Pirehill Site Case Study

Bagnall Environmental was appointed to refurbish two 25-metre trickling filters at Pirehill Sewage Treatment Works following performance issues caused by incorrect media specification. Our team delivered a full strip-out of the existing media, undertook condition assessments, and installed new compliant filter media with upgraded ventilation system. Where viable, existing infrastructure was retained to reduce waste and costs. The works were completed on schedule, restoring full operational capacity and supporting the client’s performance and sustainability goals.

Location: Pirehill STW
Client: Severn Trent Water

Two 25-metre trickling filters at Pirehill STW required urgent refurbishment due to the incorrect grade and type of media originally installed. This was causing an impact on performance. The solution involved removing the existing media and reinstating the correct specification to ensure reliable treatment moving forward.

Bagnall Environmental was contracted to carry out the full refurbishment of both trickling filters, including removal of the unsuitable media, condition assessment of the internal support systems, and installation of new compliant filter media.

Where possible, existing infrastructure was retained and reused, contributing to both cost efficiency and sustainability. New ventilation improvements and correctly specified media were installed to ensure long-term reliability and compliance with current standards.

The project was completed on schedule within a tight programme window. Through smart reuse of viable components, we delivered measurable cost savings for the client while ensuring the filters were restored to full operational performance. The solution also supported environmental targets by reducing waste and material usage.

To discuss this project in more detail, or to learn how we can support similar works, please get in touch with the team.