Yet even as contaminants continue to spread, the Air Force wants to finish part of the cleanup with a laissez-faire strategy, raising alarm at the local water board.
The approach—adopted by environmental agencies at toxic cleanup sites across the country—leaves contaminated groundwater to remain untreated and instead slowly diminish over time.
It’s a strategy that saves money for polluters but could jeopardize drinking water supplies and cost taxpayers dearly.
That includes when contaminants are expected to degrade over a period of years rather than centuries, and when there is no risk of polluted water seeping into, and spoiling, fresh water supplies.
If the pollutants aren’t correctly monitored, they could continue to spread and contaminate nearby aquifers.
In California, for example, water-quality authorities and the Air Force have been locked in a protracted battle over pollution at the George Air Force Base.
The Lahontan Regional Water Quality Control Board, the agency overseeing the cleanup, claims the contaminants won’t degrade to safe levels for up to 500 years if MNA is applied as proposed by the Air Force.
But the Air Force disputes the water board’s dim assessment of MNA for the site.
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.