Understanding Waste Classification and Waste Acceptance Criteria (WAC)

The Government’s aim of reducing reliance on landfill as a disposal option and minimising the impacts of landfills on the environment and human health has meant the introduction of more stringent regulatory procedures. In accordance with the Landfill Regulations (2005) and Waste Framework Directive (WFD) (2008/98/EC), it is a statutory requirement that a waste is characterised and also meets specific Waste Acceptance Criteria (WAC) prior to disposal at a landfill site. The waste producer has a Duty of Care to ensure that the waste is characterised and the landfill operator must also be satisfied that a Basic Characterisation, is properly completed before the waste is accepted.

Basic Waste Characterisation Testing (Air Dried Testing)

If arisings from constructions works or other waste materials are intended for disposal then there is a requirement to determine prior to disposal whether these would classify as:

  • Hazardous
  • Non hazardous

The Environment Agency’s technical guidance ‘Waste Classification (WM3, 1st edition 2015)’ which came into force on 1st July 2015, sets out the requirement for the classification. It also provides the basis for the methodology to employ in order to ensure compliance with the regulations.

The classification assesses the composition of the material and determines the concentrations of the hazardous substances in the material. The assessment of contaminated soil (excavated soil) to determine whether it is hazardous waste is dependent on the presence of “hazardous substances” exceeding particular thresholds.

The basic characterisation requires solids testing for potential contaminants, derived from the knowledge of the site history (in the case of contaminated soil) or product safety data sheet (in the case of other waste products).

The characterisation also determines the most appropriate List of Waste (LoW) code(s) for the waste. The List of Wastes (England) Regulations 2005 shows those wastes that are absolute entries (hazardous waste regardless of their concentration) and mirror entries (hazardous waste only if dangerous substances are present above threshold concentrations).

Waste Acceptance Criteria Testing

The Waste Acceptance Criteria (WAC) became mandatory in 2005 following the introduction of the Landfill Regulations.

Landfills are classified according to whether they can accept hazardous, non-hazardous or inert wastes. Wastes can only be accepted at a landfill if they meet the waste acceptance criteria (WAC) for that class of landfill

The WAC testing includes solids and leachate testing to assess which class of landfill the waste can be accepted at.

Currently there are only acceptance criteria for inert, stable-non-reactive hazardous and hazardous landfills. This means that WAC testing is only required for wastes destined for Inert, SNRH and Hazardous landfills.

If material is classified as non-hazardous, there is a choice of sending the material to a non-hazardous or an inert landfill (subject to meeting inert waste acceptance levels). Where the material is classified as hazardous, WAC analysis will be required to demonstrate that it meets the acceptance levels for hazardous landfill or stable non-reactive hazardous (SNRH) landfill.

In brief:

  • WAC testing does NOT characterise waste as hazardous or non-hazardous.
  • Non-hazardous waste does not need WAC testing unless disposal to an inert landfill is being considered.
  • If waste is characterised as hazardous then a hazardous WAC suite (or a ‘Stable Non-Reactive Hazardous’ suite if disposal to ‘Stable Non-Reactive Cell in a Non-Hazardous Landfill’ is being considered) should be tested.
  • To save time, the WAC testing can be scheduled alongside the testing for characterisation. If an inert landfill is being considered for non-hazardous waste, then a ‘Full WAC Suite’ should be scheduled. If disposal to an inert landfill is not being considered, then a ‘Hazardous WAC Suite’ should be scheduled.
  • Whilst the Environment Agency still support a single stage leaching process in the WAC test, some landfills still only accept the time stage leading test results. Check with the landfill on their requirements. If in doubt use two stage testing.
  • Check with the landfill site if there are any other criteria that need to be met under their permit.


Southern Testing are experienced in the classification and management of waste and are able to provide Waste Classification Reporting to all clients.

We can also provide advice for Waste Management Plans and the adoption of the CL:AIRE Definition of Waste: Development Industry Code of Practice.

Laboratory sample requirements:

  • Basic characterisation suite & Full WAC, Hazardous WAC or Inert WAC Suite – a 1 litre plastic tub, a 250ml amber jar, and a 60ml VOC jar (per sample)
  • No of samples to test is dependent on the heterogeneity and the volume of the material
  • 10 working days turnaround (standard)
  • 5-6 working days turnaround ( + 25% premium)

Please contact us to  discuss your testing requirements.

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