The Environment Agency has completed its inspections of sewage plants as part of its biggest criminal investigation to-date.
The probe was launched two years ago into all English water and sewerage companies to assess potential non-compliance of flow to full treatment regulations at wastewater processing sites.
Flow to full refers to the amount of water from sewer networks, surface water and rain that the plant must treat before it can discharge excess flows to storm tanks or the environment.
More than 2,200 treatment works were included in the scope of the inquiry as potentially non-compliant.
The Environment Agency identified 114 indicator sites that it deemed representative of the locations that may have been non-compliant, which it has now visited and inspected all of.
It said 10 visits per company implicated in the inquiry were carried out. The sites chosen by the Agency cover a spectrum of works ranging in size, across the entire area covered by each water company, and discharging to differing environmental and amenity sensitivities.
The Environment Agency gathered evidence from the visits into the operational practices as well as flow systems and monitors, maintenance regimes, management practices and site diaries
Data and documents are now being analysed, which the Agency said “will take many months”.
After the investigation is completed, the Environment Agency will consider all options for enforcement and sanctions.
The regulator was granted powers to distribute unlimited fines for environmental offences. However, the most serious incidents would continue to be dealt with through a criminal court, which would have not have a cap on financial penalties that could be imposed.
Separately to the EA’s work into wastewater treatment work non-compliance issues, Ofwat opened investigations into six water and sewerage companies with a focus on flow to full permits.