EPA orders monitoring of drinking water contaminated by oil extraction operations in Montana

The U.S. Environmental Protection Agency (EPA) recently ordered oil producers in Poplar, Montana to monitor contaminated drinking water in both the public water supply and private wells in Poplar and on the Fort Peck Indian Reservation. The contamination stems from a combination of a leaking oil well, unlined waste pits, spills of produced water and oil, and inadequate monitoring.

While the EPA found that the current levels of contamination are low enough so that water is still within limits considered to be safe, the agency will require companies to provide additional water treatment and/or alternate supplies if it determines the drinking water becomes a public health risk. In past orders, EPA has already required operators to provide alternate water supplies to some area residents.

The drinking water in this area is contaminated with salt, metals such as manganese, and toxic substances such as benzene, a known carcinogen, and toluene. In one instance, a local dialysis center had to be shut down due to impure water.

In a way, this is not "news." According to the EPA, authorities have known about the contaminated water in the Poplar area for several decades and have been keeping track of it as the contamination moves closer to the drinking water sources. But, this is a very important cautionary tale about the challenges in dealing with contaminated drinking water sources. One consultant, hired in 2008 to model how fast the contamination in the Poplar area is traveling, determined that under one scenario it could take more than 200 years for contaminants in groundwater to reach the city's water wells. In another scenario, it could take less than two years.

Just because an accident has not yet contaminated any drinking water wells, or only a few, does not mean a problem goes away--it can continue to pose a threat to drinking water for generations to come, and it can be very difficult to predict. Our drinking water supplies are already at risk due to many threats -- among them climate change and increasing competition for water. We must do whatever we can to protect the clean drinking water we have, as it will only become even more precious in the future.