The winter storm that blasted through the West this week knocked out a mine wastewater treatment plant in Colorado, prompting officials to warn Friday against using water from two rivers downstream in New Mexico.

Fluctuating electrical power shut down the treatment plant below the inactive Gold King Mine in southwestern Colorado on Thursday night, the U.S. Environmental Protection Agency said.

The EPA, which oversees the plant, said it did not believe downstream drinking water would be harmed.

But the New Mexico Environment Department warned against using water from the San Juan and Animas rivers because of the treatment plant failure. It said anyone who uses the rivers for drinking water or irrigation should take appropriate precautions, but it did not say what those precautions might be.

New Mexico officials said the U.S. Geological Survey will test water and sediment from the rivers.

It was not clear how long the plant would be offline. The EPA said a long-term shutdown could affect fish and other aquatic life.

Operators have not been able to reach the plant because the access road is blocked by at least one avalanche, and it could take several days to clear the route, EPA spokeswoman Cynthia Peterson said.

The plant can be operated remotely and no one was at the site when the avalanche occurred.

The plant was installed after the EPA inadvertently triggered a wastewater spill from the Gold King in 2015, contaminating rivers in Colorado, New Mexico and Utah.

Earlier Friday, two Colorado campers were found safe after they got caught in the storm.

Authorities say 20-year-old Michael Lee Gomez and 19-year-old Olivia Megan Schack, both of Arvada, were found near Ward, west of Boulder.

They had gone camping on Tuesday. The blizzard struck southeast Wyoming and northeast Colorado on Wednesday and Thursday, and the two took refuge in their car.

The storm knocked out electricity in several parts of Colorado. Thousands of homes and businesses were still without power Friday, mostly in the Denver area. Xcel Energy brought crews from other states to help with restoring service.

Colorado and Wyoming residents were still digging out Friday, but most schools and government offices reopened. Major interstates in both states were open although crews were still clearing snow from some secondary roads.