Industrialists

The West Yorksire economy has been traditionally based upon the wool textile, chemical and associated engineering industries. Coal mining has shifted eastward over the last century and is now largely disappeared.

A number of synthetic pyrethroids ('mothproofers') are manufactured in the area, mainly in Kirklees. There are particularly high concentrations in effluents from particular sewage treatment works causing problems in Mag Brook, and the rivers Holme, Colne, Calder and Spen. Yorkshire Water will further limit the amount of chemical pollution discharged to its sewage treatment works, forcing industry to pre-treat discharges so as to reduce the level of pesticides.

Pollution from chemical works are mainly concentrated on the Huddersfield and North Brierly sewage treatment works. Continuous discussions are taking place with Zeneca in Huddersfield regarding pre-treatment of discharges from the paraquat plant. Other companies within the area may also need to take similar steps to cut the concentration of pollutants.

In the drainage area of the North Brierly STW two chemical works AH Marks and Allied Colloids are extending their pre-treatment plants to reduce the discharge of trace chemicals. There is some doubt as to whether these will be sufficient to allow the river quality to meet projected targets. New toxicity based consent limits are being used to help control pollution.

Allied Colloids in south Bradford was the site of a fire in 1992. There were a number of explosions in a storage warehouse. Effluent pumps were disabled and contaminated water was lost over the site boundary. Water used to put out the fire leaked chemicals into the system via storm drains, whilst storage tanks holding the drain water at the sewage treatment works overflowed into Spen Beck. Heavily polluted water entered the river and passed into the Calder, Aire, Ouse and Humber. It was estimated that 8,000 fish were killed in the Calder and 2,000 in the Aire. Numbers of fish were already low so this was a serious impact. On January 29th 1993 Allied Colloids were convicted under the Health and Safety at Work Act and fined.

In an industrial area there is always a risk of accident and the rivers are under constant threat of freak pollution incidents.