Energy From Waste Breakthrough

21 January 2015

Costain’s upgrade of a Rugby sewage treatment works is helping Severn Trent Water generate more energy from waste.

The £3.2 million project involved the installation of sludge thickening and mixing equipment to improve digester performance at the plant’s sludge treatment facility. This has increased its gas yield, enabling Severn Trent Water to generate more renewable energy. The energy is used to power the sewage treatment works, with any surplus sold to the local electricity grid.

The project’s focus was on sludge quality – increasing the density of the sludge from the settlement tanks to provide a thicker, homogenous sludge to the digesters. This allows the digesters to operate more efficiently, improves the gas yield and so increases the efficiency of the CHP (Combined Heating Power) engines on site. Improving the performance of the digesters also has the added benefit of reducing the number of sludge tanker movements at the site.

Said Tom Pawson, Costain Senior Site Agent: “The real challenge of the project was keeping the site operational while we carried out the improvements. We managed this through close liaison with the client’s Service Delivery team, along with careful planning and an excellent team on the ground.”

The project also gave the Costain team the chance to inspire pupils at local girls’ grammar school Rugby High School.

Kathryn Lewis, Project Engineer, and Maria Melton, Senior Project Manager, visited the school to encourage young women to think about careers in engineering.

“Engineering is not always promoted to girls so it was great to be invited to the school and be able to speak to young women about what the industry is like and the great opportunities there are in the sector,” said Kathryn.

The visit was a great success, said Jas Somal, Careers Advisor at careers guidance company CSWP: “We had some very positive feedback from the students. They especially enjoyed being able to spend time with employers finding out about the range of career paths.”




Media Enquiries
Costain Communications Department
01628 842585