The U.S. Environmental Protection Agency is installing a barrier and a valve inside an old Colorado mine to prevent another wastewater spill. Two years ago the agency accidentally triggered a blowout that contaminated rivers in three states.
The 12-inch valve will regulate the flow of wastewater at the Gold King Mine near Silverton.
In August of 2015 the EPA was investigating the old mine when it inadvertently set off a 3-million-gallon surge of heavy metal-laden water into the river system.
The sludge made its way down to the San Juan River where the Navajo irrigate their crops with the river water.
The EPA has spent $29 million to reimburse state, local and tribal governments for their response efforts and to treat and monitor the water.
The EPA’s Scott Pruitt said in June the agency will reconsider previously denied claims from those seeking damages. The agency has until the end of December to act on those claims.
There are an estimated 500,000 abandoned mine sites across the U.S.