"we've had it. Enough is enough,' said Gary Locke, governor of Washington state, at a press conference, announcing that the state would sue the us energy department for failing to clean up the worst nuclear waste dump site in the us. He said the energy department had missed two deadlines for pumping radioactive liquid out of underground storage tanks at the former Hanford Nuclear Reservation in south-eastern Washington. The tanks contain deadly by-products from nearly 50 years of making plutonium for nuclear weapons, including radioactive caesium, strontium and uranium.

Hanford started during World War ii as part of the Manhattan Project to make an atomic bomb. Over the years, nearly 1,600 billion litres of hazardous liquid waste, some of it radioactive, was dumped onto the ground or shallow pits on the 901-kilometre reservation. Only the most dangerous waste went into the 177 storage tanks. The tanks are many years past their design life and have already leaked more than 4.5 million litres into the ground. In November 1997, officials of the energy department acknowledged that some of the leaks had reached groundwater that flows into the Columbia river. Scientists estimate that contaminants could reach the river within 20 years.

Environmentalists fear that water supplies used for irrigating crops could be contaminated, adding that pollutants could concentrate at high levels in salmon and other aquatic life. "How many people would want to eat agricultural products if they knew they were fed with radioactive waters?' asked Locke. There had been complaints that the state repeatedly allowed federal managers to extend timetables and delay clean-up.

Tom Carpenter, director of the Seattle office of the Government Accountability Project, said: "We are glad the state government awoke from its coma and decided to get serious. Management at Hanford has failed over and over again. They simply cannot do the job. It is time to start looking at alternatives to the department of energy.'