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Best Practice Environmental Management

Environmental Guidelines for MajorConstruction Sites

Environmental Guidelines forMajor Construction Sites

Environment Protection Authority477 Collins Street, MelbourneVictoria 3000 AUSTRALIA

February 1996

ISBN

CONTENTS

Preface....................................................................................................................................... v

1 Purpose and application........................................................................................................ 1

2 Pre-construction planning and design .................................................................................... 22.1 Environmental assessment2.2 Risk assessment2.3 Risk management

3 Environmental management plan........................................................................................... 83.1 Environment management plan3.2 Best practice documents3.3 Segment environmental control plan

4 Land disturbance.................................................................................................................. 114.1 Erosion4.2 Management of contaminated stormwater4.3 Designing erosion and sediment control devices4.4 De-watering work sites4.5 Dust control4.6 Management of stockpiles and batters4.7 Working in waterways and floodplains

5 Noise and vibration .............................................................................................................. 225.1 Operating hours5.2 Vehicles and equipment5.3 Traffic5.4 Noise abatement5.5 Vibration

6 Waste minimisation .............................................................................................................. 24

7 Contaminated material and wastes ........................................................................................ 257.1 Solid inert wastes7.2 Putrescible wastes7.3 Low-level contaminated soil7.4 Prescribed wastes

8 Other environmental issues ................................................................................................... 278.1 Emergency procedures8.2 Air quality8.3 Litter8.4 Storage of chemicals and fuel8.5 Road cleaning8.6 Protecting infrastructure8.7 Concrete batching plants

9 Inspections, monitoring and audits ........................................................................................ 309.1 Inspections9.2 Monitoring9.3 Auditing

Appendix: Check-list 35

FOREWORD

Major construction projects, such as roads and freeways, are important to Victoria's economicdevelopment. During construction, however, such projects pose a significant risk to the environment,which must be addressed by developers and contractors.

Construction practices that fail to control pollution can cause damage to waterways and wetlands, killfish, upset aquatic ecological systems and wildlife communities, and result in contamination of land andgroundwater. The risk to the environment is particularly high when work is done near coastal areas,streams and creeks, or along a river valley. When construction occurs near built-up areas, poorpractices may result in air and noise pollution which may cause annoyance and affect the health ofneighbouring communities.

This document is designed to provide developers and contractors with guidelines on how to implementsound practices that minimise environmental impacts and eliminate health risks and nuisance toresidents near a construction site.

There are also sound economic reasons for implementing good environmental practices during majorconstruction projects. Excessive sedimentation of waterways can cause flooding, require expensivedredging of navigation channels downstream or reduce the capacity of downstream water storage units,destroy valuable wetlands, and reduce commercial and recreational fishing. On-site, loss of topsoilmeans importation of replacement topsoil at substantial cost. Where construction activities cause anuisance, this places a cost on the community through loss of amenity.

Construction sites are constantly changing, and systems need to be in place to modify control measuresto maintain their effectiveness. Therefore, frequent inspection and monitoring is required to continuallycheck the effectiveness of measures.

I would encourage all companies involved in the design and construction of major roads anddevelopment projects to use these Guidelines.

Best Practice Environmental Management publications are produced by Environment ProtectionAuthority (EPA) to encourage a pro-active approach to environmental management by industry.

EPA would be pleased to receive comments on these Guidelines from the construction industry andother interested parties.

Brian RobinsonChairmanEnvironment Protection Authority

Environmental Guidelines for Major Construction Sites Page 11

1 PURPOSE AND APPLICATION

The Environmental Guidelines for majorConstruction Sites provides a useful sourcedocument to help prepare and implement aenvironmental management plan for majorconstructions sites.

The purpose of these Guidelines is to providedevelopers, contractors and governmentagencies involved with commissioning orconstructing freeways, major roads or majordevelopment projects with:

• information how to avoid and minimiseenvironmental impact, which is preferableto the less cost-effective option ofcontrolling or treating discharges to theenvironment, or undertaking remedialaction.

• information on the likely impact ofconstruction activities on the environmentand how this is to be assessed

• guidelines for undertaking risk assessmentand management

• a clear statement of environmentalperformance objectives for each segment ofthe environment

• suggested best practice environmentalmeasures to meet the performanceobjectives based on available experience

The Guidelines provide contractors anddevelopers with a framework within which duediligence obligations can be met andenvironmental damage can be avoided.

The Guidelines are not prescriptive or detailed.Application will require tailoring them toparticular site conditions and makingadjustments if the measures listed areinappropriate to the site.

Many of the measures proposed in theGuidelines are also applicable to smallerconstruction sites (less than five hectares) andshould be used where appropriate to avoid andminimise impact from such activities.

The Guidelines do not refer to State legislation,regulations or environmental policies.Developers, contractors and subcontractor,when they are used, must make themselvesaware of their legal obligations because theyare responsible for compliance.

Legislative requirements and standards areminimium standards, and projects shouldendeavour to continually improve on thesestandards.


2 PRE-CONSTRUCTION PLANNING AND DESIGN

Integrating environment protection at theproject planning stage ensures that measures toavoid and minimise pollution can be built intothe project design and work schedule. Thisapproach is more cost-effective thanestablishing controls once the projectcommences.

Once a site has been selected, it is necessary toconduct an environment assessment thatidentifies which parts of the environment maybe vulnerable to damage from constructionactivities.

Making a risk assessment is a useful way inwhich to approach this aspect of sitemanagement. Environmental risk deals with theprobability of an event causing an undesirableeffect. There are three elements to considerwhen defining risk1. They are:

• a time frame over which the risk or risksare being considered

• a probability of the occurrence of one ormore events

• a measure of the consequences of thoseevents

Based on the site assessment, project designinformation and the construction workprogram, a risk assessment of all aspects of theproject can be executed. This assessment inturn leads to a strategy to manage all significantrisks to the environment.

2.1 Environmental assessment

Understanding which segments of theenvironment are vulnerable is a prerequisite toidentifying and managing environmental risks.

1 T. Beer & F. Ziolkowski, Environmental

risk assessment: an Australian perspective,Supervising Scientist Report 102, 1995.

The assessment should not only consider theenvironmental impacts on a site, but whether ornot off-site effects are possible.

An initial assessment of the site should beconducted to identify sensitive environmentalareas or uses that require protection. These mayinclude:

• sensitive or endangered flora and fauna

• aquatic plants and animals, if a naturalwaterway is affected

• groundwater recharge areas

Depending on whether or not the constructionsite is near houses, schools or hospitals, theimpact of air discharges, noise and vibration onthe health and amenity of adjacent residents willneed to be included in the assessment.

Once the project has been approved, but beforeconstruction commences, it is important toinitiate an environmental monitoring program tocollect baseline data on all sectors of theenvironment.


ENVIRONMENTAL ASSESSMENT

Objective

To identify or obtain information on anyrelevant environmental impact that theconstruction project may cause.

Suggested measures

• Identify sensitive environmental areas oruses that may be affected by constructionactivities.

• Identify whether residents adjacent to thesite could be affected by pollution fromconstruction activities or suffer reducedamenity.

• Monitor baseline air and water quality andambient noise levels adjacent to theconstruction site.

• Conduct an assessment of expected noiselevels from construction activities whichmay affect the surrounding community.

• Conduct a desk study to identify potentiallycontaminated sites in the construction area,and sample and analyse soils that aresuspected of being contaminated beforeconstruction commences.

2.2 Risk assessment

Risk assessment is defined as the identificationand characterisation of the nature of existingand potential adverse effects to humans and theenvironment resulting from exposure toenvironmental hazards.

Risk is a function of the probability of an eventoccurring and the degree of damage that wouldresult should it happen.

Information from the environment assessment isrequired in order to conduct a risk assessment.

Details of the project design and the workprogram are also needed.

The assessment allows significant risks to beidentified so that they can be targeted foraction.

This initial risk assessment needs to beregularly reviewed. An ongoing risk assessmentis therefore an integral part of theEnvironmental Management System (seesection 3.1). This involves a review of existingrisks and identification of new risks detectedthrough the surveillance or monitoringprogram.

Risk assessment can be divided into six steps.

Information gathering

A risk assessment requires information aboutsite conditions. This information is used inconjunction with information collected duringthe environmental assessment (see section 2.1).

The following information needs to be collectedbefore construction commences:

• a map of soil types and their erosionpotential

• climate, weather patterns and stream flows

• topography and natural geographic features(including whether site is in a floodplain)

• the construction schedule

• changes to the topography of the site duringeach stage of the project

• a map of existing vegetation identifyingareas to be retained

• details of areas of cleared land at eachstage of the development, and period oftime that each section will be exposed

• changes to drainage and identification ofsources of clean and contaminatedstormwater


• calculation of stormwater flows withinmicro-catchments within the site, based ona one-in-two-year storm event (two-yearARI with intensity of six hours), for eachstage of the project

• location of stockpiles, batters, haul roadsand cuts

• nature and location of works that will occurwithin 50 metres of anatural waterway or other sensitiveenvironmental area

Hazard identification

Hazard identification involves identifyingactivities that could lead to an adverse effect onthe environment, impair human health, result ina nuisance, or decrease the amenity of residentsadjacent to a construction site.

It is necessary to consider both direct andpotential causes of hazard, which could causewater, air, land or noise pollution. Hazards mayarise out of features of the site, or the nature ofconstruction activities. For example, clearingvegetation from large areas and exposingerodible soil is a high-risk activity which maylead to dust generation and sediment run-off.

Proposed pollution prevention and controlmeasures should be considered when identifyinghazards, because if they fail, there will be anadverse impact on the environment.

Hazard analysis

Hazard analysis considers the likelihood of anenvironmental hazard being realised.

This analysis is based on previous experience,historical data for the failure rate of structuresand systems, and includes the impact of site-specific conditions which may influence risklevels. For example, if large areas of land arecleared of vegetation, the probability of astream crossing collapsing is low, while thepotential for dust problems is high.

The level of risk is also a function of time. Thelonger a risk is allowed to continue, the more

likely it is that there could be an undesirableconsequence.

Consequence analysis

Consequence analysis determines the effect onthe environment should a risk be realised. Forexample, if a temporary river crossing shouldcollapse it could be disastrous for a waterway.The failure of a sediment fence will have lessimpact on the river.

Two factors that should be considered in theconsequence analysis are:

• significant long-term consequences, such aspermanently altering the ecology of anenvironmental system

• significant short-term consequences, wherethe effects are temporary

The consequence analysis is independent of theprobability of an event occurring.

Determining the overall risk

The overall risk is a function of the probabilityof a measure, structure or system failing, or ofan event or activity causing environmentaldamage, and the magnitude of theenvironmental damage, should it fail.

Determining risk levels is an iterative process.The objective of the process is to reduce risk toacceptable levels by implementing an actionplan.

Ranking

Wherever possible, risks should be quantifiedusing scientific data, experience and judgement.Unfortunately, when risk assessmentmethodology is applied to constructionactivities, many risks cannot be quantifiedbecause of the lack of historical data. Inaddition, site-specific factors, such as sitetopography, have a major effect on risk levels.

The magnitude of the risk is either estimated orranked in order of importance. Ranking


involves listing risks relative to one another,from high to low.

Ranking risks, based on uncertain and limiteddata, requires a high degree of judgement. It istherefore important that this step is conductedby an expert with experience in assessing riskson major construction sites.

Rankings need to be reviewed as actions aretaken to eliminate or reduce the risk.

RISK ASSESSMENT

Objective

To identify and rank all potential risks that mayarise from the construction of major projects.

Suggested measures

• Collect all relevant information needed toconduct a risk assessment of constructionactivities.

• Identify, assess and rank risks to allsegments of the environment, humanbeings, nuisance and loss of amenity fromplans of the proposed development.

• Once construction commences, review therisk assessment as risk managementstrategies are implemented, inspection ormonitoring identifies new risks or whenthere are changes to the project.

2.3 Risk management

Risk management is the development of anaction plan, including measures and strategies,which reduces significant risks to acceptablelevels.

Risk management should be applied to pre-construction planning for the most cost-effective environmental outcomes.

Risk assessment and management should becontinually updated during the constructionphase.

Precautions and measures to preventenvironmental problems are preferred tostructural controls that either reduce or controlrisks.

Avoiding risks

The most effective approach is to avoid risk bymodifying the design. Selecting a route thatbypasses a sensitive environmental area,avoiding areas with high erosion potential, orretaining existing topography whereverpractical rather than undertaking major land-shaping, are examples of risk avoidance.

Reducing risks

There are several strategies that can beimplemented to reduce environmental risks.

For example, sequence works so that smallsections of the site are worked on at any onetime. If rehabilitation is commencedimmediately works are completed, the risk oferosion, contaminated run-off and dust isreduced. Keeping haul roads to a minimum androuting them to avoid erodible areas, such assloping terrain, will also help reduce dust anderosion problems. Another way of reducing riskis to avoid scheduling works on areas that posea very high risk of erosion during periods whenheavy rains and strong winds are expected.

These are some of the approaches that can betaken to reduce risk.

• Increase inspection, surveillance andmonitoring frequency so that new orunderestimated risks are quickly identifiedand managed, and any failures or imminentfailures in controls are promptly identifiedand repaired.

• Implement a preventative maintenanceprogram for pollution-control installationsto reduce the risk of equipment failure.


• Implement contingency plans, such asensuring that corrective action on a failingcontrol measure is prompt. Suchcontingency plans will reduce theenvironmental impact of a hazard.

Controlling risks

It is possible to manage risks by installingcontrol measures. For example, by constructinga sediment pond it is possible to trap silt andtreat contaminated water. Paving haul roads toreduce the generation of dust is another controlwhich can be adopted.

Large structural controls need to be plannedand installed before construction commences.These include, but are not restricted to,sediment retention basins and artificial wetlandsto treat contaminated stormwater, andstructures to reduce water velocities.

As a general principle, various sedimentinterception and control devices should beinstalled as close to the source as possible. Forexample, install wheel washes and rumble gridsto prevent dirt being taken off-site rather thaninstituting road sweeping.

RISK MANAGEMENT

Objective

To implement risk management strategies toreduce all significant risks to the environment toacceptable levels.

Suggested measures

• Develop an action plan to manage allsignificant risks to the environment.

• Implement, wherever possible, riskmanagement measures at the planning stageof the construction project.

• Select risk management options, in order ofpreference, based on avoiding risk,reducing risk and controlling risk.

• Identify major control structures, likesediment basins, stormwater diversiondrainage and artificial wetlands, and installthem before other construction activitiescommence.

• Install controls as close to the source of theproblem as possible.


IDENTIFY ENVIRONMENTAL

VALUES

ENVIRONMENTAL MONITORING

SHOULD COMMENCE

WHEN PROJECT IS APPROVED

AND CONTINUE UNTIL THE

PROJECT HAS BEEN

COMMISSIONED AND IS

OPERATING

SITE ASSESSMENT

RISK ASSESSMENT

DESIGN SPECIFICATION

AND WORK SCHEDULE

RISK MANAGEMENT ACTION PLAN

INSTALL ENVIRONMENTAL

CONTROLS

ONGOING RISK ASSESSMENT

PROJECT APPROVAL

COMMENCE CONSTRUCTION

ENVIRONMENTAL MANAGEMENT PLAN

The relationship between risk assessment, the risk management action plan,the environmental management plan and monitoring


3 ENVIRONMENTAL MANAGEMENT PLAN

3.1 Environmental management plan

The environmental management plan containsall aspects of a project’s environmentalmanagement, and should be prepared by thecontractor before work commences on anyconstruction project.

Once the environmental site and riskassessments, and risk management steps havebeen completed (see section 2), thenimplementation of risk management measures isachieved via the environmental managementplan.

A pre-requisite for the environmentalmanagement plan is for the constructingcompany to have an environmental managementsystem in place. The environmentalmanagement system establishes quality systemsto ensure consistently high environmentoutcomes for the project as a whole. BritishStandard 77502, which has gained wideinternational acceptance, or the soon to beadopted ISO 14000 series3 should be used.

3.2 Best practice documents

The environmental management plan shouldcontain best practice source documents whichcan be used to address significantenvironmental risks. These are generic, andshould be applied to site conditions via thesegment environmental control plan.

Sections 4 to 9 present some general principlesupon which best practice can be based.

2 British Standard Institute, Specification for

environmental management systems,BS 7750, 1992.

3 International Standards Organisation,Environmental management systems, DraftInternational Standard ISO/DIS 14001and 14004.

3.3 Segment environmental control plan

On large sites, it is normal to divide the areainto segments. A control plan should beprepared for each segment. Segment boundariesare selected on the basis of natural features, theplacement of sub-catchments, or associationwith different contractors.

A number of elements of the plan will be thesame for each segment, such as hours ofoperation and controls on noise and emissionsfrom vehicles. However, each segment mayrequire area-specific controls.

The controls are taken from the action planarising out of the risk management process (seesection 2.3).

The main components of a segmentenvironmental control plan are as follows:

Work scheduling

Actions taken to reduce or avoid environmentalimpact by rescheduling works, or prohibiting orlimiting certain activities from times of the yearwhen unfavourable climatic conditions exist,should be stated.

Land disturbance

Map the existing topography and changes to thelandform of each segment, as constructionprogresses.

The map should identify critical areas forprotection which may be easily erodible, suchas highly erodible soils, steep slopes, haulroads, or bare areas.

Stormwater management

It is important to have accurate informationabout on-site drainage for each micro-catchment so that control devices are


adequately designed for the expected flow andload. Such information should be available foreach change in landform that affects a micro-catchment.

Specifications for diversion drains andtemporary stormwater controls to reduce on-sitevolumes should be included in the plan.

Control installations and measures

The plan should identify the position and designspecification of structures and measures takento control:

• sediment run-off

• dirt on roads

• noise and vibration

• dust

A schedule for installation of these controlsshould be included in the plan.

Soil stockpiles and batters

The plan should address how stockpiles andbatters are to be managed.

It should include the location of all stockpiles,the interval before they are used, how they areto be stabilised, and what control measures areto be implemented while they are beingstabilised.

For permanent batters and temporary or finalslopes that have been cut during construction,the plan should indicate how these are to bestabilised and what control measures are to beimplemented while stabilisation takes place.

Special operational precautions

When work is being done near anenvironmentally sensitive area, then specialprecautions should be identified in the plan

Contingency plans

Site-specific contingency plans are required forsignificant risks that have not been controlled.For example, the plan should includeprocedures for managing stormwater fromintense storm events or repairing a controlstructure should it fail.

Rehabilitation

A rehabilitation plan should be developed assoon as possible after the design is finalised.

A schedule for stabilising and revegetatingcleared areas should be given, and an ongoingprogram to maintain rehabilitated areas shouldalso be included.

The site should be rehabilitated so that theimpact on the environment is minimal.

Maintenance, inspections and surveillance

A maintenance and inspection program shouldbe provided for all control structures andmeasures. Ongoing surveillance of the site isrequired to ensure that new risks are identifiedas they arise. This allows the environmentalmanagement plan to be adjusted to ensure thatany new risks are adequately managed.

Ongoing risk assessment and management

Construction sites are continuously changing. Itis therefore important that the initial riskassessment (see section 2.2) is updated for eachsegment. This needs to be integrated into theinspection program.

Updating the plan

The plan should be updated to addressdeficiencies identified by the monitoring oraudit program and as new risks are identifiedthrough surveillance.


ENVIRONMENTAL MANAGEMENTPLAN

Objective

To develop an environmental management planto reduce the adverse impact of constructionactivities on the environment.

Suggested measures

• A environmental management systemshould be in place, as a pre-requisite topreparing an environmental managementplan.

• Prepare an environmental control plan fordefined segments of the site for large sites,or a whole-of-site plan for smaller sites.

• The plan should implement the riskmanagement action plan, include detailedspecifications on site-specific controls andinclude a rehabilitation program in the plan.

• Base the measures in the plan on bestpractice.

• Update the plan to meet new risks or whereinspections, monitoring or audit reveal thatmeasures are ineffective.

• Update the plan to achieve ongoingimprovement.


4 LAND DISTURBANCE

Large projects usually involve extensive landdisturbance, involving removing vegetation andreshaping topography. Such activities make thesoil vulnerable to erosion. Soil removed byerosion may become airborne and create a dustproblem or be carried by water into naturalwaterways and pollute them.

Measures to address the impact of landdisturbance on the environment should beincluded in the planning and design phase of theproject, before any land is cleared.

These measures should be placed into theframework of the segment environment controlplan (see section 3.3).

4.1 Erosion

When considering land disturbance and itsconsequences, priority should be given topreventative rather than treatment measures.

To develop effective erosion controls it isnecessary to obtain information on the erosionpotential of the site where soil disturbance isplanned. Erosion potential is determined by theerodibility of the soil (type and structure),vegetative cover, topography, climate (rainfalland wind), and the nature of land-clearing.Erosion potential will also be affected by thetype, nature and intensity of earthwork.

Erosion potential of rainfall can be calculated

using the universal soil loss equation4,5.

4 C. E. Israelsen, C. G. Clyde, J. E. Fletcher,

E. K. Israelsen, F. W. Haws, P. E. Packer& E. E. Farmer, Erosion Control duringHighway Construction: Manual onPrinciples and Practices, NationalCooperative Highway Research ProgramReport 221, Transportation Research Board1980.

5 R. J. Garvin, M. R. Knight & T. J.Richmond, Guidelines for Minimising Soil

Conversion to SI metric units is given by Fosteret al. (1981)6. The erosion potential of wind canalso be calculated, and details are available in apaper by Israelsen et al. (1980)7.

Information on predicted soil losses from landdisturbance should be used to plan and engineercontrol solutions.

Ground cover provides the most effectivemeans of preventing erosion. Consequently,sediment run-off and dust controls depend onretaining existing vegetation or revegetating andmulching disturbed areas as soon as possible.

The following measures should be taken tominimise erosion:

• Keep land clearance to a minimum. • Avoid wherever possible clearing areas of

highly erodible soils and steep slopes whichare prone to water and wind erosion.

• Revegetate and mulch progressively as each

section of works is completed. The intervalbetween clearing and revegetation shouldbe kept to an absolute minimum.

• Coordinate work schedules, if more thanone contractor is working on a site, so thatthere are no delays in construction activitiesresulting in disturbed land remainingunstabilised.

Erosion and Sedimentation fromConstruction Sites in Victoria, TC-13,1979.

6 G. R. Foster, D. K. McCool, K. G. Rendard& W. C. Moldenhauer, Conversion of theUniversal Soil Loss Equation to SI MetricUnits, J. of Soil and Water Conservation,p. 355-359 1981.

7 Israelsen et al. op. cit.


• Program construction activities so that thearea of exposed soil is minimised duringtimes of the year when the potential forerosion is high, for example during summerwhen intense rainstorms are common.

• Stabilise the site and install and maintainerosion controls so that they remaineffective during any pause in construction.This is particularly important if a projectstops during the wetter months.

• Keep vehicles to well-defined haul roads. • Keep haul roads off sloping terrain

wherever practical. • Designed the slope of a cut to minimise the

angle of incline. • Cultivating the cut surface will increase

infiltration of rainfall and decrease thevelocity of water across the slope duringrain and therefore reduce erosion.

MINIMISING EROSION

Objective

To minimise the quantity of soil lost duringconstruction due to land-clearing.

Suggested measures

• Schedule measures to avoid and reduceerosion by phasing the work program tominimise land disturbance in the planningand design stage.

• Keep the areas of land cleared to a

minimum, and the period of time areasremain cleared to a minimum

• Base control measures to manage erosion on

the vulnerability of cleared land to soil loss,paying particular attention to protectingslopes.

• Mulch, roughen and seed cleared slopes and

stockpiles where no works are planned formore than 28 days, with sterile grasses.

• Keep vehicles to well-defined haul roads. • Rehabilitate cleared areas promptly.

4.2 Management of contaminatedstormwater

Soil eroded during land disturbance can washaway and contaminate stormwater.

If contaminated stormwater enters a drainageline or stormwater drainage system, it willeventually discharge into an adjacent waterwayand pollute it.

The type of sediment controls suitable for aparticular situation depend on the nature of thesite, in terms of such factors as rainfallpatterns, soil type and topography. Thesefactors need to be taken into account when


selecting appropriate controls and ensuring thatdesigns are adequate.

There are a number of ways of minimisingsediment run-off.

Reduce stormwater on the site

If uncontaminated water enters part of the sitethat has been cleared, it will quickly pick upsediment and need to be treated. Additionalwater may also add to the erosion potential,increasing the risk of pollution.

It is therefore desirable to divert cleanstormwater away from those parts of the sitewhere soil is to be exposed. This can be doneby constructing diversion banks and interceptdrains around the site while ensuring that thewater discharging from such banks or drains isdisposed of without causing erosion.

Wherever possible, the new stormwaterdrainage system should be installed before anyland disturbance activities commence. Ifpossible on-site inlets should not be connecteduntil the site has been stabilised andrehabilitated. In this way, silt-laden stormwatercannot escape the site via this route and pollutesurface waters. It will have to be treated on-site.

Water velocities

There is a direct relationship between thevelocity of water flowing over exposed soil andthe rate of erosion.

Installation of rock structures on the site toretard water flows is an effective measure toreduce erosion in areas where high water flowsare expected.

It is desirable to minimise continuous slopeswhere flowing water can scour.

To prevent scouring, drainage lines may need tobe lined or velocity-reducing structures, such ascrushed rock or geotextile placed in thedrainage line.

Slopes

Any natural drainage lines that discharge wateron to the top of a slope should be directed tograssed areas by intercept drains. Otherwisewater will run down the slope, eroding it.Perimeter banks or sediment fences should alsobe constructed at the toe of the slope to containsediment run-off.

STORMWATER MANAGEMENT

Objective

To minimise the generation of contaminatedstormwater.

Suggested measures

• Minimise the quantity of uncontaminatedstormwater entering cleared areas.

• Establish cut-off or intercept drains toredirect stormwater away from clearedareas and slopes to stable (vegetated) areasor effective treatment installations.

• Reduce water velocities.

4.3 Designing erosion and sedimentcontrol devices

There are a large number of control devices thatwill suit most circumstances. These Guidelinesare restricted to addressing the generalprinciples behind erosion and sediment controlsrather than providing detailed designspecifications.

Most damage is done in the initial part of astorm, between 30 minutes and two hours into astorm, and during prolonged storms.

Designs of control structures, therefore, need toaccount for peak run-off flows.

Where it is not possible to schedule works toavoid times of the year when high rainfall is


expected, then additional controls may berequired, such as installing extra sediment trapsor enhancing the capacity of existing controls.

Sediment interception and settling

Sediment detention dams, ponds or basins holdsediment-contaminated run-off long enough forsuspended sediment to settle out. Clarifiedwater can then be discharged to stream.

Permanent structures that will provide ongoingsediment control, after a site has beenrehabilitated, should be designed using a 50-year-recurrence interval. Examples ofpermanent structures are wetlands and majorsediment detention dams.

Temporary sediment control structures shouldbe designed to take predicted flows, based on aone-in-two-year storm (two-year ARI withintensity for six hours) and sub-catchmentareas, while contingency plans should be inplace to account for extreme storm events. Usethe Universal Soil Loss Equation8 to estimatelong-term average annual yield of sedimentfrom small uniform sections of catchments.Run-off and sediment control structures shouldbe designed and constructed to accept theexpected peak flows and sediment loads.

Interception and chemical treatment

Fine colloidal clays suspended in run-offrequire a long time to settle, often exceeding theeconomic or practical detention storagecapacity. Flocculants may need to be added tohasten settlement.

Residual flocculant in suspension should not bereleased if it degrades water quality or theaquatic habitat in natural waterways. Chemicalsludge will require off-site disposal to a landfilllicensed to accept such wastes.

8 C. E. Israelsen et al. op. cit.

Sediment filtering

Adequate controls should be placed on alldrainage lines. Silt loads should be treated asclose to their source as possible using effectivesediment traps such as geotextile fences andstraw bales.

In-stream controls

When the site is intersected by a stream, thenin-stream controls such as a rock weir arerequired to reduce water velocity and trapsediment. Special precautions should be takenwhen cleaning behind a weir to ensure thattrapped sediment is not resuspended.

Inspection, maintenance and cleaning

The effectiveness of sediment control devicesdepends on an adequate inspection,maintenance and cleaning program. Inspections,particularly during storms, will show whetherdevices are operating effectively (see section9.1). Where a device proves inadequate, itshould be quickly redesigned to make iteffective.


SEDIMENT CONTROLS

Objective

To minimise the impact of contaminatedstormwater on receiving waters.

Suggested Measures

• Install erosion and sediment controlmeasures, if possible before constructioncommences.

• Identify drainage lines and install controlmeasures to handle predicted stormwaterand sediment loads generated in the mini-catchment.

• Design and install appropriate erosion andsediment run-off control measuresappropriate to site conditions to handle aone-in-two-year storm event (two-yearARI with intensity of six hours), fortemporary structures, and a one-in-fiftyyear storm event, for permanentstructures.

• Establish an adequate inspection,maintenance and cleaning program forsediment run-off control structures.

• Ensure that contingency plans are in placefor unusual storm events.

• Continually assess the effectiveness ofsediment control measures and makenecessary improvements.


There are a large number of erosion and sediment run-off control devices which are available. Theselection and design will depend on site-specific considerations and it is beyond the scope of these tooutline how to design such installations. Further information should be obtained directly from thereferences, which are listed below:

Auckland Regional Water Board, Urban Earthworks - A Guide for Erosion, Technical Publication no.7, 1979.

Aveyard J M (ed.), Design Manual for Soil Conservation Works, Soil Conservation Service TechnicalHandbook no. 5, NSW Department of Soil Conservation and Land Management, 1982.

Department of Conservation and Land Management, Urban Erosion and Sediment Control, NSW,1992.

NSW Department of Housing, Soil and Water Management for Urban Development, NSW, 1993.

Environment Protection Authority, Construction Techniques for Sediment Pollution Control,Publication no. 275, 1991.

Garvin, R. J., Knight M. R. & Richmond T. J., Guidelines for Minimising Soil Erosion andSedimentation from Construction Sites in Victoria, TC-13, 1979.

Goldman, S. J., Jackson, K. & Bursztynsky, T. A., Erosion and Sediment Control Handbook,McGraw-Hill Book Company, 1986.

Highway Research Board, Erosion Control on Highway Construction, National Cooperative HighwayResearch Program, Synthesis of Highway Practice 18, 1973.

Pollution Control Authority, Guidelines for Erosion and Sediment Control on Building Sites, ACT,1989.

Quilty, J. A., Hunt, J. S. & Hicks, R. W., Urban Erosion and Sediment Control, Soil ConservationService Technical Handbook, no. 2, Soil Conservation Service of NSW, 1978.

Ransom M. J., Control of Erosion on Construction Sites, Department of Conservation, 1987.

Richards, D. L. & Middleton, L. M., Best Management Practices for Erosion and Sediment Control,Department of Transportation, 1978.

Rosewell, C.J. & Edwards, K., SOILOSS - A Program to Assist in the Selection of ManagementPractices to Reduce Erosion, Soil Conservation Service Technical Handbook, no. 11, NSWDepartment of Conservation and Land Management, 1988.

Scott & Furphy Pty Ltd, Design Manual for Urban Erosion and Sediment Control, National CapitalDevelopment Commission, 1988.

Water Resources Administration, Maryland Standards and Specifications, Maryland Department of theEnvironment, 1994.


4.4 De-watering work sites

After rain, pooled water is often pumped off-site. Often this water is contaminated withsuspended sediment so it is essential that itsdisposal should not contribute to waterpollution.

To remove water from the work area, the pumpintake should be kept as close to the surface ofpool as possible. Floating intakes should beused when the depth of water is sufficient. Caremust be taken to avoid pumping from thebottom of ponds, and constant supervision isrequired during pumping operations to ensurethis does not happen.

Treatment is required before discharging run-off to a natural waterway or stormwatersystem, where turbidity exceeds 30 NTU9 andis higher than upstream measurements. Hourlymeasurements of discharge water quality shouldbe taken.

Contaminated water pumped off the site should,wherever possible, be directed to vegetatedareas. Precautions should be made to ensurethat such areas don't become waterlogged andhave adequate capacity to effectively removesuspended solids.

Where vegetated areas are not available, thenwater should be directed to existing or speciallyprovided sediment control structures.

Pumping to natural waterways should besupervised through the operations.

In urban areas it may be possible to dischargecontaminated run-off to sewers. Such adischarge will require approval of the relevantsewerage authority. 9 NTU is an abbreviation of nephelometric

turbidity units, which is a measure of lightscattered as it passes through a solution. Itis not directly related to suspended material,but is a good measure of the clarity of awater sample. It can easily be measured insitu, making it a convenient measurementwhen an on-the-spot decision needs to bemade.

This option is of limited usefulness as de-watering the site will usually be required duringor immediately after rainfall, when the sewersare also be near capacity and unable to acceptany additional volume.

DE-WATERING WORK SITES

Objective

To ensure that de-watering operations do notresult in turbid water entering naturalwaterways.

Suggested measures

• Treat contaminated water pumped into thestormwater system or a natural waterwayto remove sediment if the turbidity exceeds30 NTU.

• Ensure that the level of suspended solids inwaters pumped into natural waterwaysnever exceeds the regulatory water qualitystandard.

• De-water by pumping water, whereverpractical, on to vegetated area of sufficientwidth to remove suspended soil, or tosediment control devices.

• Supervise all pumping and implementprecautions to ensure that turbidity ofpumped water is minimised.

• Monitor every hour during a pumpingoperation the turbidity of water pumpeddirectly to a natural waterway or adrainage system discharging to a naturalwaterway .


4.5 Dust control

Many of the measures taken to reduce dustproblems are the same as those taken tominimise erosion and sediment run-off.

Additional measures, not mentioned in thesections on erosion or sediment control, areoutlined below.

• Prevent the generation of dust in preferenceto applying dust suppression measures.

• Ensure in the project schedule that the areaof cleared land is minimised during thedrier months of the year, when dustgeneration is at its greatest.

• Pave and water haul roads. The frequencyof watering will be determined by weatherconditions and the erodibility of the soil. Ifadditives in the water are used to increaseits dust suppression properties, thechemical should have no adverseenvironmental impact on adjacent waterbodies.

• Water areas other than haul roads, if theyare a source of dust.

• Ensure that smooth surfaces are deepripped and left rough and cloddy to reducethe wind velocity at the soil surface.

• Construct wind fences if this is appropriatefor the site.

As a contingency measure, in areas that do nothave access to a reticulated water supply, waterstored on-site should never be less than 2,000litres per hectare of disturbed land surface.

Wherever watering is used to suppress dust,ensure it does not create contaminated run-offthat will contaminate surface waters.

DUST CONTROL

Objective

To ensure there is no health risk or loss ofamenity due to emission of dust to theenvironment.

Suggested measures

• Implement a dust prevention strategy,developed at the project planning stage.

• Take dust suppression measures, such aspromptly watering exposed areas whenvisible dust is observed.

• Install wind fences wherever appropriate.

4.6 Management of stockpile and batters

Stockpiles and batters are a potential source ofdust and sediment run-off.

Additional controls to those covered previouslyare outlined below.

• Locate stockpiles away from drainage linesto where they are protected from wind.

• Minimise the number and size of stockpiles.

• Keep topsoil separate from underburdenwhen stockpiling soil.

• Construct the stockpile with no slopegreater than 2:1 (horizontal to vertical). Aless steep slope may be required where theerosion risk is high.

• Mulch, roughen and seed with sterilegrasses any batter or topsoil stockpilewhich is to be maintained for longer than28 days.

• Treat underburden stockpiles in the sameway, but check whether they need a layer of


topsoil to provide a media for grass seedsbefore seeding.

• Circle all unstabilised stockpiles andbatters with silt fences or a drainage systemthat will collect and correctly dispose ofcontaminated water (see section 4.2).

• Locate stockpiles within ten metres of awaterway only if no other alternatives exist.This situation should be identified in therisk assessment.

• Hand water or install temporary sprinklersto suppress dust from unstabilisedstockpiles and batters.

• Finish and contour any stockpiles locatedon a floodplain so as to minimise loss ofmaterial in a flood or rainfall event.

MANAGEMENT OF STOCKPILESAND BATTERS

Objective

To manage soil stockpiles so that dust andsediment in run-off are minimised.

Suggested measures

• Minimise the number of stockpiles, and thearea and the time stockpiles are exposed.

• Keep topsoil and underburden stockpilesseparate.

• Locate stockpiles away from drainagelines, at least 10 metres away from naturalwaterways and where they will be leastsusceptible to wind erosion.

• Ensure that stockpiles and batters aredesigned with slopes no greater than 2:1(horizontal/vertical).

• Stabilise stockpiles and batters that willremain bare for more than 28 days bycovering with mulch or anchored fabricsor seeding with sterile grass.

• Establish sediment controls aroundunstabilised stockpiles and batters.

• Suppress dust on stockpiles and batters, ascircumstances demand.

4.7 Working in waterways andfloodplains

The responsible drainage body must beconsulted if there are any works that willimpact on a waterway. Changes to the physicalnature of a waterway require prior approvalfrom the responsible drainage authority.

At the design stage, consider all options toavoid working in a natural waterway.


Procedures

Where it is not possible to avoid working in astream, then additional precautions should betaken.

• Minimise the time during which work in awaterway is required, and the extent ofworks.

• Schedule works for the driest months of theyear and the lowest flow of the waterway.

• Avoid times of the year when aquaticpopulation may be under stress, such asduring migration spawning, or when foodmay be scarce.

• Establish protocols to minimisedownstream damage.

• Stabilise any disturbance to a levee or anyother bank so that erosion is avoided.

• Measure turbidity continuouslyimmediately downstream from the areas inwhich work is occurring, and modify workpractices where continuous monitoringshows degraded water quality.

• If working in a concrete channel, use

appropriate machinery to avoid damage tostructures.

Stream crossings

If in-stream activities require construction of astream crossing, it should be installed duringlow-water flows with downstream weirs inplace to trap any released sediment.

Three types of access crossings may beconsidered.

• Culvert: this type of crossing may beeffective in controlling erosion while in use,but will cause erosion during installationand removal.

• Ford: this type of crossing may only beused during periods of low flow. A ford is

not appropriate if construction willcontinue during wet periods of the year.

• Bridge: this type of crossing must be usedfor major waterways and for otherwaterways with high flows.

The crossing should be protected againsterosion, both to prevent excessivesedimentation in the waterway, and to preventwashout of the crossing.

The crossing should be positionedperpendicular to the flow and located at thenarrowest part of the stream. Damage to thestream bed and banks should be avoided. Thecrossing should be engineered to be stableunder the expected vehicle loads. Drainage overthe surface of the crossing and access roadshould have adequate controls to ensure thatsediment run-off to the stream is minimised.

If a cofferdam is used, minimum downstreamflows should be maintained that will sustain theaquatic ecology.

Stream crossings also act as sediment traps.Cleaning sediment out behind a crossing shouldfollow the same procedure as for weirs.

Contingency planning

As mentioned in section 4.3, it is best practiceto design pollution measures and controls toaccount for a one-in-two-year storm event (two-year ARI with intensity of six hours).

Contingency plans should also be in place formore intense storm events, particularly whereworks are planned to occur within a floodplain.

The contingency plan should consider theconsequences on the environment of 5, 10, 20and 100-year-frequency floods.


The contingency plan should address:

• methods to limit stormwater enteringexcavation areas

• enhancement of existing measures andinstallation of additional controls, when anintense storm event is forecast

• siting of construction facilities

• clean-up procedures, including disposal ofexcess water

• a flood warning system

• procedures for preventing the loss of spoil,fuel, chemicals or other materials thatcould adversely affect the environment

• notification of relevant authorities ifunplanned incidents occur that could posea risk to the environment

Reinstatement plan

Prior to works being undertaken on, near orwithin a waterway, a reinstatement plan shouldbe prepared and submitted for approval to theresponsible drainage authority. The planshould include:

• proposed changes to the waterway

• the impact on adjacent vegetation

• the type and form of flood protectionworks

• erosion and sediment run-off controls

• proposed methods for reinstatement of thewaterway bed and banks

• a revegetation plan addressing a period ofno less than 12 months and includingproposed species and locations, methodsfor weed control and ongoing maintenanceuntil a satisfactory level of establishedplants is achieved.

WORKING IN WATERWAYS ANDFLOODPLAINS

Objective

To minimise stress on aquatic communitieswhen working in a waterway.

Suggested measures

• Plan in-stream works so that the contacttime is minimised.

• Establish special practices so that impacts

on the waterway and disturbance of itsbanks are minimised.

• Stabilise banks and in stream structure so

that they do not contribute to the sedimentload.

• Maintain minimum flows to ensure theviability of aquatic communities andensure that there are no barriers to thepassage of fish up and downstream.

• Avoid times of the year whenenvironmental damage is expected to behighest.

• Construct in-stream crossings during lowflows, designed to be stable underexpected vehicle loads and flow regimes,that do not contribute to the sediment loadin the stream.

• Design crossings so that drainage off thecrossing does not contribute sediment loadto the stream.

• Prepare a contingency plan for high-rainevents.

• Prepare a reinstatement plan if work in astream is planned or the structure of awaterway will be altered.


5 NOISE AND VIBRATION

While no specific statutory controls exist fornoise from construction sites, all noise nuisanceshould be reduced wherever possible fromvehicles, fixed machinery within the site,blasting, general construction activities, andfrom movements of vehicles servicing the site.

5.1 Operating hours

One of the most effective means of reducingnoise nuisance from construction activities,where there are residents nearby, is to limit thetimes of operation of noisy equipment vehicles,and operations.

There are occasions when it is necessary towork beyond these times. Exceptions can bemade in cases where an activity that hascommenced cannot be stopped, such as aconcrete pour, and deliveries may need to bemade outside normal working hours to avoid amajor traffic hazard.

Documentation justifying out-of-hours workshould be maintained and authorised by sitemanagement. Local residents who are affectedby such activities should be notifiedbeforehand.

Even with such restricted hours, every effortshould be made to reduce the noise of all siteactivities.

5.2 Vehicles and equipment

Noise from vehicles and powered machineryand equipment on-site should not exceed themanufacturer's specifications, based on theinstallation of a silencer. Equipment should beregularly serviced. Attention should also begiven to muffler maintenance and enclosure ofnoisy equipment.

5.3 Traffic

There is a conflict between operationalefficiency and local amenity, with regard totraffic flows in and out of a construction site.During normal business hours when trafficdensities are high, deliveries of materials andlarge equipment can cause severe traffic snarlsand even pose a danger to other vehicles. Out-of-hours deliveries will cause noise pollutionfrom trucks moving past nearby houses.

5.4 Noise abatement

Depending on the location of the facility,suitable noise suppression or abatementmeasures may be required, such as theprovision of earthen embankments or othernoise screens.

5.5 Vibration

On road constructions, impact pile-driving maybe used to establish a base for foundations.These operations can give rise to high levels ofground vibrations.

The magnitude of the nuisance created byvibrations depends on the nature of soilstransmitting the vibration and the distance tothe nearest building.

A British study10 has found that nuisance fromground vibration and building damage isunlikely to occur if the operation is conductedat distances greater than 50 metres.

10 D. J. Martin, Ground Vibrations from

Impact Driving during RoadConstruction, Supplementary Report544, Transport and Road ResearchLaboratory, 1980.


Complaints about air vibrations from blastinghave been received from people 100 metresaway from the activity.

NOISE AND VIBRATION

Objective

To ensure nuisance from noise and vibrationdoes not occur.

Suggested measures

• Fit and maintain appropriate mufflers onearth-moving and other vehicles on the site.

• Enclose noisy equipment.

• Provide noise attenuation screens, whereappropriate.

• Where an activity is likely to cause a noisenuisance to nearby residents, restrictoperating hours to between 7 am and 6 pmweekdays and 7 am to 1 pm Saturday,except where, for practical reasons, theactivity is unavoidable.

• Noise should not be above backgroundlevels inside any adjacent residencebetween 10 pm and 7 am.

• Advise local residents when unavoidableout-of-hours work will occur.

• Schedule deliveries to the site so thatdisruption to local amenity and traffic areminimised.

• Conduct a study on the impact of groundvibration from construction activities,where these operations occur within50 metres of a building and takeappropriate action.

• Minimise air vibrations.


6 WASTE MINIMISATION

When choosing between waste minimisationoptions, the following hierarchy for wastemanagement is preferred:

(i) waste avoidance and/or reduction

(ii) reuse

(iii) recycling

Diverting the waste stream in these ways meansthat waste treatment and waste disposal optionscan be reduced.

Construction sites should pursue this hierarchyand seek out waste reduction opportunities.

To identify opportunities it is necessary toconsider all aspects of the project and thewastes it generates.

Waste can be minimised by using improvedtechnology, recycled or reused on-site, or bymaking purchasing decisions that favourrecycled products.

Wherever possible, include performancemeasures and targets for reduction, reuse andrecycling options in the environmentalmanagement plan.

Waste minimisation opportunities include:

• obtaining construction materials, paints,lubricants and other liquids in reusablepackaging or containers

• using noise barriers made from recycled

materials

• using overburden to construct temporarynoise barriers.

• using contaminated water out of sedimentdams for dust suppression and irrigatingadjacent vegetated land

• sending waste concrete from demolitionactivities to a concrete recycler instead oflandfill

• segregating and recycling solid wastesgenerated by construction activities, officesand mess-rooms

• collecting lubricating oil from theconstruction vehicle fleet and sending it to arecycler

WASTE MINIMISATION

Objective

To minimise the waste load discharged to theenvironment.

Suggested measures

• Carry out a waste minimisation assessmentwhich examines opportunities for wasteavoidance reduction, reuse and recycling.

• Reduce wastes by selecting, in order ofpreference, avoidance, reduction, reuse andrecycling.

• Incorporate waste minimisation targets andmeasures into the environmentalmanagement plan.


7 CONTAMINATED MATERIAL AND WASTES

On large construction sites, it is possible thatold tips will be uncovered or the land found tobe contaminated. Where this occurscontaminated material or soil may need to bedisposed of.

Disposal methods adopted depend on the natureof the material. To obtain this information, acomprehensive sampling and analysis programis required so that the correct route for disposalcan be determined. For an old tip, samplingshould also ascertain the odour levels, presenceof methane, groundwater levels and leachatequality.

7.1 Solid inert wastes

Solid inert waste found on construction sitesusually consists of building rubble, but mayalso include as demolition material, concrete,bricks, timber, plastic, glass, metals, bitumen,trees and shredded tyres. Such wastes should bereused, recycled, or disposed of to a landfill sitelicensed to take such wastes.

7.2 Putrescible wastes

Old tips that accepted municipal rubbish alsocontain putrescible wastes.

Putrescible wastes are defined as waste able tobe decomposed by bacterial action. It usuallyconsists of discarded food, domestic garbage,commercial wastes, grass and garden clippingsand prunnings.

As many old tips were not licensed by EPA it ispossible that other wastes were buried, and theinspection and analytical program should bedesigned to detect other materials if they arepresent.

Old tips may also contain contaminatedleachate and gases, such as methane andodorous sulphur gases.

The biological and chemical condition of the tipwill depend on its age and contents.

Excavating putrescible wastes could give rise tothe following problems:

• escape of methane and odorous landfillgases

• release of contaminated leachate

• production of litter

• prevalence of seagulls and vermin

Precautions will need to be taken duringexcavation to ensure that these problems areadequately controlled.

The controls for the excavation, disposal andrehabilitation of the remainder of the tip areoutlined below:

• Contain, extract and treat or dispose ofcontaminated water to the sewerage system,provided the appropriate approvals fromthe appropriate water board have beenobtained.

• Extract and flare landfill gases, if sufficientquantities are present.

• Control odours during excavation byminimising the working surface area andimmediately covering with a clean fill. Adeodoriser might also be needed tominimise emissions of malodorous gases tothe atmosphere.

• Limit leachate generation by minimisinginfiltration or ingress of water into thelandfill through installation of cut-offdrains, banks or bunds around theexcavation areas.


• Cap excavated areas with an impermeablematerial (0.5 metre minimum).

Transport of the excavated putrescible waste toa licensed landfill may also cause problems.Old putrescible wastes can be highly odorous,and additional measures may need to be taken,such as using sealed and covered containers.

7.3 Low-level contaminated soil

Old tips may contain soil contaminated withchemicals such as heavy metals andhydrocarbons. Construction sites may alsointersect contaminated sites, with elevatedlevels of heavy metals, hydrocarbons or othertoxic chemicals.

The classification of contaminated soil dependson the concentrations of the contaminants andtheir leachability, as described in an EPAinformation bulletin11.

The bulletin describes levels of contaminants(Table 1) which define clean fill, and cantherefore be disposed of without restriction.

The bulletin also describes levels of pollutants(Table 2) which define heavily contaminatedsoil. Disposal of prescribed wastes and heavilycontaminated soil is discussed in section 7.4.

However, if contaminant concentrations andleachabilities are between the limits in Tables 1and 2, the soil is classified as low-levelcontaminated and should be disposed of at anappropriately licensed landfill, with a letter ofapproval from EPA.

7.4 Prescribed wastes

If on-site materials that have to be excavatedare prescribed waste, as defined by theEnvironment Protection (Prescribed Waste)Regulations 1987, it will need to be transportedin accordance with the Environment Protection(Transport) Regulations 1987 to a landfilllicensed to accept such wastes.

11 Environment Protection Authority,

Classification of Wastes, Publication 448,1995.

It should be noted that care should be takenhandling prescribed wastes, so that they do notpose a health risk to workers.

CONTAMINATED MATERIAL ANDWASTES

Objective

To ensure that all contaminated materialuncovered on a construction site are excavatedand disposed of in an environmentallyresponsible manner.

Suggested measures

• Assay material uncovered on-site prior todisposal. If the wastes include putresciblewastes, then also analyse leachate andlandfill gases.

• Excavate material in a manner whichavoids off-site environmental problems.

• Seal remaining contaminated material orwastes, where only part of the tip has beenexcavated, to ensure that there is no off-siteeffect now or in the future.

• Transport odorous wastes in covered

vehicles. • Dispose of contaminated material in a

landfill licensed to take the type ofcontaminated material or wastes uncovered.


8 OTHER ENVIRONMENTAL ISSUES

8.1 Emergency procedures

Procedures should be in place, and staff trainedto deal with any emergency, which could causemajor environmental damage.

Adequate equipment, such as spill kits, shouldbe kept on-site to deal with emergency spills.

The EPA should be contacted immediately anemergency occurs on (03) 9628 5777.

8.2 Air Quality

There are three potential sources of airpollution on construction sites. They areexhaust gases from vehicles and machinery andexhaust material from chippers. Dust wasaddressed in section 4.

AIR QUALITY

Objective

To ensure there is no health risk or loss ofamenity due to emission of exhaust gases to theenvironment.

Suggested measures

• Ensure that all vehicles and machinery arefitted with appropriate emission controlequipment, maintained frequently andserviced to the manufacturers'specifications.

• Smoke from internal combustion enginesshould not be visible for more than tenseconds

8.3 Litter

On construction sites, there are two mainsources of litter, building material washed awayduring a storm and deposited into waterways,and rubbish thrown away by constructionworkers.

Litter is often caused by thoughtlessness ofstaff and the unavailability of suitable litterbins on the construction site.

LITTER

Objective

To ensure that all litter is disposed of in aresponsible manner, and is not released into theenvironment.

Suggested measures

• Maintain a high quality of housekeepingand ensure that materials are not left wherethey can be washed or blown away tobecome litter.

• Provide bins for construction workers andstaff at locations where they consume food.

• Conduct ongoing awareness with staff ofthe need to avoid littering.

8.4 Storage of chemicals and fuels

Although it may be necessary to store fuels andchemicals on project sites, this inevitablycreates an environmental risk. Spills canseverely pollute waterways and land.


Reducing the quantities of chemicals and fuelstored on-site to minimum practicable levels isdesirable. Infrequently used chemicals shouldbe ordered just before they are needed. It maybe possible to use a mini-tanker to refuelvehicles, instead of relying on a central fuellingpoint.

There are several approaches that can be takento reduce the risk of fuel spills. Steps couldinclude designing storage units to preventvehicles or fork-lifts puncturing tanks, fittingautomatic cut-offs to fuel dispensers, andmaking units vandal resistant.

Installing bunds will prevent spilt fuel escapingand causing environmental damage. Bundsshould be designed and installed in accordancewith EPA guidelines12.

Key design issues addressed in the guidelinesare height of bund walls, construction material,vehicular access, and stormwater management.Roofed bunds are strongly preferred.

Should a spill occur, then it is necessary tohave a contingency plan in place to deal withthe clean-up. It should consider issues such ascleaning up spilled material on the site,containing and cleaning up spills which haveentered waterways, disposal or reuse ofrecovered residues, and contacting keycompany and government agency personnel toadvise them of the emergency.

12 Environment Protection Authority, Bunding

Guidelines, Publication 347, 1992.

STORING FUELS AND CHEMICALS

Objective

To ensure that fuel and chemical storage issafe, and that any materials that escape do notcause environmental damage.

Suggested measures

• Minimise fuels and chemicals stored on-site.

• Install bunds and take other precautions toreduce the risk of spills.

• Implement a contingency plan to handlespills, so that environmental damage isavoided.

8.5 Road cleaning

Some sites require vehicles to move on and offthe site. It is possible that these vehicles willtransport soil off the site and deposit it on theadjacent roads.

Prevention of soil being deposited on roads ispreferable to cleaning them afterwards.

All points on the site where vehicles regularlyleave should have rumble grids and wheelwashes installed. In wet weather it may benecessary to hose mud off vehicle wheels asthey traverse the grid.

All exits leading to the above mentionedcontrols should be paved with gravel. Top dressthese paths periodically , and remove sedimentfrom the wheel wash.

Where there is only occasional use of roadcrossings (twice a day or less), or where there isinsufficient space on the site to install a rumblegrid and wheel wash then (at least) daily roadsweeping should be instituted. Care should be


taken to ensure that road sweeping does notgive rise to dust problems.

The number of times a day that road cleaningoccurs should be determined by the frequencyof road usage and the state of the roads, whichshould be inspected often.

Installation of litter traps lined with filter clothin side-entry pits will trap soil in stormwaterspilt on roads during rain.

Where soil is being transported for off sitedisposal, then all loads should be covered.

KEEPING ROADS CLEAN

Objective

To ensure that roads are kept clean of soil.

Suggested measures

• Install wheel washes and rumble grids at allmain road crossings.

• Ensure that the roads are swept at leastonce a day on uncontrolled road crossingswhen construction vehicles are travellingoff the site.

• Install litter traps lined with filter cloth inall side-entry pits .

• Cover all loads of soil being taken off sitefor disposal.

8.6 Protecting infrastructure

In built-up areas, care needs to be taken inworking near existing infrastructure servicessuch as drainage and sewerage pipes.

It is important to ensure that any existingdrainage or sewerage pipes that intersect theconstruction site or are adjacent to it are notoverstressed or damaged by movement orplacement of construction plant or materials, orconstruction activities.

Appropriate machinery must be used withinconcrete channels to avoid damage tostructures.

8.7 Concrete batching plants

Sometimes very large construction projects willestablish on-site concrete batching plants.

Plants need to be designed in accordance withEPA guidelines13.

Constructing a plant which is designed to havea throughput of greater than 100 tonnes perweek will need an EPA works approval.

13 Environment Protection Authority Concrete

Batching Plants PublicationTG 204/91, 1991.


9 INSPECTIONS, MONITORING AND AUDITS

9.1 Inspections

The frequency of inspections depends on the risks posed to the environment by each constructionactivity or the nature of the site . These recommendations should be taken as minimum frequencies. Thefrequency of inspections, monitoring and auditing recommended below is based on experience of largefreeway construction.

Installation Possible problems Frequency Remedial action

Drainage New drainage linesnot controlled

At least once everytwo days in areaswhere earth-movingis occurring

Weekly elsewhere

Install appropriate sedimentcontrols on new drainagelines

Sediment controls,silt fences and traps

Not controlledeffectively

Daily in dry weather

Within first twohours of a storm#

Three times a dayduring prolongedrainfall#

Remove sediment from trap

Replace barrier or filter material

Redesign installation

Improve maintenance

Haul roads Dust

Soil on paved roads

At least daily Pave haul roads with gravel orimpervious sealant

Install wheel wash and rumblegrid

Manually wash vehicle wheels

Increase road cleaning frequency

Cut-off and diversiondrains

Water not divertedaway from sensitiveareas

Weekly Replace or repair damaged drains

Redesign ineffective drains

Relocate incorrectly placed drains

# See also table on monitoring requirements under the same heading.



In-stream weirs Ineffectiveduring low flow

Release oftrapped sedimentduring storms

Weekly in dryweather

24 hours beforeforecast rain

Educate sediment trapped behindweir

Clean out behind weir if filled to25% capacity

Stream crossings Unstable

Releasingsediment and soilinto stream

When in use, but noless than weekly

Stop use until installation hasbeen redesigned

Vegetated bufferzones

Accidentallycleared

Weekly Revegetate

Review procedures to ensure norecurrence

Retardation andsettlement basins andartificial wetlands

Sediments noteffectivelyremoved

Weekly Redesign installation

Increase retention times

Add flocculants*

Stockpiles and bareslopes

Erosion Weekly Minimise exposure to run-off andaction of wind

Ensure stabilisation measures areeffective

Unvegetated areas Dust Daily during dryweather

Increase use of water spray onunvegetated areas

Protect untrafficked areastemporarily with mulch or geo-fabric blanket

Vehicles andmachinery

Noise pollution

Exhaust gases

Initially when vehicleor machinery isintroduced to the siteand thereaftermonthly

Ensure that mufflers and noise-shielding are effective

Ensure that emission controls areeffective and motors wellmaintained

* This option should be avoided wherever possible because it creates a problem with sludge removal.



Chemical storageareas

Spills Weekly Clean-up contaminated area

Improve bunding

Litter controls Litter on andoff-site

Daily on andoff-site

Clean-up litter originating on-site

Review number and placement ofrubbish bins

Ensure materials are not stored insuch a manner that they couldcontribute to litter

Speak to staff about the litterdisposal


9.2 Monitoring

Regular monitoring of air and water and taking of noise measurements is required to determine whetherstandards, established by the Environmental Management Plan, are being complied with. This shouldcommence before construction to provide a baseline against which data collected during constructioncan be compared.

Chemical measurements should be conducted by a laboratory registered by the National Association ofTesting Authorities (NATA), and in situ measurements should be made under the supervision of asuitably qualified person from a NATA laboratory.

Monitoring should provide information on whether standards are being complied with and sensitivesections of the environment protected. The following recommendations should be treated as minimummonitoring requirements relating only to the direct impact of construction activities. Other monitoringprograms may be required for major road projects to determine their future impact on traffic emissions.

Area of risk Purpose Monitoring activity Remedial action

Noise Determine whether anoise nuisance exists

As required bycomplainants at theirhomes

Monitor noisecontinuously at arepresentativeresidence nearconstructionactivities

Review and enhancenoise controlmeasures

Air quality (dust) Determine whether adust nuisance exists

Daily during dryweather for dustdeposits at locationsthat indicate impacton adjacent residentsor at site boundary

Improve controls ondust emissions



Water quality (chemicaland biological)

Quantifydownstreamchemical andbiological impact

Identify ineffectivesediment controlinstallations

Design chemical andbiological monitoringprogram by regularlysurveying upstreamand downstreamsites, in consultationwith water resourcemanager, to assessimpact on streamecology under allflow conditions

Install continuousmonitors forturbidity* and flow

Revise on-sitecontrols if regulatorystandards arebreached

Revise riskassessment andmanagement

Identify and repairfailed controlinstallation

Sediment controls, siltfences and traps

Determine whetherthe installation isoperating effectively

Measure turbidity onthe input and outputside of controldevices during wetweather inspections(see inspection tablein section 9.1)

Redesign controldevices

Discharge from retentionponds, artificial wetlandsand sediment dams

Determine whetherretention structuresare effectivelyremoving sediment

Weekly forsuspended solids,conductivity, pH anddissolved oxygen,and daily duringrainfall

Redesign retentionstructures

River crossings Determine whethercrossings are stable

Measure turbidity upand down streamfrom the crossingwhen in use (seeinspection table insection 9.1)

Stabilise structure

Pumping contaminatedwater to the stormwatersystem or naturalwaterway

Ensure that naturalwaters are notadversely affected bypump-out water

Measure turbidityevery hour duringpumping

Stop pumping ifturbidity exceedsregulatory standards

* Continuous turbidity monitors should be installed where work is being done in a natural waterway or

immediately adjacent (within 30 metres) of a waterway.



Excavated material Detect old fillmaterial that maycontain contaminatedsoil or rubble

Daily in areas beingexcavated

Analyse fill materialsuspected of beingcontaminated

Removecontaminatedmaterial to a landfilllicensed to accept thewastes (see section7) and ensure thatnecessary approvalshave been obtained

5.3 Auditing

Independent audits should be conducted onenvironmental performance and systems byexperts in construction activities andenvironmental management. Different peoplecan be used for each type of audit.

INSPECTIONS, MONITORING ANDAUDITING

Objective

Conduct checks on significant environmentalrisks to ensure that they are adequatelymanaged and control systems are operatingeffectively.

Suggested measures

• Establish a baseline monitoring programbefore construction commences.

• Prepare an inspection, monitoring andauditing program, designed to match theenvironmental risks.

• Ensure that remedial action is takenpromptly when monitoring,, inspections oraudit results reveal a problem inenvironment management.

• Ensure that all monitoring is conducted bya NATA registered laboratory, eitherdirectly, or under supervision.

• Arrange for regular independent audits ofenvironmental performance and theenvironmental management system.


APPENDIX 1 CHECKLIST

This Checklist summarises the specific environmental issues that need to be addressed on constructionsites. Provision is made in the list for the manager to check off each issue as it relates to the site. Theissues are listed in the same order as they appear in the Guidelines.

Issue Action taken Section

Compliance with legislative requirements Collect copies of all relevant legislation,regulations and government policy.

1

Ensure management is aware of theirrequirements and implements duediligence systems to ensure compliance.

1

Use documents collected to set minimiumstandards in the environmentalmanagement plan.

1

Pre-construction planningEnvironmental assessment Assess all possible impacts that the

project will have on the environment.2.1

Determine whether construction activitieswill intersect a contaminated site or oldtip.

2.1

Assess impact of the development on theamenity of adjacent residents.

2.1

Commence monitoring all segments ofthe environment to determine backgroundconditions.

2.1

Risk assessment information Collect all relevant information on thesite, and adjacent areas, that may beaffected by the development.

2.2

Collect relevant weather and climateinformation.

2.2

Obtain design plans, work schedules andwork programs that may contribute toenvironmental risk.

2.2

Obtain map of site topography andgenerate maps of changes in topography,as a result of the development.

2.2

Calculate stormwater flows in eachmicro-catchment for each phase of thedevelopment.

2.2

Map changes of vegetative cover and theposition of stockpiles and batters, as afunction of time.

2.2

Collect information on stream flows ofany natural waterways that will beaffected by the development.

2.2

Assessing and managing risks Identify all hazards to the environment. 2.2


Quantify hazards, whever possible. 2.2Determine consequences of each hazard. 2.2Calculate total risk level for each hazard. 2.2Rank risks. 2.2Identify all significant risks. 2.3Develop an action plan to address allsignificant risks.

2.3

Wherever possible seek to avoid risks orminimise them by modifying the projectdesign or planned work program andschedule.

2.3

Based on information of monitoring,inspection and surveillance, update riskassessment, management and theenvironmental management plan.

3.3

Pre-construction works Install stormwater drainage system(particularly to divert stormwater aroundthe site) and major sediment controlsprior to the project’s commencement.

2.3

Environmental management plan Construction company must have anenvironmental management system inplace before preparing the environmentalmanagement plan for the project.

3.1

Environmental management system Ensure that all staff are adequatelytrained.

3.1

Ensure that all procedures are writtendown.

3.1

Ensure that control and quality assurancesystems are in place to ensureeffectiveness of the environmentalmanagement system.

3.1

Prepare an environment managementplan based on the risk managementaction plan.

3.1

Prepare plan List special work procedures to avoid orreduce environmental harm.

3.2

Map cleared areas, as a function of time. 3.2Map changes of landform as a functionof time and identify control measures onthe map and position of soil stockpilesand batters.

3.2

Include any special operationalprocedures required to protect theenvironment in the work site manual.

3.2

Ensure that written contingency planshave been prepared and adequatelyresourced.

3.2

Ensure that best pactice documents forthe site are prepared and implemented.

3.2

Document maintenance, inspection andsurveillance schedule.

3.2


Prepare a rehabilitation plan. 3.2Update plan, as required. 3.2

Land disturbanceErosion Characterise erosion potential of the site

during each phase of the development.4.1

Take action to minimise clearance ofvegetation.

4.1

Implement controls and re-scheduleworks to reduce erosion.

4.1

Stabilise cleared areas as soon aspossible.

4.1

Avoid working on areas vulnerable toerosion, wherever possible.

4.1

Stormwater management Reduce quantity of contaminatedstormwater entering project site.

4.2

Reduce water velocities, whereverpossible.

4.2

Reduce stormwater flows over bareslopes.

4.2

Erosion and sediment controldevices

Design control devices to handleexpected peak water flows.

4.3

Treat intercepted water, if required,priorito discharge to the environment.

4.3

Install control devices, as required. 4.3Install in-stream weirs, as required. 4.3Implement a maintenance and inspectionschedule for control devices.

4.3, 9.1,9.2

Prepare contingency plan and ensure it isadequately resourced.

4.3

Improve design of control measures, ifthey don’t operate effectively.

4.3

De-watering work site Establish procedures to ensure thatcontminated water is not pumped into anatural waterway without adequatetreatment.

4.4

Ensure procedures are in place to ensurethat pumping operations are supervisedand monitored.

4.4

Dust control Implement a dust prevention strategy. 4.5, 4.6Pave haul roads. 4.5Ensure adequate watering or treatment ofareas that could give rise to dust.

4.5

Stockpiles and batters Implement a management program tominimise erosion and sediment runofffrom stockpiles and bare batters.

4.6

Stabilise stockpiles and batters, if theyare to remain bare for more than 28 days.

4.6

Establish sediment controls aroundunstabilised stockpiles and batters.

4.6

Working in waterways andfloodplains

Consult responsible drainage body forapproval.

4.7


Establish procedures to minimise impacton waterway.

4.7

Design and construct stream crossings, ifrequired, to minimise impact on thewaterway.

4.7

Ensure that written contingency planshave been prepared and adequatelyresourced.

4.7

Prepare and submit a re-instatement planto the relevant drainage authority forapproval.

4.7

Noise and Vibration Establish procedures that comply withlimits on working hours.

5.1

Implement procedures so that adjacentresidents are advised of out of hoursworks.

5.1

Regularly service machinery andvehicles.

5.2

Reduce noise to acceptable levels. 5.2Schedule deliveries so that they do notcause impairment of local amenity.

5.3

Install appropriate noise abatementstructures, if required.

5.4

Take measures to ensure that vibrationdoes not impact on adjacent residents.

5.5

Waste minimisation Implement a waste minimisationassessment.

6

Set waste minimisation targets. 6Implement programs to reduce waste thatneeds to be disposed of.

6

Contaminated material and soil Analyse material uncovered on site thatcould be contaminated or contain wastes.

7

Establish procedures to excavatecontaminated material or waste so as notto cause environmental problems, andseal remaining material.

7

Establish and implement procedures forappropriate transport and disposal ofcontaminated material or waste.

7

Emergency procedures Establish procedures for emergencysituations.

8.1

Air Quality Implement adequate maintenance regimefor vehicle and machinery exhausts.

8.2

Install controls on equipment or vehiclesthat are polluting the atmosphere.

8.2

Litter Establish procedures to avoid thegeneration of litter.

8.3

Install adequate litter bins on site. 8.3Implement staff awareness program. 8.3


Storage of chemicals and fuels Establish procedures to minimise thequanities of chemicals and fuels requiredto be stored on site.

8.4

Install bunding around storage areas. 8.4Implement adequately resourcedcontingency plans.

8.4

Road cleaning Install wheel washes and rumble grids, asrequired.

8.5

Implement a program for adequatecleaning of roads, if required.

8.5

Install lined litter traps in side entry pits,if required.

8.5

Ensure that trucks taking soil off site arecovered.

8.5

Concrete batching plants Obtain a Works Approval. 8.7Inspections, monitoring and audits Implement an adequate program of

inspections, monitoring and audits.9.1, 9.2,

9.3

EPA Publication 480© EPA Victoria, 1996

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