Drinking water watchdog reports new way for detecting long-lasting toxins in rivers

The Drinking Water Inspectorate (DWI has included in its latest quarterly report for England and Wales, a description of a new method to determine levels in drinking water of potentially poisonous, so-called forever chemicals – substances that take many years to degrade once in the environment.

Alongside the water quality watchdog’s list of “significant compliance breaches and a selection of water quality events considered to have learning for the wider industry” was a method for analysing highly toxic perfluoroalkyl substances (PFSAs). PFSAs originate in commonplace items included food packaging, non-stick pan coatings and outdoor clothes.

The method can detect PFSAs down to 0.1 millionths of a gramme per litre. However, while DWI said that sensitivity meets the requirements for short-chain PFSA molecules it is “sub-optimal” for long chain ones which are more toxic and more likely to accumulate in groundwater.

The analysis method uses a costly combination of liquid chromatography and a mass spectrometer which reveals the size and shape of molecules.

The inspectorate said it was working with the water industry on developing of a method for detecting all 47 PFAS that are of interest. “The outcome of this research provides learning opportunities for laboratories interested in analysing for PFAS in potable and natural waters,” the DWI said.

Another research project highlighted in the report looked at whether organophosphorus flame retardants (OPFR), were likely to be found in drinking water or its sources.

The DWI said publicly available information on how much OPFRs were used in the EU and UK was “very limited.” But it went on to say analysis of data from the Environment Agency’s monitoring programme revealed 11 OPFRs in English environmental waters. However it said the data suggested that OPFR concentrations were “low and that they are removed by some water treatment processes.”

The audit theme for this quarterly report was management of contractors.

DWI said contractors “pose a potential water quality risk and are often cited as a factor in water quality events.” It said “some good practice was evidenced, especially around supervision and communication,” but there were “shortfalls in training, procedures, including the use of approved products, water quality checks and hygiene.”

It warned: “Companies retain responsibility for contractors and are advised to carry out regular audits and hygiene checks.”