The deep underground water supplies in the U.S. are in danger—in danger of depletion because of increasing use, and in danger from pollution because of lax federal regulations that assumed that many deep-lying reservoirs would never be needed.
But they may, because water that’s difficult to extract, like oil that’s difficult to extract, is now being eyed as a future source of supply. Mexico City made news last week when officials there announced plans to begin tapping an aquifer a mile underground.
The withdrawal of water from underground reservoirs has already caused conspicuous sinking of the ground in some American cities, notably Houston. There, according to the U.S. Geological Survey, several factors—the most important being the drawdown of groundwater—have caused 100 acres of the San Jacinto Battleground State Historical Park to sink under Galveston Bay.
In the Las Vegas area, says the USGS, subsidence (sinking) caused by groundwater withdrawal has damaged houses, cracked and displaced roadways, sidewalks and curbs, and warped sewer pipes and railroad tracks, causing millions of dollars’ worth of damage.
So what’s happening to the rest of our deep groundwater? We’re pumping poison into it, according to a report by Pro Publica. The pollution comes from industrial fluids, including products from oil and gas exploration, that are injected as far as two miles into the earth. Sometimes they’re injected into aquifers formerly considered too deep to serve as drinking water supplies; sometimes they’re injected into parts of active aquifers.
There are 680,000 underground wells in the country, some old, some very new, that hold waste fluid, and permits are being issued for more such wells all the time, says the report. That’s not counting approximately 2 million abandoned oil and gas wells. (So-called Class I wells, those containing the most hazardous industrial wastes, are banned in Maine, Massachusetts, New Hampshire, Vermont and Rhode Island.)
Complicating the situation is the designation, since 1988, of all fluids that are byproducts of oil and gas drilling as non-hazardous, regardless of what they contain.
When the fluids are injected under high pressure, they may rupture the rock layers that are supposed to keep them from leaking. Pro Publica studied case histories of thousands of injection wells inspected between late 2007 and late 2010. One out of every six was found to be structurally unsound—incapable of holding its often toxic contents without leaking. And during that period, Pro Publica found, only about half the state and local agencies charged with monitoring such wells had added their findings to the federal database.
In general, the Safe Drinking Water Act protects aquifers, but the EPA has designated issued some 1,500 “exemptions,” meaning that the law does not apply to aquifers with that designation. One hundred exemptions apply to aquifers actually in use. According to reports, even now, with much of the nation wrapped in drought, it’s not difficult for an energy company to get an underground water source it wants to inject with waste water designated exempt. In Texas, uranium mining has recently led to a spate of exemptions.
“In 10 to 100 years we are going to find out that most of our groundwater is polluted,” Mario Salazar, a former Environmental Protection Agency staffer who worked on the agency’s underground injection program, told Pro Publica.•