expert witness report: water cycle impact assessment of

Expert Witness Report: Water Cycle Impact Assessment of Changing to Biomass Fuel at Redbank Power Station
Report Prepared for: Verdant Earth Technologies Ltd under instructions from Mr Ross Fox, Fishburn Watson O’Brien Lawyers.
21 October, 2021 Project No. 276
Prepared by: Sustainability Workshop Ltd
Head Office Suite 1/124 Station Street Blackheath NSW 2785 [email protected] M: 0468 423 299 www.sustainabilityworkshop.com
Document Information Project title Expert Witness Report – Water Cycle Impact Assessment of Changing
to Biomass Fuel at Redbank Power Station
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Expert Witness Report: Water Cycle Impact Assessment of Changing to Biomass Fuel at Redbank Power Station
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.EXECUTIVE SUMMARY 1. The likelihood of both the chronic (cumulative) and acute (toxic) aquatic
ecosystem impacts from the proposed development has been assessed.
2. Based on a 40 year, 6 minute time step, water balance model of the site, if
recommendations in this report are adopted, the site is predicted to discharge
less frequently than once every 10 years.
3. This occurs because the power station consumes 3,208 ML/a of raw water,
including any site generated stormwater, while producing 28.7 ML/a of runoff.
4. The volume of stormwater runoff, in a typical year, is less than 0.1% of the total
demand for raw water.
5. 99.7% of stormwater runoff is reused on the site and is lost as steam.
6. Because predicted off-site discharge would occur less than once every 10 years,
chronic aquatic ecosystem impacts will not occur.
7. During any rare discharge from the site, which is predicted to occur only during
extreme events such as the Pasha Bulker storm event, there would be a 250-fold
level of dilution of off-site discharges as they blend with catchment flows.
8. Discharge from the site is predicted to occur less than 0.0016% of the time.
9. During extreme flood events, ambient or environmental water quality is
typically extremely poor. Especially so in the Dights Creek catchment which has
been highly disturbed by both mining and agriculture.
10. On this basis, it is highly unlikely that there will be any acute aquatic ecosystem
impacts.
11. I therefore conclude that:
a. The proposal would comply with applicable guidelines being the NSW State
Government’s Organics and Composting Guidelines which set a discharge
frequency for the site, from any leachate dam, of less than 1 in 10 years.
b. That the proposal is not likely to have any adverse aquatic ecosystem
impacts.
c. The proposal would be likely to comply with typical licence limits for an
organics or composting facility.
2.0 INVESTIGATION ................................................................. 3
5.1. Existing water cycle management at Redbank Power station ...................... 8
5.1.1. Raw Water Demand ..................................................................................... 8
5.1.2. Raw Water Pond Water Level and Spill Management .................................. 9
5.2. Stockpile Area .............................................................................................. 9
5.3. Dights Creek ............................................................................................... 10
5.5. Existing Water Quality Controls ..................................................................13
5.5.1. Drive in Sediment Traps ..............................................................................13
5.5.2. Water Quality Pond .................................................................................... 15
5.5.3. Concrete Channel and Screen .................................................................... 16
5.5.4. Raw Water Pond .......................................................................................... 17
5.6. On-Site Maintenance ................................................................................. 19
6.0 PROPOSED DEVELOPMENT ............................................. 20
6.2. Proposed Woody Biomass Fuel .................................................................. 20
7.0 PREDICTING RUNOFF QUANTITY ..................................... 22
7.1. A predictive water balance model .............................................................. 22
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7.3. Modelled Land Uses – hydrologic parameters ............................................ 26
7.4. Modelled land uses adopted EMCs ............................................................. 27
7.5. Modelling the water quality pond and raw water pond .............................. 28
8.0 RESULTS & PREDICTED COMPLIANCE .............................. 30
8.1. Frequency of discharge .............................................................................. 30
8.2. Water quality impacts ................................................................................ 30
8.3. Water quality discharge during extreme events ..........................................31
8.4. Predicted compliance with applicable development standards .................. 32
9.0 MODELLING THE POST DEVELOPMENT SITE .................... 33
9.1. What are the differences between pre and post development models? ..... 33
9.2. Predicted maximum indicator pollutant concentrations ............................ 34
10.0 WATER POLLUTION RISK ................................................. 35
10.1. Risk of off-site water quality impacts ......................................................... 35
10.2. Acute risk of water pollution ....................................................................... 35
11.0 RECOMMENDATIONS....................................................... 36
Sustainability Workshop
1.1. Background 12. Sustainability Workshop was engaged by Verdant Earth Technologies Ltd through
Fishburn Watson O’Brien (FWO) Lawyers to prepare an expert report in relation to a
class 1 appeal which was filed in the Land and Environment Court on 7th May 2021,
appealing against deemed refusal of an application to modify the development
consent of the Redbank Power Station.
13. Verdant Earth Technologies Ltd is the development proponent.
14. FWO Lawyers have given instructions to Mark Liebman, the author of this report, to
provide an expert opinion with respect to the predicted ecological impacts of the
proposed development on receiving waters. The key question being “what are the
likely aquatic ecosystem impacts of the proposal and what, if any, modifications are
required to the existing water cycle management at Redbank Power Station to
mitigate any additional impacts”.
15. It is noted that previous information was provided by RGH Consulting. It is
acknowledged that the previous report did not contain sufficient information to
enable Council and the EPA to determine the application with respect to the potential
to cause any off-site aquatic ecosystem impacts.
16. Sustainability Workshop Ltd has since been commissioned to assess the impacts of
the proposal on water quality. It is requested that previous information provided by
RGH be disregarded.
17. A Curriculum Vitae is included in Appendix A of this report.
18. The opinion in this report is based on over 24 years professional civil and
environmental engineering experience with a specialist focus on stormwater quality
management, water policy, pollution prevention and eco-hydrology.
1.2. Instructions 19. FWO Lawyers have given instructions to Mark Liebman, the author of this report, to
provide his opinion with respect to the potential environmental impacts of the
proposed development on receiving waters and to identify any changes to the existing
water cycle management operations on the site to mitigate against any adverse
impacts.
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1.3. Expert Witness Code of Conduct 21. I have read the Expert Witness Code of Conduct, and agree to be bound by it, at
schedule 7 of the Uniform Civil Procedure Rules 2005 (NSW) (the “Code of Conduct”)
and confirm that to the best of my knowledge this report has been prepared in
accordance with the Expert Witness Code of Conduct.
22. At this point I have considered all information available and enquired with respect to
the development proposal. I have requested information from Verdant Earth
Technologies Ltd and inspected the site. I have prepared a revised water balance
model for the proposed development, and I am able to make an independent
determination on the potential of the proposal to cause impacts on the receiving
waters.
2.0 INVESTIGATION
2.1. Site Investigation 23. On the 6th of October, 2021, Mark Liebman, CPEng, MIEAust, attended the Redbank
Power Station with Mr Costa Tsiolkas, General Manager, and Mr Owen Hassall,
Recommissioning and Engineering Manager.
24. Following the site visit supplementary information has been provided.
25. Site observations are reflected in Figure 1.
26. During the site investigation the following was observed:
a. The proposed stockpile area including existing subsoil drainage beneath it.
Subsoil drains were located at regular intervals underneath the stockpile area
and drain directly into a concrete lined channel. Subsoil drains are embedded
in free draining gravel.
b. The capacity to provide a 2m wide grassed vegetated buffer strip between
the stockpile truck access route and the edge of a concrete lined channel
which collects runoff from the stockpile area.
c. A concrete lined channel which would intercept runoff from the stockpile
area and subsoil drains under the stockpile and direct it to a sediment and oil
trap and then into a water quality pond.
d. The water quality pond was observed to be in healthy condition, with an
internal baffle to ensure no short circuiting of flows.
e. The pond had both emergent and submerged vegetation. The pond had
many of the attributes of a well maintained and healthy constructed wetland.
f. Additional drainage features including surface drainage and a piped network
that would divert runoff from the boiler island to the water quality pond –
also after first being treated in a sediment and oil trap.
g. Numerous bunded areas on the site where chemicals are stored and where
wastewater is treated. Bunds are used to manage acute toxicity risks
emanating from an accidental spill of a chemical. I observed all bunded areas
where clean, visibly free of pollution and well maintained with all bunds
appearing to maintain their structural and liquid retention integrity.
h. The lower, more northern part of the site which includes an administration
building, wastewater treatment infrastructure, water cooling structure, joins
stormwater runoff from the water quality pond and is conveyed in a concrete
channel to a welded plastic (HDPE) lined, raw water storage pond.
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i. There was an additional screen and oil baffle and water quality monitoring
point upstream of the entry into the raw water storage. I observed the raw
water storage to be about 6 to 7m deep by visual assessment. The raw water
storage was close to empty at the time.
j. The wastewater storage, being much larger to the east of the raw water
storage. It was also lined with a welded waterproof plastic liner.
k. The mechanism by which the raw water storage overflows or spills – this is by
way of a weir close to the site entry gate. The raw water storage overflows
into a swale which heads west and then joins Dights Creek.
l. Dights Creek has been diverted around the operational area of the site and
this was approved under the previous development application. Where the
creek was diverted it remains in a stable well vegetated state, free from
visible erosion and without obvious weed infestation.
m. I observed Dights Creek downstream of the site and just after it flows under
Long Point Road. The creek appears to be in a well vegetated, stable state
with numerous riparian trees and grasses.
60 ML wastewater storage
Stockpile area
Concrete Channel with subsoil drains flows in from stockpile area
Concrete Channel collecting runoff from area south of admin building
Admin building
Water pumped into the raw storage from Hunter River
Dights Creek
Cooling Tower
3.0 DOCUMENTS 27. I have relied on the following documents:
a) Expert Witness Code of Conduct.
b) Amended Statement of Facts and Contentions from Council dated 15 September
2021.
c) Redbank Power Station – Description of Proposed Modifications for Conversation to
Fire Biomass Fuels, B&PPS Report C12198-01, dated 20 October 2021.
d) Operational Traffic Management Plan (Redbank Power Station), Ason Group, dated
20 October 2021.
e) Transport Assessment (Redbank Power Station), Ason Group dated 20 October
2021.
f) Site plan by Alstom numbered as ‘80034-001-M-GA-000-5001 A0’.
g) Site plan by Alstom numbered and ‘80034-025-M-GA-000-9176 A1’.
h) Concept study by B&PPS titled ‘Biomass Handling Plant Concept Study B&PPS
Report (C12156-03)’, by B&PPS, Rev 4 dated 18 June 2021.
i) Redbank QA/QC Supply Chain and Material Handling dated 30 July 2021.
j) Water Treatment Plant Process Flow Balance Diagram prepared by ABB and US
Filters numbered as 80034-007-P-P1-063-8551.
k) 128 MW Powerplant, Bulk Earthworks and Drainage Sheet 1 of 2, by ABB, Drawing
number 8034-002-C-BP-119-6012 Revision 3 Reissued for Construction.
l) Hunter River Salinity Trading Scheme Redbank Power Station Discharge Volumes
and Salt Loads from 2001 to 2015/2016 provided by the HSE Manager.
4.0 ADDITIONAL INFORMATION REQUIRED
28. I have sufficient information with which to make an informed decision with respect to
the potential aquatic ecosystem impacts of the proposed application.
5.1. Existing water cycle management at Redbank Power station
5.1.1. Raw Water Demand 29. A water balance for the site has been included in Appendix C.
30. Raw water is hereafter defined as either water extracted from the Hunter River or
stormwater runoff from the power station site which drains into the raw water
storage pond shown in Figure 1.
31. Broadly speaking, the power station combusts fuel to generate heat. The heat is
used to boil water and generate steam which drives turbines to create electricity.
32. A significant volume of raw water is used to cool the steam to condense it. The
steam is ultra-high-quality demineralised water, and this form of water is simply
recycled as it is expensive to make demineralised water.
33. Raw water is used to cool the steam once it has passed through the turbine without
coming into direct contact with the steam via a heat exchanger. As a result, a
significant volume of raw water is lost, through evaporation in the process as it is
used to cool and condense the steam.
34. Discussions with the General Manager and site engineers and consistent with the
water balance for the site (Appendix C) the mean demand for raw water is 366.3 kL
per hour to cool the steam. The 90th percentile demand increases 368.1 kL/hour, and
the maximum demand is 380.2 kL/hour. Approximately 39.7 kL/hour is returned to
the raw pond giving a mean hourly withdrawal rate of 401.7 kL/hour from the pond.
Refer to Point 3 on the diagram in Appendix C.
35. We note the water balance in Appendix C shows the inclusion of ash slurry
transportation water into the raw water pond. It is understood that this does not
occur.
36. As a base load power station, it is intended to operate 24-hours, 365 days per year.
Planned shutdowns to carry out maintenance would occur periodically.
37. It is therefore appropriate to extrapolate mean hourly water consumption to derive a
daily or yearly demand. Daily demand for raw water is 24 X 366.3 = 8,791.2kl/day or
8.791 ML/day. Annual demand is 3,200 ML/year.
38. Verdant Earth Technologies Ltd has a water access licence to extract up to 3,300
ML/year of raw water from the Hunter River.
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39. The raw water storage pond has a volume of 6,000 cubic metres which equates to
6ML.
40. The raw water storage is filled with water extracted from the Hunter River and is
operated so that there is always a nominal level of 4ML of raw water available in the
storage.
5.1.2. Raw Water Pond Water Level and Spill Management
41. The site is operated so that 4 ML metres of raw water is available to provide
nominally 12 hours water supply to cover the risk of a power outage or failure at the
river side pumps.
42. The raw water storage is then operated with 2 ML headroom. Headroom is defined
as air space above the operating water level to temporarily store stormwater runoff
from the site to prevent an off-site discharge.
43. A safe work Procedure (SWP-10-0004) has been adopted which describes this
operational procedure. It is broadly summarised as follows:
44. The site operators continually review Bureau of Meteorology Forecasts, and if rain is
predicted they prepare to turn off the pumps which they can do remotely from the
power station site.
45. Once rain commences and stormwater runoff from the site starts entering the pond
the pumps are turned off. Flow entering the pond is monitored both visually and
remotely from a water level and conductivity gauge installed at the entry point to
the pond.
46. Site operators then monitor the event and pumping recommences once the storm
event is over and flow and water level in the raw water pond are returned to the 4ML
typical operating level.
47. In the event of a spill from the pond, site operators are required to collect water
quality samples hourly and get them tested to comply with the licence conditions on
the site.
5.2. Stockpile Area 48. The existing stockpile area is well drained and underlain by subsoil drainage lines
which discharge directly to the drainage channel. This will prevent any pooling of
leachate at the base of the stockpile and protect groundwater.
49. The area available for storage is about 0.57 hectares and is bound to the south and
west by an earth mound and to the north by the concrete channel.
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50. The stockpile area is limited by the reach of two telehandlers which pile the fuel after
unloading from trucks.
51. The stockpile area is serviced by several spray nozzles which are used for dust
suppression across the area. Water is drawn from the water quality pond and
pumped into a holding tank prior to spraying.
52. Currently, there is a small volume of coal stored in this area.
53. During operations, the area is serviced by two large conveyors. One would be used
to accept coal onto the site and the other is used to feed coal into the power station
process.
54. There would be some minor modifications to the fuel feed process which do not
have any predicted water quality impacts. This includes minor modifications to the
conveyor system to feed biomass into the power plant.
5.3. Dights Creek 55. Redbank Power Station discharges into Dights Creek. The creek appears to be in a
stable and well vegetated state downstream of the point of discharge. The previous
diversion works have successfully created a modified but otherwise natural and
stable riparian environment.
56. The upstream catchment has been severely modified by mining as shown in Figure
2. Approximately two thirds of the catchment was disconnected due to mining and
approximately the last 1/6th of the catchment is fully cleared for farming. Any
remnant aquatic ecosystems within this catchment would be highly disturbed and
severely modified by past development.
5.4. Wastewater Discharge to the Hunter River
57. The Redbank site has a licence condition requiring it to report activities arising from
its participation in the Hunter River Salinity Trading Scheme.
58. The scheme objectives are to ensure salinity levels in the river are reduced at the
lowest community cost and the scheme is open to any participant who becomes a
creditor.
59. The source of salt produced in this industrial process originates from salty water
extracted from the river.
60. Wastewater is generated at a rate of 6.6 kL/hour (point 29 on the diagram in
Appendix C) and comes from reject water from the reverse osmosis plant on the site.
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Influent to the reverse osmosis plant has been first clarified and filtered to remove
solids and chemicals that can be precipitated.
61. There are no anti-scaling agents used to clean the boiler which would then be
present in wastewater. Because ultra-high quality deionised water is made on-site
using an RO plant, magnetite is added to the demineralised water to ensure it
doesn’t leach metals from the boiler.
62. Therefore, the wastewater contains only brine from the treatment process. All
solids, metals and other contaminants are removed from the waste stream by
thickening and pressing and then disposed of lawfully. Analysis of the pressed solids
indicates it would comply with a waste recovery order to allow the material to be
reused as a soil conditioner, i.e., it has relatively low levels of contaminants that
comply with current resource recovery orders.
63. The wastewater storage fluctuates over time as rain falls on the storage and water
evaporates. The more it rains the more the storage level builds up and vice versa.
64. From time to time the opportunity to empty the storage of its salty water is taken
when flows increase in the Hunter River and credit is not needed to discharge the
water.
65. Occasionally credit is purchased, and water is discharged using the credits when flow
rates permit.
66. Table 1 showing discharges to the Hunter River under the Scheme
FINANCIAL DISCHARGE SALT LOAD
2001 (CY) 50.6 238.1
67. The wastewater (brine) discharged from the site is licensed. It is dosed to adjust its
pH prior to any discharge.
68. Discharging wastewater to the river is not an alternative method of disposing of
contaminated stormwater from the site. While stormwater contaminants are
removed from the raw water storage pond and noting some contaminants would
originate on the site, we reiterate that all non-salt contaminants are removed from
the process prior to treatment in the reverse osmosis (RO) plants and they are not
found in the RO reject water, i.e., brine, which is discharged from the site.
69. The source of salt in the water is largely from elevated salt levels present in raw
water harvested from the Hunter River. An insignificant mass of salt would arise
from treating runoff from the site itself where salt present is the result of
atmospheric deposition.
70. The trading scheme is understood to be highly successful in reducing the salinity of
the river.
5.5. Existing Water Quality Controls
5.5.1. Drive in Sediment Traps 71. Drive in sediment and floating oil traps are present in two locations upstream of the
water quality pond. These are a simple but effective method of removing coarse
sediment and floating oil and grease. They are cleaned periodically by bob cat.
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Plate 1 Showing drive sediment trap accepting runoff from boiler island catchment.
Plate 2 Drive in sediment trap at end of stockpile channel
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5.5.2. Water Quality Pond 72. The water quality pond is a textbook best management practice which has a surface
area of about 1,600 m2 and an average depth estimated to be at least 1m. It has
peripheral macrophytes, a baffle wall to stop short circuiting of the catchment which
has an incoming stormwater pipe close to the outlet.
73. It has both emergent, submerged and floating aquatic vegetation.
74. The water quality pond accepts runoff from the stockpile storage area and the boiler
island. This would be the dirtiest parts of the existing and proposed operation with
all other elements being bunded and separated from stormwater to facilitate only
controlled discharges.
75. The pond is an effective method to further settle medium to fine grained sediment
and for removal of dissolved nutrients including ammonia, nitrate and nitrite and
orthophosphate.
76. The pond has been cleaned out periodically to remove accumulated sediment from
its base.
77. Water is removed from this pond for dust suppression of the stockpile area however
this pond has reportedly never run dry. Demands for water for dust suppression
were described as modest.
Plate 3 Showing water quality pond with steel baffle wall to stop short circuiting
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Plate 4 Water quality pond – looking north west across the pond.
5.5.3. Concrete Channel and Screen 78. There is a simple and effective gross pollutant screen upstream of the raw water
pond.
79. The screen traps gross pollutants and some coarse sediment.
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Plate 5 Gross Pollutant Screen in channel upstream of raw water storage
5.5.4. Raw Water Pond 80. The raw water pond is the final element of the treatment train on this site.
81. It functions as a large sediment basin and water storage pond.
82. It stores 6 ML of water, for the purposes of this report, 4 ML of which is considered
dead storage as it is typically filled with raw water from Hunter River.
83. Prior to entry into the raw water pond there is a final baffled sediment and oil trap.
84. Water is extracted from the Hunter River and piped into the pond.
85. The pond receives stormwater runoff from the whole site including adjacent roads.
There is a small area of the adjacent road which bypasses the pond.
86. There is flow monitoring the salinity of inflow to the pond with the probe suspended
from the gantry bridge visible in Plate 6. The water level is also monitored.
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Plate 6 baffled sediment and oil trap adjacent to raw water storage
Plate 7 Raw water pond showing combined inlet/spillway at left and raw water pipes from Hunter River with plastic liner visible.
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5.6. On-Site Maintenance 87. Maintenance of VET’s vehicle fleet occurs off site and no on-site impacts would
occur as a result.
88. The most common maintenance activity on-site is the use of grease and oil guns to
lubricate pumps, valves and motors. Oil is stored in a bunded area, containers are
filled in the bunded area and then taken to where they are needed.
89. Staff are trained to use spill kits.
90. Transformers, diesel storage, diesel fuel pump, any hazardous chemicals etc are all
stored in bunded areas to contain at least 110% of the volume of the largest tank in
accordance with relevant Australian Standards.
91. A pre-purchase due diligence site contamination assessment revealed a strong
history of operational environmental diligence and low risk acquisition for VET Ltd.
6.0 PROPOSED DEVELOPMENT
6.1. Proposed changes to the development 92. The proposed development would see minor changes to the operation of the site
(and which are relevant to consideration of the potential to have off-site water
quality impacts).
a. Minor changes to internal roadways including a new weighbridge
b. Supplementary fuel receival, storage and reclaim
c. Supplementary fuel transport equipment
6.2. Proposed Woody Biomass Fuel 94. Sources of the woody biomass would be from legal land clearing, forestry and
waste timber from timber processing operations, biomass from agriculture,
sawdust, untreated pallets.
95. 70% of the biomass sourced for the plant will be obtained from approved
forestry residues, 15% from sawmill operations and 15% from uncontaminated
wood wastes by weight only if approved and acceptable for inclusion.
96. The fuel would be chipped and graded off-site and there will not be any
processing such as wood chipping, debarking or shredding on the site.
97. No post-consumer and construction and demolition recycled timber would be
accepted eliminating any risk of copper chrome arsenate or timber painted with
leaded paint in the feedstock.
98. The proposal would see up to 850,000 tonnes per annum of woody biomass
burnt at the site.
99. On a daily basis, up to 70 trucks would deliver the biomass in a wood chip form.
This additional traffic load would result in minor additional water quality
impacts.
100. The wood chips would be stored in the stockpile which would be managed so
that the oldest on-site wood chip is conveyed into the process ahead of younger
wood chip. This is designed to avoid composting in place.
101. The physical area available for storage of woodchips would be 0.57 hectares.
102. Up to four days supply of woodchips, nominally 9,315 tonnes, would typically be
stored in the stockpile and this would ensure the oldest timber in the stockpile
was not on site for longer than a week.
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103. At a density of 300kg/m3 this would give a stockpile volume of 31,000 m3.
7.0 PREDICTING RUNOFF QUANTITY
7.1. A predictive water balance model 104. A MUSIC model was developed to simulate rainfall, runoff and the flow of storm
water through the site, a water balance model.
105. The model operates by predicting runoff volumes after considering any water
used within the site such as raw water used within the process for cooling. At
350 m3/hour this represents a large demand for water relative to the size
(footprint of the development).
106. The model predicts runoff by simulating historical rainfall falling across the site,
filling up pore capacity of soft and hard surfaces and then shedding water. It
models the water balance of ponds by simulating water inflow, evaporation and
water reuse.
7.2. Model Assumptions
7.2.1. Climate dataset 107. The model was populated with 6-minute, rainfall which allows for conservative
modelling.
108. The long time period modelled provides a high degree of reliability when
considering the whole range of hydrological events including wet periods,
extreme events such as the June 2007 storm event and dry periods.
109. The climate dataset included 40.5 years of 6-minute rainfall data from the
Milbrodale gauge – gauge number 61309. This is the same rainfall gauge that
Singleton Council, via its consultant Cardno, who carried out a review of
Singleton’s Urban Stormwater Drainage systems in November 2016.
110. This gauge has unusually high reliability and appears to be missing only a short
period of rainfall from within the whole period – 1970 to June 2010.
111. The average rainfall over the modelled period is 656 mm/annum which is well
above the long-term average of 600mm/annum for this location. This adds to the
conservatism of this model.
112. The rainfall dataset included several notable storm events as follows:
i. The 1971 flood event
ii. A 1999 event with a rainfall burst of over 132mm/hour
iii. The June 2007 Pasha Bulker event
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113. The use of such an extended period of rainfall for this continuous simulation
would provide significant confidence in the results in terms of the model’s ability
to predict how frequently runoff would occur from the site.
114. A time series of the climate data set used in the continuous simulation is shown
below in Figure 3.
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Figure 3 Time series of rainfall and evaporation from 1970 to June 2010 for the Milbrodale rainfall gauge
M Redbank M USIC m odel - Singleton - 40 years
Rainfall Evapo-transpiration
7.3. Modelled Land Uses – hydrologic parameters
115. The MUSIC model included several nodes to model the various land uses on the
site. Undisturbed areas which do not drain into the site were ignored.
116. Areas adopted for modelling are shown above at Figure 4.
117. With reference to Figure 4 we note that part of Catchment 5 has been assumed
to be diverted to the north and away from the raw water pond.
118. For this assumption to be valid, a grass swale, shown with a red arrow in Figure 5
will need to be constructed to divert part of the catchment to the south of the
electrical easement and around the raw water pond. This would be a low-cost
way of reducing the hydraulic load on the raw water pond. This catchment is not
used for site operations and remains well grassed. It is a clean land use, not
requiring treatment. None the less, runoff will be treated in a 400 long grass
swale before it is further treated in the swale that runs along the northern
boundary of the site.
119. Areas that were impervious, such as roads, boiler island, admin building, area of
raw water storage itself etc were modelled as such. The water treatment plant
was modelled as impervious.
120. Default hydrological parameters were adopted for modelling all pervious areas
except the stockpile which would be highly absorbent.
121. The stockpile area was modelled as a pervious area with a capacity to absorb
and hold water much like any soil. The stockpile also has a capacity to evaporate
water back into the atmosphere and it is understood that heat generated in
stockpiles results in enhanced evaporation.
122. Hydrological parameters were modified to reflect the depth of stockpile, the
very high rate with which water would be able to percolate into a wood chip
stockpile and the limited ability of the stockpile to hold water for many days.
123. Previous work for Borgs Manufacturing at Oberon, which is one of the top 10
largest timber processing facilities in the world, has shown that large wood chip
stockpiles do leach for several days following large rainfall events and
parameters were modified to reflect this observation.
124. As water would percolate through the pile it would follow an extended flow path
around each chip. Once on the ground water would flow laterally through the
pile at a slow rate or percolate downward to the subsoil drains. Lagging was
used to reflect this.
27
125. Model predictions show that the pile would absorb and evaporate 90% of
rainfall, with the remainder of flow released relatively rapidly as baseflow.
126. The physical area of the raw water pond and water quality pond were also
included in the model areas as 100% impervious to account for direct rainfall
falling onto them.
127. The 60 ML wastewater storage was not included in the model as it does not
discharge to Dights Creek under any circumstances.
7.4. Modelled land uses adopted EMCs 128. Event Mean Concentration values used in MUSIC were as follows:
a. Catchments 1, 2,3 and 5 default industrial EMC values were adopted.
b. For catchment C4, the values shown in Table 2 were adopted. These values have
been derived based on a number of years of frequent monitoring of runoff from
the Borgs Oberon timber production facility. The Borgs site has large stockpiles,
shreds and debarks timber and stores timber poles, sometimes for prolonged
periods. It is noted that while TSS is relatively low – lower than a road catchment
for example, levels of nutrients are substantially elevated compared to urban
stormwater and this is expected from an organics stockpile.
Table 2 Adopted Event Mean Concentrations for Catchment 4 - Stockpile
Parameter Adopted MUSIC EMC (mg.L)
Standard Deviation (log mg/L)
TSS Stormflow 39.8 0.21
TSS Baseflow 15.8 0.17
7.5. Modelling the water quality pond and raw water pond
129. The water quality pond was modelled assuming 1m depth and its surface area
was measured from a digital drawing and confirmed with aerial imagery.
130. The water quality pond was modelled as a water quality node in MUSIC.
131. Water reuse for dust suppression was modelled from the water quality pond,
assuming an average depth of water applied to the stockpile area at a rate of
1mm/day.
132. A minor modification to the water quality pond was included in the model
which is to choke flows using a 300mm high plate placed across the outlet
with a 150mm orifice hole at its base to allow flows to trickle out.
133. This still allows extreme event flows to overtop the orifice plate and flow into
the culvert.
134. The raw water pond was modelled as a sediment basin node in MUSIC as it
has no vegetation present.
135. The raw water pond is 6 ML in volume however it is understood that up to
4ML of raw water, pumped from the Hunter River would be present in the
pond.
29
136. Therefore, the drawdown limit of the pond was restricted to be equal to 2ML
to reflect the actual headroom or air space available for storage of
stormwater runoff from the site.
137. Reuse was modelled from the raw water pond node. The daily demand for
water from the pond would be 8,791.2kL/day which is 366.3 kL/hour. This
equates to a demand of just over 100 l/s for cooling from the pond.
8.0 RESULTS & PREDICTED COMPLIANCE
8.1. Frequency of discharge 138. The MUSIC model was run and a daily flux file analysed to determine the
frequency of runoff from the raw water quality pond.
139. The model predicted 3 runoff events in 40.5 years. On average, this is less
than 1 runoff event every 10 years.
140. The model predicts 99.7% of all runoff will be retained and reused on the site.
The 0.3% of runoff that is discharged occurs during the 3 runoff events where
water is discharged from the site.
141. The 6-minute rainfall data captures the storm burst and models the flux of
the raw water pond after stormwater has flowed in from the site and water
has been extracted for pumping.
142. A gross error check was conducted to check this result as follows.
143. We extracted the largest predicted single daily runoff volume from the
MUSIC model. This was predicted to occur during the June, 2007 storm event
where 133mm of rainfall was recorded at the gauge in one day. The volume
of runoff for that day was predicted to be 7,508m3. The daily demand is 8,407
m3 and so if we used a daily time step model it would result in zero discharges
from the site over the 40.5 year model period.
144. This demonstrates why it is important to adopt a 6-minute time step for
modelling and how it is a more conservative approach. It also validates that
the 6-minute time step model is correctly predicting off-site discharge events
which only occur because of rare and extreme rainfall.
8.2. Water quality impacts 145. The MUSIC model was chosen for this project because, as a continuous
simulation, it simulates the whole spectrum of flow events using real world
climate data from a gauge very close to this site.
146. This model predicts that the site effectively has no “chronic” discharges. In
other words, the site is predicted to discharge only during extreme rainfall
events.
147. One can therefore confidently conclude that provided key model
assumptions are valid, the existing and proposed development would have no
aquatic ecosystem impacts and would not result in water pollution.
148. Everyday risk for Australian streams is overwhelmingly what leads to a
decline in waterway health. This is often called urban stream syndrome –
where urban streams receive degraded runoff every time it rains, and they do
not have time to recover from one event to another.
149. Moreover, the change in flow regime, not just the chemical changes, can
result in degraded waterways. The problem is one of being directly
connected. That is polluting land uses are described as being directly
connected to creeks.
150. The existing and proposed operations at Redbank Power Station, would
remain, in water quality terms, effectively (99.7%) disconnected from Dights
Creek. This is outcome ensures that both the existing operation and the
proposal will have no adverse impacts on the creek.
151. At Redbank, 99.9984% of the time there will be no discharge from the site.
8.3. Water quality discharge during extreme events
152. Extreme events in hydrological terms happen infrequently. In the context of
this site, discharge less often than once every ten years would occur during an
extreme weather event. This equates to less than 0.0016% of the time.
153. For example, the MUSIC model predicts that one of the historical spill events
would have been the June, 2007 Pasha Bulker storm event. This event saw
more than 133mm of rainfall recorded in one day at the gauge and was the
worst flood between 1971 and 2007.
154. The external catchment draining to the point of discharge is estimated at 147
hectares. The stockpile area, which is that part of the site which would
contribute more pollution, is 0.57 hectares. See Figure 5.
155. The discharge to Dights creek from the site would see stockpile runoff diluted
by a factor of 250.
32
Figure 5 Approximate current catchment area upstream of the point of Redbank discharge
156. The extremely low frequency of discharge combined with the high level of
dilution that would occur would ensure that site discharges during extreme
events would not result in adverse impacts off the site.
157. This statement implicitly considers the very poor water quality that
naturally occurs during these extreme events from all land uses including
pristine National Parks. These events naturally shape creeks and erode
gullies and move vast volumes of debris, sediment, nutrients and tannins.
8.4. Predicted compliance with applicable development standards
158. The principal NSW government policy guideline applicable to this site would be
the “Environmental Guidelines: Composting and related Organics processing
Facilities” published by the Department of Environment and Conservation
(NSW) 2007. This document sets criteria for composting sites and has
established a 1 in 10 year discharge limit for leachate storage dams.
159. If one was to accept that the raw water storage pond was in effect a leachate
dam and that it is predicted, conservatively, to spill only 3 times in 40 years then
the proposal would comply with the only relevant NSW Government policy
document.
160. It is noted that Singleton Shire Council does not have any applicable
development water quality standards.
9.0 MODELLING THE POST DEVELOPMENT SITE
9.1. What are the differences between pre and post development models?
161. The only differences that arise in the way one would predict pollution from the
proposal lies in the use of woody biomass instead of coal. In most other
respects the proposal remains the same noting that there is a proposed minor
increase in road surface on the site and an increase in traffic.
162. The increased traffic volume of 70 trucks per day is unlikely to result in a
detectable change in predicted discharge water quality as typical industrial
EMC values inherently include multiple truck movements per day.
163. Moreover, the fact the site discharges less often than once every ten years
would ensure impact from additional traffic, if it exists, would not result in any
adverse impacts off the site.
164. The change in the reduction of ash is considered immaterial to effluent quality.
165. The principal and material difference between woody biomass and coal is
understood be as follows:
166. Coal is more likely to produce heavy metals at low concentrations in leachate
though it is known that timber can leach metals at low concentrations. It is
thought these are unlikely to be at levels which would cause harm as they have
been sourced from the soil material on which the trees have grown, i.e. they
would be naturally occurring in the environment and in the soils in that
environment.
167. Coal is more likely to produce sulphur and sulphuric acid in leachate however it
is noted that Australian coal is lower in sulphur and therefore this is less likely
to be of concern.
a. Elevated levels of nutrients, especially nitrogen and dissolved organic
nitrogen (measured as total Kjeldahl nitrogen (TKN).)
b. Elevated levels of BOD and COD.
c. At the Borgs Manufacturing site at Oberon, an EMC value for TN of 10 mg/L
is adopted. This is roughly 5 times the value of a typical industrial site.
Phosphorus too is elevated but not significantly.
34
169. None of these differences have any relevance to a determination of whether the
development proposal will result in additional off-site impacts.
170. This is because the site, because of its extraordinarily high demand for raw
water and stormwater, consumes 99.7% of all stormwater runoff and would
discharge to stormwater less than once in ten years on average.
171. The remaining 0.3% of annual runoff is diluted 250-fold and only discharged
when ambient water quality in receiving waters would, regardless of the
development proposal, be extremely poor.
9.2. Predicted maximum indicator pollutant concentrations
172. The MUSIC model was used to estimate the maximum, 40.5 year discharge
concentration of TSS, TP and TN. These are the principal pollutants of concern
emanating from a wood chip stockpile and they are the only pollutants that can
be modelled using MUSIC.
173. The predicted maximum discharge concentrations, occurring less than once
every ten years are shown in Table 3.
Table 3 Predicted Maximum Discharge Concentrations
Parameter 100th percentile
10.0 WATER POLLUTION RISK
10.1. Risk of off-site water quality impacts 174. Operation of the raw water storage to provide water needed for cooling sees the
raw water pond spill on only 3 occasions in the 40.5 years of simulation period.
175. This equates to retention of 99.7% of all stormwater runoff on the site.
176. Provided that the raw water storage is operated with 2 ML headroom, and a
condition of consent is invited to ensure this outcome, the development
proposal is extremely unlikely to result in any off-site adverse water quality
impacts.
10.2. Acute risk of water pollution 177. There are a large number of controls in place on this site to prevent and monitor
for an accidental spill including extensive use of spill bunds.
178. The site would operate under its numerous existing safe work procedures which
include spill management procedures.
179. The site operates in accordance with its Pollution Incident Response
Management Plan which can be found here:
https://verdantearthtechnologieslimited.com/verdant-new-site/wp-
content/uploads/2021/08/001-PIRMP-V4.pdf
180. This means that the development proposal, using all existing bunds and
emergency spill controls such as water level, flow, salinity and oil on water real
time monitoring, is unlikely to cause water pollution from an accidental spill.
181. It is very much in the interests of VET Ltd to ensure that any spill is detected as
soon as possible and before it has the potential to be pumped into the on-site
treatment plant where it would foul expensive water treatment equipment.
11.0 RECOMMENDATIONS 182. The following conditions of consent are invited:
a. Operate the raw water pond with a minimum of 2ML headroom. Reason: to
ensure stormwater runoff from the Redbank site occurs less often than once
in 10 years.
b. A new grassed swale, as shown by a red arrow in Figure 4, is to be
constructed. Reason: to reduce the area of catchment 5 that contributes
stormwater to the raw water pond.
c. A stainless-steel orifice plate, 300mm high, with a 150mm diameter circular
opening in its base, be placed over the outlet of the water quality pond.
Reason: to detain water in the pond for an extended period which will
improve discharge water quality and help reduce the frequency of off-site
discharge.
d. The water quality pond shall be aerated to ensure that it maintains high
levels of dissolved oxygen. Reason: there is a risk that the water quality
pond will receive elevated levels of BOD. This may result in the development
of anoxic conditions on the water quality pond under low rainfall conditions.
e. Construct a 2m vegetated buffer strip between the stockpile and the
concrete channel. Reason: this will help reduce the export of woodchip from
the stockpile.
183. When it is feasible to do so or following any observations of poor water
quality in the water quality pond, consider installing a Barramy Trap
upstream of the water quality pond. This will enable the dry storage of
woodchips which would see reduced leaching.
37
Figure 6 Example of Barramy Vane Trap installed in the Blue Mountains.
Appendix A
Curriculum Vitae
www.sustainabilityworkshop.com
Mark has 25 years of professional experience as a Chartered Civil and
Environmental Engineer. As a water engineer, he leads in areas of local government policy, water cycle management and environmental impact assessment. He often trains local and State Government and industry.
Mark sits comfortably between the private and public sectors having worked in both sectors for many years. He bridges the gap between the
two to deliver affordable sustainable designs and gain approvals often where others have struggled. Mark also works with academia, guiding research to create tangible outcomes for industry.
Career highlights include:
1) He is currently working with Blacktown Council to lead a $2 million State and Council funded research project into the long-term field performance of bioretention systems in western Sydney. This is the
only long-term study of bioretention systems.
2) Carrying out the first independent evaluation (peer review) of a
proprietary stormwater quality improvement device for Stormwater Australia.
3) Carrying out numerous peer reviews of proprietary stormwater
treatment devices for Blacktown Council and which are adopted by most other NSW Councils.
Current Positions:
Director and Principal Engineer Sustainability Workshop Pty Ltd (2012 to present) Consultant Engineer, Blacktown City Council (2013 to present) Independent Evaluation Panel – Stormwater Australia Peer Reviewer – Water Science and Technology Journal.
Name:
Qualifications:
Chartered Professional Engineer, MIEAust Bachelor of Civil and Environmental Engineering (1998) Hons (First Class), UTS Bachelor of Economics (1990), Sydney Uni
Previous Employers:
WSP & RPS in the UK 2006-2012 Storm Consulting (Australia) 2000-2006 Arup (Australia) 1998-2000
Key Capability
Hydrology and hydraulics, Water Quality Management, Water Sensitive Urban Design, Creek Rehabilitation and Stabilisation, Drainage design, Flood risk and EIA, Integrated Water Cycle Management, Strategic planning, Policy Development, Training and Capacity Building
www.sustainabilityworkshop.com
4) Principle Author of the Blacktown Water Sensitive Urban Design
Standard Drawings and co-author of the Blacktown WSUD Handbook for Development.
5) Lead Designer of the multi award winning Blacktown International
Sports Park stormwater harvesting system. Project value $6.5 million.
6) Design and implementation of the first stormwater quality offset scheme in NSW also for Blacktown Council.
7) Planning and detailed design of the stormwater drainage system
and water cycle management for a 50 hectare campus for Borgs Manufacturing at Oberon. This is a State Significant Development
that sees Borgs become one of the top 10 engineered timber producers in the world.
8) Receiving a Green Globe Award from the Premier of NSW for work
with Mirvac on the water cycle management system for Ashgrove Estate at Auburn.
9) Designing the first on-line planning tool in NSW to help developers identify applicable planning controls in the whole of the Blacktown LGA. See www.s3qm.com.au
10) Undertaking a detailed Integrated Water Cycle Management System for Area 14 at Port Macquarie.
11) Designing the first estate in NSW to include rainwater tanks – Elambra Estate at Gerringong.
12) Designing the first combined bioretention and stormwater
harvesting scheme in Australia in 2003 for Kiama Council.
Mark also peer reviews relevant (stormwater related) professional
scientific publications for the highly regarded Water Science and Technology Journal, published by the International Water Association.
Mark enjoys the dynamic of a team - leading teams of planners, Architects, scientists and engineers.
Mark is currently an active Stormwater NSW member as well as a Member
of the Institution of Public Works Engineers, Australia.
AWARDS
Mark has been responsible for leading teams of Engineers and Scientists in undertaking planning, design and construction supervision for a range of highly innovative civil and environmental engineering projects. He is
regarded as one of Australia’s leading Sustainable Urban Drainage system Engineers and his work has been repeatedly awarded.
• 2017 Stormwater NSW Award of Excellence for the Blacktown
Developer WSUD Toolkit.
• Finalist Greater Sydney Commission Planning Awards – for the
Offset Scheme developed for Blacktown City Council. • 2016 State and National Awards of Excellence in Strategic Planning
for the latest incarnation of the Blacktown WSUD and IWCM DCP.
• 2015 State Award of Excellence for the Angus Creek stormwater harvesting scheme.
• 2008 Stormwater Industry Association National Award of Excellence for a Stormwater Quality Treatment Device.
• 2008 NSW State Premier’s Green Globe Award - Ashgrove Estate.
• 2008 Stormwater Industry Association Award for Excellence in Stormwater Management for the Ashgrove Estate.
• 2008 NSW Stormwater Industry Association Award for Excellence in a Stormwater Quality Measure - Exfiltration Stormwater Treatment Systems.
• 2007 Stormwater Industry Association Awards for surface and Groundwater Management - Kinross Industrial Estate.
• Stormwater Industry Association National Award of Excellence in Water Sensitive Urban Design, 2004, for the Hindmarsh Park “Bioretention Filter and Elambra Estate Projects. This is Australia’s
premiere award for water sensitive urban design. • Finalist, Institution of Engineers, Australia, 2005 for the Kiama
Sand Filter and Elambra Estate Projects. • Case Earth Awards, 2004, Campbeltown Link Constructed Wetlands
Recent Publications (most pub’s available for download on website)
Alim A, Rahman A, Tao Z, Griffith M, Garner, B, Griffith, R and Liebman M, Green Roofs toward Sustainable Development: A scoping Review of
Australia Practice, Water Research Journal, under review.
Liebman M, Is it worth Sacrificing water quality to create publics for stormwater?, Stormwater Australia National Conference, 2021.
Liebman M, Jennings R, Eberl G, Peterson R, The challenges of building $270M of stormwater infrastructure for Blacktown City Council,
Stormwater Australia National Conference, Sydney, 2018.
Liebman, Milenkovic and Taylor, How to Make it Easy to get a DA in a Notoriously Complex LGA. Stormwater NSW State Conference, Newcastle,
2017.
Appendix B
The Law Specialists
Liability limited by a scheme approved under Professional Standards Legislation. Legal practitioners employed by Fishburn Watson O'Brien Pty Limited are members of the scheme.
Fishburn Watson O'Brien Pty Ltd ABN 70 163 802 319
Our ref RF:DP:2210330:kh Watson House 300 George Street Sydney NSW 2000
Phone (02) 6650 7000 Fax (02) 6651 4853
www.fwolaw.com
02 6650 7038 [email protected]
Mr Mark Liebman Sustainability Workshop 4 Park Avenue Blackheath NSW 2785 Privileged and Confidential
By Email: [email protected]
Dear Mark Hunter Development Brokerage Pty. Limited (t/as HDB Town Planning and Design) v Singleton Council Case Number 2021/00128111 – Class 1 Application Modification Application DA 183/1993, 112 Long Point Road, Warkworth
We refer to our letter of 17 September 2021 and provide the following further instructions.
We request that you address the following matters:
1. Describe the existing approved stormwater management system at the Premises.
2. Review the likely environmental impact of the proposed modifications with respect to the existing approved stormwater management system.
3. Identify whether the proposed modifications give rise to the need for any changes to the existing stormwater management system to ensure that the likely environmental impact is adequately managed. If so, describe the nature of those changes.
Please give me a call if you have any questions.
Yours faithfully, FISHBURN WATSON O'BRIEN
ROSS FOX Principal Accredited Specialist Planning and Environment
M:\Docs\2210330\3124730.docx
The Law Specialists
Liability limited by a scheme approved under Professional Standards Legislation. Legal practitioners employed by Fishburn Watson O'Brien Pty Limited are members of the scheme.
Fishburn Watson O'Brien Pty Ltd ABN 70 163 802 319
Our ref RF:DP:2210330:kh Watson House 300 George Street Sydney NSW 2000
Phone (02) 6650 7000 Fax (02) 6651 4853
www.fwolaw.com
02 6650 7038 [email protected]
Mr Mark Liebman Sustainability Workshop 4 Park Avenue Blackheath NSW 2785 Privileged and Confidential
By Email: [email protected]
Dear Mark Hunter Development Brokerage Pty. Limited (t/as HDB Town Planning and Design) v Singleton Council Case Number 2021/00128111 – Class 1 Application Modification Application DA 183/1993, 112 Long Point Road, Warkworth
We act for Verdant Earth Technologies Limited (formerly Hunter Energy Limited), the new owner of Redbank Power Station. HDB Town Planning and Design (HDB) lodged the modification with Council on behalf of our client. HDB agreed to be the Applicant in the Class 1 proceedings which have commenced in the Land and Environment Court.
1. Your Instructions
1.1 We would like to retain you as an expert witness addressing a contention 12(a) of the Council’s Further Statement of Facts and Contentions of 15 September 2021 relating to the impacts of the particular chemistry of the stormwater generated by the proposed development. Your expert evidence would be limited to the aspects of those matters in which you have expertise.
1.2 Contention 12(a) is as follows (italicised text marks additions in the Council’s Further Contentions):
“The Stormwater Impact Assessment submitted with the modification application does not discuss and assess the particular chemistry of the potential generation and runoff of leachate from the biomass stockpile that may contain various contaminants, tannins and lignins, and whether the existing stormwater management system at the site is suitably designed and constructed to mitigate the potential pollution of waters from leachate. The MUSIC model provided uses source nodes to represent the biomass material proposed to be stockpiled on site, and calculate the efficacy of the existing pollutant treatment train on site. It is unclear whether the source nodes in the provided MUSIC model accurately depict the chemistry of the leachate generated from the degrading biomass material, which is expected to be of
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varied toxicity, have the potential to create PH imbalance and possibly produce ammonia (NH3). It must be demonstrated that the MUSIC model accurately depicts the chemistry of the leachate from the biomass, and that the leachate is sufficiently treated by the existing treatment train before water leaves the site.”
2. Background
2.1 Redbank Power Station is located at Long Point Road and Jerrys Plains Road, Warkworth (part Lots 1-3 DP 247820 and Lots 4-5 DP247820).
2.2 The existing Redbank Power Station is a 120-megawatt power plant fuelled (historically) by coal washery tailings supplied from the Warkworth coal preparation plant.
2.3 The original development consent (DA183/93) was granted by the Land and Environment Court on 10 November 1994.
2.4 A class 1 appeal was filed in the Land and Environment Court on 7 May 2021, appealing against Singleton Council (Council) deemed refusal of an application to modify the development consent.
2.5 The modification seeks to add the use of biomass as an additional fuel among other things.
2.6 Council’s Amended Statement of Facts and Contentions (SoFC) was filed on Wednesday, 15 September 2021. The Applicant’s response to the SoFC is due 17 September 2021.
2.7 The Applicant’s further information is to be provided by 24 September 2021.
2.8 Joint reports of experts by 1 October 2021.
2.9 The matter is scheduled for hearing on 11 – 15 October 2021.
2.10 In relation to Contention 12(a), we note that:
2.10.1 The treatment of runoff from the woody biomass pile has been modelled in RGH Consulting Group’s report dated July 2021 using MUSIC modelling software.
2.10.2 Pollutant loads from a “woody biomass pile” are not defined in MUSIC, so it is not possible using default settings in the MUSIC software to model the pollutant load reductions except for TN, TP and TSS.
2.10.3 The chemistry of leachate from a woody biomass pile is influenced by tannic acids, can have a low pH and moderate chemical oxygen demand.
2.10.4 As a proxy, RGH Consulting has modelled runoff from a quarry and an agricultural site, which has not satisfied fully Singleton Council.
2.10.5 We have reference data on the chemical characteristics of woody biomass leachate, though the MUSIC modelling software does not adequately address this issue.
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2.10.6 As not all water is fully contained on the site, the site on an annualised basis will discharge around 16% of total inflow (this will need to be confirmed).
3. Expert Witness Code of Conduct
3.1 Before commencing work or undertaking any site inspections, we require you to undertake the work in accordance with the Expert Witness Code of Conduct, Schedule 7 of the Uniform Civil Procedure Rules 2005.
4. Your Preliminary Brief
4.1 Please note that you can access the documents at the link which accompanies this email. The documents are as follows:
4.1.1 Expert Witness Code of Conduct.
4.1.2 Amended Statement of Facts and Contentions from Council dated 15 September 2021.
4.1.3 Planning Report – Section 4.56 Application to Modify DA183/93 – Redbank Power Station by URBIS dated 11 August.
4.1.4 Site Layout Plan – Biomass Unload and Storage Area by HDB numbered 21017 Revision B dated 29 July 2021.
4.1.5 Proposed Redbank Power Station Plant Biomass Conversion Drawings by B&PPS numbered as ‘C12181-000-100 Rev A’, ‘C12181-000-111 Rev A’, ‘C12181-000-112 Rev A’, ‘C12181-000-113 Rev A’, and ‘C12181-000-114 Rev A’.
4.1.6 Site plan by Alstom numbered as ‘80034-001-M-GA-000-5001 A0’.
4.1.7 Site plan by Alstom numbered and ‘80034-025-M-GA-000-9176 A1’.
4.1.8 Concept study by B&PPS titled ‘Biomass Handling Plant Concept Study B&PPS Report (C12156-03)’, by B&PPS, Rev 4 dated 18 June 2021.
4.1.9 Redbank QA/QC Supply Chain and Material Handling dated 30 July 2021.
4.1.10 Noise Impact Assessment by Muller Acoustics Consulting. Rev 3, dated 11 August 2021.
4.1.11 Stormwater Management Plan Report by RGH Consulting Group, Rev E, dated July 2021.
4.1.12 Updated air quality assessment titled ‘Air Quality Impact Assessment’ by EMM, version 2 dated 9 August 2021.
4.1.13 Updated transport assessment titled ‘Transport Assessment’ by Ason Group, Issue IV, dated 10 August 2021.
4.1.14 Updated traffic management plan titled ‘Operational Traffic Management Plan’ by Ason Group, Issue III, dated 10 August 2021.
4.2 Any opinion you provide must be based wholly or substantially on specialised knowledge you have based on your study, training or experience. If you are
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unable to provide an opinion on a matter, please note this and the reasons you consider you are unable to provide said opinion.
5. Your engagement
5.1 Please note that while we have engaged you to act as an independent expert witness, our client will be responsible for any invoices issued by you.
5.2 Our client’s details are as follows:
Verdant Earth Technologies Limited ACN 624 824 791 Contact: Richard Poole, Director
0417 941 297 [email protected] Arthur Phillip Pty Ltd Level 33, 52 Martin Place SYDNEY NSW 2000
6. Next steps
6.1 Your report is required to be filed and served on 24 September 2021.
6.2 Please also confirm your availability to attend the hearing (online) from 11-15 October 2021.
6.3 Lastly, please provide our client with an estimate of your fees and engagement terms.
If you have any questions or wish to discuss this matter generally, please contact me.
Yours faithfully, FISHBURN WATSON O'BRIEN
ROSS FOX Principal Accredited Specialist Planning and Environment
Appendix C

expert witness report: water cycle impact assessment of

Documents