The spill last October was one of a series of incidents which culminated in a high-level meeting at which the Agency demanded improvements in ICI's performance (ENDS Report 268, pp 23-26 ). The company remains under the threat of prosecution for two major spills of chloroform and trichlorethylene at its Runcorn works, as well as a naphtha leak at its Wilton site.
On 2 July, Widnes magistrates heard that the VDC incident began during an operation to transfer an 18-tonne mixture of the chemical with water from a storage tank to a separator plant. An indicator designed to warn the operator of rising VDC levels was faulty. When a second alarm was activated, the operator took no action, and the separator overflowed into a bund.
When the shift changed, the operator failed to inform incoming personnel that the bund contained VDC as well as water. The new shift team eventually realised what had occurred, and decided to pump the bund's contents back to the storage tank. However, a separate overflow from an effluent tank entered the bund, and as the liquid level rose VDC leaked through a defect in the bund wall.
The VDC-contaminated liquid entered surface water drains and passed into an effluent pit. This, too, overflowed because a pump designed to empty it had been set incorrectly. The effluent entered the Weston Canal, including about 50 litres of VDC. At the height of the incident, the concentration of chlorinated hydrocarbons in the discharge was 180 times above the consent limit.
ICI Chemicals & Polymers pleaded guilty to three breaches of its integrated pollution control authorisation. It was fined £12,000 apiece for breaches of two conditions relating to the operation and maintenance of the process, and £10,000 for exceeding consent limits for the discharge to the canal. Costs of £6,000 were also awarded against the company.
After the hearing, the Agency's North West Regional General Manager, Ian Handyside, commented: "The Agency expects ICI to operate to high environmental standards. This further example of poor practice is very disappointing. ICI must learn from this and improve their environmental performance."