Church Rock Uranium Spill – 1979

Quizmasters of the world sit up and take note. Here’s the question:

‘Name the worst radioactive accident in US history – clue, it took place in 1979’. Sit back with an evil smile as all those pencils instantly scribble Three Mile Island’, and later enjoy the shocked expressions when the answer is given: ‘Church Rock uranium spill’.

Radioactive spills aren’t confined to nuclear facilities or faulty manufactured items. The raw material is uranium. Uranium is mined. Mining creates waste. Waste has to be stored. The plan at the United Nuclear Coiporation’s Church Rock Uranium Mill in New Mexico was depressingly familiar in mining history – store the effluent in a large pond behind an earth dam built on poor foundations. In this case, the plot had a nasty twist – when cracks start appearing in the dam don’t tell anyone and don’t do anything. That’s just what happened in 1977, and the weakened dam duly collapsed in July 1979.

Over 1,000 tonnes of radioactive mill waste in 352 million liters (93 million gallons) of contaminated water spilled into the Rio Puerco, producing a level of radioactivity 7,000 times greater than that permitted in drinking water. Nobody bothered to notify residents, who used the river extensively. Those suffering radiation bums were diagnosed with heat stroke and there was a half-hearted clean-up effort. End of story.

Why did this disastrous spill slip under the world’s radar? The area was remote and those most affected were Navaho Indians – many of whom worked as uranium miners and were already exposed to associated risks. The USA does not have the best of records when it comes to Native Americans. Trucked-in water was provided until 1981 but then farmers had to return to the use of irrigation water from the river, allowing residual radioactivity to pass into the local food chain.

When: July 16 1979

Where: Church Rock, New Mexico, USA

Toll: Unknown. Unlike many other serious pollution incidents no serious epidemiological studies were ever done to assess the health effects – nor have there been studies of the low-income labor force in uranium mines – despite the fact that some types of cancer have a significantly higher incidence than the national average among the Navaho people.

You should know: In 1994 the US Environmental Protection Agency belatedly mounted an investigation and clean-up at the Church Rock mine site.