In summary
- The programme is part of Yorkshire Water’s broader initiative to reduce storm overflow discharges at wastewater treatment sites across the county
- The installation of a new 110-cubic-metre storage tank will reduce storm overflow discharges near the Williamthorpe Nature Reserve
- The project will protect local water quality and support the area’s natural environment, increasing biodiversity in the surrounding lakes
Project in numbers
110k number of litres of stormwater that the new tank will contain
10 number of storm tank builds we’ve delivered for Yorkshire Water during AMP7
The need
The new reinforced concrete tank was necessary to comply with the Environment Agency’s mandated stormwater volume allowance – the volume of stormwater that must be retained before it can be discharged into nearby water bodies – under the discharge reduction plan, which takes effect this spring.
It is part of Yorkshire Water’s wider initiative to initiative to reduce storm overflow discharges at wastewater treatment sites across the county.
The solution
We constructed a new 110-cubic-metre reinforced concrete tank within the existing Williamsthorpe wastewater treatment site footprint. The tank’s construction presented some challenges which were overcome in a way that demonstrated our commitment to environmentally safe practices. While excavating, the team discovered groundwater and redundant stormwater services under the new tank footprint. We safely diverted these by capping a redundant pipe and diverting an existing stormwater pipe.
During the excavation dewatering process, we passed groundwater through a settlement tank that was regularly cleaned to remove settled solids, and through a sediment filtration sock to ensure it could be discharged in an environmentally safe manner.
To achieve sustainability objectives, the project team prioritised the use of hydrotreated vegetable oil (HVO) fuel in all machinery and established an eco-welfare unit for staff breaks. Additionally, the site reinstatement involved re-seeding grass areas with a mix that supports invertebrates.
The benefits
- Installing additional stormwater storage has enabled the treatment works to retain stormwater on-site and process it after storm events, preventing untreated overspills.
- The new tank will help reduce storm overflow discharges near the Williamthorpe Nature Reserve, protecting local water quality and supporting the area’s natural environment, increasing biodiversity in the surrounding lakes.
- This project marks a significant contribution to Yorkshire Water’s action to reduce storm overflow use and safeguard water quality in the county’s waterways.
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