United Utilities reports project cuts river tributary phosphorous levels by 63%

United Utilities has reported its reduction of phosphorus levels by 63% in a tributary of River Petteril in Cumbria where its Calthwaite wastewater treatment works discharges effluent. The water company said the nutrient removal project was the UK’s first trial of Catchment Nutrient Balancing which deploys various methods including technology and land use changes to remove pollutants.

The project had aimed to integrate catchment and treatment methods to reduce the annual phosphorus discharge into Calthwaite Beck by 150kg to cut its release into the catchment by 9%.

United Utilities said the wider catchment measures used included hedges, buffer strips and sediment ponds delivered at farm level to reduce agriculture contribution “to achieve results beyond regulatory obligations”. It also used and “innovative reactive filter media, polonite,” at the treatment plant to reduce phosphorus levels.

Environment, planning and innovation director, at United Utilities,Jo Harrison, said the trial; had “taken into account the dynamic nature of the catchment, how pollution into the River Petteril is driven by multiple sources and how it is exacerbated by storm and flooding events, in order to completely transform the Petteril’s water quality.”

The water company’s partners int he trial were: Eden Rivers Trust, Carlisle City Council, Cumbria County Council, Lancaster University, Natural England’s Catchment Sensitive Farming, The National Farmers Union, the Environment Agency, and Nestle and its fellow stakeholders

The project received additional funding of £120,000, through match-funding and collaborative working with farmers (landowners and tenants) in the areal.