Appendix D: Landfill classification - Class A requirements

Minimise the potential for instability, waste breakout or leachate breakout due to inundation by floodwaters or scouring from floodwaters

Siting - landfill not sited in 1 in 100-year or less floodplain

Design - landfill designed to remove the risks of waste breakout, leachate breakout or instability associated with flooding or inundation

2

Minimise the potential for failure of basal liner and leachate collection system

Siting - landfill not sited in an inter-tidal zone

None

3

Minimise the potential for failure of basal liner and leachate collection system

Siting - over 1 m separation between underside of landfill basal liner and maximum expected groundwater level

Design - landfill designed to remove the risk of failure of the basal liner or leachate collection system from groundwater pressure under the liner system

4

Minimise the potential for failure of basal liner and leachate collection system

Siting - landfill not within a geothermally active area

Design - landfill designed to remove the risk of failure of the basal liner or leachate collection system from geothermal activity

5

Minimise risks to landfill stability (including effects on liner integrity and leachate collection system)

Siting - landfill not sited over compressible or unstable foundation materials

Design - landfill designed to remove risks from compressible or unstable foundation materials to liner integrity, landfill stability and leachate system operation

6

Avoid contamination of adjacent surface water bodies with leachate or contaminated stormwater

Siting - no direct pathway from landfill to a significant surface water body

Design - stormwater, groundwater and leachate management systems designed to mitigate risks to surface water bodies

7

To protect the coastal marine area from adverse environmental impacts associated with the landfill

Siting - landfill not sited in coastal marine area

None

8

Avoid contamination of a viable groundwater supply

Siting - landfill not sited over permeable material

Only site over highly permeable in-situ materials such as sands or gravels (perm > 1x10^-5 m/s) if the landfill does not overlie a viable groundwater supply

Siting - landfill not sited over viable groundwater supply

Design - higher standard of engineered containment that accounts for the minimal natural containment available and includes a base and side composite liner 1.5 mm HDPE overlying 600 mm clay (10^-9 m/s) (or the equivalent)

9

Avoid contamination of a viable groundwater supply

Siting - landfill not sited over a viable groundwater supply

Siting/design - only site over viable groundwater supply if the combination of engineered and natural containment results in negligible risk of contamination of the groundwater supply

Siting - Aquitard between base of landfill and viable groundwater supply

Design - high standard of engineered containment including a base and side composite liner 1.5 mm HDPE overlying 600 mm clay (10-9 m/s)

10

Remove the risks from active faults on the containment system

Siting - landfill not sited in an area subject to seismic instability

Design - designed to remove risks from seismic activity to liner integrity, landfill stability and leachate system operation

11

Effective containment of waste, leachate and landfill gas

Design - landfill has a base and side composite liner 1.5 mm HDPE overlying 600 mm clay (max permeability 10^-9 m/s)

Design - alternative landfill liner design that provides equivalent level of risk mitigation, considered with reference to resistance to chemical degradation, hydraulic containment, physical strength and deformation characteristics, general installation procedures and expected service life (see Appendix E)

12

Effective containment of waste, leachate and landfill gas

Design - leachate collection system designed to ensure the maximum leachate head over liner is < 300 mm

None

13

Effective containment of waste, leachate and landfill gas

Design/operation - for sites with a total design capacity over 1,000,000 m³, a landfill gas flaring system

Design/operation - alternative landfill gas treatment system or use that provides equivalent level of risk mitigation

14

Effective containment of waste, leachate and landfill gas, and control of water infiltration into landfill

Operation - effective use of daily and intermediate cover

None

15

Prevention of landfill fires

Operations - management plan includes measures to prevent landfill fires

None

16

Minimise the risks associated with inappropriate waste disposal

Operations - management plan requires documentation and record keeping of waste volumes, types and source

None

17

Minimise the risks associated with inappropriate waste disposal

Operations - management plan requires a licensing system for all non-municipal waste generators. The licensing system shall require adequate information to ensure that the landfill operator is satisfied that the waste meets the Landfill Waste Acceptance Criteria

None

18

Minimise the risks associated with inappropriate waste disposal

Operations - management plan defines waste acceptance criteria monitoring procedures - a minimum of 1 in 50 commercial/industrial loads inspected

None

19

Minimise the potential for instability, waste breakout or leachate breakout due to inundation by floodwaters or scouring from floodwaters

Operations - management plan ensures adequate maintenance of surface water control system

None

20

Avoid contamination of adjacent surface water bodies with leachate or contaminated stormwater

Operation - landfill management plan ensures adequate control of surface water

None