NEC 3 Option C
The scheme was designed to increase storage capacity, reducing the risk of localised flooding and reducing spills at Whitburn and St. Peters Combined Sewer Overflows in order to comply with the requirements of the Urban Waste Water Treatment Directive.
The project was spit over several areas and cumulatively included:
- Two precast concrete attenuation tanks totaling 4,700m3
- 3,800m of surface water sewer DN225-600mm
- 1,300m3 of attenuation through construction of 3 bioretention areas
- Installation of rain gardens and other SuDS measures
The use of the above measures helped to reduce the overall conventional storage volume requirement in the catchment to 4,700m3, a great efficiency compared to the original 16,500m3. In addition to reducing storage required, the solution provided additional benefits for:
- Increased sewer capacity and flood risk reduction
- Reduced pumping and treatment costs
- Water quality, amenity and biodiversity enhancement from SUDs installed
All of the sites were in the public environment and were located in residential areas, within proximity of schools and commercial businesses. Elements of the works took place over school holiday periods, therefore careful planning was necessary for every aspect of the scheme for the duration of the programme.