SILVERTON, Colo. (CBS4) – The U.S. Environmental Protection Agency says it’s giving the Navajo Nation $465,000 to monitor water quality in the San Juan River for contamination from a massive mine waste spill last August.

The EPA says the money is in addition to $1 million the agency agreed to give the tribe last October.

The new grant was announced Thursday.

An EPA-led cleanup crew inadvertently triggered the spill of 3 million gallons of acid mine waste from the Gold King Mine in southwestern Colorado on Aug. 5. The spill tainted rivers in Colorado, New Mexico and Utah.

One of the rivers was the San Juan, which runs across Navajo land in New Mexico.

Navajo leaders have been highly critical of the EPA for causing the spill and for its response.

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