Alpheus Environmental - Case Study: Flag Fen
Centrica is a leading integrated energy company with upstream operations such as sourcing and generating energy, and downstream operations including the supply of gas and electricity to millions of homes and businesses. Centrica's vision is to be the most trusted energy company, leading the move to a low carbon future.
Until late 2000 the Centrica-owned Peterborough gas turbine power station used mains water in its demineralisation plant for boiler-feed water production. Although this is a widely used process, there are significant financial and environmental costs associated with the use of mains water for this purpose and the chemical regeneration of de-min resins, rinse water, waste chemical and wastewater disposal.
Service
Alpheus and its parent company approached the power station with a proposal to supply high purity water via an innovative membrane process, utilising sewage works final effluent as its raw water source. Following successful site trials, a 10-year Build, Own and Operate (BOO) contract was signed for the Flag Fen Water Reuse Plant.
Implementation
Commissioned in October 2000, the water reuse plant was installed at the Flag Fen sewage treatment works, approximately 1 km from the power station. Final effluent from the municipal sewage treatment plant is treated at the water recycling plant using a combination of ultra filtration (UF) and reverse osmosis (RO) membrane technology to supply the ultra pure water for use at the power station.
The fully automated plant runs on a supply-on-demand basis, uses telemetry and remote access to PC, provides stable performance and only requires a routine operator one day a week.
Outcomes
The water quality supplied to the power station has been excellent, providing an improved and far more predictable plant performance. Significant savings have been achieved in the de-min plant operating costs and chemical waste disposal costs. Health and safety benefits have also been achieved by reducing the handling of highly corrosive chemicals and traffic on site. Environmental and social benefits include a major reduction in the use of mains water, fewer chemicals discharged to the sewer and less heavy goods traffic to and from the site.
Alpheus has been successfully operating and supplying the Flag Fen water reuse plant for the last 10 years with many financial, environmental and social benefits for Centrica and its stakeholders.
The innovation and success of the Flag Fen water reuse plant has earned it a number of process and environmental awards.