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 improve the environmental health of Hogsmill River.

The Environment Agency (EA) continues to support volunteers and Citizen Scientists in monitoring water quality across the Hogsmill, focussing on known pollution hotspots. Collaboration efforts have identified misconnecting sewage outfalls causing pollution, which Thames Water have rectified.

As part of the Water Company Price Review (PR19), Thames Water are committed to deliver a river restoration scheme at Kingsmeadow by 2027. There is also a partnership investigation to assess the impacts of groundwater abstraction on natural flows. The river restoration arising from these studies are scheduled for completion in March 2030.

Thames Water are required under PR24 to increase the size of the storm tanks at Hogsmill Sewage Treatment Works to 4 times the current volume. This will reduce the number and duration of storm sewage spills.

River Restoration is supported by the Water Environment Improvement Fund (WEIF). This year the funding has supported:

• the improvement of 250m of habitat and improved fish passage at Riverhill Mill.
• 3,500 square metres of wetland habitat constructed at Tolworth Court, creating priority habitat, treating road run-off and providing flood storage.
• completion of the Chambers Mead Wetland Project Chamber Mead Wetlands - South East Rivers Trust

A recent Enforcement Undertaking (£150,000) for a pollution incident in 2020 required Thames Water to improve the Bonesgate.

The EA is committed to undertake a larger programme of wastewater asset inspections. It will have inspected 4,000 assets in England by the end of March 2025, up from 1389 the previous year, moving towards 11,500 a year by March 2027. This work will see significant improvements to water quality.