time.

d. Contamination via pesticides, herbicides etc from neighbouring farm properties

that can cause plant/microbial death, and consequently reduced system

performance.

e. Poor system maintenance.

4. Increase in volumes of groundwater-leachate beyond treatment system capacity

in events of extreme & prolonged rainfall.

5. Damages to the treatment system caused by flooding from property upgradient

(east) in extreme rain potentially coupled with excessive irrigation.

6. Fire induced damages of the treatment system caused by vandalism, lightening

and/or electrical faults.

6.2.3 Risk Analysis

The risk analysis was carried out following the principles of the Australian Standard for risk

management to identify ‘priority risks’. Risk analysis included the following two steps: i) risk

evaluation and ii) preparation of risk treatment measures. A separate landfill risk assessment

was also undertaken as part of the Geotechnical Study (Tasman Geotechnics), based on the



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risk matrix published by the Australian Geomechanics Society (AGS, 2007). This was also

used to inform the environmental risk assessment.

Environmental Risk Evaluation

In this step risks were determined using the likelihood and consequence approach, which then

enabled identification of management measures for individual determined risks.

Likelihood refers to the possibility or frequency of an environmental impact. The categories of

likelihood, consequence and risk used in the Burnie risk assessment is shown in APPENDIX

14.

In terms of risk evaluation for the Burnie leachate treatment system, the key concerns are any

implications of potential discharge of either raw or inadequately treated leachate to the

unnamed tributary, and the negative impacts of the discharge on the key iden tified

environmental and/or human receptors. Hence, the risk analysis was done for these two

concerns to develop an understanding of the severity of any risks (inherent risks) as well as

the management measures/strategies that are either already planned to be implemented or

need to be considered in order to reduce residual risks. As stated previously, in addition to

the key hazardous events, risk analysis was also undertaken for the normal system operation

which includes release of fully treated leachate to the unnamed tributary.

The risk evaluation is presented in APPENDIX 15.

In summary, there are no inherent risks that are considered unacceptable in any

circumstances and that are not possible to manage/mitigate.

The great majority of identified risks to the key environmental and human receptors from either

hazardous events or normal operations are inherently low (i.e. of an acceptable level). There

were only two risks characterised as medium and both of them are due to potential system

failure or impeded performance of wetland cell(s) that result in non-compliant quality of

leachate outflow. They are caused either by a) the system being inadequately built (not in full

compliance with the design) or b) poor maintenance. Both of these events are assumed to

occur occasionally (every 5-20 years) and the consequence of possible impacts arising from

these events are considered to be moderate given that discharge of non-compliant leachate

would potentially cause only short to medium term localised impacts.

Normal operation of the treatment system with discharge of highly treated effluent to the

unnamed creek was found to carry only low inherent risk. This is to be expected given that

potential impacts of the effluent discharge to the creek were analysed during the initial system

development and an array of measures were implemented in the system design to address

any of these potential impacts. The key arguments supporting the very low inherent risk of

normal system operation are:



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Very high quality of treated effluent – in line with EPA Draft Water Quality Objectives

for Cooee Creek and relevant ANZECC (2000) trigger values.

Discharge approach that minimise direct discharge of the treated leachate to the

unnamed tributary by maximising on-site infiltration within the last system component

(Infiltration Wetland / Wet Forest). This reduces the mass load of pollutants discharged

to the creek and enables further attenuation of infiltrated effluent.

The fact that the water quality within the unnamed tributary and Cooee Creek is

already relatively poor and both creeks are considered degraded due to historic and

current impacts from neighbouring land users. Consequently, these surface waters are

not used for swimming (or other primary recreational uses) and this is unlikely to

change in the future given declining water levels and many alternative locations.

Discharge of treated effluent (in terms of flows, pollutant concentration and mass

loads) is not considered to negatively impact on the unnamed tributary and Cooee

Creek, key creek biota, or any downstream users of these creeks.

Furthermore, discharge to the creek would help re-establish pre-development flows, since at

present a substantial proportion of leachate and groundwater (entrained within the leachate)

flows is diverted to sewer. Hence, increasing the environmental flows, particularly given

climate predictions of declining rainfall, would be a beneficial outcome of the proposed

treatment system. Restoration of environmental flows (together with the proposed creek

enhancement) would have positive impacts on the Burnie burrowing crayfish, which is the key

species of concern (the only threatened species) in this project.

Geotechnical Risk Evaluation

This quantitative geotechnical risk assessment undertaken by Tasman Geotechnics

(APPENDIX 6) and the associated hydrological stormwater runoff assessment undertaken by

Tasmanian Consulting Services (appendix to APPENDIX 6), concluded that the proposed

wetland system posed a low to very low risk.

The key findings and implications are:

Stage 1 landfill is set into the valley tract and as such the landfill is largely contained

within the natural topography.

The landfill is relatively shallow depth (10 m) and has been closed for over 10 years

(ceased receiving waste in 2004 and was capped in 2005), and has already completed

primary consolidation. The landfill cap is currently experiencing less than 2 mm/yr

settlement. The estimated weight of the proposed wetland system is ~17 kPa, which is

considered to be a minor load. Consolidation settlement of the landfill cap under the

wetland mass load is predicted to be 230 mm. Based on review of typical parameters,



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consolidation settlement is likely to be completed within 2 years of placing a load. Long

term settlement as a result of biodegradation of the landfill is estimated at 2 mm/year.

This is within the adaptive design capability of the system. Note, the stockpile of clay

materials placed on top of the landfill provides empirical data for calculating the likely

settlement of the wetlands on top of the landfill cap. The stockpile height varied from

about 3.5 m to 6 m, and by 2013 achieved a footprint of about 6000 m2 (190 m long by

between 20 m and 60 m wide) and had an estimated pressure of 52 kPa. This

compares with 24 kPa for the wetland bunds and 17 kPa for the wetland cells. Survey

data for the landfill cap was available for two dates: 04/05/2006 (before soil

stockpiling) and 05/04/2013 (before Stage 2 capping commenced, when the stockpile

was at maximum height), almost a 7 year time interval. This empirical data was used to

derive the predictive settlement model for the wetland. These have been accounted for

in the wetland freeboard design.

The surface flow wetlands will be constructed with an LLDPE liner on top of the Stage

1 landfill cap, with only shallow operating water depths, such that the bund heights will

be limited to 1.2 to 1.5 m to accommodate liner, substrate, water and freeboard for

extreme storm events. A slightly higher bund (0.1 m) will be incorporated to

accommodate long‐term settlement. The overall bund height will be less than 2 m to

avoid the potential for excessive settlement.

Leachate levels rise and fall within the landfill in response to rainfall and imply that

there is upward flow into the landfill. The flows are likely to originate at the springs, but

could also be in other areas where there has been excavations to borrow clay to create

floor of the landfill. The upward flow prevents leachate from leaking into the natural

aquifers. The landfill does have a standing leachate level within the cell, however there

is no evidence that this has an impact on the cell or containment bund.

The wetland will have minor leakage risk since it will be a LLDPE liner over existing

natural clay topsoil capping of very low permeability, and in part over a GCL liner with

very low permeability.

The proposed wetland may result in tensile strains in the capping clay (and in the

wetland structure itself) that are at the lower limit of the failure limits. This means that

the probability of either the wetland or the landfill cap being compromised is very low.

Based on Factor of Safety analysis, the current landfill containment bund has a very

low probability of failure, including when modelled with saturated waste. The presence

of the wetland (modelled as a 17kPa pressure) has a small impact on the calculated

FOS.

Placing the wetlands at least 10m from the crest will not adversely impact on the

stability of the containment bund wall.



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The preferred wetlands location on the top half of the eastern cell was assessed as

being at minimal risk of inundation from overland flows from catchments to the east of

the site or from flooding of the existing site stormwater infrastructure during extreme

1000 Year ARI events (Tasmanian Consulting Services report contained in APPENDIX

6). Quantitative modelling in this same report concluded that inundation of the

proposed wetlands located on the top third of the eastern landfill cell was not

considered to be a realistic possibility, even for extreme rainfall events.

Therefore, construction of a wetland on top of the landfill cap at least 10 m from the landfill

crest has a Low to Very Low risk profile for the hazards associated with settlement of the

landfill cap and the wetland, possible failure of the landfill containment bund, and extreme

rainfall events. Overtopping of the wetland presents a moderate risk profile if the infrastructure

at the wetland is not adequately managed.

6.2.4 Proposed Management Measures

This step in the risk assessment is about establishing the additional risk treatment measures

needed to be implemented such that those inherent risks which are above acceptable levels,

can be reduced to acceptable levels (i.e. Low).

Theoretically, risk can be treated in two ways—by reducing the likelihood or reducing

consequence. Operationally, risk treatment options can also be categorised into changes

and/or additions to the infrastructure (in the case of this proposal this would include

changes/additions to the treatment system or other infrastructure elements associated with the

treatment system) or processes.

The following measures are proposed to ensure protection of the environment, protection of

human health, compliance with the relevant legislation, and to maximise positive project

benefits.

POTENTIAL WETLAND SYSTEM FAILURE OR IMPEDED PERFORMANCE

Design

Separation of the current stormwater discharge infrastructure and the leachate

collection and treatment system to avoid untreated leachate discharge via the

stormwater system.

Conservative sizing of the treatment system to treat the 90 percentile flows and, if

required, to enable leachate recirculation and further treatment prior to discharge.



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In built storage capacity to accept and dampen variable flow volumes, including peak

storm event flows (the pump and storage capacity will accommodate >80-year event).

Multiple component system design with a sequential treatment train to ensure a

continuously high standard of treatment.

Discharge of average flow treated leachate via an on site infiltration Wet Forest to

reduce direct discharge to the creek and enable further attenuation of residual

nutrients through the soil profile.

Use of an open swale as the ultimate discharge pathway to the existing unnamed

tributary Cooee Creek for flows in excess of infiltration capacity.

Connection to sewer maintained in case of non-compliance, as final contingency.

Collection of extreme storm event leachate seepages that may occur along the

northern embankment within a phytoremediation swale.

Construction

Placement of the wetland system limited to at least 10m from the landfill crest.

Height of bunds limited to 2m.

Use of a LLDPE liner to reduce wetland seepage risks.

Construction of an emergency storage tank, recirculation system for non-compliant

water, and a connection to the TasWater sewer, as a final contingency measures.

The wetland designer will be retained during construction / contract management and

commissioning phases to ensure that all system components (e.g. liner, hydraulics,

planting, etc) and safeguard management elements are constructed as per design.

Commissioning and Operation

Performance monitoring will be conducted through the system to enable adaptive

response and to trigger emergency recirculation or disposal to sewer.

An appropriate annual maintenance budget will be included for the life of the wetland

to ensure that all required maintenance activities are done appropriately and with the

required frequency.

Operation and Maintenance Plans will be developed and will detail the required

maintenance activities and frequencies.

Appropriate equipment checks and maintenance regimes will be implemented.

Existing risk management plans will be updated to include responses to incidences

potentially connected with the treatment system. This will include incidence response

for any on site ponding and mosquito management.



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Appropriate training of staff responsible for system maintenance will be undertaken,

including preparation of user-friendly management and maintenance plans.

MANAGEMENT MEASURES TO MINIMISE/ MANAGE RISKS ASSOCIATED WITH

LANDFILL SETTLEMENT

Design

Appropriate freeboard capacity will be incorporated to accommodate the direct rainfall

volumes generated in a 1000 year rainfall event (182 mm) and to accommoda te

leachate volumes generated in an 80-year event.

Bund heights will be limited to 2m to limit settlement effects.

Construction

Heavy machinery use will be avoided along the top of the northern containment bund

Accurate surveys of base levels will be undertaken, before wetland placement.

A minimum of four (4) survey markers will be installed and fortnightly monitoring of

settlement levels undertaken across the landfill pre-during and post construction for

several months.

Operation

Annual monitoring of settlement levels across the landfill will be undertaken.

Annual assessment of the integrity of wetland cells and associated infrastructure

located on top of the landfill cap (bunds, liners, pipework, weirs etc), will be

undertaken.

Quarterly checks of wetland perimeter bunds to ensure the minimum freeboard depth

is maintained and that any localised areas that may have settled below this minimum

(200 mm) level are repaired promptly.

Any repair work required due to settlement effects (Section 6.2.3) will be undertaken,

to maintain system integrity and performance.



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MANAGEMENT MEASURES TO MINIMISE/ MANAGE RISKS ASSOCIATED WITH

PROTECTION/ENHANCEMENT OF THE CREEK ECOSYSTEM

Design

The design will accommodate flow controls (rocks, swales) to dampen velocity,

encourage sediment drop out and reduce sediment transport to the creek.

Bioengineering measures (vegetated brushmatressing, rock stabilisation) will be

incorporated to stabilise embankments and facilitate re-establishment of native

species.

A meandering swale/cascade at the discharge point will be incorporated to slow flow

velocity prior to creek discharge (for stormwater average flows and peak treated

flows).

Construction

No clearing of native vegetation will be undertaken.

Sediment controls (traps, sediment curtains) will be installed during creek

enhancement works, and sediment reused within the landfill area.

Locally native species will be used in the treatment system to avoid invasive species

entering the creek and to enhance biodiversity.

Key species will be incorporated within the wetlands to enhance the habitat value and

water quality of the creek (e.g. shade species, nesting trees, protective understorey for

avoiding predators etc).

Enhancement of the northern boundary of the site will be undertaken by replacing

grassland and weeds with dense native vegetation (Wet Forest) to reduce the risk of

weeds to the creek, provide shading, assist in phytoremediation and

evapotranspiration.

Restoration works will be undertaken in the immediate unnamed creek discharge area

to reduce weeds, enhance riparian vegetation, improve habitat and reduce erosion.

Operation

An ongoing weed management program within the wetland system and creek

discharge areas will be implemented.



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MANAGEMENT MEASURES TO MINIMISE VISUAL IMPACTS AND ENHANCE VISUAL

AMENITY AND COMMUNITY USE

No native vegetation clearing will be undertaken.

Each component of the wetland system will be appropriately landscaped in order to

visually integrate with each other and within the site.

Locally indigenous, shrubby vegetation and trees (Wet Forest) will be planted along

the northern boundary of the site within the infiltration area and swale.

BCC will provide controlled site access and interpretative walks/signage to enable

community use of the proposed system for education and research.

6.3 OTHER POTENTIAL IMPACTS AND MANAGEMENT RESPONSES

6.3.1 Air Quality

Dominant winds at the site are south westerly (most dominant) and west/north westerly. The

nearest sensitive receptors to the site are the immediate neighbouring farm properties and a

residential subdivision on Three Mile Lane Road, approximately 200m north of the site. The

surrounding site is rural.

The proposal will not generate point source odour emissions, with the potential for air quality

impacts limited to the wetland anoxia and dust during construction works. The leachate itself

has no odour since it is dominated by groundwater (>80-90%), hence the concentrations of

pollutants are very low and odours are not detectable. There is a potential for odours within

the wetland if the system is allowed to become anoxic, which would cause the build up and

release of H2S and/or methane gases. This is unlikely since the system is designed to be

shallow and aerobic, and has an operational regime that incorporates routine drawdown of

wetland cells to maintain oxygenation of the wetland sediments and to ensure aerobic

degradation of organics. These risks will be managed by a detailed operational plan and via

the existing day-to-day personnel on-site.

The subsurface component is anaerobic, but since this system is subsurface and receives

highly treated water through previous treatment steps, odours are unlikely. There is a

potential for localised odours if/when raw leachate seepages occur along the northern

embankment, however these are very small in volume and will be intercepted and treated

subsurface.

Finally, the system does not incorporate chemical dosing, and pumps are operated by existing

site power or solar, with diesel only used as backup in case of power failure. The previous use



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of the site for landfilling and the current use for waste sorting creates more odours than the

proposed project.

The following is the history of complaints regarding odours for the existing site ( documented in

the annual reporting since 2004).

No complaints have been received since cessation of sludge disposal to landfill in mid -2007.

Dust emissions may arise from loading, unloading and transport, and will be managed via

appropriate dust management practices. These will be outlined in the Contractors Construction

Management Plan, but will likely include the provision of watering trucks during construction

works.

Air quality risks and odour issues are considered to be a minor issue for this proposal.

6.3.2 Noise Emissions

There will be no noise emissions during operation above existing operations. Noise emissions

are limited to the raw leachate submersible pump. Noise during construction will be managed

in accordance with the existing EPN requirements and Mooreville Rd Management Plan, and

in accordance with an approved Construction Plan to be provided by the appointed Contractor.

Noise will be managed by restricting construction activities to daylight hours in accordance

with the Hours of Use specified in the Environmental Management and Pollution Control

(Miscellaneous Noise) Regulations 2004 - SCHEDULE 7 - Hours of Use:

Monday to Friday 7.30am to 6pm inclusive.

Saturday 8am to 6pm inclusive.

Sundays and Public Holidays 10am to 6pm inclusive.

06-07 Odour complaints from employees and public relating to disposal of new

Burnie Waste water Treatment Plant sludge. This issue was managed using odour suppression sprays and operational changes

07-08 An odour complaint relating to disposal of the new Burnie Waste Water Treatment Plant sludge. A Tip Shop Contractor employee submitted a

workers compensation claim to Workplace Standards Tasmania relating to sludge disposal. Disposal of sludge to landfill ceased on 30 June 2007.



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6.3.3 Waste Management

Potential Impacts

Minimal waste will be generated as a result of this proposal, and is limited to the generation of

sediment sludge within leachate sediment chambers and the wetland pre -filter.

The leachate contains very low levels of TSS and organics, and the system does not

incorporate any chemical dosing to aid precipitation/coagulation. Hence, it is expected to

generate very low levels of sediment/sludge (calculated at < 1 tonne per annum). The pre-filter

is designed to promote the precipitation of low level metals within this zone (with carbonates)

and this will form the main management zone, in addition to the sediment chamber within the

leachate manhole. The sediment is likely to contain high concentrations of metals and will

need to be managed as a Controlled Waste as defined by and in accordance with the EMPC

Act.

Management Responses

Accumulated sediment will be removed periodically within the deep zone of the pre -filter and

from the manhole sediment chambers using a vacuum (sucker) truck with material disposed to

an active landfill facility. Provision for mechanical access will be included in the detailed

design. Sediment removal within the sediment chambers will be undertaken annually and from

the pre-filter as required.

6.3.4 Dangerous Goods and Environmentally Hazardous Materials

The construction of the treatment system will involve the use of some combustible materials,

such as fuels for construction equipment. These materials will be used, stored and transported

in accordance with the Dangerous Substances (Safe Handling) Act 2005 and Dangerous

Substances (Safe Handling) Regulations 2009. No dangerous goods or hazardous materials

are required for wetland operation. A diesel back up generator will be installed at the raw

leachate manhole chamber (MH1) to ensure continuous pump operation in times of power

failure, however no diesel will be stored on site. The generator will be checked and refuelled

as part of weekly scheduled maintenance activities.

Contractors will be required to address the management of dangerous substances within a

Construction Management Plan.



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6.3.5 Biodiversity and Natural Values

Potential Impacts

Potential risks to threatened species in the receiving creek environment were identified during

the study undertaken by NEST in 2014. Risk factors that were noted during the survey

included: soil erosion, stock access to streams, farm/fertiliser run-off, the presence of invasive

weeds, livestock access, feral cats, rubbish, and in-stream sedimentation. Most of these risks

were associated with existing landuses (landfill, agricultural, urban etc) and associated

activities.

The natural value assessment study did not consider discharge of the treated leachate as

having a negative impact in terms of water quality; in the contrary they indicated this project

would have a positive impact. Furthermore, construction of the treatment system was also

considered to have minimal impacts assuming appropriate management plans are put in

place.

Restoration of environmental flows (together with the proposed creek enhancement) would

have positive impacts on the Burnie burrowing crayfish (Engaeus yabbimunna), which is the

key species of concern (the only threatened species) in this project. The greatest threats to

this species are water pollution, water diversion and habitat removal (Burrowing Crayfish

Group Recovery Plan 2001-2005). A major cause of decline of this species locally is the

sedimentation of creeks due to loss of riparian vegetation, and the consequent loss of in-

stream pools and muddy zones that are essential habitat characteristics (NEST 2014). The

core objectives identified for recovery of these species are as follows:

Maintain or improve water availability (especially in seepages).

Maintain or improve water quality (against pollutants, pesticides).

Maintain or improve habitat (native riparian vegetation and soil integrity).

Exclude disruptive processes from sensitive areas (seepages/marshes/streamside

areas).

Increase the reservation/protection of these species on Crown and private land .

Increase public awareness and appreciation of, and involvement in, threatened

species protection.

The reduction of siltation characteristics and enhancement of seepages is a key priority

identified for the Burnie burrowing crayfish, since the drying of sites is a major threat. The

NEST report notes that sedimentation from other neighbouring landuses and activities is a key

existing issue which has already impacted on some of the threatened species within 4 kms of

the site (Burnie burrowing crayfish, Giant freshwater lobster, Green and gold frog).



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Whilst no specific environmental water requirements (EWRs) have been set for this species,

recommendations for maintenance of habitats for these species is provided in related reports,

including the Emu River Environmental Water Requirements report, which indicated for that

river a minimum flow of 0.8 m3/sec (DPIPWE 2001).

No threatened ecological communities (TECs) that are likely to be impacted by the proposed

project as no TECs were identified within 500 m of the project site. The nearest TEC is a

wetland 2kms downstream. This wetland is hydrologically connected to the unnamed

tributary, is degraded (due to siltation and weed invasion) and is likely to either be unaffected

by the proposal or will slightly benefit from the enhanced environmental flows. Furthermore,

the project will not result in the clearing or indirect disturbance of native vegetation within or

outside of the project site, and in contrast will result in an additional 2 ha of native vegetation

and wetland habitat areas.

Swift Parrots require old eucalypts of more than one hundred years of age to provide the tree

hollows they require for breeding. The proposed project does not include any vegetation

clearing or tree removal. Quite the contrary, construction of the treatment wetland system

within the BCC landfill site and additional creek restoration efforts will result in creation of

habitats and food provision areas for avifauna.

Consequently, the project is not expected to negatively affect the visitation rates and

behaviours of migratory species in the region.


The proposed project will involve direct improvement works to the creek via removal of weeds,

revegetation and sediment controls but will also result in a higher volume of water discharging

to the creek bed, predominantly via subsurface discharges from the Infiltration Forest. These

flows (which will supplement current seepages by approximately 4 m3/sec on an annual

average basis), will help to prevent stagnation of the creek , drying of seepage zones and

subsequent loss of riparian vegetation, and will support the creation and maintenance of

muddy substrates and seasonal pools.

Sediment controls will be implemented for creek enhancement works and construction

activities near to the creek, including stormwater/leachate collection and conveyanc e

refurbishment works, construction of the infiltration wetland, and creek discharge works. Silt

curtains and sediment ponds are likely to be required to minimise sediment run-off to the creek

and transport of sediments downstream.

https://www.google.com.au/search?client=firefox-a&hs=ueY&rls=org.mozilla:en-GB:official&channel=sb&q=Quite+the+contrary&spell=1&sa=X&ei=cMobVPDEB43U8gW9qYKoDQ&ved=0CBsQvwUoAA



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6.3.6 Pests, Weeds and Diseases

Potential Impacts

Potential impacts due to pests, weeds and diseases is considered low since the proposed

treatment system will only use locally native species and weed control works will be

undertaken as part of construction works and on an ongoing basis to minimise impacts to

wetland vegetation. During construction works, the site will be managed so as to limit the

introduction and spread of introduced plant species, weeds, pests and diseases (including

Dieback Phytophthora cinnamomi), using all practical and operational means.


Management practices to prevent the spread of pests, weeds and diseases into uninfected

areas will include strict hygiene measures such as:

Dieback free construction materials will be used.

All imported soils will be certified and purchased from accredited suppliers only.

Equipment, machinery and vehicle inspection, washdown and disinfection procedures

will be implemented and enforced prior to site entry and departure

Weed control will be undertaken prior to clear and grub works.

Ongoing weed control and disease management will be undertaken in accordance with

an Operational and Maintenance Plan to be developed.

6.3.7 Dust

Potential Impacts

Dust due to construction activities will be managed during construction works to avoid impacts

to workers, neighbouring properties and the natural environment.


Dust control will be implemented during construction works in order to minimise export off site.

Water tankers will be utilised to prevent dust emissions if soil moisture is low and wind velocity

is high.



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6.3.8 Sediment

Potential Impacts

Sediment can cause impacts to the creek by reducing open water habitat and through

entrained pollutants. Sediment has caused issues within the creek system in the past , and will

need to be carefully managed during wetland construction works and creek enhancement

works.


Sediment control structures will be installed prior to commencement of work in order to negate

or minimise sediment export off site. Sediment traps and temporary lined stormwater bunds to

400mm height will be constructed to manage surface water flows during the construction

period. Silt curtains will be installed within the creek during construction of the infiltration wet

forest, stormwater swale, manhole refurbishment works and creek enhancement works.

6.3.9 Marine and Coastal

The site is not within a marine or coastal area.

6.3.10 Greenhouse Gases and Ozone Depleting Substances

Potential Impacts

The proposed leachate treatment system is not expected to significantly increase the level of

GHG emissions currently being emitted from the landfill site. This is predominantly due to the

following:

The proposed system is predominantly a passive wetland system that relies on

naturally occurring physico/chemical and biological processes to achieve pollutant

removal. As such, they have a minimal reliance on mechanical components and have

very low energy demands, and consequently operation of such systems results i n

generation of low GHG emissions.

Emissions will mostly result from construction machinery and any associated transport

to and from the site, and from pumping requirements to the wetland system, which are

equivalent to the current scenario (leachate will be pumped to the wetland instead of to

the sewer network). Pumping (electrical) requirements are relatively small and

calculated to generate approximately 10-17 t/year of CO2 emissions per year.

Given aerobic (oxidised) conditions are dominant in the proposed system, methane is

not anticipated to be produced (methane is typically produced in anoxic soils and

sediments).



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Vegetation within the proposed system will serve as a carbon sink thereby further

reducing emissions and acting as a positive GHG offset within the site.

Construction and operation of the proposed leachate treatment system will not involve

the generation or use of any ozone depleting substances.


The recirculation pump required to enable return of non-compliant leachate from the

polishing wetland back through the treatment system (contingency measure) will be

solar powered with battery storage.

A new high efficiency pump will be installed as the duty pump to minimise electrical

use and emissions (compliant with best practice standards for submersible pumps).

All equipment, machinery and vehicles used during the system construction and

operation will be well maintained in order to minimise the generation of greenhouse

gases.

Reuse of material present on site will be maximised to reduce GHG emission from

transport of off-site material.

6.3.11 Heritage

Potential Impacts

It is highly unlikely that Aboriginal artefacts will be uncovered during the treatment system

construction, since the majority of works will be on top of the landfill cap and because

excavation is limited to topsoil stripping and levelling (top 300mm only) . Furthermore, there

will be no impact on heritage buildings and/or associated historical structures arising from the

systems construction and operation.

Hence, there are no site specific heritage constraints or requirements for the project .


Given lack of impacts, no specific mitigation measures are proposed.

In the unlikely event that any artefacts or sites are discovered during system construction

/operation, all activities will cease immediately until a proper assessment is undertaken. The

appropriate personnel at the Aboriginal Heritage Tasmania (division of the Department of

Primary Industries, Parks, Water and Environment) will be contacted to assess the situation

and agree upon the appropriate management measures.



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6.3.12 Land Use & Development

The proposal does not alter the current constraints for future land use and development in

place at present, since the site is a designated landfill (Resource Recovery) facility.

6.3.13 Visual Impacts

This project will improve the visual amenity of the site and surrounding areas through the

reinstatement of significant areas of natural vegetation (~2 ha) and creek improvement works.

Visual impressions of the wetland have been provided in earlier sections (Figure 10, Figure

11, Figure 12 and Figure 13.

6.3.14 Socio-Economic Issues

The estimated capital spend on this project is ~$2 mill, with annual opex of ~$80k. Most of this

will be expended in Tasmania, except where local materials cannot be sourced (refer Table 4).

Local contractors will be used for construction works, and training opportunities provided to

BCC staff and NRM groups during the construction and commissioning stages.

The broader economic impact of this project has been discussed in previous sections and in

APPENDIX 5.

As previously discussed, this project is funded by a federal grant as part of the Stormwater

Infrastructure Development Program, with funds contingent on substantial completion of works

by June 2106.

6.3.15 Health & Safety Issues

An OH&S plan will be required to be provided by the Contractor as part of the tender

documentation, and will be compliant with the WorkHealth and Safety Act 2012 and the Work

Health and Safety Regulations 2012 and in accordance with existing BCC policies and

standards that apply to the site. This will describe the health and safety management

systems to be used during construction and operational phases.

6.3.16 Fire Risk

Potential Impacts

As discussed in Section 5.2.10, the risk of fire at the landfill site is relatively low due to the

safety procedures in place and restricted access. Construction of the proposed leachate

treatment system is not expected to significantly increase this existing low risk. The only



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additional wetland-associated factors that might contribute to fire occurrence and/or impact

extent are:

Electrical connections to pumps required for system operation.

Vegetation cover (i.e. presence of plants in surface and subsurface system

components and the phytoremediation swale) which might serve as an additional fuel

load increasing the spread and fire intensity – note this is not considered to pose a

major threat given plants will be within the wetland system (partially submerged in free

standing water or within damp ground). Most of the wetland plants are resistant to fire

hence if a fire does occur this will not impair treatment function (and is often used as a

management method to enhance wetland performance/health) .


An existing Fire Management (Action) Plan will be updated prior to the treatment

system commissioning and operation, to include any additional risks arising from the

treatment system and procedures required for their management. All employees and

contractors will be briefed during inductions on wetland-specific fire risks and

appropriate management responses.

All pumps servicing the treatment system will have lightening / short circuiting/

electrical protection installed.

Access to the system will be controlled (no unauthorised access allowed).

The construction of the treatment system will involve the use of some combustible

materials, such as fuels for construction equipment. These materials will be used,

stored and transported in accordance with the Dangerous Substances (Safe Handling)

Act 2005 and Dangerous Substances (Safe Handling) Regulations 2009.

All electrical infrastructures associated with the treatment system operations will be

constructed in compliance with the Tasmanian Electricity Code to minimise risk of

electrical faults that may act as ignition sources.

All site access roads and tracks will be maintained to acceptable fire fighting standard.

6.3.17 Infrastructure and Off-Site Ancillary Facilities

The proposed system will not have any significant negative impacts on the existing on site

and/or off-site infrastructure (e.g. roads, rail, etc).

No roads upgrade and no significant off-site infrastructure changes/upgrades will be required

to service the proposed treatment system.



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The proposed project will utilise the existing infrastructure on site, including manhole

chambers, existing pump, existing sewer network and existing internal network of roads and

access points. The main Stage 1 leachate pumping station will be refurbished to separate

leachate from site stormwater flows and will incorporate a sediment trap. The existing

connection to the TasWater sewer network will be modified to enable contingency discharge

only. Specific access paths point will be constructed to enable treatment system monitoring

and maintenance.

The construction phase will require the initial delivery of materials and construction equipment,

however this process will be managed and is not expected to pose any adverse infrastructure

impacts.

6.3.18 Environmental Management Systems

Operation of the proposed leachate treatment system will be undertaken in accordance with

the operational requirements outlined in a new EPN for the site, which will accord generally

with the existing EPN and management plan for the site (Mooreville Rd Landfill Environmental

Operations Manual, Meinhardt Infrastructure and Environment Pty Ltd, April 2005).

During the construction phase, all contractors will be properly inducted to ensure all

appropriate environmental management expectations are communicated prior to commencing

work. Contractors will need to address environmental management within an approved

Construction Management Plan, prior to commencement of works.

Appropriate training of all on site personnel will be undertaken focusing on procedures and

measures for minimising any environmental impacts possibly associated with the system’s

operation. User friendly user-friendly management and maintenance plans, and safety plans

will be prepared to ensure continuous awareness and education of all relevant employees

regarding the system operation and the responses to operational environmental concerns.

6.3.19 Cumulative and Interactive Impacts

The proposed leachate treatment system will be located on the Stage 1 landfill cap, and will

provide a positive environmental outcome when compared with the existing site context.

Construction of the system is also not expected to pose any significant negative impacts given

that the additional traffic on local and regional roads associated with the required construction

activities and the material will only be minimal. There will be no negative visual impacts, and in

contrast the project is expected to increase the visual, biodiversity and land use value of the

site itself and neighbouring properties. Hence, the proposed system is not foreseen to pose

any significant cumulative or interactive negative environmental and human health impacts.



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6.3.20 Traffic Impacts

It is expected that there will be only minor increases in traffic on local roads associated with

the construction of the proposed system (e.g. for delivery of import material and o ther

construction-associated vehicular traffic).

This temporary additional traffic is not expected to create any operational and/or safety issues

either to on-site workers or local residents.

7.0 MONITORING & REVIEW

7.1 MONITORING PROGRAM

The following objectives have been identified for the water quality and quantity monitoring

program:

1. Influent and effluent quality (physico-chemical parameters)

o To ensure that influent water quality is within the system’s treatment capacity

and that the effluent meets the required quality criteria (which will be regulated

via a new EPN/Licence).

2. Influent and effluent quantity (flows) and groundwater levels in infiltration area

o To ensure that water flows are within the wetland operational capacity and that

discharges to the infiltration forest do not negatively impact groundwater levels

and flows.

3. Vegetation and sediment quality (system health check)

o To ensure that contaminant accumulation and cycling patterns within the

wetland are understood and potentially quantified.

4. Database maintenance (quality assurance and reporting)

o To ensure maintenance of the database of all data collected is sufficient to

satisfy the abovementioned objectives, provide ease of reporting and enable

performance assessment and design/operation of future systems.

Apart from the ongoing monitoring schedule which covers influent and effluent quantity and

quality, during the first year of operation, additional monitoring locations within the treatment

train and a higher sampling and analysis frequency will be undertaken to allow fine tuning of



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operating parameters (e.g. flow and operating depths) and to optimise the performance of the

wetland system. This monitoring is important as it will ensure that the different wetland

components, such as pre-treatment, surface and subsurface flow wetlands and infiltration

forest function within their operational capacities and that any potential issues are detected at

an early stage.

The wetland monitoring program will be complemented by ongoing visual checks of vegetation

health, inspection of hydraulic components such as pipes, pits and headwalls and preventative

maintenance of mechanical components such as pumps and valves as described in an

Operational and Maintenance Plan to be developed for the site.

7.1.1 Sample Collection, Handling and Analysis

Water collection will be undertaken in a manner consistent with the relevant ‘AS/NZS 5667

Water Quality - Sampling’ Series and water samples submitted to a laboratory with current

NATA accreditation for the analysis specified. All samples will be analysed in accordance with

the current “Standard Methods for Examination of Water and Wastewater – APHA –AWWA-

WEF” or equivalent method recognised by the EPA.

7.1.2 Sampling Locations

The proposed sampling locations are shown in Figure 41.

The current monitoring schedule for groundwater locations upgradient of the proposed wetland

system (i.e. locations G2 and G3) will remain unchanged as they will not be impacted by the

proposal. Proposed sampling sites relevant to the treatment system include ongoing

monitoring points, where flows and water quality will be recorded for the life of the treatment

wetland, and additional water quality monitoring points within the treatment train, where grab

samples will be collected during the first year of operation to gauge performance and fine tune

operation.



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Figure 41. Proposed sampling locations.

Briefly, the monitoring sites are:

1. Ongoing monitoring locations (flow meter, grab samples and continuous in -situ

monitoring)

a. INF - Influent leachate, sampled at manhole 1 (MH1). This is equivalent to the

existing location (L1). A flow meter will be present at the rising main.

b. EFF 1 - Treated leachate, sampled at the outlet of the Polishing Wetland. A

flow meter and in situ pH, electrical conductivity and ammonia (ion selective)

probe will be present at this location.

c. EFF2 - Treated leachate discharge point sampled at the outlet of the Infiltration

Forest (when discharging to unnamed tributary). A level sensor and flow meter

will be present at this location.

2. GW1 - Existing groundwater monitoring location at the Infiltration Forest to be

maintained - sampling frequency will be intensified to monitor indirect discharges to the

creek.

INF

EFF 1

EFF 2 GW 1

PRE

SSF

SSF

SSFSF

SF

SF

SF

SF

SF

SF

SF

SF

SF

PF

PW

SF

SSF



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3. Additional year 1 monitoring locations (grab samples)

a. PRE - Pre-Treatment effluent, sampled at the outlet of the Pre-Treatment cell

to gauge metal removal (Fe/Mn) performance

b. SF - Surface Flow Wetland effluent, sampled at the manhole downstream of

SF6 to gauge the performance of the surface f low wetland cells

c. SSF - Sub-Surface Flow Wetland effluent, sampled at the outlet of the

subsurface flow wetlands.

7.1.3 Sampling Frequency and Parameters

The proposed frequency of monitoring and parameters to be analysed for the ongoing

monitoring program have been based on the existing EPN schedule and the proposed Water

Quality Protection levels as shown in Table 23.

In general, the same physico-chemical parameters and frequency prescribed in the current

EPN for the site have been maintained as they are considered applicable for both influent and

effluent leachate and groundwater at the infiltration area. Dissolved oxygen (DO) has been

added to the list of parameters as it provides valuable information to process control. In

addition to routine analytical parameters and grab samples continuous online flow monitoring

with flow meters at INF, EFF 1 and EFF 2 has also been included. Continuous online

(telemetry) monitoring of pH, electrical conductivity (EC) and ammonia is also proposed at

EFF 1 (Table 33) so that the operator can be notified when these parameters are outside of

their target range and take remedial action (e.g. activate recycle mechanism). During the first

year of operation, the monitoring of physical parameters and nutrients is increased to monthly

at all locations and the monitoring of metals increased to every two months at INF, PRE, EFF

1 and GW1 (Table 33). Frequency of other parameters such as cations, anions, pesticides,

hydrocarbons and E. coli in the first year will remain as per the ongoing (year 2 onwards)

schedule (Table 33).

Groundwater parameters at G1 will be reviewed on an annual basis and compared against

historical quality and water level data, rainfall data and flow rates through the wetlands.

Should no appreciable change in levels or quality occur in the first year, monitoring frequency

of physical parameters, nutrients and metals could be reduced to quarterly as per current EPN

prescription.



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7.2 MANAGEMENT TRIGGERS

Certain sample points will be installed and monitored for the purpose of preventing non -

compliant events to occur, and to trigger the appropriate management responses. This will be

detailed in a separate monitoring and maintenance manual so is only indicatively outlined

here. Preventative monitoring includes general maintenance of the wetland system, plant

health checks, geotechnical checks etc (see Sections below). In addition, specific monitoring

and management response triggers are proposed as follows:

TRIGGER 1: Trigger to activate recirculation through the treatment system.

The first trigger will be activated via an automated flow controller set to trigger recirculation

either:

1. When the infiltration wetland is at capacity and no attenuation of additional flows is

possible (i.e. there is active discharge to the creek) – measured by continuous flow

meter, AND EITHER:

a) When flows into the wetland exceed the maximum treatable design flows (1500

m3/day) – triggered by flow levels in the pump and pit infrastructure, OR

b) When one or more on-line parameters (ammonia, pH, conductivity) exceed a

specified maximum trigger value. Note, these values will be refined during the

commissioning phase once the system performance is proofed. Initially, these

will be equivalent to the compliance monitoring targets (Water Quality

Protection Levels for creek discharge) as shown in Table 23.

TRIGGER 2: Trigger to activate discharge to sewer

Flows to the TasWater sewer system are only envisaged when raw leachate cannot be

delivered to the wetland system due to pump failure (power outages plus generator failure),

which will be unlikely and infrequent (refer Section ). This will be triggered by rising water

levels in the manhole chamber (MH1) which will activate a gravity flow to the emergency

storage tank. Flows will only discharge to sewer if the capacity in the manhole chamber is not

reinstated within 24 hours (low flow events) or 6 hours (high flow events). This is activated

also by water levels rising in the tank and overflowing by gravity to the sewer network.



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Table 33. Proposed monitoring schedule for the treatment wetland

GROUNDWATER

YEAR 1 YEAR 2 ONWARDS YEAR 1 ONWARDS *

ANALYTICAL PARAMETERS UNIT

MONITORING FREQUENCY AT

PROPOSED SAMPLING LOCATIONS

INF (L1), PRE, SF, SSF, EFF1 & EFF 2



INF (L1), EFF1 & EFF 2


PROPOSED SAMPLING

LOCATION G1 (INFILTRATION

FOREST

PHYSICAL

Water Level m AHD - - monthly

Flow m³

INF - continuous online monitoring (flow meter at

MH1)

EFF 1 - continuous online monitoring (flow meter

at SF7 polishing wetland outlet - performance

monitoring)

EFF 2 - online monitoring (flow sensor and meter

at creek discharge point)

INF - continuous online monitoring (flow meter at

MH1)

EFF 1 - continuous online monitoring (flow meter

at SF7 polishing wetland outlet - performance

monitoring)

EFF 2 - online monitoring (flow sensor and meter

at creek discharge point)

-

Temperature °C monthly quarterly monthly

Alkalinity Total mg CaCO3/L monthly quarterly monthly

Conductivity µS/cmEFF 1 - continuous online monitoring

Other locations - monthly

EFF 1 - continuous online monitoring

Other locations - quarterly monthly

pH EFF 1 - continuous online monitoring



Other locations - quarterlymonthly

Dissolved Oxygen (DO) mg/L monthly quarterly monthly

Oxidation Reduction Potential Eh mV Eh mV monthly quarterly monthly

Total Dissolved Solids (TDS) mg/L monthly quarterly monthly

Total Suspended Solids (TSS) mg/L monthly quarterly monthly

SURFACE WATER AND LEACHATE



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GROUNDWATER










PROPOSED SAMPLING


FOREST

CHEMICAL

Chemical oxygen demand (COD) ** mg/L quarterly quarterly quarterly

DOC mg/L mg/L quarterly quarterly quarterly

Nutrients

Ammonia mg/LEFF 1 - continuous online monitoring



Other locations - quarterlymonthly

Nitrate mg/L monthly quarterly monthly

Nitrite mg/L monthly quarterly monthly

Total Nitrogen (TN) mg/L monthly quarterly monthly

Phosphorus Dissolved Reactive mg/L monthly quarterly monthly

Total Phosphorus (TP) mg/L monthly quarterly monthly

Major Anions

Chloride mg/L quarterly quarterly monthly

Sulphate mg/L quarterly quarterly monthly

Major Cations

Mg mg/L quarterly quarterly monthly

K mg/L quarterly quarterly monthly

Na mg/L quarterly quarterly monthly

Metals (total)

Al mg/L quarterly

As mg/L annually

Cd mg/L quarterly

Cr mg/L quarterly

Cu mg/L quarterly

Fe mg/L quarterly All monthly

Hg mg/L annually

Mn mg/L quarterly

Ni mg/L quarterly

Pb mg/L quarterly

Se mg/L annually

Zn mg/L quarterly

All every 2 months

at INF, PRE and EFF 1




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GROUNDWATER










PROPOSED SAMPLING


FOREST

CHEMICAL

OC/OP Pesticides

a-BHC µg/L

Aldrin µg/L

b-BHC µg/L µg/L

Chlordane µg/L µg/L

Chlorpyrifos µg/L µg/L

d-BHC µg/L µg/L

Diazinon µg/L µg/L

Dieldrin µg/L µg/L

Dimethoate µg/L µg/L

Disulfoton µg/L µg/L

Endosulfan I µg/L µg/L

Endosulfan II µg/L µg/L

Endosulfan sulphate µg/L µg/L

Endrin µg/L µg/L

Endrinaldehyde µg/L µg/L

Ethylparathion µg/L µg/L

Famphur µg/L µg/L

g-BHC µg/L µg/L

Heptachlor µg/L µg/L

Heptachlor epoxide µg/L µg/L

Hexachlorobenzene µg/L µg/L

Malathion µg/L µg/L

Methyl parathion µg/L µg/L

Phorate µg/L µg/L

pp'-DDD µg/L µg/L

pp'-DDE µg/L µg/L

pp'-DDT µg/L µg/L

Sulfotep µg/L µg/L

Thionazin µg/L µg/L

All annually at INF, EFF 1 and EFF 2 All annually at INF and EFF 1


All monthly



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GROUNDWATER










PROPOSED SAMPLING


FOREST

CHEMICAL

Polycyclic aromatic hydrocarbon

(PAH)

Acenaphthene µg/L µg/L

Acenaphthylene µg/L µg/L

Anthracene µg/L µg/L

Benzene µg/L µg/L

Benzo[a]anthracene µg/L µg/L

Benzo[a]pyrene µg/L µg/L

Benzo[b&k]fluoranthene µg/L µg/L

Benzo[ghi]perylene µg/L µg/L

Chrysene µg/L µg/L

Dibenzo[ah]anthracene µg/L µg/L

Fluoranthrene µg/L µg/L

Fluorene µg/L µg/L

Indeno[123-cd]pyrene µg/L µg/L

Naphthalene µg/L µg/L

Phenanthrene µg/L µg/L

Pyrene µg/L µg/L

Monocyclic aromatic hydrocarbon

(MAHs)

Ethylbenzene µg/L µg/L

om&p Xylene µg/L µg/L

Toluene µg/L µg/L

Total BTEX µg/L µg/L

Other

Cyanide total µg/L quarterly quarterly quarterly

PCB µg/L µg/L annually annually annually

MICROBIOLOGICAL

E.coli org /100 mls quarterly quarterly quarterly

Notes

** COD test method detection limit to be lowered to reflect range of values for leachate INF and EFF.



* Frequency and parameters to be reviewed following the results of the first year of operation with a view to decrease/increase sampling frequency and potentially delete unecessary parameters.


All monthly

All monthly



DPEMP

7.3 GEOTECHNICAL MONITORING

7.3.1 Construction Monitoring - Pre, During and Post Construction

General settlement of the Stage 1 landfill area will be monitored via the installation of (semi)

permanent topographical survey markers within the extent of the proposed wetlands and

beyond. These markers will be checked by a certified surveyor pre (two weeks prior to works),

during works, and post construction works (for two months) on a weekly basis. The exact

number and location of markers will be established during detailed design. Nominally at least

eight markers covering the wetland extent are envisaged to cover surface flow wetland,

subsurface flow wetland, outer perimeter buns and potentially pipe and pit infrastructure .

7.3.2 Ongoing Settlement Monitoring

In order to monitor potential settlement and changes to design levels in the wetland area, a

minimum of four (4) (semi) permanent topographical survey points will be set on the wetland

bunds to the north, east, west and south of the wetlands and monitored monthly by a certified

surveyor for the initial 6 months. After six months and provided that negligible settlement has

occurred, monitoring can be reduced to annually. The northern geotechnical monitoring point

will be located on the containment bund adjacent to the site boundary. The exact coordinates

of the points will be determined during the detailed design stage.

7.3.3 Wetland Liner Leakage Monitoring

Any leakages in the wetland liner and Stage 1 landfill cap will simply be collected by the

leachate system at the base of the waste. Contiguous flow monitoring at the wetland influent

(INF) and wetland effluent (EFF1) will allow for a water balance to be carried out for the

wetland and determine whether water losses (beyond evapo-transpiration) are occurring.

Where a gravel drainage layer above the clay capping is present, such as the northern part of

Stage 1, any leakage through the wetland would flow laterally through this gravel layer and

directed to the phytoremediation swale. After heavy rainfall events, visual checks of flows in

the infiltration swale are to be undertaken and if abnormal flows are present beyond those

expected from rainfall, further investigation will be required to ascertain the origin of flows, and

would include testing the water in the phytoremediation swale.

The existing piezometers installed along the landfill cap for monitoring of leachate standing

levels will also be retained where possible and will continue to be monitored to assist in

assessing potential wetland leakages.



DPEMP

7.4 MAINTENANCE & SYSTEM HEALTH MONITORING

7.4.1 Ongoing Maintenance Tasks

Ongoing maintenance tasks refer to those tasks which will be undertaken on a regular

(weekly, monthly or quarterly) basis. The ongoing maintenance tasks will be fully identified in

a Operating and Maintenance Manual to be done at a later stage, however as a minimum

these will include:

Maintenance Tasks for Infrastructure:

o Equipment (e.g. pumps, manholes, liner, concrete structures) – will be

inspected and maintained as per manufacturer’s specifications, and as part of

routine maintenance quarterly or biannually and after peak rainfall events.

o Operators Inspection Checklist (to be prepared as part of the Operating

Manual) – will be completed after each maintenance activity and any issues

recorded and actioned.

o Sediment levels – will be monitored quarterly and removed from sediment

chambers and pre-filter as required.

o Pipe work and weirs – will be checked for leaks and blockages weekly or

monthly and following peak events. Pipes will be cleaned periodically to ensure

they are free of any obstructions which have the potential to cause clogging.

o Manholes and valves – will be inspected to ensure function is correct and to

ensure accessibility.

o Access track and embankments –will be inspected for damage, erosion, and

weeds. Tracks will be maintained as required to ensure they remain clear and

accessible.

o Site Fencing – will be inspected quarterly to ensure public safety.

o Rock-lined distribution zones – will be inspected and cleaned as required.

Maintenance Tasks for Wetland Vegetation:

o Weed control activities – will be undertaken on a quarterly or bi-annual basis

throughout the wetland.

o Plant health, density and diversity – will be monitored on a bi-annual basis

throughout the wetland and appropriate management measures undertaken to

replace plants, undertake weed control works or apply conditioners etc if

required.



DPEMP

Maintenance Tasks for Potential Wetland Leakage:

o After heavy rainfall events, visual checks of flows in the infiltration swale will be

undertaken. If abnormal flows are present beyond those expected from rainfall,

further investigation will be undertaken to ascertain the origin of flows.

o The existing piezometers installed along the landfill cap for monitoring of

leachate standing levels will also be retained (where possible) and will

continue to be monitored to assist in assessing potential wetland leakages.

o If leakages due to issues of liner integrity are identified, the relevant section of

the wetland will be taken off-line and repaired.

Condition Assessments of the Creek Tributary - BCC, with the consent of the

neighbouring property owner, will undertake annual condition assessments of the

creek tributary from the treated leachate discharge point to Three Mile Road for the

first 3 years after construction of the treatment system. This will be to ensure the

anticipated positive creek benefits associated with improved environmental flows and

biodiversity improvement works are realised.

7.4.2 Scheduled Maintenance Tasks

Scheduled maintenance tasks are those tasks which will be scheduled annually or 3 to 5

yearly. The scheduled maintenance tasks will be fully identified in an Operating and

Maintenance Manual to be done at a later stage, however as a minimum these will include:

Maintenance Tasks for Wetland Vegetation.

o Sediment – will be removed and disposed of from pre-filter and manhole

chambers;

o Biomass thinning – will be undertaken on a 3 to 5 year harvesting plan; and

o Supplementary planting – will be undertaken in bare areas if required.

Maintenance Tasks for Landfill Settlement

o If required, repairs to wetland bund heights will be undertaken to maintain

flows and freeboard capacity. This will be achieved by adding fill material and

potentially extending the liner along any sections of the wetland bunds that

have settled below the critical 200 mm freeboard level. Weirs/pipes may

require adjustments (e.g. alter weir board positions) however this is not

envisaged as likely.



DPEMP

7.5 REPORTING

In line with the current EPN prescription, a report with the results of the water monit oring,

including sampling locations, sampling methods, chain of custody documentation and

comparison of results against the site specific treatment criteria and the Australian Water

Quality Guideline for Aquatic Ecosystems (ANZECC, 2000) Ecosystem Condition 2 (level of

protection 95% species) trigger values applying to lowland streams will be prepared and

submitted to the EPA on a quarterly basis. The results of the geotechnical monitoring will also

be submitted to the EPA within the same report.

8.0 DECOMMISSIONING & REHABILITATION

The Burnie Waste Management Centre is expected to have a long life span as a waste

recovery centre (more than 20 years), hence the wetland itself will continue to be managed as

part of the site alongside this. At some point, the data on water quality discharge from the site

may indicate that the raw leachate is acceptable for direct infiltration on-site.

In the longer term at site closure, the wetland could be repurposed as a stormwater treatment

system, eventually opened to the public as a recreational biodiversity reserve.

9.0 COMMITMENTS

A consolidated set of commitments is provided in Table 34.

10.0 CONCLUSION

This DPEMP has complied with all the requirements of the project specific guidelines. The

relevant sections are summarised in Table 35.



DPEMP

Table 34. Commitments table for the Burnie Treatment Wetlands proposal

Design &

ApprovalsConstruction Operation

1 Undertake works to separate the stormwater from the MH1 leachate chamber BCC

2 Limit the placement of the wetland system to at least 10 m from the landfill crest. BCC

3 Ensure appropriate freeboard to accommodate the 1000 year rainfall event (182 mm) BCC

4 Limit the height of bunds to <2 m to prevent excessive settlement BCC

5 Use a LLDPE liner to reduce wetland seepage risks BCC

6 Construction of an emergency storage tank and recirculation system and operate for non-compliant water BCC

7 Construct a new connection to sewer maintained in case of non-compliance, as final contingency. BCC / TASWATER

8Retain wetland designer during construction / contract management phases to ensure quality control of all system

components (e.g. liner, hydraulics, planting, etc) and safeguard management elements are constructed as per design.BCC

9Ensure interception and treatment of extreme storm event leachate seepages that may occur along the northern

embankment, within a phytoremediation swale.BCC

10Establish a new compliance monitoring point at the creek discharge point and monitor flows (continuous, on-line) and

pollutants as shown in Table 31, when discharge events occur.BCC

11Establish a performance monitoring point at the polishing wetland outlet and install on-line flow and monitoring sufficient

to determine recirculation requirements (as shown in Table 33).BCC

12 Undertake sampling in accordance with the proposed monitoring schedule shown in Table 33. BCC

13Set aside an appropriate maintenance budget to be include in OPEX for the life of the wetland, to ensure that all required

maintenance activities are done appropriately and with the required frequency.BCC

14Develop Operation and Maintenance Plans which detail the required maintenance activities and frequencies and ensure

their appropriate implementation.BCC

NO. COMMITMENT

TIMING PHASE

RESPONSIBILITY



DPEMP

Table 34 (cont.). Commitments table for the Burnie Treatment Wetlands proposal

Design &

ApprovalsConstruction Operation

15Ensure Construction Mangement Plans contain practices for managing environmental risks and safety risks during

construction works.BCC

16 Ensure Construction Management Plans comply with specifications and policies and sign off accordingly. BCC

17Update existing risk management plans to include responses to incidences potentially connected with the treatment

system. This will include incidence response for any on site ponding and mosquito management.BCC

18 Install 4 survey markers and undertake forthnightly monitoring of settlement levels across the landfill pre-during and post

construction for several months.BCC

19 No clearing of native vegetation. BCC

20Use of sediment controls (traps, sediment curtains) during creek enhancement works, and reuse of sediment within

landfill area.BCC

21Use of locally native species in the treatment system to avoid invasive species entering the creek and to enhance

biodiversity.BCC

22Undertake restoration works in the immediate unnamed creek discharge area to reduce weeds, enhance riparian

vegetation, improve habitat and reduce erosion.BCC

23 Undertake an annual condition assessment of the unnamed tributary to Three Mile Rd. BCC

24 Implement an ongoing weed management program within the wetland system and creek discharge areas. BCC

25Provide controlled site access and interpretative walks/signage to enable community use of the proposed system for

education and research.BCC

26 Undertake annual monitoring of settlement levels across the landfill. BCC

27Undertake appropriate training of staff responsible for system monitoring & maintenance, including preparation of user-

friendly management and maintenance plans.BCC

NO. COMMITMENT

TIMING PHASE

RESPONSIBILITY



DPEMP

Table 35. Summary of compliance with specific guidelines

No. Summary of response

2.2.3 Proposed System Summary Includes summary of design objectives and criteria.

2.2.4 System Components & Processes

Includes detailed description of system components and processess, including

descriptin of creek discharge regime, connection infrastructure to existing

TasWater sewer network and construction material details.

2.2.6 System OperationHours of system operation, vehicualr movements during construction &

commisioning, and operational regime.

2.2.4 System Components & Processes Provides detailed description of system components.

2.2.5 Wetland Sizing/Capacity

Provides information regarding the required treatment area, operating

depth/volumes, hydraulic loading rates and hydraulic retention times are shown

for each component (Table 1).

3 2.2.7Proposed Stormwater & Creek

Enhancement Works

Provides a brief description of proposed stormwater and creek enhancement

works expected to tie in with the proposed leachate treatment works (Figures

11, 12).

4 2.2.10 Precedent ProjectsGlobal examples of landfill remediation projects for various 'soft' uses (i.e. with

relatively lightweight loads) with minimal or no geotechnical improvements.

5 2.2.3 Proposed System Summary Includes summary of design objectives and criteria.

6 6.3.6 Pests, weeds and diseasesProvides summary of weed/pest management responses during the system

construction and operation.

7 2.2.8 Construction Provides an estimate of the raw materials that will be required for the proposed

system and likely material sources (Table 4).

6.2.4Proposed Management

Measures

6.38 Sediment

REQUIREMENTS RESPONSE

Brief description of the proposed stormwater and creek enhancement works at the BWMC

site, with particular reference to the separation of site stormwater from the

leachate/groundwater system.

Section

2.2 Construction

Measures designed to prevent the introduction or spread of introduced plant species,

weeds, pests and diseases (such as phytophthora cinnamomi ) during construction works.

2.1 Proposal description - General

Detailed description of the wetland treatment system and associated infrastructure,

including size, volume, and design criteria of the wetland ponds, wetland liner, media

and species of flora, leachate collection and transfer infrastructure, overflow storage

ponds, infiltration area and discharge swale/outlets, and connection infrastructure to

existing TasWater sewer network.

1

Description of Specific Requirements

Description of treatment process and treatment capacity (i.e. kL per day), including

residence time required for removal of contaminates and design features to allow for

draining, maintenance and variations in flow.

2

Description of precedent projects, i.e. on‐site wetland leachate treatment facilities on

top of landfills. Where information is available, provide a summary of the issues’ and

success’ of these projects.

Design criteria for the proposed infrastructure in relation to flood risk, e.g. 1 in 100 year

event.

Estimates of the quantities of major raw materials required for construction activities

(e.g. clay, sand, aggregate) and their likely sources.

Details of management practices for areas disturbed during the construction phase to

prevent sediment movement into watercourses. 8



DPEMP

9 2.2.9 Commissioning Provides a list of key commissioning items , and detail regarding the timing and

end of commissioning period (Table 5).

10 2.2.1 General Figure 2. Land boundary, site layout and location points

11 2.2.1 General Figure 3. Site Plan showing landfill stages.

12 3.1

On‐Site Treatment vs

Decommissioning & Remediation

vs Trade Waste Discharge

Summary of the assessment process that focused on the suitability of the

following options:

1) Do nothing and continue to discharge to TasWater Sewerage System under a

Trade Waste Agreement (TWA) with TasWater (Base Case).

2) Remove waste from Stage 1 Landfill and develop and dispose to new waste

cell on site (Stage 2B/C).

3) Remove waste from Stage 1 Landfill, transport and dispose to an alternate

landfill (e.g. Port Latta or Dulverton).

4) On-site treatment.

3.2Evaluation of Reuse vs Disposal

Options

Summary of the assessment process that focused on the suitability of the

following options: 1) On-site reuse , 2) Discharge within the site or above the

landfill site, and 3)Off site discharge to the downstream unnamed tributary of

Cooee Creek.

3.3Evaluation of Treatment

Approaches & Technologies

Summary of the assessment process that focused on a suitability of leachate

management approaches and technologies commonly applied on landfill sites

(e.g. physico-chemical, advanced filtration and biological systems), including

detailed evaluation of three shortlisted technologies (RO, MBR, constructed

wetlands).

14 3.4Assessment of Treatment

Wetland Locations

Summary of the assessment process that focused on the he feasibility of four

alternative locations for the construction of the proposed the on-site treatment

wetland system

5.1.2 Land Use & Planning History

5.2.11 History of Waste ManagementA summary of historical waste management activities on site that may affect the

proposal.

Appendix 13.Chronology of the Waste

Management Activities On Site

2.3 Commissioning

A description of the commissioning of the wetland treatment facility and associated

infrastructure.

2.3 Site plan

A map delineating the boundary of the Land on which the activity will take place.

A site plan showing historical landfill, e.g. stages 1A, 1B, 1C and 2A, extents and

features.

3 Project Alternatives

A discussion of the alternatives for leachate management (e.g. treatment / full

decommissioning and remediation of the landfill / continuing with the trade waste

discharge to sewer, etc).

An assessment of the options for onsite leachate treatment, with reasons for the

preferred treatment system (e.g. physic-chemical systems, filtration, biological

treatment, etc).

13

An assessment of the options for wetland treatment location, with reasons for the

preferred location.

5.2 Existing environment – Environmental aspects

History of waste management activities on site, e.g. stages 1A, 1B, 1C and 2A, including a

description of all elements of the landfill that may affect the proposal. 15



DPEMP

16 5.2.6 Groundwater

Provides detail regarding the existing hydrogeological context and groundwater

quality. Includes summary of groundwater quality data and a conceptual site

model illustrating the interactions between groundwater with leachate and

surface flows .

17 5.2.4 Leachate (Current)Provides detail regarding the leachate flows, leachate quality, and calculations

on discharge (mass loads) of key pollutants to TasWater sewer (Table 14).

18

Provides detail regarding the nature and location of the leachate seepage

including data on leachate seepage chemistry for the 3 sampling events in 2013

(Table 15).

19

Provides summary of findings of soils investigation within the leachate seepage

undertaken in April 2014 (Table 16) and the extent of leachate seepage that

occurred in August 2013.

20 5.2.7 StormwaterProvides the estimates regarding the current stormwater mass loads to the

Creek (point source discharge) (Table 19).

21

Provides detail regarding the current Protected Environmental Values (PEVs) ,

EPA Draft Water Quality Objectives for Cooee Creek and proposed Water Quality

Targets for discharge to Cooee Creek tributary (Table 23).

22Provides information regarding the known abstraction points along Cooee Creek

.

23

24

25

26

27

This section: 1) Provides details regarding the nearest sensitive receptors to the

site; 2) Explains why the proposed wetland treatment system will not generate

point source odour emissions ; 3) Summarises the history of complaints

regarding odours for the existing site (documented in the annual reporting since

2004.

6.3.1 Air Quality

Results of ambient groundwater survey and modelling to define the local groundwater

environment, including groundwater quality and description of the interaction between

groundwater, leachate and surface water. The description must include concentrations of

key groundwater quality parameters.

Description of leachate quality and quantity currently discharged to TasWater’s sewage

network, including mass loadings of key effluent parameters.

Description of leachate seepage, including the mechanisms driving the seepage, and

seepage quantity and quality, including mass loadings of key water quality parameters.

Delineation and characterisation of the leachate seepage area and extent of any soil

contamination.

5.2.5 Leachate Seepage

Identification of current Protected Environmental Values (PEVs) at the proposed

discharge location and within the expected zone of impact, including Cooee Creek. Water

Quality Objectives (WQO’s) should be proposed in relation to all identified PEVs.

Details of the water use within the catchment of the receiving environment (i.e. the

unnamed creek and Cooee Creek).

5.2.8 Cooee Creek and its Tributary

Results of the ambient water quality survey, including mass loadings of key water quality

parameters across a range of flow conditions.

6.1 Air Quality

Provide a map of the area showing the existing and proposed facility and any sensitive

receptors that could be affected by odour emissions from the proposed facility.

Describe and mark the locations (on a site map) of all potential sources of odour

emissions (i.e. wetland ponds (types), infiltration areas etc), and under what conditions

emissions may occur, e.g. commissioning, normal operation, during maintenance etc.

Discuss the potential for odour emissions from the wetland treatment facility to cause

environmental nuisance, including under worst case or upset conditions.

Identify and discuss measures to be implemented (as appropriate) to mitigate any

impacts that may cause environmental nuisance.

Provide a history of odour complaints received in relation to the existing site and the

likely causes.



DPEMP

28

29

30

31 6.2Hazard and Risk Assessment of

Key Issues

This section provides an assessment of potential environmental risks associated

with potential discharge of leachate (un-treated or partially treated leachate) to

the creek, or ponding on site, and impacts on the key relevant receptors,

including downstream water users.

32 5.2.8 Cooee Creek and its TributaryProvides detail regarding the proposed Water Quality Targets for discharge to

Cooee Creek tributary (Table 22).

33 5.2.8 Cooee Creek and its TributaryProvides detail regarding the proposed Water Quality Targets for discharge to

Cooee Creek tributary (Table 23).

34 8.0Decommissioning &

Rehabilitation

35 4.1.2 Consultation with TasWaterTaswater will undertake this assessment. They have indicated that this is

unlikely to be an issue.

This section contains the findings of an assessment of flows and pollutant mass

loads to the infiltration forest and to the creek, and includes: 1) Identification of

discharge pathways and occurrence of discharge events, 2) Indirect discharge

occurrences - Estimated mass loadings of key pollutants to wet forest; 3) Direct

discharge occurrences - Estimated Mass Loadings to Creek (i.e. creek volumetric

discharges and mass load discharges in each month and annual mass load

discharges for select pollutants); 4) Comparison of total annual discharge to the

Creek in a dry year (2014) and wet years (2012, 2013) and corresponding mass

loadings of key pollutants (Table 29 and Table 30).

Surface Water 6.1.1

Provide an assessment of the capacity of the sewerage system to receive the leachate

discharge, as part of contingencies measures.

Demonstrate that the proposed discharge(s) will satisfy the requirements of the State

Policy on Water Quality Management 1997, including compliance with any relevant

emission limit guidelines.

Recommend emission limits and trigger levels. These should be based on the character of

the receiving environment (e.g. water quality, proposed WQOs, seasonal flow).

Provide an estimate of the required life of the water treatment system (based on the

breakdown processes within the landfill), and the water quality criteria that need to be

met before the wetland system can be considered redundant (which may be based on the

quality of receiving environment, ratified WQOs, mass-loads of key contaminants etc).

6.2 Surface Water

Water balance for the site, detailing estimates of seasonal discharge to the receiving

environment, incorporating seasonal infiltration capacity and high flow/stormflow

management regimes

Identification of the discharge point from the activity to the surface water receiving

environment.

Expected quality of discharge to the surface water receiving environment (i.e. unnamed

creek), including annual mass loadings, and with comparison to ambient water quality.

The likely occurrence of discharge events to the surface environment should be clearly

understood from the water balance.

Discussion of the potential for the discharge to cause environmental impact. This should

include consideration of typical and plausible worst case situations, seasonal variations,

and potential for impact to downstream water users.



DPEMP

5.2.6 GroundwaterMass loads to the infiltration wetland are shown in Table 26. Note, this DOES

NOT report to groundwater but discharges to the Creek via sub-surface flows.

6.1.1Potential Surface Water

Impacts

5.2.5 Leachate Seepage Describes the quality and estimate of volumes

2.2.4System Components &

Processes

Describes the phytoremediation swale proposed to intercept ad treat leachate

seepage events.

38 5.2.6 GroundwaterThere is no potential given it is a groundwater discharge zone. All flows

eventually report to the Creek (conceptual site model - Figure 28).

2.2.4 System Components &

Processes

6.2Hazard and Risk Assessment of

Key Issues

40 6.1.3 Potential Geotechnical Impacts Results and relevant information summarised in these two sections.

6.2Hazard and Risk Assessment of

Key Issues

Appendix 6 Hydro-geotechnical report (Tasman Geotechnics, August 2015)

41 7.3 Geotechnical Monitoring

Discussion of the potential for the treated discharge to the groundwater environment,

including the leachate seepage, to cause an environmental impact. This should include

consideration of typical and plausible worst case situations, and potential for impact to

the surface water and downstream water users.

A groundwater monitoring and reporting program must be developed, incorporating

appropriate mechanisms to monitor for wetland leakage, landfill cap settlement and loss

of landfill integrity.

Contingency measures to ensure protection of the receiving environment (i.e. the

groundwater, surface water and downstream water users) should treated leachate

exceed proposed trigger levels (see section 6.2) (e.g. collection and re-circulation of

treated leachate through wetland facility).

The expected quality and quantity of leachate seepage, and measures to manage the

seepage.

Characteristics of the effluent following treatment, including mass loadings of key

pollutants and the expected quality and quantity discharged to the groundwater

environment via the infiltration areas.

6.3 Groundwater & geotechnical issues

36

37

39

Results of the geotechnical investigations and modelling, incorporating a discussion(s) of

the potential for wetland leakage, landfill cap settlement and loss of landfill integrity

(including containment bund), their likely impact on the receiving environment, and

details of management strategies/contingency measures to mitigate the potential impact

(as appropriate).



DPEMP

42 6.3.3 Waste Management

43

44

45 Appendix 2NEST Natural Values

Assessment Report, 2014

Not quantitatively assessed but commented on in this Section and NEST report .

Increased flows are expected to improve habitat quality for the key fauna.

46 7.0 Monitoring & Review

47

48 7.3Maintenance and system health

monitoring

Monitoring programs to ensure the proper functioning of the wetland and infiltration

system and protection of the environment on an ongoing basis.

Details of the monitoring programs

Description of maintenance regimes to ensure the proper functioning of the wetland and

infiltration system on an ongoing basis.

Description of the potential changes to the flow regime of the unnamed creek and Cooee

creek, with particular regard to water levels, and the potential impact on Burnie

Burrowing Crayfish (Engaeus yabbimunna ) populations downstream of the development.

5.2.8 and

Appendix 14.Cooee Creek and its Tributary

7.0 Monitoring and maintenance

6.5 Waste Management

Description of the management of wetland sludge/bio-solids generated on site.

6.7 Biodiversity and nature conservation values

Results of surveys for any rare, threatened, endangered and locally endemic species that

will potentially be impacted by the proposal.

Identify any freshwater ecosystems of high conservation management priority using the

Conservation of Freshwater Ecosystem Values (CFEV) database (accessible on the internet

under water.dpiw.tas.gov.au/wist/). The scope of investigation should encompass the

vicinity of the proposed development where there is likelihood of alteration to the

existing environment. The specific CFEV information used for DPEMPs should be

Conservation Management Priority Potential which is appropriate for Development

Proposals.



DPEMP

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Bouazza A and Kavazanjian E (2001). Construction on former landfills. Proceedings 2nd ANZ

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Entura (2011). Cooee Creek Flood Study. Prepared for Burnie City Council, September 2011.

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2015.



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Ezzy A. R. and Latinovic M. (2004). MRT statewide groundwater monitoring network: Data

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Mienhardt Infrastructure and Environment, (April 2005). Mooreville Road Landfill –

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NEST (2013). Burnie Waste Management Rehabilitation Program. Prepared for Burnie City

Council.

Sharman, R (2002). BEng Hons Thesis. Deakin University.

SKM (2007). Moreland Road Landfill, Environmental Review of Landfill. Prepared for Burnie

City Council. 14 March 2007.

Standards Australia (2006). HB 203:2006 Environmental risk management - Principles and

process.

Standards Australia (2009). AS/NZS ISO 31000:2009 Risk management - Principles and

guidelines.

Stevenson, M.D. and Mazengarb, C. 2010: Map 1, Burnie ‐ Landslide Inventory. Tasmanian

Landslide Map Series. Mineral Resources Tasmania, Department of Infrastructure Energy and

Resources, Hobart.).

Syrinx Environmental PL (2015). Water quality clarifications. Syrinx Memo report, Prepared for

burnie City council, July 2015.

Taylor, R. and A. Allen (2006). Waste Disposal and Landfill: Potential Hazards and Information

Needs, in O. Schmoll, G. Howard, J. Chilton and I. Chorus (eds) Protecting Guidelines for

Design and Operation of Municipal Solid Waste Landfills in Tropical Climates, 2013 Page 29.

Groundwater for Health: Managing the Quality of Drinking‐water Sources, IWA Publishing.



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Valencia, R, van der zon, W, Woelders, H. Lubberding, H.J. and Gizjen, H. (2009). Achieving

“Final Storage Quality” of municipal solid waste in pilot scale bioreac tor landfills. Waste

Management 29(1):78‐85 ∙ January 2009.

van Zomeren, A., H.A. van der Sloot, J.C.L. Meeussen, J. Jacobs, H. Scharff (2005),

Prediction of long term leachate behaviour of a sustainable landfill containing predominantly

inorganic waste. 10th

International Waste management and Landfill Symposium, October

2005, Sardinia). EU Council Directive 1999/31/EC of 26 April 1999 on the landfill of waste.



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APPENDICES



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APPENDIX 1. Burnie Waste Management Centre (BWMC) Stage 1 Landfill

Leachate Treatment Study – Option Development and Evaluation

and Preferred Option Concept Design (Syrinx Environmental PL,

July 2014).

ATTACHED SEPARATELY



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APPENDIX 2. Natural Values Assessment Report (NEST July 2014)

ATTACHED SEPARATELY



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APPENDIX 3. EPBC Referral Decision



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APPENDIX 4. Addendum to Stage 1 Landfill Leachate Treatment Study –

Design Changes & Alternative Wetland Option Assessment

(Syrinx Environmental PL May 2015).

ATTACHED SEPARATELY



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APPENDIX 5. Assessment of Alternative Leachate Management Options (BCC

May 2015).

ATTACHED SEPARATELY



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APPENDIX 6. Hydro‐geotechnical Investigation and Risk Assessment Version

2, August 2015 (Tasman Geotechnics August 2015)

ATTACHED SEPARATELY



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APPENDIX 7. Preliminary Treatment System and Associated Infrastructure

Layout



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APPENDIX 8. EPA Class Assessment of The Project Proposal



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APPENDIX 9. Proposed Wetland Species List

PLANT SPECIESDESCRIPTION

SURFACE FLOW/SUBSURFACE FLOW WETLANDS

Rushes and Sedges

Baloskion australis 'Southern Cordrush' Almost leafless rush to 0.5 metres. Flowering stems dark red-brown. Flowers reddish in spring/summer.

Baloskion tetraphyllum ' Tassel Cordrush' Soft foliaged clump-forming rush to 1.7 metres. Foliage soft green, flower spikes red-brown in spring/summer.

Baumea juncea 'Twine Sedge' Perennial emergent aquatic, creeping rhizomes, 0.5-1m. Culms blue-green.

Baumea rubiginosa Perennial emergent aquatic, creeping rhizomes, 0.5-1m. Culms dark green.

Carex apressa ' Tall Sedge'Erect clump forming perennial sedge 0.5-1.2m height. Width 1.0m. Evergreen with fast growth rate Suits most soils.

Flowering in Spring and Summer.

Carex fascicularis ' Tassel Sedge'Erect clump forming perennial sedge 0.5-1.0m height. Width 1.0m. Evergreen. Evergreen with fast growth rate Suits most

soils. Full sun to part shade. Flowering in Spring and Summer.

Carex longebrachiata 'Drooping Sedge' Tussock forming sedge to 0.6 metres with long arching flower stems.

Carex tasmanica 'Curly SedgeErect clump formimg perennial sedge 0.4m height. Width 0.4m. Evergreen. Evergreen with fast growth rate Suits most

soils. Flowering in Spring and Summer. Tasmanian threatened species.

Carex tereticaulis ' Hollow Sedge'Erect clump forming perennial sedge 1.0-1.8m height. Width 1.0m+. Evergreen. Evergreen with fast growth rate. Prefers

clay soils . Flowering in Spring and Summer.

Chorizandra enodis Perennial sedge 0.5- 1m. Very narrow blue-grey to dull green cylindrical culms. Small black flowerball seedheads.

Cyperus gunnii ' Flecked Flatsedge' Tall, tufted perennial sedge to 150cm, with short thick rhizome. Culms trigonous to terete.

Cyperus lucidus ' Candelabra Sedge'Robust perennial sedge up to 1.3 m. The leaves are thick and glossy. The flowers form an umbrella-l ike head which is

bright red when young, turning red-brown as it matures.

Eleocharis sphacelatus ' Tall Spike Rush' Perennial aquatic with stout rhizome. Culms terete to 5 m high. Permanent water.

Gahnia filum 'Chaffy Saw Sedge' Dense tufted perennial to 1.2 metres. Flowers in spring/summer. Tasmanian Bush Tucker.

Gahnia grandis 'Cutting Grass'Large tussock with plume-like flowering heads to 3.5 metres. Grass-like leaves, cutting edges. Flowers in spring/summer.

Isolepis fluitans ' Floating Clubsedge'Slender, aquatic or dry land perennial up to 15cm height.Erect and tufted, spreading or submerged. Use for ponds, wet

areas and water courses. Semi shade. Pale green or straw coloured flowers in spring/summer.

Isolepis inundata ' Swamp Clubsedge'Tufted perennial rush with stiffly erect or arching stems. Deep glossy green foliage. Purple-brown flowerheads

spring/summer. Most soil types and condition.

Isolepis stellata Tufted annual, grass-like or herb (sedge), 0.02-0.1 m high, spikelets 3-8, in a dense globular cluster; Flowers yellow-

green, Sep to Dec or Jan. Grey, black peaty or orange clayey sand, loam, sandy clay.

Juncus amabilis 'Hollow Rush'Densely tufted perennial rush 0.2-1.2m height. Width 0.2 -0.5m. Spreading from underground stems. Green flowers in

Summer. Best in seasonally moist to inundated soils.

Juncus astreptus ' Rigid Rush'Rhizomatous perennial forming tight clumps 0.6-1.0m height. Brownish green flowers in Summer. Most soils -well

drained or waterlogged.

Juncus bassianus ' Forest Rush' Rhizomatous perennial forming large clumps 0.5-1.0m height. Moist soils.

Juncus filicaulis ' Thread Rush'Densely tufted perennial rush 15-45cm height. 30-50cm width. Spreading from underground stems. Straw coloured

flowers in Summer.

Juncus gregiflorus 'Green Rush'Densely tufted perennial rush 0.4-1.7m height. Width 0.6-1.5m. Spreading from underground stems. Straw coloured

flowers in Summer.

Juncus pauciflorus 'Loose Flower Rush' Rhizomatous, colonial perennial, herb, 0.3-1 m high. Fl. Sep to Oct. Clay.

Juncus pallidus 'Pale Rush' Tall robust rush to 2.0 metres. Vigorous coloniser of poorly drained areas.

Juncus procerus ' Tall Rush'Dense robust tufted perennial rush 1.2-1.5m height. Width 0.6-1.5m. Spreads from underground stems. Straw coloured

flowers in Summer.

Juncus sarophorus ' Broom Rush'Tufted perennial rush 0.7-2.0m height. Width 0.5-1.0m. Spreads from underground stems. Straw coloured flowers in

Summer.

Schoenoplectus tabernaemontani ' River Club Rush' Creeping rhizomatous perennial sedge, 1-3.0 m height. Straw coloured flowers in Summer.



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INFILTRATION 'WET FOREST' & WETLAND BUNDS

Rushes and Sedges

Eleocharis acuta ' Common Spike Rush' Perennial sedge with creeping rhizome. Culms terete. 0.3 - 0.5m high. Seasonal wetlands.

Gahnia grandis 'Cutting Grass' Large tussock with plume-like flowering heads to 3.5 metres. Grass-like leaves, cutting edges. Flowers in spring/summer.

Gymnoschoenus sphaerocephalus ' Button Grass'This species is the dominant species of most lowland sedgelands on wet peat in Tasmania. It forms large, dense clumps

of long, narrow, yellow-brown leaves with long, cylindrical stems, each bearing a spherical terminal head of flowers.

Isolepis stellata Tufted annual, grass-like or herb (sedge), 0.02-0.1 m high, spikelets 3-8, in a dense globular cluster; Flowers yellow-

green, Sep to Dec or Jan. Grey, black peaty or orange clayey sand, loam, sandy clay.

Poa labillardierei ' Tussock Grass'Dense perennial tussock grass, common in open forests particularly in moister areas on southern slopes or in gullies

and along watercourses, on loamy soils. Suitable to clay soils. Si lver.

Xyris muelleri 'Yellow-eyed Grass'Leaves more or less spirall ing. Flowers yellow, lasting more than one day, early summer. Tasmania, in moist soil at

margins of streams and ponds.

Herbs

Billardiera longiflora 'Climbing Blue Berry'

(Climber)

Ornamental twiner grows to ~3m tall. Partial or full shade. Flowers spring and summer, producing creamy green bell-

shaped flowers that are tinged with purple. Suitable to clay soils.

Chrysocephalum apiculatum Varies considerably in form, 0.2 - 1 m in height, Suitable in clay soils. Yellow flowers.

Austrodanthonia pilosa ' Velvert Wallaby Grass' Perennial grass. Whispy white tips.

Dichondra repens 'Kidneyweed' Fast-growing groundcover. Leaves are small and kidney shaped. This plant has a creeping habit and forms a thick mat.

Diplarrena moraea 'White Flag Iris' Perennial small herb which forms thick clumps with long narrow leaves and white flowers at the ends of slender stems.

Helichrysum scorpioides Everlasting. Yellow flowers / grey foliage (daisy l ike).

Patersonia fragilis ' Short Purple Iris' Tufted glabrous herb to c. 50 cm high with purple flowers.

Triglochin procera 'Ribbon weed' Aquatic perennial. Permanent water.

Shrubs

Acacia myrtifolia 'Red-stemmed wattle'Shrub 1 - 2 m tall by 1-2 m wide. The phyllodes are ell iptic and usually slightly curved. The cream flower clusters are

globular in shape and occur on short racemes from the leaf axils in spring. Suitable to clay soils.

Acacia mucronata ' Narrow-leaved wattle' Shrub 1 - 2 m tall. Yellow flowers. 1-15m.

Acacia verticillata 'Prickly Moses'Variable height; generally rounded shrub. Phyllodes are dark green, spine-like, to 2 cm, in whorls around the stem. Pale

yellow flowers in short spikes. Yellow flowers. 5-10m. Suitable to clay soils.

Banksia marginata ' Silver Banksia'Medium shrub to 2 m tall. Leaf upper surface dark green with the lower surface white and hairy. Flowers pale yellow,

densely packed in cylindrical spikes up to 100 mm long. Suitable to clay soils.

Bauera rubioides ' Dog Rose' Scrambling shrub to 2 m high, stems extensively branched. Pink flowers. 0.3-1.5m.

Bursaria spinosa ' Prickly Box' Evergreen shrub <2 m tall, shrub or small tree <5 m tall or tree 5-10 m tall. Suitable to clay soils.

Bossiaea prostrata 'Creeping Bossiaea' Small (0.5m) prostrate shrub with yellow flowers.

Correa alba 'White Correa' Small shrub with grey foliage and white flowers. Grows to 1.5m.

Correa lawrencianaGrows to between 0.6- 9m in height, and has leaves with a shiny, dark-green upper surface. Flowers winter- spring,

typically yellow-green. Suitable to clay soils.

Daviesia latifolia ' Hop Bitter-pea' Shrub 1- 3 m with large leaves and clusters of yellow and brown pea flowers produced between Sept-Dec.

Daviesia ulicifolia Grows to 2m with yellow / red pea flowers.

Dillwynia cinerascens ' Parrot Pea' Compact shrub to 0.3-1.5m. Masses of yellow & red flowers (appearing orange)in spring.

Dillwynia glaberrima Small shrub ~1.5 metres high by 1m wide. Yellow / red flowers forming in spring.

Epacris impressa Shrub to 1-1.5m with stiff branches. Pink / red bell shaped flowers.

Hibbertia procumbens A prostrate and spreading shrub, with yellow flowers.

Leptospermum lanigerum ' Woolly Tea-Tree' Large, spreading or erect shrub, Flowers are white and appear in early summer. Suitable to clay soils.

Leptospermum scoparium Compact shrubup to 2 m tall. Leaves are variable in shape and size. White flowers, occasionally tinged with pink and

rarely red, 1 cm in diameter, occur in spring and early summer.

Leucopogon parviflorus 'Currant Bush' Erect shrub or small tree, 120–500 cm high; branchlets finely pubescent. White flowers. Suitable to clay soils.

Lomatia tinctori Small shrub to 2 m, spreading through suckers. Cream or white flowers in summer. Suitable to clay soils.

Olearia lirata 'Daisybush' Shrub to 4 m high with greyish-white branchlets and white flowers.

Oxylobium ellipticum 'Golden Rosemary' Erect to procumbent shrub to ≥ 2 m high. Yellow flowers spears. Suitable to clay soils.

Pimelea linifolia Small, erect shrub to 0.5-1.5m, with l inear leaves. Flowers usually white or very pale pink he species occurs on a range

of soils from sands to clays.

Tasmannia lanceolata 'Mountain Pepper'Tall evergreen shrub to small tree up to 10 m high. The trunk is straight, with many branches arising at acute angles.

Suitable to clay soils.

Tetratheca pilosa 'Hairy Pink Bells' Erect or spreading shrub with branches up to 1 m high, arising from stout root stock, mauve flowers.

Tall Shrubs / Small Trees (swamp) (no trees on landfill cap)

Acacia dealbata 'Si lver Wattle' Large shrub or medium‐sized tree with an erect main stem 6–15 m tall. Suitable to clay soils.

Acacia melanoxylon 'Blackwood' Medium-sized to tall tree. Suitable to clay soils.

Eucalyptus amygdalina ' Black Peppermint'

Tree to 30 m tall. Forming a l ignotuber. Bark rough on part or all of trunk and to base of large branches, finely fibrous

peppermint type, dark grey to grey-brown, smooth bark white to grey, or brownish, sometimes with ribbons of

decorticated bark in the upper branches. Suitable to clay soils.

Eucalyptus gunnii 'Cider Gum'

Small- to medium-sized evergreen tree. The bark is often persistent for several metres as a thin, grey stocking, or

shedding all over to leave a smooth, yellowish, patchy surface, weathering to white-, green- or pink-grey. Leaves are

stalked, ell iptical to ovate, to 8 cm long and 3 cm broad, concolorous, grey-green and thick. White flowers are produced

in midsummer. Grey / silver. Suitable to clay soils.

Eucalyptus obliqua ' Stringybark'

Tree to 90 m tall, or sometimes a mallee. Forming a l ignotuber. Bark rough to small branches or sometimes branches < 8

cm diameter smooth; rough bark stringy or fibrous, brown to grey-brown, longitudinally furrowed; smooth bark green or

grey. Suitable to clay soils.

Eucalyptus ovata ' Swamp Gum'Usually a medium-sized tree, but can grow up to 30 m tall. This tree is often found in swampy areas and in this

environment the tree is usually smaller in size. Suitable to clay soils.

Eucalytpus viminalis ' White Gum'Tree to 30 m high ; bark smooth or persistent on lower trunk, grey to grey-black, shortly fibrous, hard, platy, smooth

above, white, grey or yellow, shedding in long ribbons. Suitable to clay soils.

Melaleuca ericifolia 'Swamp Paperbark' Shrub or small tree to 8 m high with corky bark. Suitable to clay soils.

Melaleuca squarrosa Shrub or small tree to 12 m high with papery bark.

Nematolepis squamea 'Satinwood'Large shrub or small tree up to ~ 10m. The leaves are ell iptical , glossy green above and silvery below. Flowering

usually occurs in spring; flowers white. Suitable to clay soils.

Pomaderris apetala ' Dogwood'Widespread and abundant tree or large shrub species. One of the main components in the canopy of wet sclerophyll

forests. It has large leaves, which have irregular margins and irregularly lumpy surface. Suitable to clay soils.



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APPENDIX 10. Letters to Stakeholders

ATTACHED SEPARATELY



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APPENDIX 11. Certificate of Title

SEARCH DATE : 23-Jul-2014SEARCH TIME : 07.43 AM

DESCRIPTION OF LAND City of BURNIE Lot 1 on Plan 145841 Derivation : Part of 50000 acres granted to The Van Diemans Land Company Derived from A19301

SCHEDULE 1 BURNIE CITY COUNCIL

SCHEDULE 2 Reservations and conditions in the Crown Grant if any CONVEYANCE Made Subject to Exceptions And Reservations in favour of The V.D.L. Co.

UNREGISTERED DEALINGS AND NOTATIONS No unregistered dealings or other notations

SEARCH OF TORRENS TITLE

VOLUME

145841FOLIO

1

EDITION

1DATE OF ISSUE

22-Mar-2007

RESULT OF SEARCHRECORDER OF TITLES

Issued Pursuant to the Land Titles Act 1980

Department of Primary Industries, Parks, Water and Environment www.thelist.tas.gov.auPage 1 of 1

SEARCH DATE : 23-Jul-2014SEARCH TIME : 07.44 AM

DESCRIPTION OF LAND City of BURNIE Lot 2 on Sealed Plan 27996 Derivation : Part of Section 133, 50,000 Acres Granted to The Van Diemens Land Company Prior CT 4261/55

SCHEDULE 1 BURNIE CITY COUNCIL

SCHEDULE 2 Reservations and conditions in the Crown Grant if any SP 27996 EASEMENTS in Schedule of Easements CONVEYANCE Made Subject to Exceptions And Reservations in favour of The V.D.L. Co. created by a more fully set forth in Conveyance No. 14/322 14/322 CONVEYANCE Made Subject to Fencing Condition

UNREGISTERED DEALINGS AND NOTATIONS No unregistered dealings or other notations

SEARCH OF TORRENS TITLE

VOLUME

27996FOLIO

2

EDITION

1DATE OF ISSUE

16-May-1994

RESULT OF SEARCHRECORDER OF TITLES

Issued Pursuant to the Land Titles Act 1980

Department of Primary Industries, Parks, Water and Environment www.thelist.tas.gov.auPage 1 of 1



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APPENDIX 12. Chronology of the Waste Management Activities On Site

Stage 1 - Landfill Stages 1A, 1B and 1C were developed in the period from 1987 to 2004. The

Stage 1 landfill operations ceased in around 2004, with Stage 1A, 1B and 1C areas being

progressively capped between 2004 and 2005. A leachate rising main and second pump was

installed in late Feb 2009 to carry flows in excess of the main pump capacity (Pump 1) to the

Stage 2 Leachate Pond.

Stage 2 - Development of Stage 2A – Cell 1 and Cell 2 occurred in the period from 2004 to

2005. The life of Stage 2A was ~ 8.2 years, and was capped (interim cover) in March 2013.

Waste Facility - Construction of the Waste Transfer and Resource Recovery facility began in

April 2012 and was commissioned in Nov 2012. Pre-development it was the greenwaste

stockpile/chipping pad and runoff from the area went to stormwater to the west (minor) and

rest to the leachate pond from the eastern and southern areas.

A review of the BMWC landfill site was undertaken between 2006 and 2011, to assess the

long term needs of the Burnie Municipality, and the financial and environmental risks and

benefits of developing the remaining Stage 2B and Stage 2C areas. As a result of this review

it was proposed that a new Waste Transfer Station (WTS) be developed, and the Stage 2

landfill site would be closed and not further developed. Following the start of the WTS

operation in November 2012, the Stage 2A landfill site ceased to take waste. Since 2013 the

Stage 2A landfill Area has been capped with an interim final cover and is currently being

rehabilitated.

Pre 1987: Push pit

1987 to 2004: Development of Stages 1A, 1B and 1C

2004: Development of Stage 2A – Cell 1 and capping Stage 1B.

2005: Development of Stage 2A – Cell 2 and capping of Stage 1A & 1C.

2006: Development of Resource Recovery Area (Recycle Loop)

2012: Completion of Waste Transfer and Resource Recovery Facility and ceased

operation of Stage 2A landfill

2013: Interim cap of Stage 2A, rehabilitation.

2014: Initiation of Stage 1 leachate wetland treatment project



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APPENDIX 13. CFEV Assessment Component Report.

This document has been produced by The Department of Primary Industries, Parks, Water and Environment.

Questions concerning its content may be directed by email to [email protected]

The URL for this page is: http://wrt.tas.gov.au/wist/

Page 1 - CFEV Assessment Component Report

Important biophysical class (as predicted under pristine conditions) Biophysical Class Type: Tree assemblage Class Description: A mosaic of damp sclerophyll, wet eucalypt forest andrainforest extending from coastal north-western Tasmania, through Quamby to thenorth-eastern highlands in the north in the mid reaches of the Derwent and thelower Huon River in the south. Similar tree composition to assemblage 18. Species Composition: Acacia dealbata, Acacia melanoxylon, Allocasuarinalittoralis, Atherosperma moschatum, Banksia marginata, Bursaria spinosa,Eucalyptus amygdalina, Eucalyptus obliqua, Eucalyptus ovata Eucalyptus regnans,Eucalyptus viminalis, Exocarpos cupressiformis, Leptospermum lanigerum,Leptospermum scoparium var., Melaleuca squarrosa, Monotoca glauca, Notelaealigustrina, Nothofagus cunninghamii, Olearia argophylla, Phebalium squameum,Phyllocladus aspleniifolius, Pittosporum bicolor, Pomaderris apetala, Pomaderriselliptica, Pomaderris pilifera, Tasmannia lanceolata, Zieria arborescens Integrated Conservation Value Ranking: High Description: High Integrated Conservation Value (ICV). ICV integrates theRepresentative Conservation Value with known Special Values (eg. threatened andpriority species and communities, and priority sites). Special Values

River Report

ID: 179764

Easting: 405763

Northing: 5451938

Conservation Management Priority

Priority: Very High

Description: Very High Conservation Management Priority (CMP). The river sectionis part of a river cluster for which the conservation management is a very highpriority when development is proposed or occurs. This applies in the situationwhere further development occurs within the catchment which may contribute to achange in aquatic ecological condition or status. This CMP was derived byconsidering both its Integrated Conservation Value and land management security(by tenure).

Representative Conservation Value

Ranking: B

Description: B class Representative Conservation Value (RCV). This river sectionis within the second group of sites selected for rivers. Selection is based onrepresentativeness, rarity of classification units and naturalness.

This document has been produced by The Department of Primary Industries, Parks, Water and Environment.

Questions concerning its content may be directed by email to [email protected]

The URL for this page is: http://wrt.tas.gov.au/wist/

Page 2 - CFEV Assessment Component Report

Land Tenure Security Value: Low Description: This river section lies within a catchment that has predominantly lowsecurity of land tenure. There are no formal or mandatory restrictions in placeto ensure that the land within this catchment is managed to conserve or protectthe landscape from potential negative impacts. This includes areas of privateland, unallocated crown land, Commonwealth land, Hydro managed land and areasmanaged by other water authorities.

Name Scientific Name Type Status

burrowingcrayfish(Burnie)

Engaeusyabbimunna

ThreatenedFauna Species

Undifferentiated

platypus Ornithorynchusanatinus

Phylogenetically DistinctFauna Species

Non-outstanding



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APPENDIX 14. Risk Assessment Descriptors

Qualitative criteria for likelihood

Qualitative criteria for consequence

The level of risk caused by the previously identified hazard/hazardous events was determined

by combining likelihood and consequence in a matrix as presented below. Risk is calculated



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as the product of the likelihood of an event and the consequences of the event if it did occur:

RISK = LIKELIHOOD x CONSEQUENCE.

Risk matrix


APPENDIX 15. Risk Assessment Evaluation

RISK EVALUATION 1 - discharge of raw leachate

Potential Impact

Hazard / Event Caused By Results In Likelihood Consequence Comments Risk MitigationResidual

Risk

RARE MODERATE LOW ▪ Continual monitoring of leachate levels in

select bores

LOW

Rising leachate levels within

landfill causing saturation and

weakening of containment bund.

Consequence: Consequences of potential impacts to receptors are considered to be moderate , as they are reversible, short to

medium term since only a portion of stored leachate would likely reach the unnamed tributary, and the capacity of the unnamed

tributry (from site boundary to Three Mile Rd) is and as a result of downstream dilution.

▪ Dilution of leachate will occur within the unnamed tributary from continuous groundwater discharge and surface runoff from

neighbouring properties. This creek is already degraded- water quality is relatively poor and the creek is eroded, with limited

riparian vegetation and weeds infestation. Consequently, discharge of leachate in the event of sliding failure of the landfill

embankment is unlikely to cause major additional degradation of the creek ecosystem and/or landscape values.

▪ Confluence of unnamed tributary into Cooee Creek is approximately 4km downstream of landfill. The 'unnamed creek' is one

of many tributaries with a catchment area of only 5.2 km2 (or 5% of the Cooee Creek catchment). Consequently, discharge of

leachate to the unnamed tributary is not expected to cause major impacts on Cooee Creek , key protected species (crayfish),

livestock or recreational users.

RARE MINOR LOW

Exposed solid waste and ponding of

raw leachate on site (impacts on on-

site workers). Potential mosquito risk.

RARE INSIGNIFICANT ▪ Only a very small number of council workers are present on-site. Risk management procedures already exist on site. LOW ▪ Existing risk management plan will be

updated to include responses to incidences

potentially connected with the treatment

system. This will include incidence

response for any on site ponding and

mosquito management. Appropriate training

of all on site personnel will be undertaken.

LOW

2 Raw leachate pump failure Power outage (weather, fire,

explosion etc)

Raw leachate overflow from pump

chamber and discharge into the

unnamed creek

UNLIKELY MINOR LOW ▪ Implement apprpriate equipment checks

and maintenance regimes.

LOW

Pump clogging due to lack of /

poor maintenance

Consequence: The consequence is considered to be minor as only a relatively small volume of raw leachate would potentially

reach the creek (most would likely infiltrate) . The flows that potentially do reach the creek would be further diluted which would

significantly reduce the severity of any environmental impact as discussed under Risk 1 above.

Ponding of raw leachate on site UNLIKELY INSIGNIFICANT As explained for Risk 1, only a very small number of Council workers are present on-site. Risk management procedures already

exist on site and these will be updated to reflect the risks associated with the leachate treatment wetland.

LOW LOW

1 Sliding failure of landfill

containment bund

leading to release of: 1) raw leachate

stored within the landfill cell, 2) raw

and partially treated leachate within

the wetland or 3) solid waste to

ajacent properties.

Wetland mass/location

compromises structural integrity

of landfill bund.

▪ Deterioration of creek water quality, major mass loads of pollutants, major sediment loads, altered creek hydrology.

POTENTIAL RISKS ASSOCIATED WITH THE RELEASE OF RAW LEACHATE AND/OR SOLID WASTE TO CREEK

▪ Negative health impacts on secondary recreational users of the Creek via high level of pathogenic microorganisms, elevated concentrations of metals and organic pollutants

▪ Potential risk of vectors (bird & mosquitoes) infecting livestock and humans with pathogens

Ecological

▪ General public

Human

LOW

Key receptors

▪ Unnamed tributary / Cooee Creek - water quality, ecosystem and landscape

values.

▪ Creek biota incl potential lsited species (Burnie Burrowing crayfish)

▪ Downstream creek water users (livestock, irrigation)

▪ Negative impacts on crayfish habitat in Cooee Creek as a result of poor WQ and increased sedimentation.

▪ Recreational users, irrigation users

▪ On site workers

▪ The Stage 1 landfill potentially has up to 100ML of stored leachate/groundwater below the cap while the wetland contains ~ 9ML

of partially treated leachate in total. In the event of landfill sliding failure, only the portion of raw and treated leachate contained

above the natural valley slope and subject to the lateral failure extent could be 'released' (assuming 1 ha of affected area this

would be ~0.5 ML of wetland partially treated leachate and ~5ML of stored raw leachate). The release will not be instantaneous

(it will be seep from the solid waste and clays) and will mainly be contained on site. Any seepage or leachate overflows will be

captured frst in the phytoremediation swale, which directs leachate in excess of the swale capacity to the emergency storage

where it can be pumped direct to sewer. Any flows not captured could discharge into the creek however there is significant

capacity (~2.5 ML storage from unnamed tributary to the Three Mile Rd culvert, Entura 2011), and there would be more than

sufficient time to temporarily dam this section of the creek and pump to waste.

Likelihood: It is assumed that issues with pump failure may occur from time to time due to power failure or inappropriate pump

maintenance, however there are sufficient contingencies in place to limit discharge to the creek. This includes a duty and standby

pump with generator back-up, gravity emergency storage system (6-10 hrs) which should enable adequate response time, and a

connection to sewer if this storage reaches capacity. A breach could only occur if the fleachate flow rates exceeded sewer

capacity (e.g. extreme rain events). Note, the proposed treatment system will not increase the inherent risk profile (will be reduced

due to gravitational emergency storage and sewer connection structures).

▪ Degradation of ecosystem and landscape values within the Unnamed Creek and/or Cooee Creek; erosion, weed infestation, .

▪ Potentially negative health impacts on livestock, poor WQ prohibits pasture irrigation

▪ Potential direct exposure of on-site workers to contaminants in exposed solid waste and/or raw leachate

▪ The site topography and available areas indicate that solid waste would be predominantly contained within the site. Given the

very localised nature of potential environmental impacts (immediate neighbouring properties only) the consequence was

considered to be minor.

Likelihood: Based on the Geotechnical Study , the likelihood of sliding failure of the landfill containment bund is very rare given

the Factor of Safety (FOS) for a non-leaking wetland is higher than 4, while the FOS for the present landfill containment bund is

assessed to be at least 4.5 (recommended FOS is 1.5). Based on the calculated FOS, placing the wetlands at least 10m from

the crest will not adversely impact on the stability of the containment bund wall.

Solid landfill waste spills to adjacent

propert/ies

Raw leachate discharging to the

unnamed tributary and possibly Cooee

Creek

Further erosion of landfill embankment

due to water spillages potentially

creating channels over embankment


RISK EVALUATION 2 - discharge of partially treated leachate

Potential Impact

Hazard / Event Causes Result Likelihood Consequence Comments Risk MitigationResidual

Risk

1 Leakage of the wetland treatment

system

UNLIKELY MINOR Likelihood: It is considered unlikely that wetland seepage will not cause impacts given the following: LOW LOW

▪ Any localised seepage through the wetland liner and leachate migration through landfill would be retarded by the existing

underlying GCM or compacted clay liner.

Impairment of wetland performance due

to need for repairs.

▪ Wetland liners (GCL and HDPE) can accommodate large settlement. Liner (HDPE) accommodates a tensile strain of 1-10%,

hence can tolerate differential settlements of at least 450mm without breakage. Bunds have sufficient freeboard t accomodate

settlement.

Consequence: The consequence of any potential impacts are considered minor given the following:

▪ Seepage rate through compacted landfill clay cap is about 1% of typical daily flow rate from groundwater drainage system, so

additional flows due to seepage would be minimal . Due to these low flows, lateral seepage would be mostly contained on site

as a wet spot around the wetland. All ponded leachate would be partially treated further reducing the severity of any impacts to

on-site workers.

▪ System has a phytoremediation swale along the northern embankment which intercepts and treats seepage events if they

occur.

▪ Wetland cells can be individually isolated/bypassed for repair if required, without impacting performance of rest of wetland

▪ Any localised breakages in the wetland liner &/or bund settlements are easily repaired.

Likelihood: It is considered rare for this event to occur because settlement is unlikely to cause more than a localised effect and

because wetland volumes are small and if spill over the landfill banks will be contained within the phytoremediation swale and

emergency storage.

LOW ▪ Annual surveys of wetland bunds to track

changes.

LOW

Consequence: Considered to be minor since:

Ponding of the leachate on site,

potential direct exposure of on site

workers and potential mosquito issues.

▪ Released leachate will be partially (e.g. ammonia) or fully (metals and organics) treated for key pollutants.

▪ Spills will be intercepted by the phytoremediation swale along the northern embankment with excess captured within the

infiltration wetland.

▪ Treated leachate that does discharge into the unnamed tributary will be diluted as a result of continuous groundwater and

surface water discharge to creek.

▪ Any on site ponding of treated leachate will be localised, short term and appropriately managed under normal management

regimes on site. Given the relatively good quality of treated leachate , any direct exposure of on site workers is not expected to

cause any significant issues.


b) Lateral seepage through the

wetland bund onto the clay capping.


2 Failure of wetland embankments Differential settlement of landfill

leading to localised subsidence

of wetland cell bunds and

overtopping of leachate.

▪ General public

▪ On site workers

Differential settlement of landfill

cap potentially impacting liner

integrity and/or overtopping from

wetland bunds. a) Seepage through the clay liner

base into the existing clay capping

POTENTIAL RISKS ASSOCIATED WITH THE RELEASE OF PARTIALLY AND/OR INADEQUATELY TREATED LEACHATE TO CREEK

Key receptors


values. ▪ Deterioration of creek water quality, increase in pollutants mass loading, sediment loads, altered creek hydrology.

Ecological

▪ Negative impacts on crayfish population in Cooee Creek as a result of poor WQ and increased sedimentation.

▪ Downstream creek water users (livestock, irrigation) ▪Impacts on the ecosystem and landscape values within the Unnamed Creek and/or Cooee Creek; erosion.

Human ▪ Potentially negative health impacts of minor WQ deterioration on livestock and pasture irrigation


▪ Potential direct exposure of on-site workers to contaminants in partially treated leachate

▪ Negative health impacts on secondary recreational users of the Creek via increased level of pathogenic microorganisms, elevated concentrations of metals and organic pollutants

Lateral seepage through landfill

containment bund resulting in

discharge of leachate to the

environment

▪ Existing risk management procedures will

be amended to include management of this

risk.

MINOR

▪ Only a small volume of leachate will potentially be discharged to the creek. Wetland volumetric capacity is approximately 9ML

, and in a case of embankment failure only a very small portion of this volume (depending on the scale of failure across the

system) will be released over the containment bund (likely <1 ML)

Partially treated leachate being

discharged directly over landfill

containment bund and disharging to

the creek.▪ Existing risk management plan will be

updated to include responses to incidences

potentially connected with the treatment

system. This will include incidence

response for any on site ponding and

mosquito management. Appropriate training

of all on site personnel will be undertaken.

RARE


RISK EVALUATION 2 - discharge of partially treated leachate cont.

Potential Impact


Risk

1. Not built to design Quality of the final effluent non-

compliant with set performance

targets.

POSSIBLE MODERATE ▪ Any deviation to design will be corrected before practical completion and commissioning of the system. MEDIUM LOW

Discharge of effluent of inadequate

quality to the creek.

Ponding of partially treated effluent on

site.

▪ Performance monitoring will be conducted

through the system to enable adaptive

response and to trigger emergency

recirculation or disposal to sewer

2. Cold weather (biological

performance compromised)

UNLIKELY MINOR ▪ System has been conservatively designed and modelled using site specific temperature data and conservative removal

coefficients for various pollutants. Many contingencies are included within the system design to accommodate reduced

performance without impacting on the quality of the final effluent.

LOW LOW

3. Change in leachate chemistry

beyond design ranges for

prolonged period of time

UNLIKELY MINOR ▪ Leachate is already in maturation phase so large fluctutaions extremely unlikely. Conservative wetland sizing has been

considered in the design.

▪ Wetland design is based on 5 years of site specific leachate quality data which shows stable conditions and on well

established leachate treatment wetland performance data (international literature).

LOW LOW

4. Contaminated via pesticides,

herbicides etc (weed

management - neighbouring

farms) that can cause

plant/microbial death, and

consequently reduced system

performance

UNLIKELY MINOR ▪ Wetlands are known to deal well with and degrade most of the currently used pesticides (Kadlec & Wallace, 2008).

Herbicide damage likely to be minor - wetland plants have high resilience and recover well from spray drift.

LOW LOW

5. Poor maintenance LIKELY MODERATE ▪ Wetlands are robust systems. Each wetland cells can be isolated/ bypassed for repair if needed, without impacting others. MEDIUM ▪ Appropriate maintenance budget will be

include in OPEX for the life of the wetland.

LOW

▪ Performance monitoring/maintenance

activities will be conducted through the

system to enable adaptive response and to

trigger emergency recirculation or disposal

to sewer.

▪ Appropriate training of staff responsible for

system maintenance will be undertaken,

including preparation of user-friendly

management and maintenance plans.

4 Extreme, prolonged rainfall

events

Discharge of inadequately treated

leachate to the Creek.

UNLIKELY MINOR Likelihood: It is considered unlikely that this event will occur and cause impact on key receptors given the following: LOW LOW

▪ Conservative sizing of system to accommodate the 90 percentile flows in the treatment process, ability to contain and enable

treatment via recirculation of up to 1500kL/day (20-year event peak flows), and ability to discharge to sewer.

▪ Project improves the current risk profile by separation of stormwater and leachate.

▪ Treatment system is operated on a maximum inflow rate ensurig consistency of treatment performance - flows in excess of this

are contained in the emergency overflow tank flow and in worst case discharged to sewer.

Consequence: Given all the safeguards in place, if this event does occur it would involve a discharge of only very small volumes

of partially treated leachate from the system. This is considered to potentially create only minor issues due to a major dilution

within the unnamed tributary (which would be especially high in those prolonged high rain event) and the fact that effects would

not be long term.

3 Failure or impeded performance

of wetland compromising the quality

of leachate outflow



▪ General public

▪ On site workers


Key receptors

Volumes of groundwater-leachate

cannot be accommodated in the

collection/conveyance

network, or treatment system.



Ecological







▪ The proposed system includes two safe guards to prevent discharge of inadequately treated final effluent: a) A recirculation line

that ensures non-compliant effluent is recycled through the treatment train before discharge; b) A contingency connection to

sewer.

▪ Design approach based on the sequential treatment train, multiple treatment cells, and conservative removal coefficients ensure

that any temporary failure of individual cells to perform properly will be compensated by the rest of the system without jeopardising

the overall system performance.

▪ Performance monitoring will be conducted

through the system to enable adaptive

response and to trigger emergency

recirculation or disposal to sewer

▪ Wetland designer will be retained during

construction / contract management

phases (e.g. superintendency) to ensure

that all system components and safeguard

management elements are constructed as

per design.


RISK EVALUATION 2 - discharge of partially treated leachate cont.

Potential Impact


Risk

5 RARE MINOR Likelihood: The hydrological study (Tasman Geotechnics Aug 2015) indicated that a rain event causing erosion and landslide

would be extremely rare (>1,000 years). While inappropriate irrigation activities could somewhat impact on this, the event would

still be classified as rare.

LOW LOW

Consequence: The consequence of this event is considered minor given the multiple contingencies in place and that this would

be localised to only a portion of the wetland system.

6 Vandalism 1. Exposed pipework connecting and

within wetland cells destroyed resulting

in leachate leakage.

UNLIKELY MINOR ▪ Most pipes will be buried and hence will not be damaged by fire. Exposed pipes if destroyed will not cause wetland operation to

cease. Any leakage (or any damage) can be easily and quickly localised and cells by passed. Site is fenced with access controls

in place to prevent unauthorside access.

LOW Unauthorised access control to wetland area LOW

Lightening 2. Plants burnt impacting system

performance.

POSSIBLE INSIGNIFICANT ▪ Most wetland plants are resistant to fire and will regrow rapidly after fire. Burning will not impact on the key removal

mechanisms by rhizosphere/soil microorganisms. Plant regrowth will enhance pollutant removal (a high rate of nutrient uptake

occurs after burning).

LOW Install lightening / short circuiting/ electrical

protection to pumps.

LOW

Electrical faults 3.Wetland bund liner melted causing

leachate leakage.

UNLIKELY MINOR ▪ Impervious HDPE liners will be buried and hence will not be exposed to above ground fire. LOW LOW

Fire within wetland system causing

physical damage to the system and

its components



▪ General public

▪ On site workers


Key receptors



Ecological







Flooding from adjacent property

upgradient (east) of landfill land and

material transport directly onto the

wetlands system.

Extreme weather and flooding

exacerbated by excessive

irrigation, soil creep, and farming

activities.

Physical damage of the treatment

system, compromised structures, and

reduced treatment performance

resulting in discharge of effluent of

inadequate quality.


RISK EVALUATION 3 - normal operation

Potential Impact

Hazard / Event Causes Result Likelihood Consequence Comments Risk Mitigation MeasuresResidual

Risk

1 Normal operation of the proposed

on site treatment system

UNLIKELY INSIGNIFICANT It is considered unlikely that discharge of appropriately treated effluent from the treatment wetland will cause any significant

detrimental impacts on the receiving creek(s) and downstream users given the following:

LOW LOW

▪ Very high quality of treated effluent: Final effluent will be treated to a high standard prior to any discharge - water quality targets

for key contaminants of concern are in line with EPA Draft Water Quality Objectives for Cooee Creek and ANZECC (2000)

Aquatic Ecosystems - 95% level of protection, ANZECC (2000) recreational - secondary contact & ANZECC(2000) Primary

industry - short term irrigation and livestock drinking.

▪ Direct discharge of treated leachate (and mass loading to the creek) will be minimised through maximising on-site infiltration

within the last system’s cell (Cell 5 – Infiltration Wetland / Wet Forest). It is expected that most of the treated leachate ( 91% of

summer-autumn flows, and 78% of winter-spring flows) will discharge indirectly via subsurface infiltration to the Creek, utilising

land along the northern embankment within the landfill site boundary. Only during high rainfall events, flows in excess of the

infiltration capacity of the Infiltration Wetland would overflow directly to the Creek via a weir/cascade.

▪ Relatively poor condition of the unnamed tributary and Cooee Creek due to historic and current impacts from the landfill and

adjacent rural properties and residential developments. The unnamed tributary (for up to 3 km downstream of the landfill site) is

considered to be degraded, with relatively poor water quality and evidence of erosion, high weed extent, stock impacts and

limited riparian vegetation. In terms of water quality the Creek system is classed as ANZECC Ecosystem Condition 2: Slightly to

moderately disturbed systems and Ecosystem Condition 3: Highly disturbed system. based on the ANZECC (2000).

Consequently, discharge of highly treated effluent that is of much better quality than either of the creeks is unlikely to jeopardise

the quality of these surface waters. In terms of pollutant load, calculated annual loads of pollutants likely to be directly discharged

to the creek in storm events are relatively low - TSS<4 kg, TN, 17 kg, TP , 0.2 kg, Fe, 8 kg, Mn,5.4 kg. These mass loads are

considered small overall and lower than what probably occurs typically at the site, both as a result of discharges directly to the

Creek when flows exceed the 20 year ARI capacity of the pipe, pump and pit infrastructure, and also due to short duration storm

events which exceed the pump capacity and result in overflows from the MH1 chamber to the Creek. The potential impacts of

these pollutant loads are considered even less significant considering continual inputs from neighbouring properties.

▪ Discharge to the creek would help re-establish pre-development flows, since at present a substantial proportion of leachate

and groundwater (entrained within the leachate) flows is diverted to sewer. Hence, increasing the environmental flows, particularly

given climate predictions of declining rainfall, would be a beneficial outcome of the proposed treatment system.

▪ Unnamed creek is not used for recreation and this is unlikely to change in the future given declining water levels and many

alternative locations.

▪ Creek biota incl potential lsited species (Burnie Burrowing crayfish) ▪ Negative impacts on crayfish population in Cooee Creek as a result of lower WQ and increased sedimentation.

▪ Downstream creek water users (livestock, irrigation)

POTENTIAL RISKS ASSOCIATED WITH THE RELEASE OF FULLY TREATED LEACHATE TO THE CREEK

Key receptors

Ecological


values. ▪ Deterioration of creek water quality, increase in pollutant mass loadings, creek sedimentation , changes in creek hydrology.

▪ Degradation of ecosystem and landscape values within the Unnamed Creek and/or Cooee Creek; erosion, weed infestation, .

Discharge of treated effluent causing

1) degradation of the unnamed tributary

and Cooee Creek (WQ, ecosystem &

landscape values), and/or 2. negative

impacts on creek recreational users

and/or other downstream users

(irrigation, livestock drinking)

Human ▪ Potentially negative health impacts on livestock and negative impacts on pasture irrigation

▪ Recreational users, irrigation users ▪ Negative health impacts on secondary recreational users of the Creek via high level of pathogenic microorganisms, elevated concentrations of metals and organic pollutants

▪ General public ▪ Potential risk of vectors (bird & mosquitoes) infecting livestock and humans with pathogens

Discharge of treated effluent from the

on site treatment wetland compliant

with current discharge standards

(ANZECC etc)

▪ On site workers ▪ Potential direct exposure of on-site workers to treated leachate.

development proposal & environmental management … city council... · 2015-11-27 · 6.3.15...

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