Wells firm’s invention removes reservoir pollution

By Laura Linham 15th Jul 2026

Local News by Laura Linham 6 minutes ago

A Wells-based environmental technology company has successfully tested a material designed to remove harmful phosphate pollution from water and reuse the recovered nutrient as fertiliser. Rookwood Operations, based at East Higher Farm in East Horrington, worked with Bristol Water on the trial at Herriotts Mill Pool, which flows into Chew Valley Lake.

The trial used Rookwood's Phosphate Recovery Material, known as PRM, to capture dissolved phosphate before it entered the wider reservoir. Bristol Water first announced the results in March, with the Wells firm's work receiving fresh coverage from BBC News and BBC Points West this week.

Phosphorus is a natural resource needed for food production, but in large quantities it can become a pollutant in lakes and reservoirs. Bristol Water said it can drive harmful algae growth, damage biodiversity and make drinking water harder to treat.

Rookwood's material is placed inside permeable cartridges and works as water flows through them. The process needs no electricity, working passively with the existing flow of water through the pool.

As water passes through the cartridges, the material binds with dissolved phosphate and captures it before it can reach Chew Valley Lake. Once saturated, the cartridge can be replaced and the phosphate-rich material removed for reuse as a slow-release agricultural fertiliser.

The trial found that the material could capture phosphate in real-world conditions, including when it was present in very low concentrations. Bristol Water said the installation was designed to fit into the existing water structure at Herriotts Mill Pool while respecting the sensitivity of the Site of Special Scientific Interest.

Liam Pearce, Chief Commercial Officer at Rookwood Operations, said Herriotts Mill Pool had shown the material delivered "real, measurable improvements in water quality". He said it consistently removed phosphate, including during low-nutrient periods, and also captured other nutrients.

Helen Gavin, Environmental Lead at South West Water, said managing raw water quality in reservoirs was important for both treatment and ecological reasons. She said the results provided evidence that the material was a practical and sustainable solution that could support wider goals for improved water quality and resilience.

Rookwood Operations was founded in Somerset by Jane Pearce, Liam Pearce and Josh Hares. The company says its work is focused on recovering nutrients from water and returning them to land, creating a circular alternative to mined phosphate fertilisers.

Following the successful trial, Bristol Water and Rookwood are now exploring whether the technology could be deployed more widely. No specific future locations or dates have been confirmed.