Waste Acceptance Criteria (WAC)

Waste Acceptance Criteria Testing (WAC)

WAC testing became mandatory in 2005 following the introduction of the Landfill Regulations.

The Landfill Directive requires that waste is properly characterised and meets specific Waste Acceptance Criteria (WAC) prior to disposal at a landfill site.

It is important to recognise that WAC testing does NOT characterise waste as hazardous or non-hazardous.

Testing to WAC limit values is required for wastes disposed of to landfills for hazardous and inert waste as well as all wastes disposed of in cells for stable non-reactive hazardous waste.

WAC testing includes a combination of solids testing (for the total composition of the waste) and leachable content to ensure that waste is properly characterised and to determine which class of landfill the waste can be accepted at.

Once the dry solids / basic characterisation testing has been completed the WAC test is then used to further categorise the soils:

Non Hazardous Waste – non-hazardous waste can be sent to an appropriate landfill for non-hazardous waste, or of it meets certain provisos it can be classified as inert waste. There are two ways in which the soil may be classified as inert waste. Firstly as a listed waste or secondly by showing that it falls within certain chemical limits from the WAC test.

Hazardous Waste –   soils indicated to be hazardous waste require further testing before they can be accepted at landfill (the hazardous WAC test). If the chemical testing falls within the Hazardous WAC then the soil may be sent to an appropriate landfill for hazardous waste. If the chemical test results exceed the hazardous WAC then the soil is deemed unsuitable for landfill and the soils should be treated in a way to allow them to pass.

The Council Decision sets specific limits, commonly referred to as ‘WAC leaching limits’, for a sub-set of the components that the waste producer must consider in the Basic Characterisation. These apply to all wastes destined for disposal in a landfill for hazardous, stable non-reactive hazardous and inert waste. These limits are independent of the test data used to determine if a waste is hazardous or non-hazardous. Waste producers cannot use them to decide whether their waste is hazardous or non-hazardous, which they must do before they can decide which class of landfill is suitable for their waste.

The WAC limits are based on:

  • Total concentration limits for the organic components and pH; as well as Leachable components.

Nicholls Colton can advise, undertake the laboratory testing and provide the necessary information for your waste classification.

In order to save time and costs Nicholls Colton recommend that the WAC testing is undertaken at the same time as the testing for the basic characterisation.