Purpose
The Morecambe sewerage system collects at Schola Green Wastewater Pumping Station, located in the west end of the town. From there, flows for treatment are pumped 6km to Morecambe Wastewater Treatment Works (WwTW), which is situated to the south, near to the village of Middleton. Both sites have sea outfall pipelines which discharge effluent into Morecambe Bay. The Schola Green outfall is a storm overflow (which operates intermittently when the system is overloaded) and the Middleton outfall, discharges effluent from the WwTW.
United Utilities awarded C2V+, a joint venture between VolkerStevin and Jacobs, the Morecambe Catchment Strategy contract under their Construction Delivery Partner Framework. The project purpose was to improve bathing waters and the environment, reduce outfall spills, comply with tighter permit controls, future-proof wastewater treatment assets and optimise operation and maintenance.
What we did
We updated the pumping station and wastewater treatments works with new process and storage assets, fit for modern environmental standards and the town’s growing population. At Schola Green, we built two new reinforced concrete covered storm tanks with capacities of 11,000m3 and 13,000m3and laid a second 500mm diameter, 6km long sewage transfer main pipeline to Middleton.
At Morecambe wastewater treatment works, we completely replaced the biological treatment process using the latest Nereda technology. We installed new ultraviolet treatment plants, converted five existing treatment tanks into tidal storage and constructed an additional new tank. We upgraded the land-based section of the existing sea outfall and upgraded the four outfall diffusers in the tidal mudflats.
We established the best and most efficient whole-life solution for United Utilities and its customers and undertook all works within the footprints of the existing sites. We optimised storage capacity and pass forward rates within the constraints which included limited space at both facilities, the need to reuse existing assets, and poor ground conditions at Morecambe WwTW.
Our solution increases pass forward from Schola Green by 65%, whilst maintaining all new works within the WwTW’s existing boundary. We designed and installed three compact Nerada granular activated sludge tanks, which greatly speed up the sludge settlement process. Also, no final settlement tanks are needed, saving considerable space. Through collaboration with the client, we also omitted primary settlement tanks.
We limited construction works that involved excavation due to Morecambe WwTW’s high groundwater levels. The site also had historical contamination issues. By raising the inlet screens 12m above ground level, the system flows to gravity and therefore we could construct the new processes with minimal excavation, or below-ground supports.
We optimised pass forward flow to ensure the 2.5km long outfall at the WwTW could be reused. However, to ensure it remained fit for purpose, we used a jack-up barge to place segmented steel cannisters on top of the four diffuser ports. This will increase discharge speeds and therefore prevent blockages, which had affected the diffuser previously.
We sensitively managed a series of stakeholders when constructing the 6km long transfer main. We worked with Network Rail to gain the necessary consents to tunnel below a live rail line. We halted works and removed equipment to allow a large funeral to proceed at Morecambe Football Club.
Project successes
We upgraded the treatment facilities to meet stricter Environment Agency permits and increase quality, capacity and resilience. United Utilities’ Whole Life Programme Manager, Geraud Ramond, commented: “The project is a real success for United Utilities. It was delivered safely, below its initial budget, on time and allowed us to meet our regulatory commitments. The NEREDA plant performance is exceeding our expectations, allowing us to consistently meet the requirements of the environmental permit.”
We put considerable effort into local fundraising and community initiatives - taking part in beach cleans, donating blood, collecting for food banks, and raising money for the RNLI and MacMillan through cake sales, Dry January, and Morecambe Carnival. We secured 120 WOW! awards, which come via client or customer nominations and acknowledge outstanding customer service. We also distributed nearly 100,000 newsletter updates and spent 350 hours in the community over the project course.
United Utilities recognised our excellence with its Health and Safety Project of the Year award in 2019, whilst the wider industry recognised the excellence at the British Construction Industry Awards (BCIA) where the project won the Utility Project of the Year. The BCIA judges commented: “Being a winner at this event is an incredible achievement. This was an impressive project with a clear project brief. The judges particularly liked the investment in innovation and reducing carbon, with use of digital technology to support efficiencies.”