Challenge

Seaton Carew sewage treatment works was in need of a substantial upgrade to improve asset condition / performance and to provide extra treatment capacity to accommodate recent and predicted growth within the catchment.

Seaton Carew flows from the Hartlepool area are screened to 6mm then degritted at Seaton Carew headworks. The full treatment flow of up to 950 l/s is then pumped inland via a 2km 900mm-diameter rising main to Seaton Carew sewage treatment works at Brenda Road.

At the sewage treatment works, it receives full treatment (primary, secondary and UV disinfection) before returning via a 2km 1200-mm diameter gravity return pipeline to Seaton Carew headworks. The recorded population equivalent is approximately 120,000. However, an assessment of actual flows and loads indicated a population equivalent of up to 250,000.

Solution

A feasibility study was undertaken by ELIQUO HYDROK asset delivery and the recommendation was to utilise an innovative and creative technology to provide the extra treatment capacity required.

In April 2016, ELIQUO HYDROK installed a combination of the Integrated Fixed-Film Activated Sludge (IFAS™) system, which grows on a Biotextil Cleartec material, and the Fine Bubble Diffused Aeration (FBDA) system within the existing four aeration lanes providing the additional treatment capacity.

The alternative to this was to build two additional aeration lanes, at a capital cost of approximately £2 million more. The whole life cost, incorporating power and maintenance, will also be less.