At toxic cleanup sites across the country, environmental agencies have allowed groundwater contamination to go untreated and slowly diminish over time — a strategy that saves money for polluters but could cost taxpayers dearly and jeopardize drinking water supplies.
Alvarez is particularly critical of the use of MNA at radioactive waste sites around the country, where it’s estimated that certain radionuclides will take millions of years to naturally degrade to safe levels.
It appears that most state environmental agencies, which supervise many cleanups, do not keep data on MNA use over the years.
“Their only source of drinking water is groundwater.” More than $100 million already has been spent on an active cleanup of the pollution over the years.
But contaminants are continuing to spread, and the Lahontan Regional Water Quality Control Board, the agency overseeing the cleanup, claims that they won’t reach safe levels for up to 500 years if MNA is applied as proposed by the Air Force.
That directive, and the EPA’s updated guidelines, state that MNA shouldn’t be applied when, among other things, the source of pollutants isn’t yet under control, when the tainted groundwater still is spreading and when the contaminants won’t break down to safe levels within a “reasonable” period.
At some Superfund sites, critics say, MNA has been applied in circumstances that clearly violate the agency’s guidelines.
While EPA guidelines call for MNA only where pollution will degrade to safe levels within a reasonable period, it is one of the techniques being used at the Hanford Nuclear Reservation in southwestern Washington State along the Columbia River.
Cheryl Whalen, an official regulating the cleanup for the Washington State Department of Ecology’s Nuclear Waste Program, downplayed environmental concerns about the plume.
“Monitored Natural Attenuation says, ‘we’re not going to do anything because it costs too much money,’” she said.