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Trant Engineering Ltd

Milverton WRC

Delivering enhanced environmental protection with process and dosing upgrades at Wessex Water's Milverton WRC
By: Sami Bessaad, Project Manager at Trant Engineering
Published: October 15, 2026

Milverton WRC

The multi-million pound investment at Wessex Water’s Milverton Water Recycling Centre (WRC) ensures significant new protection for rivers, streams and waterways in west Somerset, meeting the Water Framework Directive requirements and tightened phosphorus consents.

Wessex Water has invested in two schemes in some of Somerset’s most rural areas to safeguard the environment and reduce discharge of untreated wastewater into watercourses. One of the schemes, which took place near the village of Milverton, delivered process upgrades to provide enhanced wastewater treatment prior to being returned to the environment. This included a new ferric dosing system alongside measures to ensure the sewer system is not overwhelmed during heavy storm events.

The site

Milverton WRC is a biological filtration works near Taunton and treats domestic wastewater for around 1850 PE. Final effluent is discharged into Hillfarrance Brook, a tributary of the River Tone. A significant upgrade was required as part of the Environment Agency’s WINEP programme to meet new AMP7 regulatory requirements and strengthen the site for the future. The upgrade included meeting a new phosphorus consent of 1.0mgP/L as well as significantly increased stormwater storage capacity.

Project delivery

The delivery team selected for the upgrade works consisted of Wessex Water’s in-house engineers, YTL Construction, civil engineering contractor Envolve Infrastructure, design consultants SWECO, and mechanical and electrical contractors Trant Engineering, whose in-house Innovation, Design and Solutions (IDS) team carried out the detailed electrical design.

To mitigate overflows to the river during high intensity rainfall events, Trant Engineering converted an existing, redundant primary settling tank to stormwater storage, increasing the holding capacity to 168m3. This included new return pumps, mixer, and cleaning system, as well as event duration monitoring (EDM). The stormwater capacity was more than tripled, allowing 168,000 litres of water to be held before being returned to the system for safe treatment. Trant Engineering installed a new GRP inlet channel with actuated flow control penstock and MCERTS-compliant flow measurement to improve flow monitoring.

New ferric dosing plant

The new phosphorus consent of 1.0 mgP/L would be met by chemical dosing. Trant Engineering installed the ferric sulphate dosing system which consisted of a 10 m³ storage tank, complete with pH control linked to the existing caustic soda dosing system, to ensure compliance with the new 95th percentile total iron consent of 4 mgFe/L in the final effluent. The dosing system was designed for flexibility, allowing operators to adjust feed rates in response to variations in influent phosphorus concentrations, flow, and process conditions, helping minimise both chemical usage and residual iron in the treated effluent. For final effluent polishing, Trant Engineering installed two Pile Cloth Filters (PCF), each equipped with dedicated feed pumps, instrumentation, and automatic backwash control, providing reliable solids removal and maintaining effluent clarity.

Together, the ferric dosing system and cloth filters form an integrated chemical treatment solution, ensuring the plant consistently meets the tight phosphorus limit while optimising chemical efficiency and protecting the receiving water. Also allowing real-time monitoring and control, giving operators confidence in compliance and reducing the risk of environmental impact from overdosing.

Additional upgrades

Trant Engineering upgraded the pumping station with variable speed drives together with new level instrumentation and controls, and on the main works, provided new recirculation and works return pumping stations, new MCC and DNO kiosks, upgraded the power supply and replaced the transformer.

Strengthened environmental protection

Despite several scope changes during the project, good collaboration with the other X12 Partners ensured the project was completed on time, meeting all EA’s regulatory output dates. The electrical design, equipment supply and installation was successfully delivered by Trant Engineering.

The project is part of the Wessex Water investment programme to upgrade infrastructure and reduce the frequency of storm overflow discharges. The upgrade has ensured ongoing regulatory compliance, enhanced operational resilience and strengthened environmental protection for the surrounding communities.

 

 

For More Information, contact us at https://www.trant.co.uk

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