“Thames Water must urgently reduce their phosphate pollution of the Pang”

Anglers in West Berkshire are keeping up the pressure on Thames Water to clean up the River Pang.

The water company now says it plans to “review” phosphate pollution stripping at Hampstead Norreys and Compton sewage treatment works, located in the headwaters of the Pang chalk stream.

The Tidmarsh Fly Fishing Club says excessive phosphate levels from untreated wastewater are threatening the biodiversity and health of the river ecosystem.

“High phosphate levels lead to a process called eutrophication, which causes an increase in algae,” explained Peter Devery, secretary of the Tidmarsh Fly Fishing Club.

“This, in turn, depletes dissolved oxygen in the water, deteriorating water quality and harming plants, wildlife, and fish.”

The Pang, one of only 200 chalk streams in the world, flows from West Berkshire into the River Thames at Pangbourne.

The Environment Agency currently classifies the Pang as being in “poor” ecological condition.

The river has been inundated with raw sewage and since the beginning of July 2024 has suffered from more than 430 hours of untreated sewage discharged from Thames Water’s sewage works.

“To date, Thames Water has refused to include phosphate stripping in its development plans, despite the Pang being the company’s chosen chalk stream recovery project, one of its ‘flagship catchments’ and the focus of a programme aimed at improving the catchment so it is not adversely affected by water resource or water quality pressures,” said Mr Devery.

The heavily indebted water company is currently awaiting approval from industry regulator OfwatT for its next five-year business plan, which will run from 2025 to 2030.

Last week it got a £20bn bailout to restructure its finances.

The plan does not currently include phosphate stripping technology at these two West Berkshire sewage works.

However, Thames Water said it would review this after a grilling at the West Berkshire Council scrutiny commission meeting earlier this month.

Citizen science data collected by the Tidmarsh anglers for the Angling Trust’s Water Quality Monitoring Network has consistently detected high phosphate levels in the Pang.

Additionally, water quality monitoring by Action for the River Kennet has estimated that Thames Water’s sewage works account for over 52 per cent of the phosphate pollution in the river.

“Another six years of excessive phosphate levels in the headwaters of the Pang will seriously damage a chalk stream which is already in poor condition,” said Mr Devery.

“This review is a step in the right direction.

“If Thames Water is committed to reversing the damage done to their flagship chalk stream for recovery, they must urgently reduce their phosphate pollution of the Pang.”