In May, the Agency called ICI to a high-level meeting to express concern over a spate of incidents at works in Cheshire and on Teesside (ENDS Report 268, pp 23-26 ). ICI vowed to "redouble efforts" to ensure the safety of its operations.
However, in early June ICI suffered two more spills within five hours. The Agency's Operations Director, Archie Robertson, said it was "outrageous that within weeks of ICI being called to a meeting with the Agency where it promised to clean up its act, its plants have been involved in two further leaks."
In one incident, at ICI's Wilton works, light gasoline oil leaked from a distillation plant as it was restarted after an overhaul. An unknown quantity escaped to the river Tees, but a permanent oil boom across the discharge and the use of oil-absorbent materials prevented serious pollution of the estuary. The Agency served an enforcement notice requiring ICI to review its training and operating procedures.
The other spill occurred at Tioxide's Greatham works. Titanium tetrachloride (TiCl4), used to produce the pigment titanium dioxide, leaked into cooling water in a heat exchanger. In an hour or so, the resulting highly acidic solution corroded pipework and leaked into the environment.
Tioxide drained water from the heat exchanger, but this permitted neat TiCl4 to escape. The spill rapidly hydrolysed to form a cloud of hydrochloric acid mist and dense white fumes of titanium oxychloride. The emergency services closed a nearby trunk road, and residents in nearby villages were advised to stay indoors.
The Agency estimates that up to five tonnes of TiCl4 entered the cooling water system, with over two tonnes reaching the environment. Tioxide says that less than one tonne escaped.
The Agency served a prohibition notice barring Tioxide from restarting the process until it has repaired the plant, reviewed maintenance and inspection arrangements, and put forward improved instrumentation and procedures to detect plant failure. The notice was still in force at the end of June. Tioxide refused to comment on the financial losses arising from closure of the plant, which accounts for some 20% of the Greatham works' production capacity.
Archie Robertson commented: "This is not the first leak of this material from the plant so we feel justified in taking this tough action. ICI have had previous opportunities to put things right and have failed to do so."
The spill was the worst at the Greatham site since the 1980s. In contrast to ICI's other operations on Teesside, however, Tioxide appears to have reduced the frequency of unauthorised releases over the past two years. Two significant releases of TiCl4 were reported in the first half of 1996, but only two minor releases occurred in the 12 months before the latest spill. Unauthorised releases of chlorine from the works also appear to have been reduced substantially.
However, the Agency's tolerance of such incidents appears to have reduced significantly. The new Government has made it clear that it expects tougher enforcement of environmental regulations - and the Agency, stung by criticism of its performance, sees a tougher stance as essential in its bid to win public confidence.
The latest incidents may have caused some worries for ICI's senior managers in the light of their recent assurances to the Agency. Under section 157 of the Environmental Protection Act 1990, company directors and managers can be prosecuted for an offence committed with their consent or connivance or attributable to their neglect.
Several directors of small firms have now been fined, jailed or disqualified for health and safety or waste offences, but none has been convicted of a pollution offence. An Agency spokesman told ENDS that in principle it was keen to prosecute directors, but pointed out: "We have to prove causality beyond reasonable doubt along each link in the chain. The larger the company, the harder it is to meet that test."