We publish our annual compliance figures here (last updated March 2020).
Compliance of samples
Samples are taken at the point the effluent is released into the environment. They’re tested for several indicators of the discharge's potential polluting impact. If the result for any indicator is above a set limit, the sample fails the compliance test.
The graph below shows the number of non-compliant samples per calendar year, as recorded by the Environment Agency:
We take thousands of samples each year from around 300 separate locations. As such, compared to the handful of samples that fail each year, the vast majority are compliant. However, we take every instance of non-compliance seriously.
To protect the environment and public health, the indicators for the potential polluting impact of a sample are set very low. As a result, failed samples are usually only slightly above these thresholds and pose no significant risk to people or the natural world.
Our final effluent compliance data
For details of which sites have had samples taken during each calendar year, please download the .xlsx spreadsheet below:
Final effluent compliance data 2017–19