Cray Valley

Cray Valley has been operating under the Integrated Pollution Control (IPC) Regulations since their inception in 1990. These regulations are enforced by the Environment Agency, who guide operations in order to improve a company’s environmental performance by reducing their emissions.

The Effluent Treatment Plant (ETP) at Cray Valley was installed in direct response to an Environment Agency Improvement Action Plan to reduce the Chemical Oxygen Demand (COD) and the solids loading of the site’s effluent.

An Aerobic Biological Effluent Treatment plant was selected as it gives the best performance in reducing the COD and solids loading. This was an innovative solution, as this type of treatment plant was not widely used outside of the water treatment industry.

All of Cray Valley’s process water effluent is treated by the ETP in a 3 stage process which removes over 95% of the neat effluent COD and solids loading. This far exceeds the requirements of the Environment Agency.

The plant is carefully monitored on a daily basis and at each stage of the process in order to maintain optimum performance.

In line with Cray Valley’s Integrated Pollution Prevention Control Permit, granted by the Environment Agency, Cray Valley constantly investigate methods of improving the treatment of our effluent, with the aim of further reducing our effect on the Environment.

THE TREATMENT PROCESS

The untreated effluent is mixed with surface water
in a collection tank where it is adjusted for pH.

The resulting mixture is then fed into the primary bio-reactor vessel where the main treatment activity takes place.

Bacteria within the tank, process the waste, breaking down the harmful components and reducing the COD.

The treated waste is then passed in to a settlement tank which removes the solids.

The resulting clear, treated effluent, conforms to the discharge limits set by the Environment Agency to ensure that there are no harmful effects upon the estuary’s eco-system.