Chemical and Textile Industries

Textiles have long formed the traditional industrial base of the West Yorkshire economy. Factories are widely located in the Calder Valley. They generate particular problems related to the use of 'mothproofing insecticides' and detergents. Discharge of these chemicals is mainly a problem in the Kirklees area with the Mag Brook, and rivers Holme, Colne, Calder and Spen adversely affected. In 1992 the Environmental Quality Standard (EQS) was exceeded in these rivers for a number of substances. Since 1994 strict discharge limits have been set in order that this problem be alleviated.

Residues from chemical manufacture in the Calder catchment are mainly concentrated on Huddersfield and North Brierly STW. New sewage treatment works are being built near the Zeneca works which should significantly improve water quality below the paraquat plant. In the drainage area of North Brierly STW two chemical companies, AH marks and Allied Colloids, are extending their pre-treatment plants to reduce the concentration of trace chemicals in their discharge. However, there is some doubt, expressed in the Catchment Management Plan, that these steps will be sufficient to achieve its River Quality Objectives (RQO) or EQS.