Landfill Sustain Guide

DEPARTMENT of PRIMARY INDUSTRIES, WATER and ENVIRONMENT

Landfill Sustainability Guide 2004

Environment Division GPO Box 44 Hobart, Tasmania, 7001

Disclaimer This document has been produced and published by the Tasmanian Department of Primary Industries, Water and Environment (DPIWE). This document is not a substitute for independent legal or professional advice. Although every care has been taken in the production of the work, neither the Crown in the right of the State of Tasmania nor any servant or agent of the Crown accepts responsibility for any loss or damage suffered at any time by any person as a result of any error or inaccuracy in the publication, whether or not the error or inaccuracy has resulted from negligence or any other cause. The information contained within this document is designed to give guidance to the landfills, within Tasmania, and is necessarily general. Specialist advice may be required for specific sites or issues.

Acknowledgements • •

Victorian Environment Protection Agency (EPA) Meinhardt Consultants

For further information please visit www.dpiwe.tas.gov.au/landfills or email [email protected]

© Crown in Right of the State of Tasmania This work is copyright. Apart from any use permitted under the Commonwealth Copyright Act 1968, no part may be reproduced without written permission from the Department of Primary Industries, Water and Environment, GPO Box 44, Hobart Tasmania, 7001.

TABLE OF CONTENTS 1.

BACKGROUND.....................................................................................................1 1.1

1.2

1.3

1.4

1.1.1 1.1.2 1.1.3 1.1.4 1.1.5 1.1.6 1.2.1 1.2.2 1.2.3 1.3.1 1.3.2 1.3.3 1.4.1 1.4.2

2.

INTRODUCTION ..................................................................................................... 1

What is the purpose of the Sustainability Guide?................................................................................................1 Who should read the Sustainability Guide? ..........................................................................................................2 What activities does the Sustainability Guide address?.....................................................................................2 What does the Sustainability Guide contain?......................................................................................................2 How do I use the Sustainability Guide? ..................................................................................................................2 Implementation Timeframe ......................................................................................................................................3

PRINCIPLES AND ISSUES ......................................................................................... 4

Principles .........................................................................................................................................................................4 Environmental issues ....................................................................................................................................................4 Statutory framework.....................................................................................................................................................5

CLASSIFICATION OF LANDFILLS............................................................................... 7

Landfill Classification System....................................................................................................................................7 Waste types ....................................................................................................................................................................8 Specific Disposal Requirements for Certain Waste Types ................................................................................11

ACCEPTANCE OF CONTROLLED WASTES ................................................................ 13

Tasmanian waste tracking and classification system.......................................................................................13 Analytical Testing........................................................................................................................................................13

LANDFILL SITING AND PLANNING........................................................................16 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12

3.

DEMAND ............................................................................................................. 16 COMMUNITY LIAISON .......................................................................................... 17 GEOLOGY........................................................................................................... 17 HYDROGEOLOGY................................................................................................. 18 BUFFER DISTANCES ............................................................................................... 19 SURFACE WATERS................................................................................................. 21 INFRASTRUCTURE.................................................................................................. 21 FLORA AND FAUNA.............................................................................................. 22 GEOCONSERVATION AND GEO-HERITAGE............................................................ 23 HISTORIC AND CULTURAL HERITAGE ...................................................................... 24 LAND OWNERSHIP AND USE.................................................................................. 24 SITE SELECTION ................................................................................................... 25

DESIGN ..............................................................................................................27 3.1

3.1.1 3.1.2 3.1.3

3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11

4.

LEACHATE CONTAINMENT AND COLLECTION ........................................................ 28 Leachate Barrier ..........................................................................................................................................................28 Leachate Collection System for Category B and C Landfills.........................................................................32 Leachate Management for Category B and C Landfills .................................................................................34

SURFACE WATER MANAGEMENT .......................................................................... 36 GROUNDWATER MANAGEMENT FOR CATEROGY B AND C LANDFILLS...................... 37 LANDFILL GAS MANAGEMENT .............................................................................. 39 CONSTRUCTION QUALITY ASSURANCE FOR ENGINEERED LINERS ............................. 40 WASTE MINIMISATION ......................................................................................... 41 SITE SECURITY ...................................................................................................... 42 SIGNAGE............................................................................................................ 43 TRAFFIC MANAGEMENT........................................................................................ 43 PLANNING TO MINIMISE OFF-SITE IMPACTS........................................................... 44 PLANNING FOR REHABILITATION........................................................................... 44

OPERATION........................................................................................................46 4.1 4.2

4.3 4.4

4.5

4.2.1 4.2.2 4.2.3 4.3.1 4.3.2 4.4.1 4.4.2 4.4.3 4.4.4 4.4.5 4.5.1 4.5.2

WASTE MINIMISATION ......................................................................................... 46 WASTE HANDLING ............................................................................................... 47 Waste acceptance and screening ........................................................................................................................47 Waste placement and compaction .....................................................................................................................48 Waste covering............................................................................................................................................................49

WATER MANAGEMENT ......................................................................................... 51 Leachate collection and management..............................................................................................................51 Surface water management..................................................................................................................................51

NUISANCE MANAGEMENT ................................................................................... 52 Dust.................................................................................................................................................................................52 Litter................................................................................................................................................................................53 Nuisance fauna and weed species .......................................................................................................................53 Odour .............................................................................................................................................................................54 Noise...............................................................................................................................................................................54

FIRES................................................................................................................... 55 Fire prevention .............................................................................................................................................................55 Fire control ....................................................................................................................................................................56

4.6 4.7 4.8

4.9

4.7.1 4.7.2 4.8.1 4.8.2 4.8.3 4.8.4 4.9.1 4.9.2 4.9.3 4.9.4 4.9.5 4.9.6

5.

TRAFFIC MANAGEMENT........................................................................................ 56 STAFFING ............................................................................................................ 57 Training requirements.................................................................................................................................................57 Occupational Health and Safety ...........................................................................................................................58

MONITORING PROGRAMS.................................................................................... 58 Groundwater................................................................................................................................................................58 Surface water...............................................................................................................................................................61 Leachate.......................................................................................................................................................................63 Landfill gas....................................................................................................................................................................63

DOCUMENTATION FOR REPORTING AND REVIEW.................................................... 65 Waste acceptance records......................................................................................................................................65 Filling Plan.....................................................................................................................................................................66 Contingency and cost planning ............................................................................................................................66 Incident Management..............................................................................................................................................67 Annual report ...............................................................................................................................................................68 Five-yearly review........................................................................................................................................................68

REHABILITATION AND AFTER-CARE .....................................................................70 5.1 5.2 5.3

5.4

6.

5.3.1 5.3.2 5.3.3 5.3.5 5.4.1 5.4.2 5.4.3 5.4.4 5.4.5

INTRODUCTION ................................................................................................... 70 POTENTIAL POST-CLOSURE USES ........................................................................... 70 FINAL REHABILITATION ......................................................................................... 72 Removal of site structures.........................................................................................................................................72 Additional compaction ............................................................................................................................................73 Completion of capping............................................................................................................................................73 Emissions management............................................................................................................................................79

AFTER-CARE ........................................................................................................ 79 Maintenance ...............................................................................................................................................................79 Monitoring.....................................................................................................................................................................80 Site closure....................................................................................................................................................................81 Reporting.......................................................................................................................................................................81 Site sign-off...................................................................................................................................................................82

REFERENCES.......................................................................................................83 6.1 6.2 6.3 6.4

LEGISLATION....................................................................................................... 83 GUIDELINES......................................................................................................... 84 STANDARDS......................................................................................................... 85 SOFTWARE........................................................................................................... 85 LIST OF APPENDICES APPENDIX A

Suggested plant species............................................................... 85

LIST OF TABLES Table 1.1 Table 2.1 Table 2.2 Table 2.3 Table 3.1 Table 3.2 Table 3.3 Table 4.1 Table 4.2 Table 4.3 Table 4.4 Table 4.5 Table 5.1 Table 5.2

Landfill Classification System ........................................................... 7 Landfill Categories ....................................................................... 19 Distance between Landfills and Sensitive Receptors ...................... 20 Example of a Site Selection Matrix ................................................ 25 Landfill Category and Parameter Matrix ........................................ 29 Landfill Surface Water Requirements ............................................. 36 Landfill Site Security Requirements ................................................. 42 Landfill Placement and Compaction Requirements.......................... 48 Landfill Minimum Cover Requirements ............................................ 50 Landfill Surface Water and Turbidity Limits....................................... 51 Groundwater Monitoring Parameters............................................ 60 Surface Water and Leachate Dam Monitoring Parameters .............. 62 Indicative Landfill Cap Requirements (Clay / Composite Cap)......... 74 Recommended Application of Topsoil for Plant Categories .............. 75

LIST OF FIGURES Figure 3.1 Figure 5.1

Elements of Landfill Design for Category B and C Landfills................. 27 Representation of the Various Component Layers. ......................... 76

GLOSSARY / ACRONYMS After-care

The period of time, usually up to 25 - 50 years after a landfill ceases to accept waste stream. After-care consists of monitoring and maintenance of the closed landfill.

Amenity

The current existence of healthy, pleasant and agreeable (community) surroundings.

ANZECC

Australian and New Zealand Environment and Conservation Council (now superseded by EPHC).

Aquifer

A saturated permeable geologic unit that can transmit significant quantities of water under ordinary hydraulic gradients.

ARMCANZ

Agriculture and Resource Management Council of Australia and New Zealand

AS

Australian Standards

ASLP

Australian Standard Leaching Procedure.

Beneficial use

The environmentally benign and useful application or use of a resource that is of public benefit, including welfare, safety, health or aesthetic enjoyment.

Best Practice Environmental Management (BPEM)

As defined in Section 4 of the EMPCA, 1994

Bioremediation

The remediation or decontamination of any contaminated matter by the use of processes involving biological organisms.

Board

Means the Board of Environmental Management and Pollution Control established under section 12 of the Environmental Management and Pollution Control Act 1994

Buffer distance

The distance between the tipping area of a landfill site and a segment of the environment to be protected.

Category A Landfill

Landfills able to accept solid inert material and fill material. Also referred to as Solid Inert Landfills.

Category B Landfill

Landfills able to accept the same wastes as Solid Inert Landfills as well as low level contaminated soil and putrescible waste. Also referred to as Putrescible Landfills.

Category C Landfill

Landfills able to accept the same wastes as Putrescible Landfills as well as contaminated soil, controlled waste, other hazardous waste and special waste. Also referred to as Secure Landfills.

Capping

The placement of one or more layers to form either a temporary or permanent covering above the waste.

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Cation Exchange Capacity

When applied to clay, means the ability to exchange naturally occurring cations with cations from leachate in contact with the clay. This exchange can over time alter clay permeability.

Cell

A section of a landfill.

Clay

Fine-grained sedimentary rock of low permeability that is capable of being shaped when moist.

Clean fill

Soil, rock, concrete, asphalt or similar non-putrescible material that is not contaminated by other waste; and does not contain contaminated levels exceeding limits for fill material set by the Director in Bulletin 105, Classification and Management of Contaminated Soil for Disposal.

Closure

Cessation of all waste placement activities either with a cell or the entire landfill.

Composting

The process of the aerobic conversion of organic materials by micro-organisms into soil conditioners, compost or humus. It is a process that must be carried out under controlled conditions yielding cured products.

Controlled waste

Wastes currently defined in Section 3 of the Environmental Management and Pollution Control Act 1994 (EMPCA) and the Environmental Management and Pollution Control (Waste Management) Regulations 2000.

Cover material

Material approved by the Regulatory Authority for use to cover waste deposited within a landfill.

Decomposition

The physical, chemical and biological break down of waste materials by micro-organisms.

Director

Director of Environmental Management as defined in the EMPCA

DP&EMP

Development Proposal Management Plan

DPIWE

Department of Primary Industries, Water and Environment

EMP

Environmental Management Plan - a detailed plan for the development, operation, rehabilitation and after-care of a landfill (generally replaces the DP&EMP after initial establishment of the landfill is completed).

EMPCA

Environmental Management and Pollution Control Act 1994.

Engineered Clay Liner

A liner that is constructed by mechanical transformation of locally available materials.

EPHC

Environment Protection and Heritage Council.

EIN

Environmental Infringement Notice

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Environmental

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EPN

Environment Protection Notice

Fill material

Material consisting of clay, soil and crushed rock that is not contaminated or mixed with any other material.

Fines

(a) Very small particles, particularly. those smaller than the average in a mixture of particles of various sizes, or the fine-grained sediment that settles slowly to the bottom of a body of water. (b) An engineering term for the clay- and silt-sized soil particles with diameters less than 0.074 mm.

Geo-synthetic Composite Liner (GCL)

A liner that includes a layer of imported low permeability material (eg bentonite clay) protected by two or more geotextile layers

Geomembrane

A synthetic impervious material such as HDPE in conjunction with a geo-synthetic composite liner.

Geotextile

A synthetic boundary layer that is used to protect an area above or below the geotextile.

Greenhouse gases

Gases, such as methane and carbon dioxide, which contribute to the greenhouse effect, which in turn is thought to cause global warming.

Gully

A channel or small valley cut by concentrated runoff but through which water commonly flows only during and immediately after heavy rains or during the melting of snow.

Groundwater

Water saturating the voids in the soil and rock; water in the zone of saturation in the Earth’s crust.

HDPE

High Density Polyethylene (see geomembrane).

Hydraulic gradient

A change in the hydraulic head along a fluid flow path that determines the direction of groundwater movement.

Hydraulic conductivity

This is the speed that water (including leachate) will flow within the substrata. Commonly referred to as the K-Value.

Hydrogeology

The study of subsurface water with the emphasis on direction of flow, interconnections and interactions with the surrounding strata.

Inert waste

Wastes that do not undergo environmentally significant physical, chemical or biological transformations and have no potentially hazardous content once landfilled. Substantial quantities of inert waste may be derived from building and demolition works, including bricks, concrete, glass, plastics, metal, and timber. Inert waste must not be contaminated or mixed with any other material.

Landfill gas

Gaseous emissions from the decomposition of waste. Also called ‘biogas’.

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Landfill liner

A landfill liner used to separate the waste material from the natural substrate. A landfill liner may be either constructed from natural in situ material (e.g. clay) or from artificial material (e.g. geomembranes or GCL),

Landfill site

A waste facility used for the purposes of disposing of waste to land.

Leachate

Liquid that is either released by or has percolated through waste and contains dissolved or suspended forms of gases, other liquids and solids.

Leachate Dam

As used in this document means an engineered dam using a HDPE geomembrane as a landfill liner that contains leachate or contaminated water.

Level 1 Activity

As defined in Section 3 of EMPCA

Level 2 Activity

As defined in Section 3 of EMPCA

Level 3 Activity

As defined in Section 3 of EMPCA

Liner

A barrier between the waste deposited in a landfill and the underlying substrata c.f. engineered liner.

Liquid waste

Any waste product that is in liquid form. The difference between a solid and liquid waste is defined as to whether the waste product is spadeable (able to be lifted and moved in heaps with a spade).

Lithology

A term applied to the study of sediments, referring to their general characteristics. Lithology generally relates to descriptions based upon hand specimens and outcrops rather than microscopic or chemical features

LUPAA

Land Use Planning and Approvals Act 1993

Methane (CH4)

An explosive, odourless and colourless gas produced in a landfill by organic waste undergoing anaerobic decomposition.

Monitoring Bore

A bore that is installed into a previously drilled hole. Various sections of the installed bore may be slotted to allow movement of groundwater through the bore.

Mulching

The size-reduction of organic materials using one or more of the following processes: cutting, milling, shredding, grinding and other means. The mulch is then usually pasteurised.

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Municipal waste

Wastes arising from the three waste sub-streams: (a) Kerbside domestic waste - household solid and inert waste placed out for kerbside collection (b) Other domestic waste - residential solid and inert wastes. (c) Other Council waste - Council generated solid and inert waste arising form street sweepings, litter bins, parks and garden clean ups and tree lopping.

NATA

National Association of Testing Authorities.

NEPM

National Environment Protection Measure

NTU

Nephelometric Turbidity Unit

OH & S

Occupational Health and Safety

Operator

A person who has the management or control of the landfill (other than as an employee).

Organic waste

One or more of the following types of waste: garden, untreated wood fibrous, vegetables, fruits, cereals, bio-solids, manures, fatty foods, meat, fish and fatty sludges.

PCB

Polychlorinated biphenyls.

Permeability

Saturated hydraulic conductivity (K-Value).

Permit

A permit granted under the Land Use Planning and Approvals Act 1993

PEVs

Protected Environmental Value(s)

Planning Authority

Means a Local Council

Putrescible

Defined in Section 1.3.2.

Regulatory Authority

The authority responsible for the environmental regulation of particular activities, normally as follows: (a) Level 1 activities and planning matters: Local Council. (b) Level 2 activities: Director of Environmental Management. ( c ) Proposed level 2 activities: The Board of Environmental Management and Pollution Control.

Rehabilitation

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The overall process of landfill closure, capping, revegetation, monitoring and after-care.

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Remediation

Work for the rehabilitation and monitoring of premises the subject of a permit and that is required by the conditions of a permit to be carried out: ( a )While the premises are being used for the purpose to which the permit relates, ( b )After the premises cease being used for the purpose to which the permit relates, or (c)Both.

RMPS

Resource Management and Planning System

Run-off

The portion of precipitation that drains from an area as surface flow.

Seismic activity

Vibrations within the earth or along its surface caused by movements or fracturing within the lithosphere

Sludge

Semi-liquid waste produced as a by-product of an industrial process.

Soil Plasticity Index

The difference between the liquid limit and the plastic limit is the range of water content over which the soil is plastic.

Sustainable Development

Managing resources in a way and at a rate, that enables people and communities to provide for their social, economic and ecological needs without compromising the ability of future generations to do the same.

TCLP

Toxicity Characteristic Leaching Procedure.

Uniformity Coefficient

Measure of uniformity in the grading of a material. A numerical expression of the variety in particle sizes in mixed natural soils, defined as the ratio of the sieve size through which 60% (by weight) of the material passes to the sieve size that allows 10% of the material to pass. It is unity for a material whose particles are all of the same size, and it increases with variety in size (as high as 30 for heterogeneous sand).

Valley

A linear, low-lying tract of land bordered on both sides by higher land and frequently traversed by a stream or river. All valleys have been cut by running water over time.

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1.

BACKGROUND 1.1

INTRODUCTION The Landfill Sustainability Guide for siting, design, operation & after-care of landfills (the ‘Sustainability Guide’) supersedes the draft Tasmanian Landfill Code of Practice released in November 1996. The draft Code of Practice has often been referred to in assessment processes and in permit conditions. The new Sustainability Guide also supersedes two other related draft documents, the Guidelines for the Rehabilitation of Refuse Disposal Sites and Guidelines for the Establishment and Management of Landfill Sites for Construction, Demolition and Solid Inert Wastes, released in May 1996. The concepts and principles in the draft documents represented best practice environmental management at the time of development but are now dated. Since that time, understanding of best practice for landfill design, operation, management and groundwater protection has advanced significantly. This is reflected in the adoption of increasingly stringent standards for landfilling in other Australian states and internationally.

1.1.1 What is the purpose of the Sustainability Guide? The aim of the Sustainability Guide is to provide a consistent and effective framework for minimising environmental impacts arising from the siting, design, operation and rehabilitation of landfills in Tasmania. The objectives of the Sustainability Guide are to: •

help developers establish and manage landfilling activities in compliance with environmental legislation and policies;

•

promote consistency in the regulation of landfills in Tasmania;

•

clearly identify the issues that need to be managed and options for their management;

•

inform industry and the community of acceptable standards for landfills; and

•

encourage high level landfilling standards based on the most effective, affordable and innovative mix of mechanisms available.

The Sustainability Guide is designed to help landfill operators achieve good environmental performance. While the Sustainability Guide itself is not a legally enforceable document, permit conditions (which are legally enforceable) are likely to be derived from the acceptable standards and recommendations described within the Sustainability Guide. The standards described in this Sustainability Guide should also be taken into consideration when preparing Development Proposal and Environmental Management Plans (for proposed new sites) and when reviewing Environmental Management Plans (for existing sites).

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1.1.2 Who should read the Sustainability Guide? The Sustainability Guide provides information relevant to regulators, consultants, operators and proponents of landfills. All personnel included in planning, owning or operating a landfill need to be familiar with this Sustainability Guide. The Sustainability Guide also provides the broader community with an understanding of the standards expected of Tasmanian landfills.

1.1.3 What activities does the Sustainability Guide address? The Sustainability Guide is designed to apply to all landfills that are assessed by the Board of Environment Management and Pollution Control (i.e. landfills that are Level 2 activities). However, the principles should be applied to all landfills.

1.1.4 What does the Sustainability Guide contain? The following chapters present environmental issues that should be addressed at particular stages of a landfill’s ‘life’. The Sustainability Guide presents ‘acceptable standards’ and ‘recommendations’ for each of the environmental aspects associated with these standards. Acceptable standards provide the minimum requirements for performance-based environmental management and regulation of landfills, and the recommendations provide guidance on possible means of achieving these standards. The acceptable standards may be prescriptive on certain key issues. The Sustainability Guide is structured so that users can focus their attention on issues relevant to their site (i.e. selecting a site, designing a new site or an extension to an existing site, operating or rehabilitating a site). Although this guideline parallels best practice environmental management at the time of writing, best practice is likely to evolve over time. Therefore, the document will be updated periodically. Any major updates will be undertaken in consultation with proponents and landfill operators.

1.1.5 How do I use the Sustainability Guide? Regulators should utilise the acceptable standards as a basis for drafting and reviewing landfill permit conditions, unless there is no environmental justification for doing so at a particular site. Landfill operators must comply with all permit conditions and should also review the range of recommendations in the Sustainability Guide and select those most appropriate for the particular site. Proponents seeking to deviate from the acceptable standard requirements of the Sustainability Guide will be required to develop the case to justify such deviation on environmental grounds to the satisfaction of the Regulatory Authority. Innovation in achieving best practice environmental management is encouraged provided it has a sound basis in science.

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The Sustainability Guide is not intended to encompass all aspects of environmental protection relevant to landfilling activities. References are provided to other policies and guidelines where appropriate. Users are encouraged to undertake further reading to ensure that they are fully aware of requirements and approaches to minimising environmental risk and financial liability. Proponents and operators are encouraged to continually improve performance through innovation and uptake of appropriate, internationally recognised practices to achieve better environmental outcomes. Since this Sustainability Guide may not be applicable to every situation, users should seek further information or advice from the relevant Regulatory Authority when planning to adopt practices discussed in the Sustainability Guide.

1.1.6 Implementation Timeframe The Regulatory Authority will progressively implement this Sustainability Guide over time as site permit conditions are written or reviewed, subject to normal consultative processes and appeal provisions. Section 2 of this Sustainability Guide ‘Landfill Siting and Planning’ will generally not be applied to existing landfills; all other Sections of the Sustainability Guide will be progressively applied to all landfills. Section 3 ‘Design’ will be applied to new cells at existing landfills, and extensions of landfills from the date of this Guide. Operators of existing landfills will be expected to comply, as a minimum, with all acceptable standards in sections 3, 4 and 5 by no later than June 2009, unless the operator can demonstrate comparable reductions in environmental risk by other solutions, subject to approval by the Regulatory Authority.

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1.2

PRINCIPLES AND ISSUES 1.2.1 Principles Waste management performs a critical role in public health and safety and amenity. Effective waste management also provides an opportunity to conserve resources through effective avoidance and diversion of waste. This is effectively expressed through a hierarchy of waste management options, which are listed below in order of preference: a) avoidance b) reuse c) recycling d) energy recovery e) disposal This hierarchy recognises that waste is best reduced or avoided at the point of production or generation, and that there is a need for strategies for re-using and recycling those wastes that are generated. Inevitably, some residual wastes will need to be disposed of to landfill, but this should only occur when options further up the hierarchy are not practicable. Disposal of controlled and non-degradable wastes might also include ‘containment’ as they will remain in situ for some time. Controlled wastes may also be subjected to treatment in order to render them safe for reuse or containment. The EMPCA requires that landfill disposal of residual waste does not cause significant environmental harm. To achieve this, existing and potential landfill operators need to be aware of the risks landfilling poses to the quality of air, water, land and community amenity. Operators need to manage these risks effectively and operate in accordance with sustainable development principles.

1.2.2 Environmental issues The environmental issues of primary concern to the community and the Regulatory Authority in relation to landfilling operations are as follows: Water Quality Surface waters and groundwater can be polluted by leachate from landfill sites (leachate is the liquid released by, or water that has percolated through, waste). Leachate may cause serious water pollution if it is not properly managed. Surface water run-off from land surrounding a landfill disposal area can cause unacceptable sediment loads in receiving waters, while surface water infiltration of wastes can lead to excessive generation of leachate.

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Air Quality Landfill gas contains methane, carbon dioxide and a variety of potentially corrosive, toxic or odorous components. Emissions of methane and carbon dioxide contribute significantly to the ‘greenhouse effect’. Uncontrolled migration of landfill gas to the root zone of plants may lead to vegetation dieback. Methane can also present an explosion risk and if not used, a wasted energy / fuel source. Significant uncontrolled landfill gas emissions are not a satisfactory landfill practice. Land Management All land is valuable, and the impact of its use as landfill needs to be sustainable. Proper care of a landfill as a valuable asset should result in effective remediation to a landform that blends with its surroundings and can be used for other purposes following closure. Resource Conservation Resource conservation goals include diverting waste materials that can be re-used or recycled from landfills to minimise the loss of capacity, and managing the site to ensure that potentially reusable materials are not received and properly documenting the nature of wastes received. Health Impacts The very nature of a landfill disposal site means that disease vectors and pathogens will be present. Ongoing implementation of programs to minimise the presence and transfer of pathogens must be undertaken. Other Impacts Other potential impacts from landfills include fire, dust, noise, odour, pest plant and animals, and litter. These may occur on or in the neighbourhood of the landfill site. Water and air pollution remain important issues after the landfill is closed. Good engineering design and operational practices will greatly reduce the risk of problems during rehabilitation and after-care (e.g. leachate collection, capping and landfill gas control). 1.2.3 Statutory framework The Sustainability Guide has been developed to further the objectives of Tasmania’s RMPS, which encourages sustainable development of Tasmania’s resources. The RMPS includes legislation and supporting policy relevant to solid waste management, including:

DPIWE

•

Land Use Planning and Approvals Act 1993 (LUPAA);

•

Environmental Management and Pollution Control Act 1994 (EMPCA);

•

Environmental Management and Management) Regulations 2000;

•

State Policy on Water Quality Management 1997; and

•

Classification and Management of Contaminated Soil for Disposal (Bulletin 105)

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Pollution

Control

(Waste

5

Landfills that receive 100 tonnes or more of solid waste per annum are determined to be a “level 2 activity” under Schedule 2 of the EMPCA. Consequently, regulatory approval is required from the Board for the design and operation of these landfills. According to the RMPS framework, applications to develop and operate a landfill are made to the relevant Planning Authority. The Planning Authority assesses the planning aspects of the proposal and refers the permit application to the Board of Environmental Management and Pollution Control (the Board) if it is a Level 2 activity. The Board conducts an environmental impact assessment in accordance with the EMPCA and will advise the Planning Authority of the environmental conditions that must be attached to the permit, if the application is not refused. The Board and the Planning Authority decide on the proposal after a public comment period and an integrated environmental and planning assessment has taken place. The decision is subject to appeal by the applicant or the public representors. To gain approval, proponents must demonstrate that the acceptable standards outlined in the following chapters will be achieved. Proponents may select the best mix of controls for site development and management to achieve the required outcome and document these in the Development Proposal and Environmental Management Plan (DP&EMP). In general, a DP&EMP will consider the impact of the development and demonstrate the means to mitigate these impacts, and will address issues including (but not limited to) those described within this Sustainability Guide. Proponents can obtain further guidance on the information that is required from the Regulatory Authority and the Planning Authority. In the operational phase, the activity will be subject to a permit with specified conditions designed to give effect to this Sustainability Guide. Enforcement action can be taken where permit conditions or EMPCA are breached. An existing permit may be modified through an environment protection notice if changes in the permit are required. When the magnitude or nature of the proposed change is environmentally significant or the development is a significant intensification of use, a new development application is likely to be required. If the nature or quantity of wastes entering a landfill changes, the Regulatory Authority must be informed.

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1.3

CLASSIFICATION OF LANDFILLS 1.3.1 Landfill Classification System Three categories of landfill are established: Category A:

Solid Inert Landfill

Category B:

Putrescible Landfill

Category C:

Secure Landfill

Table 1.1 describes the types of wastes that may be accepted at each category of landfill for disposal. Some acceptable standards and recommendations vary according to these categories. Table 1.1

Landfill Classification System Landfill Category A

B

C

(Solid Inert)

(Putrescible)

(Secure)







Fill material







Low level contaminated soil



?



Contaminated soil







Contaminated soil for remediation







Putrescible waste







Controlled waste



?



Waste type

Solid inert material (includes clean fill) Potentially contaminated material 1

Key:

DPIWE

  ?

permitted not permitted may be accepted, subject to approval by the Regulatory Authority for the type of waste. Analytical testing may be required.

1.

The basis for classification of potentially contaminated material is defined in DPIWE Information Bulletin 105, Classification and Management of Contaminated Soil for Disposal.

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1.3.2 Waste types Descriptions of each waste type shown in Table 1.1 are provided below. Note that some substances such as cytotoxic waste may not be suitable for disposal at any landfills (see Section 1.3.3). Certain wastes may require treatment prior to disposal. Solid inert material may be defined as waste which will not degrade in the short term, and which has a negligible risk to the environment (see also the definition of solid inert waste). Examples of solid inert material may include: •

inert building and demolition waste (see exclusions below);

•

clean fill;

•

wood;

•

bricks;

•

inert synthetic materials

•

concrete;

•

rocks; and

•

fencing material.

Solid inert materials as defined above do NOT include: •

asbestos sheet and asbestos fibre;

•

contaminated soil;

•

treated timber;

•

tyres;

•

putrescible waste;

•

green waste;

•

recyclable metal items

•

all other waste from domestic, government, commercial and industrial sources not specifically listed above.

Re-use and recycling options should be closely examined for solid inert wastes. Potentially contaminated materials are materials that may contain metals, organic substances or other wastes that will have a harmful effect on the environment if disposed of in an inappropriate manner. DPIWE Information Bulletin 105, Classification and Management of Contaminated Soil for Disposal, establishes four distinct levels of ‘soil’ as follows: 1. Fill material; 2. Low Level Contaminated Soil; 3. Contaminated Soil; and 4. Contaminated Soil for Remediation.

DPIWE

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Soils may require testing by appropriately qualified and accredited personnel to determine the appropriate means of disposal. Note that Contaminated Soil for Remediation is generally not considered acceptable for disposal without prior treatment to reduce the concentration of contaminants or leachability of contaminants. Contaminated Soil may only be accepted at Secure Landfills, whereas Low Level Contaminated Soil may be accepted at nominated Putrescible Landfills for use as intermediate cover. Further information is provided in DPIWE Information Bulletin 105, Classification and Management of Contaminated Soil for Disposal. Putrescible waste may be defined as waste containing major components able to be decomposed by bacterial action, often resulting in offensive odours. This includes: •

household domestic garbage, either set aside for kerb-side collection or delivered by the householder directly to the landfill;

•

local Council generated waste (e.g. waste from street-sweeping, litter bins and parks);

•

food waste from industrial or commercial sources such as restaurants, food markets, supermarkets etc.;

•

paper and cardboard, and

•

green waste.

Some putrescible wastes that decompose readily are ideal for composting operations - see Guidelines for Recycling of Organic Wastes in Tasmania (DPIWE 1996a) for further details. Controlled Waste is defined in EMPCA as follows: (a) a substance that is controlled waste within the meaning of – (i) the National Environment Protection Measure entitled the Movement of Controlled Waste Between States and Territories made by the National Environment Protection Council on 26 June 1998, as amended from time to time; or (ii) any National Environment Protection Measure substituted for the Measure referred to above, as amended from time to time; and (b) a substance that is prescribed by the regulations to be controlled waste.

DPIWE

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The Environmental Management and Pollution Control (Waste Management) Regulations 2 0 0 0 further prescribe waste to be controlled waste if it exhibits an environmentally significant characteristic (as listed in the above National Environmental Protection Measure) and is one of the following: (a) derived or arising from agricultural produce or veterinary chemical products within the meaning of the Agricultural and Veterinary Chemicals (Control of Use) Act 1995; (b) a dangerous good within the meaning of the Dangerous Goods Act 1998; (c) derived or arising from poisons within the meaning of the Poisons Act 1971; (d) a waste within the meaning of the Quarantine Regulations 2000 of the Commonwealth, as amended; (e) a scheduled waste within the meaning of a National Management Plan; or (f) any other waste declared by the Director, by notice published in the Gazette, to be waste consisting of, or containing a quantity of, a pollutant that when placed in, or discharged into, the environment may: (i)

directly or indirectly cause environmental harm; or

(ii)

give rise to the abnormal concentration of any substance in any plant, animal or organism above natural concentrations; or

(iii)

adversely affect the use or value of the receiving waters for recreational, commercial, domestic, agricultural or industrial purposes; or

(iv) contain sufficient heat, or be likely to generate sufficient heat by itself or in combination with other matter, to ignite or cause fire; or (v)

give rise to undesirable, abnormal or harmful growth of a plant, animal, virus or organism.

Because of the hazardous nature of controlled wastes, strong emphasis should be placed on reducing the amount of waste at the source. Recycling and treatment options should also be explored prior to disposal (e.g. certain organic solvents and waste oils may be recycled or reclaimed, and some may be suitable for biological treatment).

DPIWE

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Inevitably some controlled waste is included in the municipal waste (e.g. domestic paint stripper, batteries, pesticides, solvents or smoke detectors that contain radioactive material). Where practical, controlled wastes in the domestic waste stream should be identified and strategies developed for removal and separate treatment and disposal. With all forms of waste treatment however, there are usually residues that require landfill disposal. Such residues may need to be immobilised by chemical fixation or encapsulation to prevent the leaching of contaminants into surface or ground waters. The chemical constituents of most controlled wastes require analysis before disposal to landfill to ensure compliance with levels specified by the Regulatory Authority (See Section 1.4). In general, controlled wastes can be accepted for disposal only at Secure Landfills, however disposal of some controlled wastes (e.g. tyres, asbestos and sharps that have been appropriately packaged) may be allowed in Putrescible Landfills at the discretion of the Director of Environmental Management.

1.3.3 Specific Disposal Requirements for Certain Waste Types Asbestos must be transported and disposed under strictly controlled conditions. Sites used for the disposal of asbestos waste need to have permits for this purpose. Removal, transport and disposal of asbestos waste must be in accordance with relevant environmental and occupational health guidelines. Liquid waste: Receipt of liquid wastes at landfills is generally not considered best practice environmental management. Liquid w a s t e , including domestic grease trap wastes and septic tank pump-outs, should be managed according to one of the following options. 1.

Liquid wastes that exhibit high biochemical oxygen demand may not be suitable for some sewer and wastewater treatment systems. Such wastes may be able to be tankered directly to an anaerobic digester or similar wastewater treatment plant.

2.

Wastes may be dewatered by press, evaporation, centrifuge, etc. Liquids may then be reused or directed to sewer as appropriate.

3.

Solids may be recovered for disposal at a Category C landfill and liquids directed to sewer via an appropriate pre-treatment facility.

4.

Wastes may be applied to land – subject to detailed assessment and in most cases requiring winter storage.

5.

Wastes may be diverted to an approved composting facility (may require winter storage).

Application of these options is subject to the availability of facilities, authority approval and permit conditions. Clinical and related wastes should be managed in accordance with a method approved by the Director of Environmental Management.

DPIWE

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Material containing Polychlorinated Biphenyls (PCBs) should only be dealt with in accordance with the National Strategy for the Management of Scheduled Waste (ANZECC 1993) and the Polychlorinated Biphenyls Management Plan (ANZECC 1999). Disposal of non-scheduled solid PCB waste to landfill must be approved by the Regulatory Authority and must conform to the requirements for discharge to air, water, and land that apply to the treatment and disposal of scheduled PCB waste. Any waste believed to be radioactive (excluding domestic smoke detectors) should not be accepted at a landfill without approval from the Department of Health and Human Services and the Director. Sludges destined for disposal at an approved landfill must be of a spadeable consistency unless the landfill is approved by the Regulatory Authority to receive liquid sludge. The water content of the waste sludge should be reduced by on-site treatment (e.g. belt press, centrifugation, drying beds) at the plant of origin to ensure easier waste handling and to reduce the volume of leachate generated by landfill disposal. Sludges should generally be tested for contaminants prior to acceptance at a landfill (see Section 1.4.2). Industrial sludges may contain significant amounts of potentially hazardous materials, including heavy metals that typically exhibit increased solubility under acidic conditions commonly found in landfills. In particular, pH levels in the early stages of burial (when the pH is generally around 5.0 - 6.5 for the first two years increasing to pH 6.5 - 7.5 after ten years) pose a significant risk of increased contaminant solubility. Where sludge is found to be acidic or slightly alkaline, it should be treated with lime prior to disposal to increase pH and to minimise the potential for leaching. Tyres may be stockpiled and managed separately provided the number does not exceed 500 and stored in individual lots of 150 or less. Disposal of tyres is allowed only at landfills that have specific approval from the Regulatory Authority

DPIWE

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1.4

ACCEPTANCE OF CONTROLLED WASTES It is essential that wastes disposed to landfill have acceptable chemical properties (e.g. in relation to degradability, toxicity of breakdown products, and potential for bioaccumulation). It is difficult to define what is acceptable for disposal based solely on the waste’s source: not all industrial wastes are hazardous, nor are all domestic wastes classed as non-hazardous. Furthermore, the presence of hazardous constituents in a waste stream does not necessarily imply that the waste as a whole is hazardous (e.g. the hazardous components may be chemically bound in an inert matrix). Information concerning the environmental availability of the hazardous component is needed to allow for this possibility. There are two means of assessing the hazard associated with a particular waste (or load): • reference to the Tasmanian waste tracking system when it becomes available; or • testing the total concentration and leachability of contaminants.

1.4.1 Tasmanian waste tracking and classification system A waste tracking system is being developed for implementation in Tasmania to document relevant information regarding waste loads and allow movement of waste to be tracked from generation through to disposal. Landfill operators may be able to use details contained within the waste transport certificates provided by the waste generator as the basis for assessing the suitability of the waste for disposal within a given facility in accordance with their operating conditions. Classification will be according to the physical and chemical nature of the wastes, the industry from which it originates, and hazardous contaminants of the waste. The National Environment Protection (Movement of Controlled Waste Between States and Territories) Measure will form the basis for controlled waste characterisation. Responsibility for classification of waste material will lie with the waste producer.

1.4.2 Analytical Testing If there is doubt as to whether material is controlled waste, it must be treated as if it were controlled waste or it must be subjected to analytical testing by the owner of the material. This testing must be undertaken before waste is removed from a site. Information on the nature of a waste stream that is believed to be potentially hazardous may be obtained through analytical procedures carried out by a National Association of Testing Authorities (NATA) accredited laboratory. The suitability of particular wastes for acceptance to landfill may subsequently be determined by comparing the results of the test procedure with acceptance criteria.

DPIWE

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A common parameter for tests is the total concentration of contaminants. This is a standard test for contaminated soil and is most appropriate for wastes that may break down rapidly in a landfill and release high concentrations of contaminants. Conversely, a contaminant may not be 'available' due to low solubility or some other chemical or physical characteristic. Consequently, testing should generally also address the mobility of organic and inorganic contaminants in such a way as to simulate leaching that may occur in a landfill environment over a period of time. Tests that are appropriate for determining such characteristics include the ‘Australian Standard Leaching Procedure’ (AS 4439.3-1997) and the ‘Toxicity Characteristic Leaching Procedure’ developed by the United States Environmental Protection Agency. In general, the acceptability of tested wastes should be assessed against criteria provided in DPIWE Information Bulletin 105, Classification and Management of Contaminated Soil for Disposal as follows: •

where test results are equivalent to those acceptable for ‘Fill Material’, wastes may be disposed at any landfill;

•

where test results are equivalent to those acceptable for ‘Low Level Contaminated Soil’, wastes may be disposed at Solid Inert and Putrescible Landfills;

•

where test results are equivalent to those acceptable for ‘Contaminated Soil’, wastes may only be disposed at Secure landfills; and

•

where test results are equivalent to those acceptable for ‘Contaminated Soil for Remediation’, wastes may only be disposed at Secure landfills under the following circumstances; a. the wastes undergo treatment to immobilise the hazardous component (e.g. chemical treatment, fixation, encapsulation or micro-encapsulation) or to remove the hazardous component (e.g. landfarming) and follow-up testing; or b. the wastes are stored, subject to regulatory Authority approval, pending the development of suitable facilities for treatment or disposal of the waste.

Advice must be sought from the Regulatory Authority when uncertainty exists over whether a waste is controlled waste or over the interpretation of test results.

DPIWE

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Additional Directions Before controlled waste can be accepted at a landfill: (i)

the permit conditions must explicitly allow the type waste to be accepted, and;

(ii)

if required by the permit conditions, a case specific approval should be sought in relation to each consignment of waste, and;

(iii)

the approval of the landfill manager must be obtained.

Any waste stream believed to be particularly hazardous by virtue of its explosive nature, flammability, reactivity, or corrosivity should not be accepted at a landfill without pre-treatment to minimise or remove the hazard. If environmental problems occur as a direct result of landfill operations, then failure to implement controls for the disposal of controlled wastes may expose operators to environmental and financial liabilities. Operators should be aware of the industries in the area that are likely to produce controlled wastes and, if wastes from these industries are disposed at the landfill, ensure that acceptance and disposal complies with permit conditions. The capability of a landfill to accept a given type of controlled waste is not determined solely by its categorisation. It is possible for a wellmanaged site to be unsuitable for the disposal of some (if not all) controlled wastes due to poor physical site characteristics. Conversely, a site with ideal physical characteristics may not be approved for disposal of particular wastes due to poor management history.

DPIWE

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2.

LANDFILL SITING AND PLANNING The selection of a new landfill site is critical to minimising the impact of a facility on the environment. Careful selection will minimise the design and operational controls required to ensure environmental protection of the site and surrounding environments. By selecting the most suitable site, the impact of the facility on the environment can be minimised, as can operational and rehabilitation costs. It is important that any potential landfill sites identified are assessed against standard criteria. The following section provides criteria and the minimum acceptable standards for any potential new landfill site. Where appropriate the provisions of this section will also be applied to extensions of existing landfills. This section will not be applied retrospectively to existing landfills. Compliance with the acceptable standards listed below should be demonstrated in the Development Proposal and Environmental Management Plan, in accordance with the Resource Management and Planning System.

2.1 DEMAND Acceptable Standard A proposal for a landfill (or an extension to an existing landfill) must consider the demand for further landfill space. Recommendations Proponents should review accurate and recent information regarding the demand for a new landfill, which may include the following: •

types and quantities of waste generated within the envisaged ‘catchment’ for the proposed landfill;

•

current disposal pathways for these waste materials;

•

projected waste quantities and types requiring disposal at landfill (e.g. accounting for demographic change or establishment of reuse and recycling infrastructure); and

•

remaining capacity and forecast closure dates for landfills currently used for disposal of waste from the area under consideration.

This information should be used to determine the expected types and volumes of waste that will require disposal at the proposed landfill (i.e. the expected demand). Avoidance and diversion of wastes from landfill is a principal aim of waste management (refer to Section 1.2.1). Any landfill proposals, or proposals for the extension of existing landfill facilities, should demonstrate how this aim will be met (e.g. by providing recycling drop-off centres or repair and reuse centres at the landfill).

DPIWE

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2.2 COMMUNITY LIAISON Acceptable Standard Community liaison should be conducted throughout the life of all landfills, commencing during site selection to ensure local communities are informed and aware of the proposal. Community liaison should be conducted in an open and timely fashion, and allow local knowledge to be obtained. Recommendations The community should be provided with adequate information and opportunity to comment. This may be provided through public meetings, pamphlets, information booths at local events etc. The detail of information provided will vary from proposal to proposal but should always include an assessment of the potential impacts of a proposal on the local community (e.g. employment opportunities, altered traffic volumes, noise and odour). It is important that the community is able to readily contact an informed representative of the proponent regarding landfill site selection, and that a response is provided to any concerns raised in a timely fashion. A record of community comments regarding potential landfill sites and responses should be maintained by the proponent.

2.3 GEOLOGY Acceptable Standard Landfills must be located on stable land that is able to support the weight of the landfill over an extended period. Sites must also provide a natural unsaturated attenuation layer below any liner system to minimise downward movement of leachate. In accordance with the above, landfills will not be able to be located in: •

karst formations;

•

sandstone terrains;

•

slipping substrate;

•

dune formations;

•

areas of high permeability soils and sub strata (i.e. fractured rock) or

•

areas identified as having significant geoconservation potential.

Landfills must not be sited within 1 km of major tertiary (first order) fault lines that present risk associated with seismic activity (e.g. fault lines displaced in the Holocene period). Landfills must not be located in either gullies or deep valleys, unless detailed engineering and hydrological design and modelling work has been completed.

DPIWE

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Recommendations A geotechnical assessment of the stability of the site should be conducted. This assessment should be prepared by a suitably qualified professional in accordance with relevant Australian Standards, and contain (as a minimum): •

a description of the local and regional geology;

•

an assessment of the geotechnical stability of the site, including slope stability and seismic considerations;

•

mineralogy of the area, including the shrink / swell characteristics of the soil and underlying strata;

•

permeability of soils and rock strata; and

•

susceptibility of the site to seismic activity

This assessment should identify any need for engineered assistance to support the landfill. In areas where subsurface mining has been conducted, it is important to guard against ground collapse. The mineralogy assessment should estimate differential movement of the landfill liner from the ground. It is preferable to source material for landfill lining, covering and capping on-site or from the surrounding area. Sites with geologies conducive to this and that provide a natural attenuation layer (i.e. impermeable clayey soils) are preferable.

2.4 HYDROGEOLOGY Acceptable Standard Landfill sites must be selected to minimise their potential impacts on PEVs of groundwater. Unless specific controls are incorporated into the design and management of a landfill, landfills must not be located: •

in areas of potable groundwater;

•

below the regional water table;

•

in groundwater recharge areas; or

•

in permanently swampy terrain.

Recommendations A detailed assessment of groundwater should be completed by a qualified and experienced hydrogeologist during the site selection phase (this may be combined with the geological assessment). This assessment should include (but not be limited to) groundwater:

DPIWE

•

depth;

•

gradient and flow direction;

•

quality (local and regional);

•

interaction with surface water; and

•

potential and actual beneficial uses.

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The parameters of this assessment may be used to indicate the potential impact of a landfill on groundwater. If an appropriate site is identified that is partially below the regional water table, the base of the landfill could be raised to be above the water level. This would allow for creation of an ‘attenuation zone’ between the landfill and water table. Design at such sites would need to be of the highest possible engineering standard consistent with the landfill category. Table 2.1 Landfill Categories Landfill Category Depth between waste and water table at seasonal peak

A (Solid Inert)

B (Putrescible)

C (Secure)

2 metres

5 metres

5 metres

2.5 BUFFER DISTANCES Landfills have the potential to impact on a number of sensitive land uses. Buffer distances between a landfill and sensitive land uses should be sufficient to: −

prevent surface water from carrying sediment or contaminants off the landfill site;

−

ensure that air traffic is not exposed to potential hazards from birds; and

−

ensure that local amenity is not detrimentally affected by unpleasant odours, litter, noise, vermin or dust.

Acceptable Standard Landfills must be located with sufficient distance between the boundary of the landfill site and adjacent, sensitive land uses. Recommendations The use of sufficient distance between the landfill and sensitive receptors (e.g. residential zones) will minimise the requirement for other stringent controls. Suggested minimum distances are shown in Table 2.2.

DPIWE

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Table 2.2 Distance between Landfills and Sensitive Receptors Landfill Category A (Solid Inert)

B (Putrescible)

C (Secure)

Permanent watercourses (excluding farm dams)

50 m

100 m

100 m

Landing grounds and airfields

10,000 m

10,000 m

10,000 m

300 m

500 m

500 m

Residences

Where the separation distances shown in Table 2.2 cannot be maintained, the Regulatory Authority and the Planning Authority should ensure that the landfill, the sensitive receptor or both, are constructed and managed using appropriate impact attenuation technologies. A reduced buffer distance for airports may be acceptable if proponents can demonstrate to the Federal Airport Commission or the Civil Aviation Safety Authority that a site bird management program will adequately reduce the risk of aviation accidents. The buffer distance to residences for landfills can be reduced where a detailed assessment, including noise, particulate (dust) and odour modelling, indicates that the amenity of the residences will not be reduced. It is important to ensure that landfill buffer distances can be maintained for the life of the landfill. In setting buffer distances consideration must be given to sensitive land uses other than those listed in Table 2.2 (e.g. agricultural areas that are prone to disease transmission, and food processing facilities).

DPIWE

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2.6 SURFACE WATERS Acceptable Standard Potential impacts upon surface waters must be considered in the siting of landfills. The ongoing potential impacts of landfills must be minimised so as not to significantly impact upon the environment (e.g. surface water runoff and occasional occurrences including floods). In light of the above, landfills are unlikely to be acceptable in: •

sensitive water supply catchments;

•

1-in-100-year floodplains; or

•

wetlands.

Recommendations An assessment of a region’s climatology, including rainfall and evaporation rates, should be conducted to ensure effects of rainfall or surface water can be appropriately managed. The assessment should consider uncertainties and the potential for future variations in rainfall and moisture balance resulting from climate change

2.7 INFRASTRUCTURE Acceptable Standard The distance for transport of materials (e.g. incoming waste and outgoing recyclables) must be taken into account in the location of a landfill. Transportation must occur safely with minimum disruption to the community. Adequate transportation infrastructure for a landfill must be determined prior to submission of the DP&EMP (or EMP). Recommendations A transportation study of potential landfill sites should be conducted. This should identify potential waste transportation modes, for example road, rail, etc. The capacity of the existing network to cope with predicted traffic flows should be assessed and additional infrastructure required as a result of the landfill identified. Transportation of waste through residential and other sensitive land uses should be minimised, for example by placing the landfill entrance away from such areas. The availability of services (including reticulated water, power and sewerage) should be identified. Where reticulated water is not available, sufficient area for water storage for fire-fighting purposes must be provided on the site. Where there is no sewage infrastructure, consideration needs to be given to alternative methods of leachate management such as leachate dams.

DPIWE

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2.8 FLORA AND FAUNA Acceptable Standard The development and operation of landfills must minimise the impact upon threatened flora and fauna and threatened forest and non-forest vegetation communities, particularly where the landfill occupies land that has previously been subject to minimal disturbance. The operation of landfills must also avoid the introduction and spread of pest plants and animals and diseases. Recommendations Any existing data on flora and fauna present on the site and surrounding land should be reviewed, in order to determine the abundance, distribution and conservation priority of species and communities present or potentially present. Suitably qualified professionals should conduct a survey of the flora and fauna habitat of potential landfill sites and their surrounds. Proponents may apply to limit the extent of these surveys if it can be demonstrated that extensive information is already available for the site. Further information on surveys may be obtained from the Resource Management and Conservation Division of DPIWE. Land clearing must be minimised to reduce the destruction of habitat for threatened flora and fauna species and communities and to minimise soil exposure and erosion. Landfill and infrastructure siting must be designed to minimise the risk of introduction and spread of Phytophthora cinnamomi in susceptible vegetation. Landfills must be operated in a manner that minimises their attractiveness to wildlife as an area to feed in and to prevent the spread of weeds. Species identified in flora and fauna surveys that are listed under Tasmania’s Threatened Species Protection Act 1 9 9 5 may not be damaged or destroyed without an appropriate permit being issued from the relevant section of government. Landfills must not be located in areas where they have the potential to significantly impact upon threatened species and ecological communities identified in the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 without written approval of the Commonwealth Environment Minister. Threatened forest and non-forest vegetation communities should not be adversely impacted by landfills. Where landfill proposals involve the clearing of forest vegetation, a Forest Practices Plan may be required in accordance with the Forest Practices Code. Threatened forest communities are protected through the code. There is also a moratorium on the clearing of threatened non-forest communities in areas covered by new Forest Practices Plans.

DPIWE

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The Tasmanian Government has announced that it will protect threatened non-forest vegetation communities. Clearance and conversion to other uses of these communities on proposed landfill sites should be avoided. Further advice on threatened non-forest vegetation communities may be obtained from the RMC Division of DPIWE. The Regional Forest Agreement was signed by the State and Commonwealth Governments in November 1997 and seeks to achieve a balance between resource use and conservation of Tasmania’s biodiversity through the establishment of a series of reserves that are comprehensive, adequate and representative. One of the guiding principles of the RFA was that “wherever possible” protection of these forest communities would be by reservation on public land. Landfills must not be located on public land in areas where they have the potential to significantly impact on species or communities identified as requiring further protection under the Regional Forest Agreement 1997. Landfills should not be located on private land in areas where they have the potential to significantly impact on species or communities identified as requiring further protection under the Regional Forest Agreement 1997 without having given due consideration to their protection under the Nature Conservation Act 2002.

2.9 GEOCONSERVATION AND GEO-HERITAGE Acceptable Standard The development and operation of landfills must not impact upon areas that have been identified as significant in relation to their geologic, geomorphic or pedologic values. Recommendations A search of the Tasmanian Geoconservation Database maintained by DPIWE will identify any areas currently listed. Such areas are not suitable for development or use as a landfill. World Heritage Areas and State Reserves are also unsuitable. Additionally, a geoconservation and geoheritage survey of proposed landfill sites should be conducted. The survey should identify any areas of geological, geomorphic or pedologic significance. A brief for this type of survey can be obtained from the Nature Conservation Branch, DPIWE.

DPIWE

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2.10 HISTORIC AND CULTURAL HERITAGE Acceptable Standard Historic and cultural heritage must be identified, and if required appropriate approvals must be obtained prior to disturbance. Recommendations A search of the Tasmanian Heritage Register, maintained by the Tasmanian Heritage Council under the Historic Cultural Heritage Act 1995, will identify any areas currently listed. Such areas are not suitable for development or use as a landfill. World Heritage Areas are also unsuitable. If the proposed landfill is located on land scheduled in the Tasmanian Aboriginal Lands Act 1995, then endorsement by the Tasmanian Aboriginal Land Council will be required. Historic cultural heritage areas should be identified. The survey should identify any items or areas of historic cultural heritage. The Tasmanian Heritage Council and Tasmanian Aboriginal Land Council should be notified of any such items or areas identified and guidance sought.

2.11 LAND OWNERSHIP AND USE Acceptable Standard Ownership of land to be used for a landfill must be defined and appropriate permission obtained prior to submission of the DP&EMP. The future use of the land upon completion of filling and rehabilitation must also be considered. Recommendations Written consent from land owners should be obtained prior to submission of the development application and accompanying DP&EMP to the Planning Authority. If a landfill is to be developed on Crown land, written consent is required from the Minister responsible for the relevant Act under which the land is managed. The planning requirements for each site should also be considered (e.g. whether the current zoning of a site is appropriate for use as a landfill). Landfills can cause major problems during and after their rehabilitation if they are not properly planned and filled. Potential end uses of the area should be considered when a landfill is planned, or when extensions to existing sites are being considered. The selection of the end-use of the site should be compatible with the expected settlement of the landfill surface; otherwise continued maintenance to monitor grades and levels may be required.

DPIWE

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2.12 SITE SELECTION Acceptable Standard Landfills must be located in accordance with the land zoning under the local planning scheme. Furthermore, site selection should include preliminary assessment of other sites to determine appropriateness for use as a landfill disposal area. Recommendations To select a landfill site, it is important that all areas addressed above are considered. Prior to site selection, proponents should identify several potential sites and conduct a preliminary assessment of each to determine their appropriateness for use as a landfill. It is important that all sites identified have the capacity to accept the projected waste quantities and types. By addressing the above criteria in a comprehensive and consistent manner, the most appropriate landfill site should recommend itself for selection. In some cases, sites may not meet the acceptable standards and should therefore be excluded. Where several sites are suitable, further assessment of economic, environmental and social factors regarding each site may be required to determine the most appropriate site. An effective means of identifying the most suitable site is to compare and rank sites according to a matrix (as shown by the example in Table 2.3). Table 2.3

Example of a Site Selection Matrix Site Selection Criteria1

Site

Demand





Community





Geology

Hydrogeology









(etc)





X Y Z 1.

Criteria shown in Table 2.3 are by no means exhaustive

Some criteria will have greater influence over site suitability than others. It may be appropriate to ‘weight’ each criterion according to the expected costs and resources required to comply with the acceptable standards detailed in this section. Community consultation is essential during the initial site selection process to identify relevant local and significant issues.

DPIWE

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Proponents should document all information obtained throughout the site selection phase to clearly demonstrate that the selected site meets acceptable standards. It is important to establish background data on soil, water and air quality to identify benchmarks with which to compare future sample results. It should be recognised that this list is not comprehensive and further information should be sought at local Government level before decision making is undertaken using the site selection matrix

DPIWE

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3.

DESIGN Careful design of a landfill prior to construction will minimise environmental problems during its operating life and will reduce the need for expensive retrofitting of Best Practice Environmental Management technologies later. From the date of this Guide the provisions of this Section will be applied to extensions of existing landfills, which will be dealt with as a separate entity from the existing landfill. From June 2009 all operators of landfills will be expected to comply with this Section. Acceptable Standard

DP&EMPs for level 2 landfills and supporting information in relation to landfill extensions or new cells must be prepared according to site-specific ‘Guidelines for the preparation of a DP&EMP’. These Guidelines are typically issued on behalf of the Regulatory Authority. As a minimum, new landfills and/or cells must be designed with regard for the following: -

containment and collection of leachate;

-

management of surface water;

-

landfill gas management; and

-

future rehabilitation.

Recommendations Figure 3.1 illustrates the typical design elements to be used for Category B and C landfills. Category A landfills do not need to implement the same design elements as Category B and C landfills (e.g. engineered liners and internal cell walls) as solid inert wastes present a reduced environmental risk. Figure 3.1

Elements of Landfill Design for Category B and C Landfills

Other issues to be addressed during landfill design include:

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•

assurances regarding the quality of construction;

•

site security (e.g. fencing);

•

signage; and

•

traffic management.

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3.1

LEACHATE CONTAINMENT AND COLLECTION Acceptable Standard Landfills must be designed so that pollution of water by leachate is prevented. Recommendations A typical system will comprise: •

a barrier between waste and the underlying groundwater, soil and substrata;

•

a collection system to minimise the quantity of leachate accumulating at the base of the landfill; and

•

procedures and infrastructure for appropriate management of the leachate generated.

•

Diversion of uncontaminated surface water away from the landfill

3.1.1 Leachate Barrier Acceptable Standard Landfills must be designed to contain leachate over the time that the waste poses a risk to protected environmental values for groundwater. An engineered clay liner is the minimum control required for Putrescible landfills. Secure landfills require a geo-synthetic composite liner with geomembrane (e.g. HDPE) as a minimum (refer to Table 3.1). In relation to pre-existing landfills that do not comply with the design specifications outlined in Table 3.1, the operator must be able to justify to the Regulatory Authority that environmental harm is not occurring.

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Table 3.1

Landfill Category and Parameter Matrix Landfill Category

Parameter

A (Solid Inert)

B (Putrescible)

C (Secure)

Natural geology if suitable. Engineered clay liner may be required in some circumstances

Engineered clay liner if geology suitable and < 10 year landfill life. If not, geosynthetic composite liner required and /or geomembrane

Suitable geology and engineered clay liner, geosynthetic composite liner and geomembrane

Default thickness of clay liner (minimum)

NA

1m

>1m

Required in-situ permeability coefficient of clay liner

< 1 x 10-8 m/s 1

< 1 x 10-9 m/s

Distance between watertable (at seasonal peak) and waste

>2m

>5m

Type of leachate barrier

Minimum floor gradient towards drainage lines

3%

Maximum side gradient

33%

1. Higher permeability may be acceptable provided that management procedures are in place that guarantee that only inert materials can enter the site.

Recommendations An adequate hydrogeological investigation should be conducted by a competent hydrogeologist to prove the substrate’s effectiveness as a barrier. This assessment should include (as a minimum): •

the lateral extent, thickness and homogeneity of the material;

•

the permeability of the material to leachate and gas;

•

the integrity of the material, and the presence of any imperfections that may compromise its effectiveness (e.g. root holes, cracks or gravel layers); and

•

any possible reactions between the material and the leachate.

Use of the natural geology does not preclude engineering to provide a uniform, graded floor to allow for leachate collection. Where the integrity of the natural material is compromised due to imperfections (root holes, cracks, gravel layers or other heterogenous material), an engineered compacted clay liner, geomembrane or Geo-synthetic composite clay liner is to be used.

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An engineered compacted clay liner if used should exhibit the following characteristics: •

preliminary construction to prepare a stable sub-base, utilising either natural geology or suitably impervious material. The material should provide a firm platform for compaction of the clay liner (if used);

•

clay with the following properties; 

no rock or soil clumps greater than 50 mm in any dimension;



> 70 per cent passing through a 19 mm sieve;



> 30 per cent passing through a 7.5 mm sieve;



> 15 per cent passing through a 2 mm sieve;



soil plasticity index > 10;



cation exchange capacity > 10 mEq/100g;



be homogeneous in clay content (i.e. no sandy lenses, pebbles or cobbles);

 low potential for desiccation and cracking; and  minimal long-term degradation with exposure to leachate; •

construction and compaction in successive layers of suitable thickness (e.g. 150 mm) that allow penetration of the topmost layer by compaction equipment to knead the underlying layer for bonding; and

•

the surface of each layer should be scoured to prevent excessive permeability due to laminations.

If the clay liner is constructed well in advance of filling, it may need temporary protection against cracking and desiccation. A temporary covering of 300 mm compacted and wetted sand or soil may be placed, and then removed before placement of the drainage layer (see Section 3.1.2). Density, hydraulic conductivity and moisture content need to be controlled by regular testing by a NATA accredited laboratory using recognised Australian Standards during installation of the liner, in addition to quality assurance checks on a regular basis. A geo-synthetic composite liner, geomembrane or a combination of both is recommended for sites where:

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local geological or hydrogeological conditions are particularly sensitive (e.g. perched watertable or permeable substrata);

•

the landfill is expected to have a long operating period (i.e. longer than 10 years); or

•

insufficient clay is available.

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Data on the physical characteristics of available geomembranes should be obtained from manufacturers to allow comparison and selection of the most appropriate product. These data should include: •

resistance to chemical attack;

•

ability to withstand weathering (e.g. UV exposure and wetting);

•

strength to withstand tensile force;

•

flexibility to accommodate elongation;

•

resistance to punctures and other damage;

•

joining method; and

•

ease of repair.

An installed geomembrane should be protected by either an overlay of soil with low abrasive properties or by a synthetic geotextile to protect against puncturing and load-induced damage. Installation of a leachate detection layer beneath the liner of a Category C cell is strongly recommended. Tools Assessment and design of the leachate barrier will require a water balance calculation and a soil cover model. Use of modelling software is recommended (e.g. the Hydrological Evaluation of Landfill Performance model or ‘HELP’ – available on-line at http://www.wes.army.mil/). Trained and experienced hydrogeologists should undertake modelling. Calculations should model two or more consecutive years with high inflow of water (i.e. 90% wet year) to provide sufficient capacity for leachate generation across the operational life of the landfill. Other programs such as Pollute and V-Leach can assist in modelling the capacity of specific barrier systems to control and manage diffusive flows.

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3.1.2 Leachate Collection System for Category B and C Landfills Acceptable Standard Category B and C landfills must be equipped with a leachate collection system. Leachate accumulating on the liner must not exceed a hydraulic head of 0.3 metres above the lowest point of the liner. Excess leachate must be collected in a leachate collection system and prevented from escaping from the landfill into groundwater or surface waters. Separate collection systems must be installed for leachate generated in cells that receive controlled or other hazardous wastes. Recommendations The leachate collection system should generally contain as a minimum, perforated leachate collection pipes and a sump for leachate extraction. A drainage layer and leachate collection dam may also be required. A drainage layer should be placed immediately above the leachate barrier, and should exhibit the following characteristics: •

extend over the entire base of the landfill;

•

minimum thickness to be at least two times the largest particle in the aggregate and ensure adequate drainage from highest points of the landfill base;

•

hydraulic conductivity not less than 1 x 10-3 m/s; and

•

constructed from aggregate with the following properties;  85% of material greater than or equal to 40 mm in any dimension;  95% of material greater than or equal to 20 mm in any dimension;  uniformity coefficient less than 2;  fines content less than 1 per cent;  contains no material that would be susceptible to chemical attack (e.g. limestone); and  category C landfills should have two drainage systems installed.

Perforated pipes should be installed at regular intervals (e.g. 25 m) on the base of the landfill to direct leachate to the leachate dam. These pipes should exhibit the following characteristics:

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a minimum diameter of 150 – 200 mm;

•

be flexible;

•

sufficient strength to bear the weight of waste;

•

a minimum longitudinal gradient of one percent, and

•

be capable of being cleaned and inspected using remote equipment.

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Pipes should be placed on evenly prepared bedding material within trenches, and movement of heavy vehicles should be controlled to avoid pipes being crushed. A leachate sump should be placed at the end of the downstream gradient of the collection pipe system. Pipes should be ‘drowned’ in this sump to prevent clogging with silt. The sump should be recessed below the liner to ensure that the pumping equipment remains operational. A leachate collection dam and associated drains may be constructed as part of the management process, and should have the following properties: •

a geomembrane liner leachate barrier;

•

lysimiters installed beneath the liner to determine any flow characteristic;

•

sufficient volume to accommodate leachate generated in the landfill during two consecutive years of high inflow of water, plus freeboard of at least 1.0 m; and

•

sufficient volume to accommodate a 1 in 20 years 24 hour storm event.

Tools Assessment of the capacity required for the leachate dam will require a water balance calculation (see Section 3.1.1). The spacing for collection pipes may be derived from Giroud’s equation or similar. Giroud’s equation is as follows: Tmax (2 cos ß) √ (tan 2 ß + 4q/k) - tanß

L= Where:

L Tmax k ß q

= = = = =

spacing between drainage pipes (m) maximum leachate head over liner (m) permeability of drainage layer (m/s) slope of the liner leachate seepage rate into drainage layer (m/s).

The pipe spacing may need to be less than that calculated to account for clogging of the drainage layer. Calculations could be made on a worstcase basis to accommodate for clogging (e.g. use an assumed permeability of the drainage layer that is two orders of magnitude worse than the designed permeability).

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3.1.3 Leachate Management for Category B and C Landfills Acceptable Standard Leachate must be managed to prevent contamination of surface or ground waters, prevent offensive odours and minimise human contact with the leachate. Recommendations Leachate may be managed through one or a number of the following options: •

evaporation;

•

discharge to sewer (either with or without treatment);

•

on-site treatment;

•

on-site re-use; and

•

recirculation on to waste to enhance degradation.

In areas where evaporation exceeds rainfall, e.g. eastern Tasmania, evaporation should occur within a closed system that prevents release into surface or ground waters. Typically, evaporation occurs in a dam that has been designed with sufficient surface area to prevent the accumulation of a ‘backlog’ of unevaporated leachate. Discharge to sewer will require a sewerage connection and agreement with the responsible authority regarding the volume and quality of leachate to be discharged. Some treatment may be required, particularly to control the salinity and ammonia content, before discharge to sewer is permitted. Refer to Guidelines for Acceptance of Liquid Waste to Sewer 1994, DPIWE On-site treatment generally involves the use of two additional dams, one for treatment of leachate with aerobic bacteria, and one to store treated leachate prior to further management. Design and management of such a system should ensure that there is sufficient oxygen for bacteria, that the bacterial floc is kept in suspension, and that large fluctuations in leachate quality and volume are avoided. Alternative treatment methods (e.g. chemical or thermal treatment) may be considered if other management options are impractical, or if high levels of treatment are required to ensure environmental protection. On-site re-use may include use as a dust suppressant or retention as fire fighting water. Leachate may also be used for irrigation, subject to approval from the Regulatory Authority. This procedure must be strictly controlled, subject to detailed chemical analysis and expert determination of application rates.

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Tools If evaporation is to be used as the primary means of disposing of leachate, then the dam needs to be designed with sufficient surface area to ensure that the system can accommodate the volume of leachate generated over a year. This may be calculated by using the following formula: 1,000V 0.8E - R

A= Where: A V E R

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= = = =

dam surface area (m2) annual volume of leachate (kL) median annual evaporation (mm class A pan) median annual rainfall (mm).

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3.2

SURFACE WATER MANAGEMENT Acceptable Standard Uncontaminated surface water must be prevented from mixing with waste and/or carrying sediment or contaminants off the landfill site. This will minimise the generation of leachate, and avoid erosion of cover material or waste from the landfill. Recommendations Landfills should be designed with bunding and drains to intercept and divert surface water run-off from entering areas that have been filled or are actively being filled. The design of these drains should provide sufficient capacity to capture and divert storm water as described in Table 3.2: Table 3.2

Landfill Surface Water Requirements Landfill Category

A (Solid Inert)

B (Putrescible)

C (Secure)

All runoff from a 24 hour 1- in - 10 year storm event

All runoff from a 24 hour 1 - in - 20 year storm event

All runoff from a 24 hour 1 - in - 50 year storm event

Design of control measures should also consider the likelihood of flooding or failure of dams that may result from more severe storm events (e.g. 1–in–100 year). Impact of potential climate change should be considered. Further surface water management measures may be needed, particularly with relation to erosion control, depending on: •

the topography of the site (and subsequent velocity of run-off);

•

the nature (and quality) of the water environment where run-off will be discharged;

•

the typical intensity of storm events; and

•

the extent of vegetation cover in the catchment area.

Potential controls include:

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directing water flow over flat slopes (or spread across the slope);

•

shallow, heavily-vegetated surface water and

•

channelling run-off to water supply dams (e.g. for fire fighting or dust suppression) where available.

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dams and swales;

36

3.3

GROUNDWATER MANAGEMENT FOR CATEROGY B AND C LANDFILLS Acceptable Standard Landfill design must include provision for groundwater monitoring bores. Recommendations A network of groundwater monitoring bores should be installed under the direction of a suitably qualified hydrogeologist. This network should meet the following requirements: Number of bores •

at least one bore located higher up the hydraulic gradient than the landfill site to provide background groundwater quality data;

•

at least two monitoring bores in close proximity to the landfill, with more required at: 

larger sites;



sites that will have long operating lives (e.g. >10 years); and



sites where high risks of contamination may arise due to wastes deposited or hydro-geological conditions;

•

at least one bore lower down the hydraulic gradient than the landfill; and

•

bore locations and depths should encompass all aquifers that may be affected by the landfill.

•

bore installation should take into account potential for cross contamination of multiple aquifer systems.

Monitoring bore design For a simple aquifer, single, fully slotted bores are sufficiently reliable. For multiple aquifers, a nest of monitoring bores slotted over different intervals, multi-port bores or a combination of both is considered suitable. The selected monitoring bore design should include, as a minimum: •

suitable strength pipe;

•

gravel-packed slotted sections;

•

adequate cement / bentonite seals between slotted sections; and

•

a standpipe with adequate cement-based grout seals near ground level and a secure and lockable cover.

Additionally, measures should be taken to prevent surface water and extraneous material such as insects from getting into the bore.

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Bores should be highly visible and their locations properly documented to ensure that they are not inadvertently covered or otherwise damaged during operations. Locations of each bore should be recorded in Australian Map Grid coordinates using a digital global positioning system or other recognised survey equipment. The coordinates for each bore should be supplied to the Regulatory Authority and to Mineral Resources Tasmania. The location of each bore should also be documented on the filling plan (see Section 4.9.2). Geological strata encountered during bore installation should be carefully logged and recorded.

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3.4

LANDFILL GAS MANAGEMENT Acceptable Standard Landfill gas must not present a source of odour or an explosion or toxicity hazard. The contribution to greenhouse gas emissions should be minimised. Recommendations New Putrescible and Secure landfills (and extensions to existing Putrescible and Secure landfills) should be designed to assist in capture and oxidation of methane. Measures that will achieve this include: •

designing deep cells (e.g. more than 10 m) with high ratios of volume to surface area;

•

ensuring that the filling plan minimises the period that each cell is open;

•

scheduling installation of gas control measures to occur before the peak flow of gas (e.g. within 2 years of the start of filling);

•

use of composts and mulches to oxidise emissions through the landfill cap; and

•

design of a landfill gas collection system, comprising some of all of the following elements: 

vertical and / or horizontal gas bores;



stacks for venting or flaring (venting without flaring is to be phased out at major landfills by December 2004); and



capture and combustion for heat or electricity production.

Furthermore, the design of infrastructure for landfill gas management should incorporate the use of lightning conductors to minimise the risk of explosion and fire resulting from electrical storms. Tools Formulae for calculating methane generation rates may be obtained from the National Greenhouse Gas Inventory Workbook for Waste (Australian Greenhouse Office 1998) and Methane Capture and U s e : Waste Management Workbook (Environment Australia 1997). Modelling software may be used for these calculations, such as the Landfill Area-Based Emissions Spreadsheet (available on-line at http://www.npi.gov.au/) or LandGEM (available on-line at http://www.epa.gov/). Note that equations are vulnerable to uncertainty due to underlying assumptions and poor data, and may either underestimate or overestimate methane fluxes.

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3.5 CONSTRUCTION QUALITY ASSURANCE FOR ENGINEERED LINERS Acceptable Standard A Construction Quality Assurance (CQA) plan must be developed and implemented to ensure that the landfill construction meets design requirements. The CQA plan must be able to verify that the materials used comply with specifications, and that the method of construction / installation is appropriate to meet design requirements. Recommendations The CQA plan should contain the following information: •

material and construction specifications;

•

testing methods and frequency;

•

corrective action; and

•

provision for appropriate documentation.

All earthworks should be tested and inspected by an independent geotechnical engineer. A report by a NATA accredited testing body of all testing, and an assessment of compliance with the specification and drawings should be prepared by the proponent. This document should be reviewed by the Regulatory Authority before the liner construction is accepted. Parameters to be addressed for the compacted clay liner should at least include the following: •

physical testing of permeability of the compacted clay liner (including dependent factors e.g. clay composition, moisture content, compaction, permeability, field placement techniques and liner thickness);

•

inspections to check for oversized clods of clay, poorly compacted or dry areas, and the homogeneity of the clay;

•

the ability of the natural geology and/or sub-base to support the landfill without affecting the integrity of the liner system as a result of differential settlement;

•

measures to protect the clay liner from desiccation and erosion; and

•

a survey at the completion of construction to confirm that the correct grades have been attained.

Parameters to be addressed for geomembranes should at least include the following:

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Suitable conditions for the reception and storage of rolls prior to placement;

•

an inspection of the liner surface to remove objects that may damage or puncture the liner, or rough areas that may prevent direct contact between the liner and the geotextile or layer material;

•

an inspection of the geomembrane to check for defects;

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•

minimisation of tensile stress (e.g. from thermal expansion / contraction);

•

Testing of seams to ensure proper joins; and

•

an inspection of anchoring points on surfaces with gradients > 10% is completed.

Factors to be addressed for the drainage layer should at least include the following: •

aggregate is washed prior to placement to remove fines;

•

appropriate particle size to provide the designed hydraulic conductivity;

•

placement of aggregate avoids damage to the landfill liner;

•

all surfaces are at correct grades;

•

correct thickness of material;

•

pipes are placed on even bedding material;

•

pipes are properly joined; and

•

if a sealant is used to join the pipes, this sealant must be resistant to any corrosive effects of leachate.

Tools Procedures for geotechnical testing are set out in AS 3798-1996 Guidelines on earthworks for commercial and residential developments. Suitable laboratory permeability testing procedures are described in AS 1289.6.7.1–1999 Soil strength and consolidation tests – Determination of permeability of a soil– Constant head method for a remoulded specimen. Other standards within AS 1289 Methods of Testing Soils for Engineering Purposes should also be reviewed.

3.6 WASTE MINIMISATION Acceptable Standard Landfills must be designed to allow for recovery and diversion of selected waste materials, in accordance with the waste management hierarchy described in Section 1.2.1. Recommendations Design the site to accommodate operations to recover and divert suitable wastes delivered to the landfill. Adequately sized hardstand areas will be required for stockpiles of recovered material and allow space for future development. Recycling contractors should be able to access these areas with their machinery and, if appropriate, on-site machinery should be installed for reprocessing (e.g. concrete crusher). Prior to the public accessing the tipping face, areas of acceptance should be designated. Such areas should be specifically designed to provide opportunity for separation of wastes into reusable, recyclable and residual streams. DPIWE

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Where appropriate, site designs should incorporate ‘tip shops’ for the sale of recovered and reprocessing materials. These shops should be placed so that they are easily accessible to the public (e.g. in close proximity to the gatehouse).

3.7 SITE SECURITY Acceptable Standard Access to the site must be controlled to minimise risks to safety of livestock and public, as well as controlling unauthorised entry and waste dumping. Public access to active tipping areas must be kept to a minimum. Recommendations The default parameters listed in Table 3.3 should be applied: Table 3.3

Landfill Site Security Requirements

Parameter

Landfill Category A (Solid Inert)

Site perimeter fencing

B (Putrescible)

C (Secure)

Stock – proof (e.g. post and wire)

Tipping area fencing

NA

Public access to active tipping areas



Wire mesh > 2 m high Restricted public access

No public access

More stringent requirements may be required at sites where there is significant risk of unauthorised entry. Lockable security gates should be installed and maintained at all landfills. Where practical, landfills should be designed so that waste brought on site by the public (e.g. small vehicles and trailers) is placed in transfer bays or similar intermediate points for management by site staff. Scavenging should be actively discouraged at all landfills. Access to high-risk areas within Secure landfills (e.g. cells receiving controlled wastes, leachate dams) should be limited to authorised persons only.

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3.8 SIGNAGE Acceptable Standard Signs must be erected and maintained in reasonable condition to clearly convey important operational and safety information. Recommendations Signage may encompass the following: •

direction and distance to the site (to be installed at major intersections and other appropriate locations en route to the site);

•

hours of operation and tipping fees (to be installed at the gate or gatehouse);

•

wastes that are not accepted at the landfill, and the nearest location for disposal;

•

hazards and dangerous areas on the site (e.g. leachate dams);

•

items that can be recycled and the locations within the site where recyclable items should be deposited for collection / processing;

•

responsibilities (e.g. vehicle operators must ensure that the remnants of their load or material stuck to the underside of the vehicle or the wheels does not litter public roads);

•

prohibited activities (e.g. litter on approach roads, burning waste or unauthorised disposal of waste) and the penalties for offences; and

•

contact staff / organisations and relevant telephone numbers to report any fire or other emergency at the site.

3.9 TRAFFIC MANAGEMENT Acceptable Standard Movement of vehicles to and from the landfills must not present safety concerns or pose a nuisance with regard to noise and road grime. Recommendations Design of the site should place trafficked areas (e.g. entrance gate and internal access roads) away from sensitive uses such as adjacent dwellings. Internal access roads should be sealed where dirt is likely to accumulate on both the road surface and vehicle tyres, particularly where this dirt is likely to be transported off-site. Operators of landfills should consider the stability of the ground on which large commercial vehicles empty their loads.

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Manual or mechanical washing areas should be provided to wash vehicle wheels and undercarriage where needed, in order to prevent transportation of dirt on to external access roads. The site operator is responsible for deciding which cleaning method is appropriate to suit the nature of site traffic. Hand-held pressure washing hoses, drive-through immersion bunds and rumble grids are options that may suit different operations. Waste water from vehicle washing must be collected and managed as leachate (see Sections 3.1.2 and 4.3.1). Liaison may be required with relevant authorities and waste transporters to limit access routes and, if necessary, permitted vehicle speeds. Install traffic control devices (e.g. traffic islands, merging lanes and slip roads) at the entrance of the landfill. Recessed entrances to the landfill may reduce the formation of queues adjacent to the site. 3.10 PLANNING TO MINIMISE OFF-SITE IMPACTS Acceptable Standard Landfills must be designed to ensure that operations minimise off-site impacts resulting from dust, litter and noise so that environmental nuisance is not caused. Recommendations Design of the site should incorporate natural and / or constructed site features that reduce off-site impacts resulting from dust, litter and noise. Dust and litter may be minimised by windbreaks (e.g. existing vegetation and natural depressions). Noise emissions can be moderated by earthen bunds and depressions, and sensitive design of traffic management features (e.g. road locations, design of rumble grids and speed humps). Appropriate buffer distances between the landfill and sensitive use areas should be maintained (see Section 2.5). 3.11 PLANNING FOR REHABILITATION Acceptable Standard Landfills must be designed with regard for the rehabilitation and after-care of the site. Recommendations The initial design of the landfill should provide for final rehabilitation of the site, and should include a conceptual plan of the post-closure land use. Chapter 5 of this Sustainability Guide describes in detail the preparation and implementation of a Rehabilitation and After-Care Plan later in the life of the landfill. The Rehabilitation and After-care Plan should determine final site contours. These should be designed to aid drainage by directing surface water runoff away from the area being rehabilitated. The final landform should be sympathetic to the local landscape (i.e. designed to blend in). Estimation of the total expected volume of waste to be deposited in the landfill should form part of the final site contour design.

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It is important to remember that leachate will continue to be generated after the closure of a landfill, and allowance needs to be made for this in the planning of rehabilitation works and on-going monitoring. Landfill gas will also continue to be generated after the closure of the landfill. Topsoil removed during landfill construction should be conserved and stockpiled for use as part of final capping and contouring. In order to preserve indigenous plant seeds for revegetation, topsoil stockpiles should not exceed 1 metre in height. The Rehabilitation and After-care Plan must be submitted to the Regulatory Authority for approval when developed. The plan must be updated at least every 5 years or 6 months prior to closure of any stage of the landfill, whichever is sooner.

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4.

OPERATION 4.1 WASTE MINIMISATION Acceptable Standard Landfill operators must provide for recovery and diversion of waste materials, in accordance with the waste management hierarchy described in Section 1.2.1. Recommendations It is preferable for recoverable materials to be diverted prior to acceptance at the landfill, rather than through salvaging at the tipping face. Site staff or a licensed salvager may recover materials from the tipping face only if the landfill operator can demonstrate that safety issues are fully addressed. Typically, a waste minimisation system will be in place to provide opportunities for recovery of resources prior to the waste being received at the landfill (for example kerbside recycling). Screening at the landfill gate is also strongly recommended. Landfill operators should examine their pricing policies and education programs to encourage waste minimisation. Landfill operators should develop procedures for diversion and recovery of selected waste materials that are suitable for: •

reuse;

•

reprocessing; or

•

recycling.

Reuse will be most appropriate for materials that can still be used in their current form and are practical to recover (e.g. received at the site in sufficient volume or in relatively homogeneous streams). Selected solid inert wastes (e.g. bricks, steel and timber) and household goods may be appropriate for reuse. Appropriate procedures for selection and interim storage of diverted materials will be essential for quality control (e.g. covered storage areas and basic safety testing for electrical goods). Reprocessing will be most appropriate for materials that cannot be reused in their current form. This may include car bodies, electrical goods, and concrete, and it may also be appropriate to stockpile green waste for shredding. Recycling facilities should be provided at the site for the storage of recyclable materials. Storage facilities should cater for commonly recycled items (e.g. glass, bottles, aluminium cans, paper and cardboard but may also extend to more specialised materials (e.g. batteries, motor oil)). Operators should develop a plan for processing and marketing recyclable materials, and for disposal of contaminants. This plan should be developed in consultation with the Regulatory Authority and recycling industries. DPIWE

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Further information may be obtained from the Guidelines for the Establishment & Management of Waste Transfer Stations (DPIWE 1996c).

4.2 WASTE HANDLING 4.2.1 Waste acceptance and screening Acceptable Standard Landfills must accept only those wastes that are consistent with the appropriate category of the landfill under the Landfill Classification System and as stipulated in the permit conditions (see Section 1.3.1 and 1.3.2). Recommendations A viewing platform should be constructed at the gatehouse to screen incoming loads. Additional screening equipment may include closedcircuit television cameras or mirrors. Staff at the gatehouse should be able to communicate with staff at the tipping area, particularly where incoming loads are deemed to require follow-up screening (e.g. covered loads from non-regular customers). Handheld VHF radios or similar portable devices are ideal. Sites should be staffed at all times that they are open and receiving wastes. Where a site is not staffed, the permit holder/operator must demonstrate that procedures are in place to control what is deposited in the landfill. Particular criteria for refusal to accept as solid inert material are as follows: •

materials that are likely to create cavities or voids;

•

soluble materials that may lead to the emission of a pollutant in contravention with the EMPCA or the State Policy on Water Quality Management 1997;

•

material that may present a hazard or risk to humans or the environment during handling or over the term of disposal; and

•

engine oils or greases.

Operating procedures should be developed to ensure that loads posing a particular risk (e.g. dusty material) are suitably managed to prevent environmental problems. Final screening should be undertaken at the tipping area to identify and respond to high-risk loads (e.g. dust, litter, fire ignition sources). Where appropriate, operators must ensure that the hazard associated with a particular waste (or load) has been assessed prior to transport of waste to the landfill. Responsibility lies with the generator and transporter of the waste to contact the operator of the landfill to gain prior approval before disposal. Sealed drums and other containers should not be accepted unless their contents are clearly identified and are suitable for deposition at the landfill

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Related controls are suggested as part of acceptance criteria for controlled and other controlled waste (see Section 1.4), signage (see Section 3.8) and training (see Section 4.7.1). 4.2.2 Waste placement and compaction Acceptable Standard Waste must be placed in a manner that minimises litter and pest animal problems, and optimises use of landfill space. Waste must be placed in a manner which will maximise its stability, reduce long term risks arising from degradation/settling and optimise the operation of the landfill. Recommendations Default parameters for placement and compaction are shown in Table 4.1: Table 4.1

Landfill Placement and Compaction Requirements

Parameter

Plant equipment

Landfill Category A (Solid Inert)

B (Putrescible)

C (Secure)

Bulldozer

Multi-purpose landfill vehicle or compactor

Compactor

NA

>650 kg/m3

>850 kg/m3

Minimum compacted density Maximum height of waste ‘lift’ Size of active tipping area Width of active tipping face Slope of tipping face

2m Not more than 50 m by 30 m 4 – 5 m per truck < 50%

Waste should be placed at the base of the tipping face and pushed upwards to form a layer of waste or ‘lift’. Waste should be subject to 3 – 5 passes with plant equipment to maximise compaction (and therefore minimise settlement over time). The tipping face should be sloped to allow safe movement by plant equipment, and should not be greater than that shown in Table 4.1 unless it can be demonstrated that both the waste and cover material are stable. Active tipping areas should be kept as small as practicable. Wastes should be mixed whenever possible to minimise voids within deposited waste.

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Clean fill materials are to be evenly spread across the face to minimise bulking and to ensure as uniform and homogeneous a mixture as possible. Some controlled wastes (e.g. quarantine and medical wastes) may require immediate burial. A trench should be excavated immediately before arrival of the waste at the landfill. The controlled waste must be covered with other material immediately after deposition. Appropriate guidelines prepared by relevant authorities (e.g. Australian Quarantine and Inspection Service) should be consulted to ensure correct management of controlled wastes. Volume reduction may involve one or a number of the following stages: •

mechanical separation of accepted wastes into different categories (e.g. putrescible, solid inert);

•

biological treatment of putrescible waste to increase density and reduce the potential for generation of leachate and landfill gas;

•

shredding to render a more homogeneous waste stream; and

•

compaction and binding of waste into solid bales to increase density and reduce both litter and demand for cover material.

Related controls are suggested as part of waste minimisation (see Section 4.1). 4.2.3 Waste covering The coverage of waste is intended to: •

control the penetration of rainwater;

•

control and minimise the risk of fire;

•

minimise landfill gas emissions and suppress site odour;

•

reduce fly propagation and pest animal issues;

•

decrease litter generation; and

•

ensure that the landfill surface is suitable for traffic movements.

Acceptable Standard Putrescible and controlled wastes must be completely covered by a suitable material at the completion of daily landfill operation or more frequently as required.

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Recommendations Default minimum parameters for cover are shown in Table 4.2: Table 4.2

Landfill Minimum Cover Requirements

Parameter Daily cover Weekly cover

Landfill Category A (Solid Inert)

B (Putrescible)

C (Secure)

NA

30 cm

30 cm

30 cm soil

NA

NA

Intermediate cover Final cover Stockpile of cover material

30 cm Refer to Section 5.3.3 Sufficient for two weeks of operation

NB: Individual landfills may have separate faces for each different category of waste.

Intermediate cover is used to close a cell that will not receive additional lifts of refuse and will be exposed for more than 90 days before final cover is applied. Final cover or ‘capping’ forms a low permeability barrier to limit water ingress into the waste, control gas emissions and promote revegetation. Capping should be an ongoing part of operation, and is addressed further in Section 5. Landfill operators may apply to the Regulatory Authority for use of any cover material (e.g. foams, mulch, gravel, plastic film or matting) as an alternative to soil, or an alternative thickness of soil, provided they can demonstrate compliance with acceptable standards. Wet and readily degradable materials should not be used as cover unless measures are taken to address landfill gas generation. Existing cover should be punctured or removed before further filling occurs so that perched water tables will not form. Conversely, cover in areas where further filling is unlikely for the short term should be maintained to minimise cracking (e.g. through moisture control or by using a roller).

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4.3

WATER MANAGEMENT 4.3.1 Leachate collection and management Acceptable Standard The leachate management system must be maintained to prevent infiltration to ground water and release to surface water, prevent offensive odours and minimise human contact with the leachate. Recommendations Design of leachate management systems is discussed in Section 3.1.3. Ongoing management will be tailored to suit the option(s) selected for a particular site. There should be periodic removal of sediment from the collection dam, with sediment being deposited in the landfill. Salt and other residual materials need to be cleared from evaporation dams when the dams are removed from use. Furthermore, leachate discharges to sewer should be tested in accordance with Trade Waste Agreements. Excluding discharges direct to sewer, leachate must not be released from the landfill unless appropriate analytical testing has confirmed, to the satisfaction of the Regulatory Authority, that it is suitable for release. Tests should be tailored to suit the risk of contamination and the sensitivity of the receiving environment. Further information is contained in Section 4.8.3. 4.3.2 Surface water management Acceptable Standard Surface water must be prevented as far as practicable from mixing with waste (thereby generating leachate) and from transporting sediment, waste material or contaminants off the landfill site. Discharges to surface waters must meet the turbidity limits shown in Table 4.3; or must not exceed turbidity of the receiving waters: Table 4.3 Landfill Surface Water and Turbidity Limits Landfill Category

Parameter A (Solid Inert)

B (Putrescible)

C (Secure)

Maximum NTU

50

50

50

Median NTU

<25

<25

<25

Maximum NTU

100

100

100

Median NTU

<50

<50

<50

Dry weather discharge

Wet weather discharge

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Recommendations Areas that will be exposed for 30 days or more should be stabilised to prevent soil erosion. Areas where no further filling will occur should be progressively capped and re-vegetated (see Section 5.3.3). Offsite discharge of surface water that may have been in contact with disturbed areas should only occur from controlled points (e.g. dams). Visual inspections and / or chemical testing should be undertaken to ensure that sediment or other contaminants do not exceed acceptable standards. The level of testing required should be determined by the risk of contamination and the requirements of the State Policy on Water Quality Management 1997 and/or PEVs for the receiving water. All water that has entered waste filled areas and water that has been contaminated by leachate should be handled and treated as leachate (refer to Sections 3.1.3 and 4.3.1).

4.4 NUISANCE MANAGEMENT 4.4.1 Dust Acceptable Standard Landfill operators must minimise the generation of dust at the landfill site. Where generation of dust does occur, the dust must be controlled to ensure that environmental nuisance does not occur beyond the landfill boundary. Recommendations Unsealed road surfaces and material stockpiles should be regularly sprayed with water, especially in areas with clay soils and during dry, windy conditions. The trafficable area of the landfill should be kept as small as possible. Completed landfill sections should be rehabilitated as soon as possible. Procedures should be developed for managing the acceptance and placement of dusty wastes to minimise transportation off-site. Related controls are suggested as part of traffic management (see Section 3.9) and procedures for waste handling (see Section 4.2).

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4.4.2 Litter Acceptable Standard Landfill operators must take all reasonable steps to prevent litter generation, to minimise litter leaving the site and must regularly clean up litter adjacent to the landfill. Recommendations Landfill operators should develop procedures for managing the acceptance and placement of lightweight, loose wastes to minimise transportation off-site (e.g. deposition of high-risk loads in sheltered areas of the landfill site or directly upwind of litter fences, and more frequent covering of waste). Transportable litter fences should be installed around the active tipping area at landfills with strong prevailing wind conditions or which have been known to generate litter nuisance. Such fences should be at least 4 m high, be portable (i.e. able to be re-sited when the tipping area is relocated) and able to withstand strong winds whilst loaded with litter. All site fences and gates should be cleared of litter on a weekly basis. More frequent attention is likely to be required during windy periods. Operators should incorporate regular (e.g. weekly, or in conditions of high winds daily) retrieval of all litter transported offsite into their maintenance work program. Operators should develop risk management procedures to minimise the number of vehicles transporting uncovered loads of waste to the landfill (e.g. communication with drivers and company managers, keeping records of offending vehicles). Related controls are suggested as part of signage (see Section 3.8) and procedures for waste handling (see Section 4.2). 4.4.3 Nuisance fauna and weed species Acceptable Standard Landfill operators must actively discourage the presence of nuisance animals and weed species to avoid public health impacts and environmental degradation. Recommendations Water storage areas on site should be limited to those required for water for fire fighting purposes, leachate containment and storm water control. Professional pest control providers should be engaged to eliminate pest animal infestations. Any proposed baiting programs should be developed in consultation with DPIWE.

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Landfills that have large populations of birds present may (providing approval has been given by the Regulatory Authority) use deterrents in conjunction with normal operating procedures, including the following: •

nets over glide-paths and water storages;

•

anti-perch strips on structures; and

•

active measures (e.g. gas guns, mimicked distress calls or predator decoys).

Sites should be regularly inspected to check for the presence of weed species. Materials used for site revegetation (e.g. seeds and mulch) should be of high quality and free of weeds. Weed species should be controlled using appropriate techniques. Related controls for weed species are suggested as part of procedures for waste handling (see Section 4.2). 4.4.4 Odour Acceptable Standard Landfill operators must minimise the generation of unpleasant odours at all times. If odours are apparent, the odours must not be detectable outside the boundary of the landfill site. Recommendations Application of controls suggested as part of procedures for waste handling (see Section 4.2) should minimise the transmission of odours off-site. 4.4.5 Noise Acceptable Standard Activities on the site must be managed so as not to cause environmental nuisance. As a general guide the equivalent continuous A-weighted sound pressure level (Leq) of the sound emitted from the site should not exceed 50 dB(A), when measured within twenty-five metres of a noise sensitive building. The sound level is to be measured and adjusted for tonal and impulse components in accordance with AS1055. The Leq is to be measured over a period of between 10 and 15 minutes. If the landfill site is to operate outside the hours of 0700 to 1800, this level should be reduced to 45 dB(A) between the hours of 1800 to 2200, and further reduced to 40 dB(A) between the hours of 2200 and 0700 (0900 on Sundays) the following morning. Higher sound pressure levels may be acceptable in areas with significant ambient noise from other sources.

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Recommendations The Acceptable Standard will normally be achieved by restricting operations to the hours of 0700 to 1800 Monday to Saturday and 0900 to 1800 on Sunday. Waste may be accepted outside of normal operating hours where a one-off prior arrangement has been agreed with a waste generator/transporter that has a valid need for such. Operators should ensure that all site machinery is configured to minimise noise disturbance (e.g. mufflers and exhaust silencers, noise sensitive reversing beepers), is regularly maintained, and is operated in accordance with relevant noise standards. Related controls are suggested as part of siting (see Section 2.5) and planning to minimise off-site impacts (see Section 3.10).

4.5 FIRES 4.5.1 Fire prevention Acceptable Standard Landfill operators must not allow fires to be lit on any part of the landfill or within the landfill boundary, and must extinguish any fires that do occur as quickly as possible. Recommendations Combustible wastes should be covered with inert materials after placement at the tipping area or stockpiles of combustible materials (e.g. tyres, timber, dry green waste) should be divided into small piles or windrows (i.e. so that any burning material can be kept away from or readily separated from additional fuel). All fuels or flammable solvents used for on-site operations should be stored in accordance with AS 1940 - 1993 Storage and Handling of Flammable and Combustible Liquids. Storage areas should be located on unfilled land and adequately bunded so that any release of raw or burning liquid will not cause a fire in the filled waste or impact on surface water. If the site is a designated tyre storage site then the stockpile should be managed in accordance with the performance standards specified by the Regulatory Authority. Related controls are suggested as part of signage (see Section 3.8) and procedures for waste handling (see Section 4.2).

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4.5.2 Fire control Acceptable Standard Landfill operators must demonstrate sufficient capacity to extinguish any fires that occur on site. Powered pumps and high-capacity hoses must be installed. Fire fighting water must be available at all times. Sites lacking a reticulated water supply suitable for fire fighting must store water on site, with a sufficient volume to control fires. Recommendations Post-fire surveys using thermal imaging equipment are likely to be required to identify remaining hot spots, following suppression of visible evidence of fire. Firebreaks should be constructed and maintained around the perimeter of the landfill and, where appropriate, between filled areas, stockpiles of combustibles and site buildings. Any firebreaks must be constructed to the satisfaction of the relevant fire authority. Suitable additional fire fighting equipment should be installed adjacent to flammable liquid storage areas and site buildings. All fire fighting facilities should be visually checked for damage on a weekly basis and test operated every three months. All fire fighting equipment should be clearly signposted. Vehicular access should be maintained at all times. A site-specific fire management plan should be developed by the landfill operator to minimise the incidence and impact of fire.

4.6 TRAFFIC MANAGEMENT Acceptable Standard Landfill operators must provide safe and convenient access for vehicles delivering waste to the landfill. Recommendations Road surfaces in all areas of the site that are open to the public (e.g. recycling area and residual disposal area) should be regularly maintained. Where small vehicles (e.g. cars) are permitted to directly access the tipping area, they should be directed to a position in the tipping area that is separate from that used by larger vehicles that are emptied mechanically. Due to their relative instability on soft ground, tri-axle tipping trailers should not be permitted to tip at the tip face except at isolated locations or where they are isolated from other traffic during their tipping activity.

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4.7

STAFFING 4.7.1 Training requirements Acceptable Standard Staff must be adequately trained to ensure that operations are environmentally responsible and the workplace is safe. Staff must be familiar with the environmental permit conditions that may be relevant to their work to the extent necessary to ensure compliance. Recommendations Training requirements will vary according to landfill size, types of waste accepted, and diversity and complexity of site operations. The duration and complexity of training should be determined by the role of particular staff and the competencies required to fulfil these roles. At a minimum, staff training is to ensure that: •

all operators of compaction or earthworks equipment are skilled at undertaking all tasks required of them;

•

all staff or consultants, who operate water sampling or water testing apparatus are familiar with required testing and sampling protocols and methodologies;

•

all staff are familiar with emergency procedures (e.g. fire fighting) and the EMP;

•

staff who inspect or direct the placement of incoming wastes are capable of accurate data recording, and are skilled at identifying wastes that are unacceptable; and

•

staff are familiar with this Sustainability Guide.

Where practical, training should be supplied through formal programs (e.g. short courses) provided by accredited training institutions. Awareness programs or other means to develop a commitment to environmentally responsible management and work practices should accompany formal training programs.

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Occupational Health and Safety

4.7.2

Acceptable Standard Operators must be aware of and comply with current legislation relating to occupational health and safety. Recommendations Landfill operators must address OH&S issues including (but not limited to): •

plant and equipment operation;

•

handling practices, including storage and handling of potentially hazardous wastes;

•

protective clothing;

•

equipment safety and maintenance;

•

occupational noise;

•

traffic management; and

•

public safety.

•

operator health issues (e.g. medical vaccinations)

4.8 MONITORING PROGRAMS 4.8.1 Groundwater Acceptable Standard Regular, representative sampling of groundwater must be conducted to ensure early detection of any contamination by leachate and to demonstrate compliance with any statutory requirements. In accordance with the State Policy on Water Quality Management 1997, relevant water quality standards (trigger values ) from the latest revision to the Australian Water Quality Guidelines (ANZECC and ARMCANZ 2000) will be used to set the water quality objective unless otherwise specified by the Environmental Management and Pollution Control Board. Recommendations A network of groundwater monitoring bores should be installed. number and design of bores is discussed in Section 3.3.

The

Samples should be taken by a suitably qualified person, in accordance with AS 5667.1:1998 Water Quality – Sampling – Guidance on the design of sampling programs, sampling techniques and the preservation and handling of samples and AS 5667.11:1998 Water Quality – Sampling – Guidance on sampling of groundwaters. Samples should be analysed by a NATA accredited laboratory or a laboratory otherwise approved by the Regulatory Authority. Typical parameters are detailed in Table 4.4. Operators may wish to put forward a case justifying a reduced list of monitoring parameters. DPIWE

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The frequency of sampling indicated in this table is to be followed for three years unless otherwise approved by the Regulatory Authority. The landfill operator may apply to exclude parameters and / or vary the frequency of sampling after this time if it can be consistently demonstrated that the parameters measured do not pose an environmental risk.

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Table 4.4

Groundwater Monitoring Parameters Monitoring Frequency by Landfill Category

Monitoring Parameters Group

Group 1

Group 2

Group 3

Group 4

DPIWE

1 (Solid Inert)

2 (Putrescible)

bore depth

6 monthly

Ground water depth

6 monthly

static hydraulic head

6 monthly

3 (Secure)

PH

6 monthly

Quarterly

Quarterly

Conductivity

6 monthly

Quarterly

Quarterly

TDS

6 monthly

Quarterly

Quarterly

Total Nitrogen

6 monthly

Quarterly

Quarterly

Ammonia

6 monthly

Quarterly

Quarterly

Nitrate

6 monthly

Quarterly

Quarterly

Nitrite

6 monthly

Quarterly

Quarterly

Orthophosphate

6 monthly

Quarterly

Quarterly

Total phosphorus

NA

Quarterly

Quarterly

Redox potential (Eh)

NA

Quarterly

Quarterly

DOC

NA

Quarterly

Quarterly

COD

NA

Quarterly

Quarterly

Total CN (as CN)

NA

Quarterly

Quarterly

Total Iron (Fe)

NA

Quarterly

Quarterly

Copper (Cu)

NA

Quarterly

Quarterly

Zinc (Zn)

NA

Quarterly

Quarterly

Chromium (Cr)

NA

Quarterly

Quarterly

Manganese (Mn)

NA

Quarterly

Quarterly

Nickel (Ni)

NA

Quarterly

Quarterly

Lead (Pb)

NA

Quarterly

Quarterly

Cadmium (Cd)

NA

Quarterly

Quarterly

Chloride

NA

Quarterly

Quarterly

Calcium

NA

Quarterly

Quarterly

Sulphate

NA

Quarterly

Quarterly

Sodium (Na)

NA

Quarterly

Quarterly

Potassium (K)

NA

Quarterly

Quarterly

Magnesium (Mg)

NA

Quarterly

Quarterly

Arsenic (As)

NA

Initially then 12 monthly

6 monthly

Mercury (Hg)

NA

Initially then 12 monthly

6 monthly

Selenium (Se)

NA

Initially then 12 monthly

6 monthly

Total Petroleum Hydrocarbons (TPH) and Benzene,

NA

Initially then 12 monthly

6 monthly

Toluene, Ethyl-Benzene, and Xylene (BTEX)

NA

Initially then 12 monthly

6 monthly

Polynuclear aromatic hydrocarbons

NA

Initially then 12 monthly

Yearly

Organophosphate pesticides

NA

Initially then 12 monthly

Yearly

Organochlorine pesticides

NA

Initially then 12 monthly

Yearly

Polychlorinated biphenyls

NA

Initially then 12 monthly

Yearly

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Further assessment should be undertaken and the need for remediation investigated whenever the concentration in a discharge is likely to cause a significant change above background concentration (i.e. determined from upstream ground or surface waters) for one or more of the parameters outlined in Table 4.5 on consecutive sampling runs. The Regulatory Authority should be notified of these differences in accordance with Section 5.4.4. 4.8.2 Surface water Acceptable Standard Surface water must be monitored on a regular basis to detect and respond to any pollution from the landfill and to demonstrate compliance with any statutory requirements. Recommendations Monitoring points should be established at the point(s) of discharge from the landfill. Samples should be taken by a suitably qualified person, in accordance with AS 5667.1:1998 Water Quality – Sampling – Guidance on the design of sampling programs, sampling techniques and the preservation and handling of samples and AS 5667.6:1998 Water Quality – Sampling – Guidance on sampling of rivers and streams. Samples should be analysed by a NATA accredited laboratory or a laboratory otherwise approved by the Regulatory Authority. Parameters to be sampled and analysed should be selected from Table 4.5. Operators may wish to put forward a case justifying a reduced list of monitoring parameters. The frequency of sampling indicated in this table is to be followed for three years unless otherwise approved by the Regulatory Authority. The landfill operator may apply to exclude parameters and / or vary the frequency of sampling after this time if it can be consistently demonstrated that the parameters measured do not pose an environmental risk. Further assessment should be undertaken and the need for remediation investigated whenever the concentration in a discharge is likely to cause a significant change above background concentration or water quality objectives if established (i.e. determined from upstream ground or surface waters) for one or more of the parameters outlined in Table 4.5 on consecutive sampling runs.

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Table 4.5

Group Group 1

Surface Water and Leachate Dam Monitoring Parameters

Monitoring Parameters

1 (Solid Inert)

2 (Putrescible)

3 (Secure)

PH

6 monthly

Quarterly

Quarterly

Conductivity

6 monthly

Quarterly

Quarterly

TDS

6 monthly

Quarterly

Quarterly

NA

Quarterly

Quarterly

Turbidity

6 monthly

Quarterly

Quarterly

Total Suspended Solids

6 monthly

Quarterly

Quarterly

Alkalinity (as CaCO3)

6 monthly

Quarterly

Quarterly

Total Nitrogen

6 monthly

Quarterly

Quarterly

Ammonia

6 monthly

Quarterly

Quarterly

Nitrate

6 monthly

Quarterly

Quarterly

Nitrite

NA

Quarterly

Quarterly

Total phosphorus

6 monthly

Quarterly

Quarterly

Orthophosphate

NA

Quarterly

Quarterly

DOC

NA

Quarterly

Quarterly

COD

NA

Quarterly

Quarterly

E. coli

NA

Quarterly

Quarterly

Total CN (as CN)

NA

Quarterly

Quarterly

Total Iron & dissolved Iron (Fe)

NA

Quarterly

Quarterly

Aluminium (Al)

NA

Quarterly

Quarterly

Copper (Cu)

NA

Quarterly

Quarterly

Zinc (Zn)

NA

Quarterly

Quarterly

Chromium (Cr)

NA

Quarterly

Quarterly

Manganese (Mn)

NA

Quarterly

Quarterly

Nickel (Ni)

NA

Quarterly

Quarterly

Lead (Pb)

NA

Quarterly

Quarterly

Cadmium (Cd)

NA

Quarterly

Quarterly

Chloride

NA

Quarterly

Quarterly

Calcium

NA

Quarterly

Quarterly

Sulphate

NA

Quarterly

Quarterly

Sodium (Na)

NA

Quarterly

Quarterly

Potassium (K)

NA

Quarterly

Quarterly

Magnesium (Mg)

NA

Quarterly

Quarterly

Arsenic (As)

NA

6 Monthly

Mercury (Hg)

NA

Selenium (Se)

NA

Total Petroleum Hydrocarbons (TPH)

NA

Benzene, Toluene, Ethyl-Benzene, and Xylene (BTEX) Polynuclear aromatic hydrocarbons

NA

Organophosphate pesticides

NA

Organochlorine pesticides

NA

Polychlorinated biphenyls

NA

Initially then 12 monthly Initially then 12 monthly Initially then 12 monthly Initially then 12 monthly Initially then 12 monthly Initially then 12 monthly Initially then 12 monthly Initially then 12 monthly Initially then 12 monthly

Redox potential (Eh)

Group 2

Group 3

Group 4

DPIWE

Monitoring Frequency by Landfill Category

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NA

6 Monthly 6 Monthly 6 Monthly 6 Monthly Yearly Yearly Yearly Yearly 62

4.8.3 Leachate Acceptable Standard Leachate must be regularly monitored to establish its quality and assess suitable management options. Recommendations Samples should be taken by a suitably qualified person, in accordance with AS 5667.1:1998 Water Quality – Sampling – Guidance on the design of sampling programs, sampling techniques and the preservation and handling of samples and AS 5667.10:1998 Water Quality – Sampling – Guidance on sampling of waste waters. Samples should be analysed by a NATA accredited laboratory or a laboratory otherwise approved by the Regulatory Authority. Monitoring parameters and triggers for further assessment and remediation are the same as those specified for surface waters (see Section 4.8.2). Lesser requirements will be applied where all leachate discharge is directed to sewer. Monitoring locations should be established in the leachate collection sump at the base of the landfill liner and, if required, at points upstream and downstream of the landfill in any receiving waters. Related controls are suggested as part of leachate management (see Section 4.3.1). 4.8.4 Landfill gas Acceptable Standard Major landfill sites must have landfill gas management infrastructure operating by 31 December 2004 (see National Greenhouse Strategy Implementation Plan (State Co-ordinated measures – Tasmania). Recommendations Where landfill gas collection systems have been installed, regular monitoring of gas composition, combustion efficiency and flow rate should be undertaken to enable annual reporting of emissions from the system. Alternatively, stack emissions can be measured directly following flaring. Where landfill gas is not collected, regular monitoring should be undertaken to detect whether landfill gas presents a source of odour or an explosion or toxicity hazard, and to estimate greenhouse gas emissions. Landfill gas monitoring should include both surface and subsurface programs.

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Subsurface monitoring devices should be installed in areas of the site where waste has been placed and either intermediate or final cover has been applied. Installation may either form part of a gas collection network or comprise a nest of monitoring bores positioned around the perimeter of the site. The depth of the monitoring network should be equal to the greatest depth of waste. Devices should be capable of detecting sufficiently low concentrations of landfill gas to identify off-site migration. Surface monitoring should demonstrate that the cover and (where present) gas collection system is effectively controlling landfill gas emissions. Areas of the site where waste has been placed and either intermediate or final cover has been applied should be traversed in a systematic pattern with a handheld detection device. Readings should be taken on calm days (i.e. winds below 10 kph) at a height of 5 cm above the ground, as well as in depressions or surface cracks. Monitoring should be undertaken by a suitably qualified person in accordance with relevant Australian Standards, including AS 3580.11.11993: Methods for sampling and analysis of ambient air - Determination of volatile organic compounds - Methane and non-methane volatile organic compounds - Direct-reading instrumental method. Monitoring should be conducted on a quarterly frequency (unless otherwise approved by the Regulatory Authority) and should measure methane concentrations as a minimum. Where odours are of particular concern, surface monitoring should also measure hydrogen sulphide. The landfill operator may apply to vary the frequency of sampling five years after closure of the tipping area if it can be demonstrated that there have been no emissions. Further assessment and remediation should be undertaken if subsurface concentrations exceed 1.25% (v/v) or if surface concentrations exceed 500 ppm (v/v).

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4.9

DOCUMENTATION FOR REPORTING AND REVIEW All landfills must demonstrate compliance with the specific permit conditions placed on each facility, and provide data to enable monitoring of performance against State-wide strategic policy, through preparation and maintenance of the following documentation: • waste acceptance records; • filling plans; • monitoring analysis (interpretation of results including charting) • contingency and cost planning; • incident reporting; • annual reports; and • five-yearly reviews (EMP). Preparation of this documentation for reporting and review does not preclude development of other documents (i.e. operations manual, environmental management systems, etc). 4.9.1 Waste acceptance records Acceptable Standard Landfill operators must maintain accurate records of the amount, type, source (where known) and management of wastes received at the landfill. Recommendations Waste data should be collected against categories that reflect the Draft National Solid Waste Classification System (CRCWMPC 1993) and are compatible with the Australian Waste Database or approved modified versions. The Premier’s Local Government Council has endorsed a move toward mandatory waste data collection and reporting by landfill operators, to be implemented via permit conditions. Specific inventory records will need to be maintained in relation to certain categories of controlled waste, where specified by the Regulatory Authority. Staffed sites should incorporate data collection into acceptance procedures so that information is recorded for every movement of waste in and out of the site. This should include data from the weighbridge if one is installed on-site, or a volumetric estimate if no weighbridge is installed. Appropriately trained people should survey un-staffed sites for at least a two-week period each year. Mass loss through on-site composting or other processes may need to be identified to allow a mass balance calculation of wastes received and disposed. Waste acceptance data should be compared against results of annual survey of the site on an annual basis to check the accuracy of data.

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4.9.2 Filling Plan Acceptable Standard The landfill must be managed in a systematic manner. A filling plan must be prepared by the permit holder and operator. Recommendations The filling plan should at the minimum encompass the following information: •

documentation of the filling process;

•

demonstration that site operations are under control;

•

an estimate of the volume of waste landfilled;

•

an estimate of the level of compaction; and

•

a calculation of the remaining site capacity.

This plan should be updated through regular geometric surveys. The filling plan section of site drawings should be updated when each cell is started or completed. The site should be surveyed annually by an independent registered surveyor. Surveys will use the same grid and standard height datum for successive filling plan contour recordings. The filling plan for Putrescible and Secure landfills should identify the type of waste in each cell and the locations used for deposition of controlled wastes. 4.9.3 Contingency and cost planning Acceptable Standard Landfill owners must demonstrate that appropriate procedures are in place, and that sufficient funds are available to cover expenditure requirements for environmental management during landfill operation, rehabilitation and after-care. Recommendations Landfill owners and operators should identify and analyse the resources required to conduct operations, including rehabilitation, as well as to respond to incidents including, but not limited to:

DPIWE

•

excessive leachate seepage through liner;

•

failure of leachate or gas collection systems;

•

escape of leachate from leachate dam;

•

contamination of groundwater or surface water, either within or outside the site;

•

illegal dumping of inappropriate waste;

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•

landfill gas (e.g. underground off-site migration, significant and ongoing odour problems);

•

fires;

•

erosion or subsidence of the landfill cap; and

•

failure to establish or maintain vegetation on the landfill cap.

Owners and operators should utilise this analysis to evaluate all of the costs of landfilling and establish mechanisms to cover these costs. Mechanisms that may be adopted include: •

financial planning strategies;

•

effective structures for landfill fees;

•

establishment of an accumulating fund; and

•

insurance policies (including discounted group schemes).

•

Operators should document their analysis and contingency planning process to the satisfaction of the Regulatory Authority, and undertake a review of it every five years or in conjunction with routine EMP reviews. This document should include, as a minimum:

•

a description of the response procedures for each contingency;

•

the estimated costs of landfill operation, rehabilitation, after-care and contingency response;

•

descriptions of how these costs estimates were derived or preferably independent verification of the costings; and

•

demonstration of capacity to cover costs.

A copy of this document should be forwarded to the Regulatory Authority. 4.9.4 Incident Management Acceptable Standard Landfill owners must document the occurrence of, and response to, any complaints and incidents that may cause environmental harm. All reasonable and practicable action must be taken to minimise the adverse environmental effects resulting from an incident. The responsible person must notify the Director, as soon as reasonably practicable but not later than 24 hours after becoming aware of the release of a pollutant occurring as a result of any incident in relation to that activity, if this release causes or may cause serious or material environmental harm. Notification must include details of the incident, its nature, the circumstances in which it occurred and any action that has been taken to deal with it.

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Recommendations Operators should immediately inform the Regulatory Authority by telephone or facsimile if an incident occurs. Examples of incidents that might need to be reported immediately include: •

placement of inappropriate waste (e.g. controlled waste at Solid Inert and Putrescible landfills);

•

fire at the landfill;

•

accidental release of leachate into surface water surface water courses;

•

identification of significant difference(s) in monitoring indicator parameters;

•

failure of an environment protection system (e.g. landfill liner); and

•

any other incident that could potentially pose an environmental hazard.

or any other

A written report of the measures taken in response, including preventative actions, should be provided to the Regulatory Authority within 2 weeks following the incident, unless otherwise directed by the Regulatory Authority 4.9.5 Annual report Acceptable Standard Landfill owners must prepare a report on activities at the landfill within each year, including all matters of environmental significance, and make this document available to the Regulatory Authority and to the general public. Recommendations The contents of the annual report should include (but not necessarily be limited to) the following items: •

results and analysis of data (including charting over time) to determine trends from monitoring programs for groundwater, leachate, surface water and landfill gas;

•

summaries of waste acceptance records;

•

results of site inspections;

•

summary of complaints / incidents and responses; and

•

review of compliance with permit conditions;

4.9.6 Five-yearly review Acceptable Standard Permit conditions will normally require landfill owners to fully review their Environmental Management Plan every five years.

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Recommendations The review process should be supported by a systematic review of annual reports, contingency and cost plans, filling plan and incident reports. Results of the review, including revisions to the EMP, need to be submitted to the Regulatory Authority for approval. Major works or changes to landfill operation outside the 5 yearly cycle will still require appropriate approval from the Regulatory Authority prior to commencement.

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5.

REHABILITATION AND AFTER-CARE 5.1 INTRODUCTION Landfills can impact upon the environment many years after the completion of filling activities. It is important that all landfills are rehabilitated and that an after-care management program is implemented upon completion of filling activities. This will help mitigate potential environmental impacts, and allow the land to be reused. Where new landfills, or extensions to existing landfills, are proposed, landfill rehabilitation must be considered in the landfill / extension proposal. Once a landfill is rehabilitated, it is important that monitoring of the site continues and that rehabilitation measures, for example leachate extraction and collection systems, are maintained for an appropriate period of time. This is commonly referred to as landfill ‘after-care’. Rehabilitation consists of both ongoing and final phases. Ongoing rehabilitation of a landfill should occur throughout the life of the landfill as various landfill cells / areas are completed. Final rehabilitation works should commence within 90 days of permanent cessation of disposal operations in each stage of the site (e.g. each 0.5 ha), unless otherwise agreed with the Regulatory Authority.

5.2 POTENTIAL POST-CLOSURE USES It is essential to investigate potential end uses of the area when a landfill is planned, or when extensions to existing sites are being considered. Closed landfills generally cannot be used for sensitive uses, such as residential allotments because they may be subject to subsidence and they are likely to be classified as contaminated sites, meaning that a detailed risk assessment will normally be required prior to changing to a more sensitive land use. Where landfills are capped, activities carried out on the surface of old landfills should be restricted to ensure protection of public health and the environment. Acceptable Standard Potential uses of closed landfills must be determined as early as possible in the landfill life (i.e. during the planning stage), so that the landfill is designed and operated in view of its proposed end use.

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Recommendations The proposed end use should maximise the amenity of the land consistent with protection of public health and the environment. Rehabilitated landfill sites should not be considered for the following uses: •

houses or other buildings;

•

sealed roads (unless appropriate geotechnical assessments have been conducted);

•

intensive and fast moving sports unless specialist advice has been received; and

•

placement of services (unless they are compatible with the end use of the site).

Landfill/landfill extension design should consider future land uses of the site and incorporate any needs of such uses into the design and operation of the landfill. Future land use plans for a site should be flexible enough to ensure that any changes in community, planning or environmental needs can be accommodated. Periodic reassessment of future land uses should be made throughout the life of the landfill. It is important to consult relevant stakeholders when determining potential and actual end uses for closed landfill sites. These include the local community, planning authorities, the Regulatory Authority etc. Consultation with stakeholders during the planning phase should ensure overall strategic plans for an area and community needs are considered. Possible end uses for completed landfill sites include: •

forest, woodland or arboretum;

•

dog exercise zone;

•

picnic areas;

•

trails for cycling, horse-riding, jogging and walking;

•

golf practice range;

•

outdoor concert venue;

•

wildlife corridor;

•

grazing; and

•

industrial buffer zone.

These end uses may not be appropriate for all landfill sites. Uses should be assessed on an individual site basis. The selection of the end-use of the site should be compatible with the expected settlement of the landfill surface, otherwise continued maintenance to monitor grades and levels may be required.

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Due to risks associated with landfill gas emissions, contamination of land and water, and subsidence, houses or other buildings should not be built on closed landfills. Even if piling to a solid foundation is undertaken, problems may still occur due to ground settlement around the building. Differential settlement can make it extremely difficult to construct roads over completed landfill sites. Only unsealed roads should be considered, unless a thorough engineering or geotechnical evaluation of the site demonstrates that sealed roads are appropriate. Services (e.g. water, drainage and sewage) may be installed if compatible with the end use of the site. The placement and construction of such services in the landfill site needs to consider risks of failure and resultant environmental impacts (e.g. water from a burst service pipe can accelerate landfill settlement in the vicinity of the fractured pipe and increase the generation of landfill gas). 5.3

FINAL REHABILITATION Once adequate planning has been undertaken and the landfill rehabilitation and after-care plan approved by the Regulatory Authority, rehabilitation works should be undertaken as follows: •

removal of site structures;

•

additional compaction;

•

completion of capping;

•

completing of vegetation establishment;

•

leachate management;

•

landfill gas management; and

•

surface water controls.

5.3.1 Removal of site structures Acceptable Standard All structures that are not compatible with the intended final use of the site must be removed from landfill sites. Recommendations The site should be cleared of structures that may impede the rehabilitation process or are incompatible with the intended final use of the site. Fences may be retained during rehabilitation, as they are useful for site security and may keep out browsing animals.

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5.3.2 Additional compaction Acceptable Standard Before final capping and rehabilitation, landfills must be allowed to settle for at least 2 years after cessation of landfilling to minimise instability due to the presence of voids. Recommendations Waste should be compacted as much as possible. Bulky waste that was improperly buried or protrudes from the edges of filled areas may need to be removed and disposed of correctly. Related controls are suggested as part of waste handling (see Section 4.2). 5.3.3 Completion of capping Acceptable Standard Site capping and re-vegetation must ensure that the final surface provides a barrier to the migration of water into the waste (providing the design is a containment system), controls emissions to water and atmosphere, promotes sound land management and conservation, prevents hazards and protects amenity. Site caps must ensure that water infiltration through the cap is no more than 75% of the anticipated seepage rate through the landfill liner. Moisture within the cap must remain sufficiently stable to prevent cracking or other deformation. The capping layer must be shaped to allow lateral drainage. Steep slopes must be battered with the overall gradient being a maximum of 1 vertical to 3 horizontal. Recommendations Final capping and revegetation should be applied only after deposited refuse has settled and the area has become stable. After landfilling has been completed for a cell, waste material should be covered until such time that final capping can be applied. A report indicating time lines for final capping should be submitted to the Regulatory Authority within 60 days after final placement of waste in that area, however approval may be sought from the Regulatory Authority to extend this period to 180 days due to exceptional circumstances. A range of landfill cap designs should be considered to determine the configuration that is most suitable to the site. In general, designs may include clay capping and/or use a composite of clay and a geomembrane, however innovative approaches (e.g. capillary barrier and monolith soil layers) may also be considered.

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Clay and composite landfill caps consist of one or a number of layers. Table 5.1 shows the indicative requirements for landfill caps, and suggested layer thicknesses for each category of landfill. Figure 5.1 provides a graphical representation of the various components required and their related thicknesses. Table 5.1

Indicative Landfill Cap Requirements (Clay / Composite Cap) Layer

Landfill Category A (Solid Inert)2

Clean Fill Material

0.3 m

0.3 m

-

0.3 m

0.3 m

If required

0.6 m

> 0.6 m

-

If required

Yes

If required

0.3 m

0.3 m

-

Yes

Yes

Geomembrane or geosynthetic composite liner (includes geotextile layer(s))3 Drainage Layer Geotextile (if required) Final Layer (includes topsoil)1 Minimum Total Indicative Cap Depth 1. 2. 3.

C (Secure)

0.3 m

Gas Drainage Clay Capping (permeability of less than 1 x 10-9 m/s)

B (Putrescible)

0.5 m 0.8 m

0.5 to 1 m 2.0 m

>1m 2.5 m

The proportions of clean fill and topsoil in the final layer may vary provided that a minimum of 250 mm of topsoil is provided. Minimum requirement may not be necessary for Category A landfills. If the landfill liner is of a high standard and meets best practice environmental management and no groundwater or surface water contamination has been demonstrated, then the Regulatory Authority will give consideration to using alternative capping material (e.g. clay with a permeability greater than 1 x 10-9 m/s).

Additional material may be required in some instances. A preferred landfill cap design should be provided to the Regulatory Authority as part of the landfill rehabilitation and after-care plan (see Section 3.11). Fill material should be deposited in a 300 - 500 mm layer above the final layer of compacted waste and shaped to the intended final contour. It is important that material utilised for this purpose meet the requirements identified in Section 1.3.2. A gas drainage layer should have a minimum thickness of 300 mm. To prevent encrustation, the calcium carbonate content of the layer should not exceed 10% by weight. Clay should match the properties for that utilised for liner construction (see Section 3.1.1). Where suitable clay is not available, other impermeable material (e.g. bentonite) may be used as a substitute. DPIWE

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A clay cap should not be left exposed for prolonged periods of time, as this will probably lead to cracking, which will increase infiltration rates. Clay will need to be replaced if cracking or desiccation occurs Geomembranes or geo-synthetic composite liners should be considered as an additional moisture barrier for Putrescible landfills, if clay material is unavailable or not suitable. Secure landfills require a geomembrane or a geo-synthetic composite liner. A drainage layer comprised of coarse sand, pebbles or gravel directly above the clay layer will allow more rapid shedding of water and will reduce percolation through the cap. The drainage layer should be designed so that sufficient moisture remains in the final layer to support vegetation and prevent the cap from drying out and cracking. Water balance calculations incorporating local rainfall data should be used to confirm that these parameters will be met. The final layer of the landfill cap should consist of clean fill (see Table 5.1) and topsoil. Ideally, topsoil from local sources should be used. As new areas of the landfill are developed, topsoils should be stripped and stockpiled separately to be used as the final layer. The depth of soil to be provided depends on the vegetation intended for the site (e.g. deeprooted vegetation planted in shallow soil layers may penetrate the landfill cap and provide a pathway for water to infiltrate the landfill). Recommended soil depths for the growth of the following types of plants are provided in Table 5.2. Table 5.2

Recommended Application of Topsoil for Plant Categories Type of Plant

Depth of Soil

Grasses and sedges

100 mm

Shrubs

250 mm

In general, a soil layer more than one metre thick will be less likely to experience seasonal moisture fluctuations (e.g. waterlogging in winter or desiccation in summer). Good quality topsoil should be used for the upper soil layer. However it is possible to use clean fill material for the remainder of the final layer. A mixture of bio-solids and shredded or composted green waste may also be used as a soil substitute in the lower horizon of the final layer, in accordance with the Tasmanian Bio-solid Reuse Guidelines (DPIWE 1999). Advice from the Regulatory Authority is recommended. Advice on the choice of plants and subsequent soil requirements should be sought from a suitably qualified horticulturist. Compaction of the topsoil should be avoided as this will restrict vegetation growth by reducing water penetration and root growth. Loose tipped soils will encourage deeper roots, providing wind stability, water and nutrient availability, and most importantly shoot growth.

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Figure 5.1:

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Representation of the Various Component Layers Required and their Related Thicknesses for Landfill Cap (refer to Table 5.1 for further details).

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5.3.4 Vegetation Acceptable Standard Vegetation must be selected with regard to the particular area and appropriate native species utilised. Vegetation must be selected after consideration of the following; •

local climate (e.g. rainfall, wind) and soil conditions;

•

long-term viability;

•

ongoing maintenance requirements;

•

design of landfill cap;

•

capacity to prevent erosion of the landfill cap; and

•

final site use.

Recommendations A list of species potentially suitable for planting at rehabilitated landfill sites in Tasmania is provided in Appendix B. Marsh and sedge species should be selected for low lying, drainage lines and leachate basin areas. Selection for other parts of the site should be made in accordance with the criteria shown for the acceptable standard. Plants may be established through direct seeding or, if either rapid growth is required or browsing is a problem, through planting seedlings. Direct seeding Seeding may involve one or a number of methods, including: •

native seed regeneration,

•

hydro mulching and

•

pre-feed seeding.

Native seed regeneration can utilise seeds held in topsoil sourced from the site or spreading of seed bearing native brush to assist in preventing erosion and retaining soil moisture. This ensures that indigenous plants are regenerated. Additional requirements for soil stockpiles are discussed in Section 3.11. Hydro-mulching involves high pressure spraying of a wet mixture of seed and mulching material such as paper or wood fibre in a fluid over the land surface. Hydro-mulching is generally used for rehabilitating large areas.

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Pre-feed seeding uses dry powder coatings to assist with germination and protect against insect and fungal attack. A combination of the above methods may provide the best results (e.g. pre-feed seeding combined with hydro-mulching allows for quick germination and suppression of weeds while seeded species germinate). Seeds may be purchased from commercial suppliers or collected by a botanist, horticulturalist or a trained community group (e.g. Landcare or Greening Australia). Planting seedlings Seedlings may be planted using mound planting methods Mound planting involves preparation of topsoil mounds 3 – 4 m wide and 1 m high, with sloping sides that blend into the landscape. Maintenance of sufficient moisture for vegetation growth in the mound can become an issue (particularly during the early establishment phase). This technique can permit the planting of vegetation that may be sensitive to landfill gas. Growth rates are generally faster from tube stock than plants from larger containers due to shock and adaptability to soils. However, it is important that tube stock is planted into wet soil when planting and moisture levels maintained. Small mesh guards or grow bags should be used to prevent grazing and frost damage. Management Plantings should be properly managed to ensure that they receive sufficient moisture and nutrients, and to prevent damage. Early applications of fertiliser will be beneficial to growth, especially where final cover is low in available nitrogen and phosphorus. Applications of NPK fertiliser at a rate of up to 250 kg per hectare will generally support growth by native species without 'burning' them. However, this should be confirmed with the supplier of the plant species. Follow-up applications may be required in future years. Consideration should be given to the potential impact of fertilisers on weed growth. Irrigation can play a major part in the success or failure of plant species, although native plants will usually only require a small amount of watering in the drier months. Surface water can be collected and used for irrigation purposes, and a range of distribution options should be considered including drip feed systems, full pressure sprays, and agricultural and travelling sprinkler systems. The use of mulch has a major bearing on growth success, soil moisture content, surface erosion, soil composition, weed suppression and the level of maintenance required in rehabilitation of landfills. Generally, mulches inhibit weed growth by blocking light, and are best spread around established plants. All mulch should be pasteurised to ensure that weed seeds, plant pathogens and pests are removed. DPIWE

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Grazing or browsing animals (e.g. wallabies, rabbits and sheep) may inhibit growth of vegetation. Site fencing installed during landfill should be maintained to prevent grazing or browsing. Fence maintenance may also deter vandals and arsonists. Potential uprooting by the wind should be addressed and consideration given to local wind regimes, local climate, elevation, topographical exposure and the rooting conditions and requirements of favoured species. Staged Approach It is recommended that a staged approach be used for species revegetation. Initially leachate tolerant grasses and shrubs should be planted, however, as leachate generation decreases over time more deeply rooted plant species such as small trees can be planted. 5.3.5 Emissions management Acceptable Standard Landfill rehabilitation must ensure that leachate, landfill gas and surface water emissions do not cause environmental harm. Recommendations Controls established during the design phase (see Sections 3.1, 3.2 and 3.4) and operational phase (see Sections 4.3 and 4.8) should be maintained after closure until the Regulatory Authority is satisfied that the risk of significant environmental harm has diminished sufficiently.

5.4 AFTER-CARE Landfill after-care typically lasts up to 25 to 30 years after a landfill ceases to accept wastes. After-care must continue until the Regulatory Authority approves cessation of such activity. The requirements of after-care vary, generally reducing over time. Landfill after-care consists of two main activities – monitoring and maintenance of a closed landfill. 5.4.1 Maintenance Acceptable Standard A post-closure maintenance program must be established to ensure that the landfill does not cause environmental harm after site closure. The program should focus on preventing emissions to water, emissions to the atmosphere, and protection of land use and local amenity. Maintenance must continue until the Regulatory Authority approves cessation.

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Recommendations Maintenance of the landfill cap may include: •

maintaining design contours (i.e. adding fill material / topsoil in depressions);

•

sealing any cracks to prevent water infiltration; and

•

restoration of vegetation to prevent erosion.

Regular maintenance of the leachate collection and treatment systems, landfill gas extraction system and surface water sediment controls will minimise the risk of failure of these systems / controls. A maintenance schedule should be developed that defines what maintenance will be conducted and the frequency of such maintenance (e.g. servicing pumps). Additional maintenance may be required if the monitoring regime identifies any failures. 5.4.2 Monitoring Acceptable Standard Ongoing monitoring of closed landfills must ensure that the potential impacts of a landfill are scrutinised to the same degree of certainty as during the life of the landfill. Monitoring must identify failure of any environmental protection measures in a timely fashion, and must continue until no longer required by the Regulatory Authority. Recommendations Monitoring should address the following issues: •

groundwater;

•

surface water;

•

leachate;

•

landfill gas;

•

surface settlement; and

•

vegetation.

Requirements for leachate, groundwater, surface water and gas monitoring in Section 4.8. should be reviewed in consultation with the Regulatory Authority for the after-care period. Land settlement should be monitored on a regular basis. Vegetation should be inspected quarterly during the first two years following closure to identify areas of stunted growth or dieback, successful species, soil condition, soil moisture levels, and other parameters as required.

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5.4.3 Site closure Acceptable Standard The landfill operator / owner must ensure that waste materials are not received for disposal by the facility after landfill operations cease. Any waste materials that are accepted for use in the rehabilitation must be strictly documented and reported in the same fashion as for an operating site. Recommendations The landfill operator should provide adequate public notification, including signage and media notices, of the closure of the landfill. The site should be secured to prevent unauthorised dumping. The landfill operator / owner should advise neighbouring residents of a contact person to discuss any issues. A record of complaints (e.g. odour) must be maintained in the same manner as during operation. 5.4.4 Reporting Acceptable Standard The following reporting requirements apply to all closed landfills. •

demonstration that the landfill has been rehabilitated in accordance with the requirements of the landfill rehabilitation and after-care plan;

•

regular monitoring information on rehabilitated landfill sites; and

•

timely notification of any unusual monitoring results or maintenance required.

Recommendations A rehabilitation completion report should be submitted to the Regulatory Authority once rehabilitation works are complete. This report must contain sufficient information to demonstrate that rehabilitation has been completed (e.g. ‘as-constructed’ drawings and relevant quality assurance documents). Owners of a rehabilitated landfill should provide an after-care report to and at a frequency specified by the Regulatory Authority, typically once every 2 years in the initial stages of rehabilitation. The report should include as a minimum: • • • •

results of site monitoring; maintenance records; a record of complaints; and an explanation of incidents or other unusual events (e.g. additional maintenance).

Where the Regulatory Authority has agreed to reduce the frequency of monitoring, the period between reporting may be extended appropriately. If necessary, the owner must prepare an incident report (see Section 4.9.4).

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5.4.5 Site sign-off Acceptable Standard The landfill owner must clearly demonstrate that the landfill does not pose a threat to the environment before applying to the Regulatory Authority to cease after-care activities. Recommendations Generally, landfills should be monitored up to 30 years after their closure, however this timeframe may be decreased if the landfill is designed, operated and rehabilitated to a high standard. It is imperative that sufficient information from an extended period of time is provided before applying to the Regulatory Authority to cease after-care activities. The Regulatory Authority will base any determination that the landfill is stable and non-polluting on the results of the monitoring program over a number of years. Approval for the cessation of after-care activities will only be considered where: •

gas concentration levels fall to less than 1.5 % carbon dioxide at surface level for a period of 12 months;

•

waste is stabilised and there has been no settlement of the waste in the previous two years. This could be determined by the composition of leachate changing to a low level of contamination posing no environmental hazard;

•

groundwater monitoring indicates groundwater;

•

surface assessments demonstrate stable and effective surface water drainage; and

•

documentation that the approved rehabilitation and after-care plans have been fully implemented.

no

contamination of

Once cessation of after-care has been approved, the landfill rehabilitation and after-care plan will be considered fully implemented and no additional monitoring or maintenance of the site will be required as a result of its use as a landfill. The site will be placed on the contaminated sites register managed by the Regulatory Authority to ensure that future purchasers of the site are aware of its history.

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6.

REFERENCES 6.1 LEGISLATION State Aboriginal Relics Act, 1975 Agricultural and Veterinary Chemicals (Control of Use) Act 1995 Dangerous Goods Act 1998 Environmental Management Management) Regulations 2000

and

Pollution

Control

(Waste

Environmental Management and Pollution Control Act 1994 Historic Cultural Heritage Act 1995 Land Use Planning and Approvals Act 1993 National Parks and Wildlife Act 1970 Poisons Act 1971 State Policies and Projects Act 1993 State Policy on Water Quality Management 1997 Tasmanian Aboriginal Lands Act 1995 Threatened Species Protection Act, 1995 Commonwealth Environment Protection and Biodiversity Conservation Act 1999 Quarantine Regulations 2000

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6.2

GUIDELINES ANZECC (1993) National Strategy for the Management of Scheduled Waste, Australian and New Zealand Environment and Conservation Council, Canberra. ANZECC (1994) National Hazardous Waste Classification System, Australian and New Zealand Environment and Conservation Council, Canberra. ANZECC (1999) Polychlorinated Biphenyls Management Plan, Australian and New Zealand Environment and Conservation Council, Canberra. ANZECC and ARMCANZ (2000) Australian Guidelines for Water Quality Monitoring and Reporting, Paper No. 7, Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand, Canberra. CRCWMPC (1993) Draft National Solid Waste Classification System, Version 6, September 1993, developed by the CRC for Waste Management & Pollution Control Ltd for Environment Australia, University of New South Wales, Sydney. Available WWW: http://www.civeng.unsw.edu.au/ DELM (1996a) Guidelines for Recycling of Organic Wastes in Tasmania Department of Primary Industries, Water and Environment, Hobart. DELM (1996b) Environmental Assessment Manual Department of Primary Industries, Water and Environment, Hobart. DELM (1996c) Guidelines for the Establishment & Management of Waste Transfer Stations Department of Primary Industries, Water and Environment, Hobart. DELM (1998) Draft Guidelines for the Disposal of Medical Waste Department of Primary Industries, Water and Environment, Hobart. DPIWE (1999) Tasmanian Biosolids Reuse Guidelines, Department of Primary Industries, Water and Environment, Hobart. DPIWE (2000) Towards a Waste Management Policy: Discussion Paper for Comment Department of Primary Industries, Water and Environment, Hobart. DPIWE (2004) Classification and Management of Contaminated Soil for Disposal Department of Primary Industries, Water and Environment, Hobart. Environment Australia (1997) Methane Capture and Use: Waste Management Workbook, prepared by Aquatech for Environment Australia, Canberra. NGGIC (1998) Workbook for Waste, Workbook 8.1, Reprinted Version 1 with Supplements, National Greenhouse Gas Inventory Committee (Australian Greenhouse Office), Canberra. USEPA (1992). Test Methods for Evaluating Solid Waste, Physical/Chemical Methods (Third Edition and Updates I & II), SW-846, Office of Solid Waste and Emergency Response, United States Environmental Protection Agency, Washington DC.

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6.3 STANDARDS AS 1289 Methods of Testing Soils for Engineering Purposes AS 1289.6.7.1–1999 Soil strength and consolidation tests – Determination of permeability of a soil– Constant head method for a remoulded specimen AS 1940-1993 Storage and Handling of Flammable and Combustible Liquids AS 3580.11.1-1993: Methods for sampling and analysis of ambient air Determination of volatile organic compounds - Methane and nonmethane volatile organic compounds - Direct-reading instrumental method. AS 3798-1996 Guidelines on earthworks for commercial and residential developments AS 3831:1998 Waste management – Glossary of terms AS 4439.3-1997 Wastes, sediments and contaminated soils - Preparation of leachates - Bottle leaching procedures AS 5667.1:1998 Water Quality – Sampling – Guidance on the design of sampling programs, sampling techniques and the preservation and handling of samples AS 5667.6:1998 Water Quality – Sampling – Guidance on sampling of rivers and streams AS 5667.10:1998 Water Quality – Sampling – Guidance on sampling of waste waters. AS 5667.11:1998 Water Quality – Sampling – Guidance on sampling of groundwaters

6.4 SOFTWARE Hydrological Evaluation of Landfill Performance model – available online at http://www.wes.army.mil/ LandGEM - available on-line at http://www.epa.gov/ Landfill Area-Based Emissions http://www.npi.gov.au/

Spreadsheet - available on-line

Note: Landfill operators should use more recent versions of all documents listed in Section 6, where available.

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at

APPENDIX A - Suggested Plant Species 1.

INTRODUCTION

All species listed in Appendix 1 have been divided into categories based on a broad geographical requirement. Further divisions have been made, based on climatic conditions, altitudes and nutrient levels and where one condition is constant the lists are based on the other criteria. This breakdown should aid in the selection of species suitable for particular locations around the sites. Each individual species has been given a rating based on a system of crosses. This system is not only a measure of the suitability of a particular species for colonisation but also a measure of the practicability of species application ie seed application, cost and extraction difficulty. The rating system is: xxxx

Excellent coloniser, economical species to apply.

xxx

Good coloniser, relatively economical species to apply.

xx

Moderate coloniser or seed difficult to obtain economically.

x

A coloniser but not altogether suited to disturbed sites, or seed very difficult to obtain economically.

Banksia Marginata is a good example of a species that grows well under the majority of State conditions, but unfortunately the seed is difficult to extract in large quantities, therefore it only receives a moderate rating, xx.

WEST COAST AND SOUTH-WEST HIGH RAINFALL SKELETAL SOILS Accacia mucronata Banksia marginata Casuarina monolifera Eucalyptus nitida Leptospermum glaucescens Leptospermum nitidum Leptospermum scoparium Melaleuca squamea

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Acacia melanoxylon Acacia mucronata Acacia verticilata Banksia marginata Cassinia aculeata Casuarina monolifera Eucalyptus nitida Eucalyptus ovata Hakea lissosperma Leptospermum glaucescens Leptospermum lanigerum Leptospermum nitidum Leptospermum scoparium Melaleuca squamea Melaleuca squarrosa Oxylobium ellipticum

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PEATS

MINERAL SOILS (eg derived from volcanics) Acacia dealbata Acacia melanoxylon Acacia mucronata Acacia verticillata Banksia marginata Cassinia aculeata Eucalyptus delegatensis Eucalyptus nitida Eucalyptus obliqua Eucalyptus ovata Gaultheria hospida Hakea lissoperma Helichrysum dendroidium Leptospermum glaucescens Leptospermum lanigerum Leptospermum nitidum Leptospermum scoparium Melaleuca squamea Melaleuca squarrosa Oxylobium ellipticum

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HIGH ALTITUDE PEATS Acacia mucronata Banksia marginata Casuarina monolifera Eucalyptus nitida Gaultheria hispida Hakeal lissosperma Leptospermum glaucescens Leptospermum nitidum Leptospermum rupestre Leptospermum scoparium Melaleuca squamea

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CENTRAL PLATEAU GREATER THAN 1000M Banksia marginata Eucalyptus coccifera Eucalyptus gunnii Eucalyptus subcrenulata Hakea lissosperma Leptospermum nitidum Leptospermum rupestre

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700 – 1000M Acacia dealbata Acacia mucronata Acacia verniciflua Acacia verticillata Banksia marginata Callistemon pallidus Cassinia aculeata Eucalyptus amygdalina Eucalyptus coccifera Eucalyptus dalrympleana Eucalyptus delegatensis Eucalyptus gunnii Eucalyptus pauciflora Eucalyptus rodwayii Gaultheria hispida Hakea lissos[perma Helichrysum lanigerum Oxylobium ellipticum

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MINERAL SOILS (EG DERIVED FROM VOLCANICS) Acacia dealbata Acacia melanoxylon Acacia mucronata Acacia verticillata Banksia marginata Cassinia aculeata Eucalyptus delegatensis Eucalyptus nitida Eucalyptus obliqua Eucalyptus ovata Gaultheria hispida Hakea lissosperma Helichrysum dendroidium Leptospermum glaucescens Leptospermum lanigerum Leptospermum nitidum Leptospermum scoparium Melaleuca squamea Melaleuca squarrosa Oxylobium ellipticum

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HIGH ALTITUDE PEATS Acacia mucronata Banksia marginata Casuarina monolifera Eucalyptus nitida Gaultheria hispida Hakea lissosperma Leptospermum glaucescens Leptospermum nitidum Leptospermum rupestre Leptospermum scoparium Melaleuca squamea

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MIDLANDS Acacia dealbata Acacia mearnsii Allocasuarina verticillata Banksia marginata Banksia spinosa Eucalyptus amygdalina Eucalyptus ovata Eucalyptus pauciflora Eucalyptus rodwayii Eucalyptus viminalis Leptospermum lanigerum

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Melaleuca ericifolia, Melaleuca gibbosa, Callistemon pallidus and Dodonea viscosa may also be suitable for planting in the Midlands.

SOUTH-EAST LOW ALTITUDE, LOW RAINFALL POOR SOILS (ie. Derived from mudstones or granites) Acacia genistifolia Acacia mearnsii Acacia myrtifolia Acacia retinoides Acacia stricta Allocasuarina littoralis Allocasuarina verticillata Banksia marginata Bursaria spinosa Callitris rhomboidea Dodonea viscosa Eucalyptus amygdalina Eucalyptus globulus Eucalyptus risdonii Eucalyptus rubida Eucalyptus tenuiramis Leptospermum grandiflorum Kunzea ambigua

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FERTILE (ie. Derived from dolerites) Acacia dealbata Acacia longifolia Acacia mearnsii Acacia melanoxylon Acacia myrtifolia Acacia retinoides Acacia riceana Acacia stricta Acacia verniciflua Banksia marginata Bursaria spinosa Callistemon pallidus Casuarina littoralis Casuarina stricta Dodonea viscosa Eucalyptus amygdalina Eucalyptus globulus Eucaylptus ovata Eucalyptus pulchella Eucalyptus regnans Eucalyptus rubida Eucalyptus tenuiramis Eucalyptus viminalis Leptospermum glaucescens Leptospermum grandiflorum Leptospermum lanigerum Leptospermum scoparium Melaleuca squarrosa Melaleuca squamea

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NORTH-EAST HIGH RAINFALL, LOW ALTITUDE Refer back to West Coast mineral soils. LOW RAINFALL, LOW ALTITUDE (including Flinders Island) Acacia botrycephela Acacia dealbata Acacia mearnsii Acacia melanoxylon Acacia mucronata Acacia retinoides Acacia verticillata Banksia marginata Bursaria spinosa Cassinia aculcata Casuarina littoralis Casuarina stricta Eucalyptus amydgalina Eucalyptus delegatensis Eucalyptus globulus Eucalyptus obliqua Eucalyptus ovata Eucalyptus pauciflora Eucalyptus sieberi Eucalyptus viminalis Kunzea ambigua Leptospermum granidlorum Leptospermum lanigerum Leptospermum scoparium Melaleuca ericifolia Melaleuca squarrosa Oxylobium ellipticum

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HIGH ALTITUDE, GREATER THAN 800M Banksia marginata Eucalyptus amygdalina Eucalyptus cocifera Eucalyptus dairympleana Eucalyptus delegatensis Eucalyptus gunnii Eucalyptus pauciflora Eucalyptus rodwayii Hakea lissosperma Leptospermum lanigerum Melaleuca squamea

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NORTH AND NORTH-WEST HIGH RAINFALL AREAS Refer to West – South-West mineral soils. LOW ALTITUDES (including King Island) Acacia dealbata Acacia longifolia Acacia melanoxylon Acacia mucronata Acacia retinoides Acacia verticillata Banksia marginata Bursaria spinosa Cassina aculeata Casuarina littoralis Casuarina monolifera Dodonea viscosa Eucalyptus amygdalina Eucalyptus nitida Eucalyptus obliqua Eucalyptus ovata Eucalyptus viminalis Helichrysum dendroidium Leptospermum glaucescens Leptospermum scoparium Leptospermum lanigerum Melaleuca ericifolia Melaleuca squamea Melaleuca squarrosa Oxylobium ellipticum

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COASTAL DUNES Acacia sophorea Ammophia arenaria Banksia marginata Carpodrotus rossii Casuarina littoralis Casuarina stricta Leptospermum laevigatum Myoporium insulare

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NORTH-WEST – WEST Acacia longifolia Acacia retinoides Acacia sophorea Banksia marginata Bursaria spinosa Casuarina monolifera Eucalyptus nitida Eucalyptus ovata Eucalyptus tenuiramis Eucalyptus viminalis Leptospermum glaucescens Leptospermum laevigatum Leptospermum lanigerum Leptospermum scoparium Melaleuca ericifolia Melaleuca squamea Melaleuca squarrosa

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EAST TO NORTH-EAST (including Flinders Island) Acacia botrycephela Acacia genistifolia Acacia retinoides Acacia sophorea Banksia marginata Bursaria spinosa Callitris rhombidea Casuarina littoralis Casuarina stricta Casuarina stricta Eucalyptus amygdalina Eucalyptus globulus Eucalyptus tenuiramis Eucalyptus viminalis Kunzea ambigua Leptospermum grandiflorum Leptospermum lanigerum Leptospermum scoparium Melaleuca squarrosa

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