The Environmental Protection Agency has released a preliminary report about the fate of metals contained in the waste spilled last summer from Colorado’s Gold King Mine. The agency says most of metals came to rest in the bed of the Animas River. Arizona Public Radio’s Ryan Heinsius reports.

The EPA estimates more than 880,000 pounds of metals spilled from the mine. The report says the waste was diluted as it flowed downstream, but some of the metals reached the San Juan River in New Mexico.

The report didn’t confirm which metals were in the waste, but researchers believe it likely contained cadmium, copper, lead and mercury, among others.

In August, workers with the EPA accidentally triggered the spill of more than 3 million gallons from an inactive mine near Silverton, Colo. By the time it flowed into the San Juan River, many farmers on the Navajo Nation had stopped irrigating their crops. Some went weeks without water, and tribal officials are still assessing the spill’s affects to those communities. Navajo President Russell Begaye has said he’s considering legal action against the EPA.

Officials with the agency say pollution in the Animas and San Juan rivers returned to pre-spill levels shortly after the incident.