Copford STW - Secondary Wastewater Treatment Plant in Colchester, Essex

Copford STW is a secondary wastewater treatment plant located in Copford Green, near Colchester, Essex, England. It serves a population of approximately 4,243 people and has a designed capacity of 4,700 m³/day, with an average discharge volume of 944.64 m³/day. The plant is situated in a rural area within the county of Essex. As a secondary treatment facility, Copford STW provides biological treatment to remove organic matter and suspended solids. Under the EU Urban Waste Water Treatment Directive (91/271/EEC), which the UK implemented prior to Brexit, secondary treatment is the minimum standard for inland freshwater discharges from agglomerations of this size. The plant's capacity utilization suggests it operates well below its design capacity, indicating room for future growth. The treated effluent is discharged into local watercourses that ultimately drain to the North Sea via the River Colne and the Colne Estuary. The plant's proximity to the coast (within 10 km) means its discharge can influence coastal water quality, particularly in the sensitive estuarine environment of the Colne Estuary, which supports diverse aquatic life and important bird populations.

Copford STW discharges into the River Colne catchment, which flows through Colchester and into the Colne Estuary, a designated Site of Special Scientific Interest (SSSI) and part of the Essex coastline. The estuary supports saltmarsh, mudflats, and important bird populations. The plant's secondary treatment helps protect this sensitive downstream environment from excessive nutrient loading and organic pollution.