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DEPARTMENT OF DEFENCEENVIRONMENT AND ENGINEERING BRANCH
DIRECTORATE OF CONTAMINATION ASSESSMENT, REMEDIATION ANDMANAGEMENT
Contamination Management Manual
Annex DLegacy Waste Sites (Landfills)
March 2018, Amended August 2019
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© Commonwealth of Australia 2018This work is copyright. Apart from any use as permitted under the Copyright Act1968, no part may be reproduced by any process without prior written permissionfrom the Australian Government Department of Defence.Announcement statement—may be announced to the public.Secondary release—may be released to the Australian Government Department ofDefence, its contractors and their equivalents in United States of America, Canada,New Zealand and Great Britain.All Defence information, whether classified or not, is protected from unauthoriseddisclosure under the Crimes Act 1914. Defence information may only be released inaccordance with the Defence Security Manual as appropriate.First edition 2018
SponsorDirectorate of Contamination Assessment, Remediation and Management
DeveloperEnvironment and Engineering Branch
Issued byAlison Clifton with the authority of Assistant Secretary Environment and EngineeringBranch
Effective DateMarch 2018
Amendment DateAugust 2019
Review DateAugust 2020 or when changes to processes require an update
Amendments to the document can be proposed as required. Proposals foramendment of this document are to be forwarded to:
Director of Contamination Assessment, Remediation and ManagementEmail: [email protected]
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Quick Reference GuideWhy it is an issue for Defence?
Human Health Risk
Legacy waste disposal sitesmay present a health andsafety risk to site workersthrough exposure pathwaysthat may include directcontact and inhalation.Health, safety andecological risks may arisefrom contaminationdepending upon the nature,extent and concentration ofthe contaminant andexposure pathway.
Environmental Risk
Lack of, or inappropriate,management and monitoringof contamination associatedwith legacy waste disposalsites may present a risk tothe surrounding environmentthrough migration into soil,air and waterbodies.
Defence Capability
The project delays andremediation costsassociated with managingunexpected contaminationduring excavation works canhave a significant impact onDefence capability andoperations.
Mandatory requirements The following requirements are mandatory when undertaking project work on or in the vicinity of
legacy waste sites, noting that investigation works may not be required if the risk can be definedand managed to an acceptable level.
Review the Garrison Estate Management System Environmental Factor Management –Contaminated Site Records (GEMS EFM – CSR) to access and review available data and sitehistory (current and former land use).
Conduct a site investigation and collect environmental samples, where required, if sufficientinformation does not exist to inform the risk of potential or actual site contamination. Siteinvestigations may include a Pre-construction Contamination Assessment (PCA), Stage 1Preliminary Site Investigation (Stage 1 PSI) and/or a Detailed Site Investigation (Stage 2 DSI),as necessary based on risk.
Identify risk management measures for legacy waste sites in the design stage of projects.
Identify sensitive receptors (waterways, structures, etc) surrounding legacy waste or fly-tippingsites to determine appropriate management and monitoring measures.
Manage and maintain known legacy waste sites to minimise ongoing risks to Defence capability,the environment and sensitive receptors.
Undertake and incorporate routine monitoring or non-routine sampling of sites and maintenanceprograms, as necessary to identify management failures (cover/capping and infrastructure) andexceedances against adopted guideline values for various parameters.
Flag any exceedances or issues with Defence and consult with Defence regional environmentalpersonnel.
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More information Defence Environment and Sustainability Manager (ESM)
Draft Defence Unexploded Ordnance Management Manual
Defence Contamination Management Manual
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Table of contentsQuick Reference Guide ............................................................................................................................ ii
Abbreviations........................................................................................................................................... vi
1. Introduction.....................................................................................................................................1
1.1 Background..........................................................................................................................1
1.2 Purpose................................................................................................................................1
1.3 Defence Documentation ......................................................................................................1
2. Regulatory Overview......................................................................................................................3
2.1 Overview ..............................................................................................................................3
2.2 Landfills ................................................................................................................................6
3. Contamination Risk ........................................................................................................................7
3.1 Background..........................................................................................................................7
3.2 Conceptual Site Model.........................................................................................................7
4. Projects and Contamination Management...................................................................................10
4.1 Background........................................................................................................................10
4.2 Case Studies......................................................................................................................10
4.3 Case Study 1: Unplanned exposure of legacy waste site .................................................11
4.4 Case Study 2: Management of known legacy waste site ..................................................13
4.5 Management ......................................................................................................................14
5. Data and Reporting ......................................................................................................................18
5.1 GEMS EFM – CSR ............................................................................................................18
5.2 Geographic Information Systems ......................................................................................18
6. References...................................................................................................................................19
Table indexTable 2-1 Summary of State and Territory Guidance on Landfills.......................................................6
Table 3-1 Contaminants of potential concern ......................................................................................8
Table 4-1 Management considerations..............................................................................................14
Figure indexFigure 1-1 Overview of Defence Environmental Documentation and Annex D ....................................2
Figure 3-1 Contamination Risks at Exposed and Buried Waste Sites ..................................................9
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GHD | Report for Department of Defence – Annex D – Legacy Waste Sites (Landfills), 4130231 | vi
AbbreviationsAbbreviation Meaning
ACM Asbestos Containing Material
ASC NEPM National Environment Protection (Assessment of Site Contamination)Measure 1999 (Cth) (NEPC 2013)
BTEX Benzene, Toluene, Ethylbenzene and Xylenes
CH4 Methane
CO Carbon monoxide
CoPC Contaminants of Potential Concern
CSM Conceptual Site Model
CSR Contaminated Sites Record
DCARM Directorate of Contamination Assessment, Remediation and Management
DEQMS Defence Estate Quality Management System
ECC Environmental Clearance Certificate
EO Explosive Ordnance
EPA Environment Protection Authority or Agency
EPBC Act Environment Protection and Biodiversity Conservation Act 1999 (Cth)
EMOS Estate Maintenance and Operations Services
ESM Environment and Sustainability Manager
GEMS EFM – CSR Garrison Estate Management System Environmental Factor Management –Contaminated Site Record
GIS Geographic Information System
HSE Health, Safety and Environment
LOCR Legal Obligations and Compliance Register
NEPC National Environment Protection Council
NEPM National Environment Protection Measure
PAH Polycyclic Aromatic Hydrocarbon
PCA Pre-construction Contamination Assessment
PCB Polychlorinated Biphenyl
PDS Project Delivery Services
PFAS Per- and Poly-Fluoroalkyl Substances
Stage 1 PSI Stage 1 Preliminary Site Investigation
Stage 2 DSI Stage 2 Detailed Site Investigation
TRH Total Recoverable Hydrocarbon
UXO Unexploded Ordnance
VOC Volatile Organic Compound
WHS Act Work Health and Safety Act 2011 (Cth)
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1. Introduction1.1 Background
On-site surface disposal and/or burial of waste has historically occurred on some Defence sitesdue to various planned and unplanned activities. Illegal dumping sometimes referred to as 'flytipping' is also known to have occurred from time to time, particularly where Defence propertiesadjoin other land tenures and public roads. These legacy waste disposal sites (referred to aseither “landfills” or “waste disposal – solid source types” in the Garrison Estate ManagementSystem Environmental Factor Management – Contaminated Site Record (GEMS EFM - CSR), mayor may not have been recorded or managed. Potential health and safety risks to Defencepersonnel or contractors who undertake work in or adjacent to these sites must be consideredand addressed. Buried wastes can be exposed when soils are excavated during maintenanceor construction activity or through changes in landform.
Contaminants released from the decomposition of buried or landfilled waste could potentiallycause risks to both human health and the environment where there are exposure pathways.Exposure pathways could include:
Contact with waste exposed during excavation
Contact with waste exposed as a result of inadequate contamination management andmonitoring measures
Appropriate containment of contaminants within landfills is necessary to minimise risks and toavoid impacts to Defence operations and capabilities.
Contamination at a legacy waste site refers to existing chemical contamination of soil, water andsediment associated with historical/past industrial activities and practises that have now ceased.
1.2 Purpose
This guidance on legacy waste sites is to assist Defence personnel and contractors supervisingDefence works that may encounter contamination (soil, sediment and water) associated withhistorical landfills or landfilling activities across the Defence Estate.
The information in this document relates to environmental (e.g. soil, water and sediment)contamination and not to the condition of buildings or structures (e.g, the presence of hazardousbuilding materials). The reader is directed to the Work Health and Safety Group for assistancewith these matters.
1.3 Defence Documentation
This guidance document is an Annex to the Defence Contamination Management Manual andsupports compliance with site contamination management policy as detailed in the DefenceEnvironment and Heritage Manual. An overview of where this Annex fits into the Manual ispresented in Figure 1-1.
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Figure 1-1 Overview of Defence Environmental Documentation and Annex D
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2. Regulatory Overview2.1 Overview
Defence and its contractors must operate to comply with all Commonwealth legislation,including the Work Health and Safety Act (WHS Act), Environmental Protection and BiodiversityConservation Act (EPBC Act) and the National Environmental Protection (Assessment of SiteContamination) Measures (NEPM). Reference can be made to the Defence Legal Obligationsand Compliance Register (LOCR) found on Defence Estate Quality Management System(DEQMS).
Defence may not be subject to State and Territory law in all situations. Whether or not Defenceis bound by State and Territory law is a complex issue and legal advice must be obtained toconfirm whether a particular State or Territory law is applicable to Defence. Defencecontractors must comply with relevant State or Territory laws.
Guidance relating to the assessment of site contamination is outlined in the NationalEnvironment Protection Council (NEPC) 1999 (Cth), National Environment Protection(Assessment of Site Contamination) Measure (NEPM) as amended in May 2013.
2.1.1 NEPM
The National Environment Protection (Assessment of Site Contamination) Measures 1999 (Cth)(the ASC NEPM) was made under the National Environment Protection Council Act 1994 (Cth).The ASC NEPM is the national guidance document for the assessment of site contamination inAustralia. It is given effect by the National Environment Protection Measures (Implementation)Act 1998 (Cth) for the Commonwealth and individual legislation and guidelines in each Stateand Territory.
The National Environment Protection Council (NEPC) agreed to vary the NEPM by approvingan amending instrument to the ASC NEPM in 2013.
All assessments of site contamination on the Defence Estate are to be undertaken inaccordance with the recommended process and guidance provided in the ASC NEPM.
The purpose of the ASC NEPM is to establish a nationally consistent approach for theassessment of site contamination; to ensure sound environmental management practices by thecommunity, including regulators, site assessors, site contamination consultants, environmentalauditors, landowners, developers and industry parties.
The desired outcome of the ASC NEPM is to provide adequate protection of human health andthe environment, where contamination has occurred, through the development of an efficientand effective national approach to the assessment of site contamination.
The ASC NEPM and schedules are available for download through the NEPC website. TheASC NEPM Toolbox contains additional information including calculators, spreadsheets andother supporting documents to assist with application of the amended ASC NEPM.
2.1.2 Commonwealth Work Health and Safety Act 2011
The Work Health and Safety Act 2011 (Cth) (WHS Act) commenced in 2012 and is regulated byComcare, a Commonwealth Government agency that works in partnership with the Safety,Rehabilitation and Compensation Commission. The WHS Act provides for a nationallyconsistent framework to protect workers and other persons against harm to their health andsafety through the elimination or minimisation of the risks so far as reasonably practicable.
Under the WHS Act, employers must take all reasonably practicable steps to ensure the healthand safety of its employees and those who are at or near a workplace under the employer'scontrol. This means that Defence and its contractors have obligations to protect the health andsafety of workers and others operating within the vicinity of contaminated land that is on or nearto a workplace under Defence control.
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Model Codes of Practice administered by Safe Work Australia provide practical guides toeliminate and minimise the risks to health and safety as required under the WHS Act.
Any controls outlined in the Defence Work Health and Safety Manual (SafetyMan) must beimplemented when managing contaminated materials.
2.1.3 Environment and Heritage Manual
The Environment and Heritage Manual (EHM) (2019) describes the agreed approach toenabling Defence capability through long-term sustainable management of the environment.The EHM provides instruction and policy guidance for all Defence personnel and contractors onDefence’s legislative obligations and stewardship goals in line with the Defence EnvironmentalPolicy and Environmental Strategy 2016-2036.
The Defence Environment and Heritage Manual is an administrative policy framework documentthat applies to all Defence personnel.
The EHM is divided into 13 chapters addressing:
Chapter 1 – Environment and heritage management in Defence
Chapter 2 – Environmental assessment and approval
Chapter 3 – Heritage management
Chapter 4 – Domestic biosecurity
Chapter 5 – Native species and communities
Chapter 6 – Soil management;
Chapter 7 – Bushfire management
Chapter 8 – Pollution prevention
Chapter 9 – Site contamination management
Chapter 10 – Estate water management
Chapter 11 – Estate energy management
Chapter 12 – Waste minimisation and management
Chapter 13 – Estate climate adaptation
Each chapter links back to a Strategic Aim of the Defence Environmental Policy and providessupporting documentation to support the implementation of the policy. Chapter 9 addresses sitecontamination management.
2.1.4 Environment Protection and Biodiversity Conservation Act 1999 (Cth)
The Environment Protection and Biodiversity Conservation Act 1999 (Cth) (EPBC Act) is theAustralian Government’s central piece of environmental legislation. It provides a legalframework to protect and manage matters of national environmental significance.
The EPBC Act protects:
The environment, where actions proposed are on, or will affect Commonwealth landand the environment; and
The environment, anywhere globally on land and water, where a Commonwealthagency – including the Department of Defence – are proposing to take an action.
The EBPC Act also protects nine matters of national environmental significance:
World heritage properties
National heritage places
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Wetlands of international importance (Ramsar wetlands)
Listed threatened species and communities
Listed migratory species
Commonwealth marine areas
The Great Barrier Reef Marine Park
Nuclear actions (including uranium mining)
A water resource in relation to coal seam gas development and large coal miningdevelopment.
Defence uses a comprehensive environmental impact assessment and approval program tounderstand and manage the impacts of its activities on the environment and heritage, and toensure compliance with the EPBC Act.
Under the Defence Environment and Heritage Manual, the Director of Environmental Planning,Assessment and Compliance (DEPAC) is the Defence technical authority for determiningcompliance with the EPBC Act. All matters that may trigger the EPBC Act are to be referred toDEPAC.
DEPAC undertakes a self-assessment against the Significant Impact Guidelines 1.1 and 1.2published by the Department of the Environment and Energy to determine if a ‘significantimpact’ EPBC Act protected matter is likely. The self-assessment process considers the natureand extent of contamination and if the presence, disturbance, removal or remediation of existingcontamination is likely to have a significant impact on EPBC Act protected matters. Where asignificant impact to the environment is ‘likely’ the action must be referred to the Minister for theEnvironment and Energy to make a determination on whether a proposed action is a ‘controlledaction’.
For more information with regard to the EPBC Act refer to http://www.environment.gov.au/epbc/.
2.1.5 Off-site migration
The Defence Project Manager should obtain professional advice to inform the reporting andmanagement of any contamination that is found to have migrated off-site into a State/Territoryjurisdiction. Delineating the nature and extent of the off-site contamination will assist Defence toimplement appropriate mitigation measures and to manage any legal implications. A link to thevarious State and Territory environmental agencies can be found in the Defence ContaminationManagement Manual. Any interaction with State or Territory environmental regulators must onlyoccur after first consulting the Directorate of Contamination Assessment, Remediation andManagement (DCARM) and if applicable the Environment and Sustainability Manager (ESM).
2.1.6 Defence Legal Obligations and Compliance Register
Defence and its contractors must operate to comply with all Commonwealth legislation,including the WHS Act, EPBC Act and the ASC NEPM. In addition, Defence and its contractorsshould be generally familiar with the legislative and other regulatory requirements associatedwith the site activities undertaken relevant to the State or Territory in which the site is located.Contractors must comply with State and Territory laws where applicable. Reference can bemade to the Defence Legal Obligations and Compliance Register (LOCR) found on DEQMS.
2.1.7 National Waste Policy
The National Waste Policy (2018) provides the federal government’s national framework forwaste and resource recovery in Australia. It outlines roles and responsibilities for collectiveaction by businesses, governments, communities and individuals, and is intended to guide
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collaboration between all levels of Australian government, business and industry to implementtailored waste management solutions in response to local and regional circumstances.
The policy identifies five overarching principles underpinning waste management in a circulareconomy. These include:
Avoid waste
Improve resource recovery
Increase use of recycled material and build demand and markets for recycled products
Better manage material flows to benefit human health, the environment and theeconomy
Improve information to support innovation, guide investment and enable informedconsumer decisions
Defence’s Waste Minimisation and Management Policy, contained in the Defence Environmentand Heritage Manual is aligned with the principles of the National Waste Policy.
2.2 Landfills
2.2.1 State and Territory Guidelines
Defence references landfill guidelines within each State and Territory, established byEnvironment Protection Authorities or Agencies (EPAs) and other environment agencies, whereapplicable to manage these sites.
Table 2-1 Summary of State and Territory Guidance on Landfills
State/Territory Relevant Guidance Document
New South Wales NSW EPA (2016) Environmental Guidelines, Solid Waste Landfill Guidelines.
Victoria EPA Victoria (2015) Best Practice Environmental Management: Siting, design,operation and rehabilitation of landfills (Publication 788.3).
Queensland Department of Environment and Science (2013) Guideline: Landfill siting,design, operation and rehabilitation.
South Australia EPA South Australia (2019) Environment Management of Landfill Facilities -Solid waste disposal.
Western Australia No jurisdiction specific guidance; however, reference is typically made to:
EPA Victoria (2015) Best Practice Environmental Management: Siting, design,operation and rehabilitation of landfills (Publication 788.3).
Tasmania EPA Tasmania (2004) Landfill Sustainability Guide.
Northern Territory EPA Northern Territory (2013) Guidelines for the Siting, Design, andManagement of Solid Waste Disposal Sites in the Northern Territory.
Australian CapitalTerritory
No jurisdiction specific guidance; however, reference is typically made to:
EPA Victoria (2015) Best Practice Environmental Management: Siting, design,operation and rehabilitation of landfills (Publication 788.3) and the ACTEnvironmental Protection Authority (2010) Hazardous Materials EnvironmentProtection Policy.
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3. Contamination Risk3.1 Background
Organic and inorganic chemicals, nutrients and gases are released during the decomposition ofburied waste. Contamination can also be caused by the buried waste itself, for example oils andgreases, paints and contaminated soils. The resulting contaminants are characterised by thetype of waste present and the method of disposal and containment. Contamination risks arisewhen legacy waste sites are not identified and appropriately managed. This can occur whenlegacy waste sites are not adequately characterised, clearly delineated, mapped and recorded.Contaminants within the landfills can be transported via contamination pathways such as soilerosion, air, groundwater flow and stormwater runoff.
Gases and vapours released from the decomposition of waste may present a human health riskthrough inhalation, or an explosion risk through the build-up of gas.
Contamination of soil, surface water and groundwater occurs when contaminated water(leachate) drains out of a landfill through infiltration or as run-off. Contamination may result in anenvironmental risk to water quality through connected ecosystems. Contamination may alsohave potential to cause a human health risk where there is direct contact.
3.2 Conceptual Site Model
As described in the ASC NEPM, a Conceptual Site Model (CSM) describes the contaminationsources, pathways and receptors and the potential linkages between these.
The initial CSM is constructed from the results of a Stage 1 Preliminary Site Investigation(Stage 1 PSI) and is the basis for defining where potential source-pathway-receptor linkagesmay exist, which require further investigation. The CSM must be continually reviewed andupdated throughout the assessment process to inform subsequent decisions on whether furtherinvestigation or contamination management actions are required.
The CSM should identify complete and potential pathways between known or potentialcontamination sources and receptors. Where the pathway between a source and a receptor isincomplete, the exposure to chemical substances via that pathway cannot occur, but thepotential for that pathway to be completed (for example, by abstraction of groundwater or achange in land use) should be considered in all stages of assessment. The CSM can also beused to consider where management measures would reduce the likelihood of an exposurepathway becoming complete.
The essential elements of a CSM are:
Known and potential sources of contamination and contaminants of concern including themechanism(s) of contamination (e.g. ‘top down’ spill or sub-surface release from corrodedtank or pipe).
Potentially affected media (e.g. soil, sediment, groundwater, indoor and ambient air).
Human and ecological receptors.
Potential and complete exposure pathways.
For contaminated land site investigation reports (e.g. Stage 2 Detailed Site Investigation(Stage 2 DSI) the CSM is to be presented as a graphic, a table or flow chart and adequatelydescribed in written text.
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3.2.1 Contaminants of Potential Concern
The Contaminants of Potential Concern (CoPC) associated with Defence legacy waste sitesmay be broad ranging depending on the types of wastes present. Contaminants that maytypically be encountered on Defence sites are listed in Table 3-1, and are categorised based onthe key contamination transport pathways, including soil, surface water, groundwater and air.
There is also potential for unexploded ordnance (UXO) or explosive ordnance (EO) waste to bepresent in legacy waste sites, and these materials must be managed in accordance with theDraft Defence Unexploded Ordnance Management Manual (DUXOMM).
Table 3-1 Contaminants of potential concern
Contaminants of potential concern Soil Surfacewaters
Groundwater
Air
Suspended and dissolved solids
pH, salinity (electrical conductivity)
Cation exchange capacity
Metallic elements (eg arsenic, barium,beryllium, boron, cadmium, chromium, copper,lead, iron, nickel, zinc and mercury)
Nitrogen, ammonia, nitrate and nitrite
Total phosphorus and orthophosphate
Herbicides and pesticides (organochlorine andorganophosphate)
Polychlorinated biphenyls (PCBs)
Petroleum hydrocarbons (TRH, BTEX, phenolsand PAHs)
Per- and Poly-Fluoroalkyl Substances (PFAS)
Volatile organic compounds (VOCs)
Asbestos and other contaminated material
Methane (CH4) and carbon monoxide (CO)
Hydrogen sulfide
3.2.2 Graphical Conceptual Site Model
A visual representation of a CSM relating to legacy waste sites and the potential contaminationsources, pathways and receptors is presented in Figure 3-1
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Figure 3-1 Contamination Risks at Exposed and Buried Waste Sites
4. Projects and ContaminationManagement4.1 Background
Legacy waste disposal sites that are inappropriately managed may represent a risk to humanhealth, the environment and other sensitive receptors. Inappropriate management can result inreduced Defence capability, which can be significantly impacted when work is stopped ordelayed due to incidents or unexpected finds.
Appropriate management measures in project design and delivery must be devised andcommunicated to relevant personnel to address the potential risks associated with legacy wastesites. Contamination management measures for legacy waste sites should, so far as reasonablypracticable, seek to eliminate health and safety risks to sensitive receptors surrounding allknown landfill sites and to reduce the risk of further migration of landfill contaminants throughthe soils or groundwater.
4.2 Case Studies
The following case studies highlight the contamination risks related to legacy waste sites andidentify management measures and sources of further information to address thesecontamination issues. These case studies are hypothetical examples only and are not based onactual events.
4.3 Case Study 1: Unplanned exposure of legacy waste site
4.3.1 Scenario
The construction of a vehicle maintenance facility with sub-floorinspection bays is proposed for a currently undeveloped area of a base.There is a 12 week construction program to achieve Defence capabilityrequirements. The proposed vacant land has a regularly maintainedgrass cover and is clear of structures.
The Stage 1 PSI conducted during the project design phase did notidentify contamination that would delay the construction works. Defenceengaged a contractor to deliver the new facility, which included bulkearthworks and excavation. Excavation of the vacant land exposed apreviously unidentified historical disposal site characterised byuncontrolled and poorly consolidated fill.
Construction work is stopped while health and safety risks are assessedand an investigation is undertaken to determine the type and extent ofwaste present. Waste covers an area of approximately 600 m2 to anaverage depth of two metres below ground level, and is predominantlycomposed of construction and demolition waste, including potentialasbestos containing materials (ACM).
A risk assessment is prepared, and in consultation with the DefenceEnvironment and Sustainability Manager (ESM) and the constructioncontractor, it is determined that the waste has to be removed. Projectwork is delayed by three weeks, affecting Defence operations andcapability.
4.3.2 Risks
HSE – Buried or fly tipped waste may expose construction workers tocontaminated materials and the risk of inhalation of contaminants suchas asbestos fibres. Contaminants may also migrate via leachate,groundwater or vapour into the surrounding environment and structures, resulting in additionalpotential health or environmental risks.
Defence Capability – Ceasing work to manage unexpected waste causes project delays andadditional management and remediation costs. During the construction of an asset, thesedelays and costs can have a significant impact on Defence capability.
4.3.3 Key considerations and management measures
Is an Environmental Clearance Certificate (ECC) required?
Has the Stage 1 PSI characterised the full extent of buried waste and any contaminatedsoil within the project area?
Is a Pre-construction Contamination Assessment (PCA) in the footprint of the constructionarea required to allow a physical and chemical characterisation of the waste? Has theexposed waste been classified and associated risks assessed accurately?
Has a risk assessment been conducted to determine the most appropriate method ofremediation of the legacy waste site in the context of the infrastructure design anddevelopment - for example, consideration of capping material in-situ, full or partialremoval?
Have the appropriate disposal permits been obtained through the relevant state orterritory regulatory framework for any necessary offsite disposal of contaminated waste orsoil?
Why is this an issue?Exposed waste poses ahealth and safety risk toworkers and acontamination risk to thesurrounding environment.Remediation works createdelays and additionalcosts that effect Defencecapability by delayingproject work.
How can I manage it?Undertake Stage 1 PSI toconfirm ground conditionsand potentialcontaminants.Flag any issues early withDefence and agree on asuitable managementapproach.
Where can I get help? Defence
ContaminationManagement Manual
Defence ESM
4.3.4 Further information Defence Contamination Management Manual
Defence ESM
4.4 Case Study 2: Management of known legacy waste site
4.4.1 Scenario
A known legacy waste site/landfill is present on a Defence site that wasin use for approximately 10 years between 1970 and 1980. The site issituated on low-lying, flood prone land with an ecologically sensitivewetland 80 m to the west, a residential development 100 m to the northand various Defence buildings, some with basements, within 200 meast of the dump. A football field is located between the waste site andthe on-site buildings.
The waste site was periodically used to dispose of waste frominternational training exercises and messing activities (food and septicwaste). A new trench was opened for each annual training exercise,where waste was dumped and covered with soil at the completion ofthe activities. No fully engineered caps were installed over the trenchesand they were not lined. Historical reports indicate that potential ad hocwaste was disposed of in the area which included hazardous wastes,oils and greases, asbestos and other building materials. Previousenvironmental investigations indicate that the disposal site covers anarea of approximately one hectare.
A maintenance contractor undertaking routine slashing of grass overthe known disposal site reported a patch of dead vegetation andponding liquid on the eastern side of the site, approximately 100 mfrom the wetland. The maintenance contractor reported the incident toDefence, and following consultation with the Defence ESMs,investigations into the source of the liquid were undertaken.
4.4.2 Risks
HSE – Inadequate management and maintenance of known landfills can lead to the migration ofcontaminants into sensitive receptors, both on-site (barrack basements and playing field) andoff-site (residential areas and the ecologically sensitive wetland). Risks include exposure viainhalation of contaminants (accumulation of gas in the barrack basements and residentialareas), direct contact with contaminants (contaminants in playing field soil) and environmentalrisk (contaminants migrating into the wetland).
Defence Capability – Detection of contaminants in any of the surrounding sensitive receptorscould impact on site operations until management and remediation measures are implementedor improved, which could affect Defence capabilities.
4.4.3 Key considerations and management measure
Is there a closure and site environmental management plan that is relevant to the landfill? Ifnot, is one required?
Are there sensitive receptors that have not been identified? Is there a need to review existing data e.g. monitoring wells that are routinely sampled or to
establish or update an ongoing environmental monitoring program to collect additional data? Do the monitoring (routine and non-routine) results exceed relevant guideline values? Are further measures required to understand the full extent of contamination (such as
gas/groundwater monitoring wells, water quality sampling and engineered capimplementation)?
Is remediation of the landfill required to mitigate risk to an acceptable level?
4.4.4 Further information
Defence Contamination Management Manual Defence ESM
Why is this an issue?Former landfill sitesrepresent a risk to humanhealth and the environmentif not properly managed andmaintained.
How can I manage it?Undertake regularmonitoring to identifyexceedances againstrelevant guideline values.Flag any exceedances withDefence and implementfurther managementmeasures where necessary.
Where can I get help? Defence Contamination
Management Manual Defence ESM
4.5 Management
A staged approach may be required to understand, characterise and to manage the potential forcontamination at legacy waste sites and surrounding land.
Each stage of works should be considered as a discrete task, and hold points arerecommended at the completion of each stage to consider whether progression to the nextstage is required.
A Stage 1 PSI and/or Stage 2 DSI may already have been completed for many legacy wastesites across the estate, and pollution prevention or contamination management measures maybe in place. For these sites, a review of existing reports, data and documentation that may beavailable on the GEMS EFM – CSR must be undertaken as a priority before works proceed.
A summary of some of the key items to be considered is provided in Table 4-1. Stages shouldbe completed as necessary to ensure the risk of contamination is managed.
Table 4-1 Management considerations
Stage of works Summary of points for consideration Next steps
Pre-constructionContaminationAssessment (PCA)
Review of the GEMS EFM – CSR. Limited soil sampling in the footprint of the
construction area. If groundwater is shallow andconstruction will require dewatering considercollection of groundwater samples also.
Analysis of samples for the CoPC, includingthose discussed in Section 3.2.1.
A PCA is suitable forconstruction projectswhere spoil, and / orwaste water, needs to becharacterised for re-use,temporary stockpiling orfor off-site disposal.Obtain approval fromDefence (reuse) orregulator (off-sitedisposal) based on thedata and any relevantECC conditions.
Stage 1:Preliminary SiteInvestigation
Establish historical use of the area through adesktop review and interviews with personsfamiliar with historic legacy waste sites use.
Understand the physical setting of the site(including soils, hydrogeology and hydrology).
Document all works undertaken. Risk assessment based on the Contamination
Risk Assessment Tool (CRAT).
The findings of the Stage1 PSI should becommunicated to theDefence Project Managerfor the decision toproceed to the Stage 2DSI.An ECC may be required.
Stage 2:Detailed SiteInvestigation
Investigation of potentially contaminatedmedia (including soils, sediments,groundwater, and surface water), withsufficient samples collected to understand thenature and extent of contamination.
Sampling for explosive residues must beconsistent with guidance documentation asdiscussed in Section 2.2, and with ASC NEPMand Australian Standards for other CoPCs.
Geophysical investigation techniques arerecommended in areas where burials or UXO1
may be present. Develop a CSM to assess the risk to receptors
under the existing land use, and any proposedredevelopment included during site works.
Document all works undertaken. Update to CRAT.
The scope of works forsite investigations andfindings of the DSI shouldbe discussed with, andcommunicated to theESM for longer termmanagement of the site.An ECC may be required.
Stage of works Summary of points for consideration Next steps
Stages 3 – 5:
RemediationPlanning,Implementationand SiteManagement
Undertake risk assessment or remediationoptions analysis and design, as required, todefine further remediation or management.
Establish procedures for the remediation ormanagement of contamination to minimise anyunacceptable risks of potential exposure tocontamination. This process must include a stopwork procedure.
Allow for uncertainty by developing contingencyprocedures.
Implement and manage the works inaccordance with the established procedures.
Document works undertaken, includingvalidation of any remedial works.
Site management options and/or monitoringrequirements to be established post completionof necessary assessment.
An ECC may be required.
Decommissioning Consideration must be given to contaminationresidues on infrastructure. eg PFAS or PCB’s inconcrete
Prior to demolition works, an assessment of thecontamination status of infrastructure surfacesmust be undertaken so that disposal or recyclingoptions for building materials can bedetermined.
An ECC may be required.
Note:1 Assessment methods and technologies for UXO are beyond the scope of this document, and reference must be
made to the DUXOMM, where this type of assessment is required.
4.5.1 Project management
Various projects on the Defence Estate may interact with legacy waste sites, including but notlimited to maintenance activities (such as slashing of grass and landscape managementprograms), demolition of structures and infrastructure development (including bulk earthworksfor structures, roads or underground services).
Adopting best practice project management will support project officers to obtain relevantbackground information and to identify and address risks before a project commences tominimise project delays. The following management measures must be implemented, whererelevant:
Review the GEMS EFM – CSR to access and review available data and site history(current and former land use).
Perform Stage 1 PSIs or PCAs during the design phase of projects to confirm the groundconditions, and to identify potential contaminants that could affect project work andDefence capability.
Obtain historical data relating to the ground conditions, and undertake soil or watersampling to characterise the site against relevant criteria, where required.
Incorporate the management or remediation of risks for known landfills into the designconsiderations of project work that is proposed in the vicinity of these sites.
Review risk management continuously as the project progresses.
Where unknown legacy waste sites are identified by contractors undertaking maintenanceor construction works, the contractor must report the incident to the Defence ProjectManager or the party who engaged them – e.g. the Estate Maintenance and OperationsServices (EMOS) or Project Delivery Services (PDS) Contractor. The Defence ProjectManager, will then advise the Defence ESM. An Environmental Incident report must becompleted an Environmental Incident Report.
Where unknown legacy waste sites are identified by Defence personnel, e.g. during atraining activity, the location of the waste site must be recorded and reported to theDefence point of contact and/or ESM.
Newly identified legacy waste site(s) must be recorded on the GEMS EFM – CSR. TheDefence or contracted Project Manager should provide relevant CSR records toresponsible Defence personnel and/or contractors conducting works in the vicinity ofthese CSR’s. CSR’s can be recorded via an ECC, contract document, site inductionand/or start-up meeting.
Contractors must provide timely notification of any identified contamination issuesincluded new contaminated sites, with the appropriate Defence Project Manager or theparty who engaged them. This issue must be elevated to the directorate or branch withinDefence who is responsible for the project and the ESM. These parties may specifysupplementary management measures.
4.5.2 Contamination management
Management of legacy waste sites must aim to avoid or to minimise the spread ofcontamination and human and environmental health and safety risks. This can be achieved byestablishing the source and characteristics of the types of waste that have been disposed (sofar as reasonably practicable) and by identifying sensitive receptors, waterways, structures andsite personnel etc. in the vicinity of known sites, to inform any required management andmonitoring measures. Reference to relevant State or Territory environment authority guidelineson the construction and maintenance of landfill components, as summarised below can informmanagement.
Soil cover – A suitable soil cover should be placed over the legacy waste site when buriedwaste is not planned to be removed for the purpose of development. The cover should beappropriate for the waste type, the intended use of the area and the surrounding environment.As a minimum, the cover must limit water infiltration and subsequent leachate generation.
Capping management – In some cases, investigation and risk assessment may determine thatan engineered capping system is required to effectively isolate buried waste and to managepotential environmental impacts. The capping must be designed to isolate buried waste from thesurrounding environment, limit water infiltration and leachate generation, reduce landfill gassurface emissions where biodegradable/putrescible waste has been buried, and provide astable sustainable landform for the intended end use.
Stormwater management – If waste is exposed, stormwater must be diverted around thewaste to avoid contamination. If stormwater becomes contaminated or suspected to becontaminated, further infrastructure should be designed and installed to collect and treat waterbefore it is released. Refer to the PPMM Stormwater Management (Annex 1I).
Leachate management – Leachate collection, containment, treatment and an appropriatedisposal method will be required if sufficient volumes of leachate are produced or are seepingout of a landfill.
Landfill gas management – Landfill gas management is generally not required for the types oflegacy waste sites that typically exist on the Defence Estate. However, a landfill gas riskassessment may be required to determine management requirements depending on thecharacteristics of the contaminants identified through investigation. The ESM or Defence ProjectManager must be consulted to determine the need for the risk assessment.
Groundwater management – Groundwater management may be required if the landfill is notlined and the leachate is seeping into the underlying aquifer. Information on the presence andintegrity of the liner is required to assess the potential for impacts to groundwater.
Monitoring – Where management measures are implemented, routine monitoring is required.Monitoring should include physical monitoring of the infrastructure integrity (capping failure,leachate seepage, etc.) and chemical monitoring, through gas monitoring and water sampling,where relevant. Chemical monitoring results are to be benchmarked to adopted guidelinevalues, to identify any exceedances that indicate management measures have failed. Any newmonitoring wells installed should be included in the routine groundwater monitoring schedule foreach Service Delivery Zone.
Defence personnel or Contractors must report any exceedances or issues to the DefenceProject Manager or party who engaged them in accordance with the requirements of their scopeof work. When exceedances are identified, the Project Manager will consult with ESMs todetermine whether further management or remedial measures are required to manage risk.
5. Data and Reporting5.1 GEMS EFM – CSR
Data and reports generated as part of the investigation and assessment of legacy waste sitesmust be captured in the GEMS EFM – CSR.
The GEMS EFM – CSR is the database used to capture environmental information across theDefence estate, and provides access to historical contamination investigation reports forDefence properties. Contaminated site records are geo-referenced and they can be accessedby Defence personnel or contractors with Defence Restricted Network (DRN) Access.
Contractors/Consultants working on behalf of Defence must provide reports, updated andcompleted GEMS Data Load Tool (GDL) (for new or existing CSRs), CRAT, ESdat andGeographic Information System (GIS) files relating to contamination to their Defence point ofcontact, Project Manager or ESM who will be responsible for auditing and validatingsubmissions and ensuring the upload of information into the GEMS EFM – CSR.
Refer to the Defence Contamination Management Manual, Annex L – Data Management.
5.2 Geographic Information Systems
All mapping GIS data is required to be provided to Defence in National Spatial InformationManagement System (NSIMS) metadata format. The Defence NSIMS metadata tool is availablethrough an online search and on DEQMS.
Refer to the Defence Contamination Management Manual, Annex L – Data Management.
6. ReferencesDepartment of Environment and Science Queensland (2013) Guideline: Landfill siting, design,operation and rehabilitation.
Department of Defence (2017), Pollution Prevention Management Manual - Annex 1I – PollutionPrevention Guideline Stormwater Management.
Department of Primary Industries, Water, and Environment (Environment Division) Tasmania(2004) Landfill Sustainability Guide.
EPA Northern Territory (2013) Guidelines for the Siting, Design, and Management of SolidWaste Disposal Sites in the Northern Territory.
EPA South Australia (2007) Environment Management of Landfill Facilities (municipal solidwaste, and commercial and industrial generated waste).
EPA Victoria (2015) Best Practice Environmental Management: Siting, design, operation andrehabilitation of landfills (Publication 788.3).
NSW EPA (2016) Environmental Guidelines, Solid Waste Landfill Guidelines.
