South West Water hosts the UK's first municipal trial of a rotary press for sludge

South West Water ran a five-day trial of the Fournier Rotary Press at its Newham Sludge Treatment Centre in Truro, Cornwall, in October. It was the first municipal trial of the technology in the UK (H2O Global News). The company is looking for ways to meet tighter dryness requirements for biosolids spread on farmland.

What we know

• Why it is being tested: under WINEP, biosolids recycled to land must reach at least 25% dry solids by 2030 (Water Magazine). The company says the press could cut energy and polymer use while removing more water, reducing the volume of sludge to transport and process.
• Speed: the press was commissioned and producing cake within hours of installation.
• Dryness: on-site monitoring recorded untreated cake at 28–32% dry solids.
• Why Newham: the site was chosen for its mix of sludge produced on site and imported from other works (H2O Global News).
• Other claimed benefits: lower odour, noise, chemical use and vibration.
• Full results: still under review, to be shared "over the coming months".

Biosolids manager Sue Hind called the early results "extremely encouraging". Fournier's global sales director, Kim Falby, described the trial as "flawless".

What others are reporting

H2O Global News carried the same release, with the vendor's comments and the site-selection rationale. Neither outlet published independent performance data. The 28–32% figure is for untreated cake, while the 25% threshold applies to the final product spread to land. The two numbers are not a like-for-like comparison until the full results are out.

Background

Newham was upgraded in a £6.8m scheme sanctioned in 2018. The scheme added Nereda granular-sludge reactors and doubled sludge-handling capacity from 40 to 80 m³/h, using a centrifuge with lime post-treatment to produce "enhanced" cake for agricultural use (Water Projects Online). The trial therefore tests the rotary press against an existing centrifuge line.

Pressure on sludge to land is not only about dryness. According to the Environment Agency, 96% of UK sludge is recycled to land. Its sludge strategy, updated in January 2026, proposes moving sludge spreading under the Environmental Permitting Regulations and revoking the Sludge (Use in Agriculture) Regulations. That would bring tighter controls on how and where biosolids are spread.

What we don't know yet

There is no published data yet on throughput, polymer dose, energy use per tonne of dry solids, capture rate or capital cost, or on how the press compares with Newham's centrifuge. It is also unclear whether South West Water plans a longer trial or procurement.

What to watch

• The full trial results, and whether they include energy and polymer comparisons with the existing centrifuge.
• Whether other sewerage companies run trials ahead of the 2030 dry-solids requirement.
• Progress on moving sludge into the environmental permitting regime.