PFAS Risk Screening Project Phase 4, Work Package 5 - Landfill Emissions Assessment

This contract is for the project entitled Landfill Emissions Assessment. This work programme is sub-divided into four ‘Lots’ which sit under the overarching PFAS Risk Screening Project which is now entering Phase 4 (2022 – 2025).

The wider PFAS Risk Screening Project, aims to assess and tackle the risks arising from a group of “forever chemicals” which are contaminating soil, groundwater, surface waters and gases that may pose a risk to human health. These four ‘lots’ build on previous work undertaken jointly by the EA and Defra on PFAS and a wider range of persistent organic pollutants (POPs). These chemicals are causing a global pollution problem. And the nature and scale of the problem in the UK is only now being fully realised.

The overarching objectives of the current studies (outlined below as four separate work packages) is to build on the outputs from preceding studies, to act on recommendations and to improve our understanding and knowledge. This will be achieved by developing sampling programmes to collect leachate, gas condensate, biosolids (sludges), groundwater, surface water and landfill gas from a variety of landfills and Sewage Treatment Works (STW) and/or Wastewater Treatment Works (WWTWs) and analyse for a number of POPS, PFAS and other hazardous substances.

The four lots comprise of:

• Lot 1 - Targeted sampling and assessment of non-hazardous raw and treated leachates, gas condensates and bio-solids (sludges) from a variety of on-site leachate treatment plants to evaluate percentage removal of PFAS and POP substances.
• Lot 2 - Assessment of PFAS and POPs in non-hazardous landfill leachate compared to other sources within domestic and industrial wastewaters.
• Lot 3 - Assessment of PFAS and POPs emissions/releases from non-hazardous landfill leachates to surface and groundwaters from unlined and lined non-hazardous landfills.
• Lot 4 - Study of a PFAS suite and other trace gas emissions from non-hazardous landfills.

This task aims to assess the proportional loading of PFAS and POPs from raw and treated non-hazardous landfill leachates against those reported at wastewater/sewage treatment works.

This task aims to gather additional non-hazardous landfill leachate and groundwater/ surface water samples and evaluate PFAS and POPs emissions to the environment via contaminant migration from unlined and lined landfills to the underlying and surrounding groundwaters and/or surface waters.

This task aims to:

• identify PFAS and qualify and quantify the potential release from non-hazardous landfills involving the sampling from key gas emission locations around targeted landfills, including where possible:

o gas condensates

o raw gas (wellheads) from the gas field

o raw gas inlet to either landfill gas engine and/or flare

o combustion gas treatment systems (landfill engines and flares stacks)

• sample and analyses landfill trace gases as described in Appendices 2 and 3 in the EA report, The Quantification of trace components in landfill gas (P1-491 TR) to update our existing records.