Huddersdale STW - Major Wastewater Treatment Plant in Kirklees, West Yorkshire

Huddersfield STW is a major wastewater treatment facility located near Mirfield in Kirklees, West Yorkshire, England. Serving a population of approximately 281,000, it is one of the larger treatment plants in the region, managing municipal wastewater from the Huddersfield area. The plant operates under the UK's regulatory framework, which implements the EU Urban Waste Water Treatment Directive (91/271/EEC). For agglomerations of this size (over 150,000 population equivalent), the directive requires secondary treatment as a minimum, with tertiary treatment in sensitive areas. The plant's discharge is regulated by the Environment Agency under the Environmental Permitting Regulations. Treated effluent is discharged into the River Calder, a tributary of the River Aire, which flows into the Humber Estuary and ultimately the North Sea. The River Calder supports diverse aquatic life and is an important watercourse in West Yorkshire, contributing to the region's ecological health and water quality management.

The plant discharges into the River Calder, which flows into the River Aire and then the Humber Estuary before reaching the North Sea. The Calder catchment supports diverse fish populations and is an important ecological corridor. The Humber Estuary is a major estuarine ecosystem with extensive mudflats and saltmarshes that provide habitat for migratory birds and fish.