The Environmental Protection Agency regulates more than 80 contaminants in drinking water. But one of the more dangerous threats -- radon -- is not among them.
The National Academy of Sciences joined the EPA last month in saying that nearly 200 people die each year from radon in tap water. The naturally occurring carcinogen, without odor or taste, is in the water of 20 million Americans.
But since 1991, Congress has blocked the EPA from implementing proposed limits for radon in drinking water.
The fight over radon typifies the debate that often hamstrings efforts to regulate drinking water: Is the risk of a particular contaminant worth the cost of cleaning it up?
And many hope the resolution of the radon issue, which is supposed to be settled next year, will yield a new approach to settling such debates.
"It comes down to whose risk and whose cost," says Greg Helms, an EPA official who helped write the agency's proposed radon limits for water. "With drinking water . . . (people) see the cost more directly, so there is more debate."
In radon's case, the EPA's proposed limits would force about 27,000 water systems, mostly in the mountain states of the West and the Northeast, to spend a lot of money on new treatment equipment. The cost of simply running that equipment is estimated at about $272 million a year.
Sen. Bob Smith, R-N.H., who has led efforts to block implementation of the EPA's proposed radon limits, says that price is simply too high.
"It's not a perfect world," says Smith, who represents a state where the vast majority of all well-water systems would not meet the EPA's proposed radon limit. "If you have limited resources, you have to prioritize."
What should be the priority, he adds, is taking care of radon in the air.
That's because the National Academy of Sciences' estimate that 200 die each year from radon in water pales next to its other finding -- that 19,000 die annually from radon in the air, usually by breathing radon gas trapped in basements. Either way, the result is lung cancer (radon in drinking water causes lung cancer because it's released as a gas during showers).
EPA officials argue that the answer is not to ignore the need for limits on radon in water, but to try to control all pathways for radon exposure. Besides, officials say, the cost of controlling water-related radon deaths is relatively low -- about $3 million per death.
"There was an informal benchmark that $6 million to $8 million per (life saved) was about as much as we were going to spend," Helms says.
In the world of environmental regulation, he adds, "that's pretty cheap."
By Aaron Davis, USA TODAY
