The San Juan River flows through the Navajo Reservation as a cow grazes Aug. 12, 2015, alongside a field that uses river water for irrigation in Shiprock, New Mexico. Toxic wastewater from the Gold King Mine in Silverton contaminated the San Juan River in northern New Mexico. This week, the Navajo Nation filed a claim for more than $160 million in damages connection to the spill.
The San Juan River flows through the Navajo Reservation as a cow grazes Aug. 12, 2015, alongside a field that uses river water for irrigation in Shiprock, New Mexico. Toxic wastewater from the Gold King Mine in Silverton contaminated the San Juan River in northern New Mexico. This week, the Navajo Nation filed a claim for more than $160 million in damages connection to the spill.Associated Press file

A cleanup team led by the U.S. Environmental Protection Agency triggered the August 2015 spill while working at the Gold King Mine near Silverton.

The 3 million gallon blowout tainted rivers in Colorado, New Mexico and Utah with tons of toxic heavy metals including arsenic, mercury and lead.

In a letter Monday to the EPA, attorneys say the tribe awaits more than $3 million in unreimbursed expenses for costs through Sept. 30 to deal with the spill that contaminated the San Juan River.

The tribe also is seeking $159 million for 10 years of health monitoring and other assessments.

According to EPA data, as of Aug. 5 of this year, the agency has paid $1,067,756 to the Navajo Nation.

By comparison, Silverton and San Juan County (Colorado) requested and received $380,000 for costs incurred from the mine blowout.

La Plata County has received $172,000 in costs, and is still asking for another $90,000, county spokeswoman Megan Graham said in September.

And the city of Durango was reimbursed $146,875 of its $444,032 request.

EPA data indicates the agency has paid more than $5.2 million in connection to the spill, as of Aug. 5.

Herald Staff Writer Jonathan Romeo contributed to this report.