Question to the Department for Environment, Food and Rural Affairs:

To ask the Secretary of State for Environment, Food and Rural Affairs, what steps his Department is taking to tackle the risk to groundwater and drinking water from trifluoroacetic acid (TFA) and trifluoroacetate resulting from refrigerants used in air-conditioning and in heat pumps.

Trifluoroacetic acid (TFA) is one of a group of thousands of substances collectively called poly- and per-fluorinated substances (PFAS), which are highly persistent in the environment. As a group they are being considered under a risk management options analysis under UK chemical regulation (UK REACH). The Environment Agency (EA) also considers TFA as part of its priority and early warning system for chemicals.

We are aware of some concerns raised about TFA and trifluoroacetate in relation to the breakdown of certain refrigerants, in particular hydrofluoro-olefins (HFOs). HFOs are used increasingly as replacements for hydrofluorocarbons (HFCs) due to their much lower Global Warming Potential.

HFCs are powerful greenhouse gases and their use is being phased down. Defra is reviewing the legislation covering HFCs to ascertain whether we can go further in support of the UK's net zero target. This will include assessing the adequacy of existing leak prevention, detection and repair measures, as well as the possibility of reducing further the use of HFCs.

The 2018 UN Montreal Protocol Environmental Effects Assessment Panel (EEAP) report concluded there was minimal risk to human health or the environment from TFA from HFOs used as refrigerants. However, we continue to monitor the latest scientific assessments and will take on board their conclusions, including as part of our review.

Activities with the potential to impact upon the quality of groundwater are regulated through the Environmental Permitting (England and Wales) Regulations 2016 (EPR). The EPR provide for ongoing supervision and control by the EA to ensure that groundwater activities are only permitted to operate where the risks to groundwater are well understood and mitigated. The EA does not currently monitor TFA in groundwater.

Refrigerants used in ground source heat pumps are designed and installed to be contained within closed loop systems having no connection to the surrounding environment. Should any evidence show that systems have leaked, the EA has powers to serve notices requiring remediation of any impacted groundwater, surface water or soils.

Drinking water quality is a devolved matter and the information provided therefore relates to England only.

The Drinking Water Regulations require that, in order to be considered “wholesome”, drinking water must not contain any substance at a level which would constitute a potential danger to human health.

The topic of PFAS substances is not new. The Drinking Water Inspectorate has provided guidance to water companies since 2009 and this has recently been updated to reflect current knowledge. The guidance requires water companies to ensure these chemicals are adequately considered in their risk assessments. Should the EA find evidence to suggest that the closed loop systems have leaked, it will inform relevant water companies of any potential risk, and the water companies will consider initiating monitoring for the chemicals at any of their works where appropriate.