Post by WaterProjectsOnline

JUST PUBLISHED: Lanchester STW MMB's Case study detailing Northumbrian Water's phosphorus removal and ammonia compliance upgrade at Lanchester for river water quality and environmental improvements Lanchester Sewage Treatment Works, located near Durham, plays a vital role in treating wastewater for over 5,700 people, with future growth projected. As part of Northumbrian Water’s AMP7 WINEP programme, a major upgrade was delivered to meet tighter Water Framework Directive requirements for phosphorus and iron—while maintaining existing ammonia, BOD, and suspended solids.   The solution centred on replacing legacy reed beds with modern tertiary treatment. A new pumping station now lifts flows to three nitrifying submerged aerated filters (NSAF), delivering enhanced ammonia removal. Downstream, two Mecana tertiary solids removal (TSR) units provide high-efficiency polishing before discharge to Smallhope Burn.   A key innovation was the introduction of a gravity-fed recirculation system. Instead of installing a new pumping station, treated effluent is automatically returned to the head of the works during low flows—maintaining optimal biological conditions while reducing carbon, cost, and operational risk.   The scheme also included new chemical dosing systems (caustic and ferric dosing) for phosphorus removal, MCERTS-compliant flow measurement, upgraded power infrastructure, and a site-wide washwater system. Careful design was required to overcome constraints such as restricted access, existing services, and ecological considerations, with reed bed removal offset through biodiversity measures.   Delivery was underpinned by strong collaboration between Northumbrian Water, Mott MacDonald Bentley, and the wider supply chain. Weekly planning sessions and digital tools, including 3D modelling, supported efficient decision making and buildability.   This scheme demonstrates how smart engineering, collaboration, and sustainable design can modernise existing assets. Commissioned in 2025, the project successfully achieved regulatory milestones, ensuring compliance with future consent standards while improving environmental outcomes.   The successful delivery of the project relied on the collaborative expertise of MMB and its specialist supply chain partners, including:   NWG (Northumbrian Water Group) Mott MacDonald Bentley | MMB David Hartley Turner & Townsend Castle Keep & Co Surveys ELIQUO HYDROK De Nora Aquazone Limited GRUNDFOS Intelect Armah Switchgear Ltd NPS Engineering Group Limited Aureos IDEC North East Pipeline Solutions Limited NOV SIRIS Environmental ADL Developments Selwood Ltd Hydrainer Pump Hire Ltd Peter Cassidy (Leeds) Ltd FP McCann Ltd Teward Bros Ltd   Read the full case study: https://lnkd.in/eQRiMnV7 #wastewatertreatment #ammoniaremoval #phosphorusremoval #chemicaldosing