Chemical factory blaze aggravates aquifer pollution fears

The Cox Chemicals site at Overley, near Telford, blazed for ten hours last February. Drums of chemicals exploded in the heat and the 150 fire-fighters who attended the blaze were severely hampered by the risk of chemical contamination. The site continued to burn for a week and specialist contractors were needed to demolish the main building.

Cox Chemicals bought, mixed and repackaged pesticides and other chemicals for resale in the Third World. The fire was only one of a string of environmental irregularities at the site, which was well known to the local waste regulation authority (WRA) through various legal proceedings dating back six years.

The company was acquired by its present owner in 1987 and it was at about this time that Shropshire WRA first became concerned about the activities and condition of the site. Investigations revealed that the company had bought redundant Ministry of Defence chemical stocks and the site should have been licensed as a waste transfer station.

A licence was applied for and granted in 1988, but the following year the WRA obtained samples which showed that chemical waste had been illegally buried on the site. In June 1991 Cox Chemicals was convicted under the Control of Pollution Act 1974 and a section 16 notice was served requiring the excavation of the material. The company duly carried this out and the waste was sent to a licensed facility.

In March 1992, Cox agreed to investigate another part of the site at the WRA's behest. The investigations uncovered 40 tonnes of waste which were found to be heavily contaminated with organochlorine pesticides.

The NRA believed that the level of contamination was high enough to present a threat to groundwater. And so another section 16 notice was served on the company in June 1992 requiring it to remove the waste within 28 days and to carry out further site investigations.

Cox appealed against the terms of the notice and this was partly heard on 5 February by Telford magistrates. The case was adjourned until 2 March but, in the interim, the site burned down. The appeal was subsequently dismissed.

In the meantime, the NRA had discovered that a nearby spring, used by a farmer for watering cattle, was contaminated with four chlorinated solvents. Analyses showed trichloroethylene at up to 780µg/l, 1,1,1 trichloroethane at up to 56µg/l and traces of carbon tetrachloride and chloroform. The spring was taken out of use.

At the time of the fire, the NRA succeeded in preventing pollution of nearby watercourses with the co-operation of the fire brigade. However, two days later, water from the well was found to be contaminated with pesticides and heavy metals.

The NRA found 1,000µg/l of diazinon, 100µg/l of malathion, 16µg/l of mercury and cadmium and zinc in excess of drinking water standards. The compounds have not been detected in subsequent samples but the NRA believes that the chemicals were flushed into the groundwater by fire-fighting water and still pose a pollution threat to the sandstone aquifer. The site stands on a volcanic plug and is surrounded by the aquifer, which supports many public drinking water abstractions.

Pollution moves slowly in the sandstone and the travel time to the nearest public supply borehole, three kilometres away, is estimated to be several decades. The NRA now intends to make a more detailed risk assessment.

Following the failure of its appeal, Cox was required to carry out further sampling, drill 11 boreholes under the NRA's supervision, and repackage chemical wastes lying around on the site. According to a WRA inventory, the wastes included 1,200 drums containing acids, alkalis, solvents and pesticides, as well as many drums with no labels.

The fire rendered the site unusable and Cox Chemicals was allowed extra time to comply with the section 16 notice. In May, it had not complied and the WRA prosecuted. In August, the company was fined o1,000 by Telford magistrates.

The WRA says the company has now done 95% of the repackaging and much of the sampling work, but has not started to drill the required boreholes. Further charges are now being considered.

Following the fire, eight charges have also been laid by the Health and Safety Executive. Six charges against the company relate to unsafe storage and handling of highly flammable liquids, contraventions of general duties to protect employees and the public, and a failure to obey a prohibition notice. Mr Shand, Cox Chemicals' managing director, has been charged with obstructing HSE officials, and that the firm's failure to comply with a prohibition notice was attributable to his neglect or done with his consent or connivance.

Since the fire and for reasons best known to itself, the company has changed its name to Cox Environmental.