An exclusive investigation by the Guardian suggests England is to diverge from EU water monitoring standards. Campaigners fear the change of approach could lead to more pollution in England’s rivers and waterways if the new measuring methods are less rigorous.

While in the EU, England was covered by the water framework directive (WFD), and a national chemical and ecological survey of rivers was conducted annually. After Brexit, the WFD was transposed into English law. From 2016 the government decided to test water quality under WFD every three years rather than annually.

This is the latest example of the UK diverging from EU environmental standards. Recent analysis found that many toxic chemicals and pesticides banned in the bloc since Brexit are not outlawed for use in the UK. Ministers have also sought to rip up EU-derived sewage pollution rules for housebuilders.

In 2019, the last time the full water assessments took place, just 14% of rivers were in good ecological health and none met standards for good chemical health. The government has said it does not intend to deliver a complete update until 2025, the latest permissible date under the new WFD.

The Guardian can reveal that the government will be using its own, as yet undisclosed methodology to assess river health. Activists say this may make it harder to compare the state of the country’s rivers against those in the EU, and will leave the public in the dark over pollution from sewage and agriculture.

Government officials met stakeholders to tell them about the change. A source from an NGO present in the meeting said: “When asked how this would affect assessments against the target set out in the government’s environment improvement plan, officials commented that this data would no longer be used for that purpose, and that Defra were looking to use the Natural Capital and Ecosystem Assessment (NCEA) process to assessment performance. I question how developed the work on the NCEA is and whether this is suitable.”

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