The quality of San Juan River water on the Navajo Nation has returned to what it was before a spill at a Colorado gold mine sent toxic sludge into the waterway, federal officials said Thursday.

The testing by the U.S. Environmental Protection Agency along with that of the Navajo EPA has prompted tribal President Russell Begaye to consider lifting an advisory against using the river to water crops.

Begaye has said he would not advise hundreds of farmers on the Navajo Nation to do so until the tribe's own testing declared the river safe.

Those results will be provided at a meeting later in the day with farmers in Shiprock, New Mexico, tribal spokesman Mihio Manus said.

The U.S. Environmental Protection Agency said testing of surface water collected over a week in Hogback, New Mexico, showed water quality at the same levels as those measured before the mine waste reached the reservation. The agency has taken full responsibility for the Aug. 5 spill at the Gold King Mine.

Manus said Begaye will talk with farmers about flushing irrigation canals and possibly opening them up this weekend. The EPA said it will provide technical assistance.

Hundreds of Navajos farm along the San Juan River grow squash, melons, corn and other crops to sustain their families and to sell at roadside stands and a tribal fair in October in Shiprock.

After the spill, federal agencies, including the EPA and the U.S. Bureau of Indian Affairs, arranged for water to be hauled to tribal communities and hay to be delivered for livestock.

Not all the water has been welcomed.

Shiprock farm board member Joe Ben Jr. complained that water coming from tanks delivered by an EPA contractor contained oil and didn't smell right.

Begaye and Navajo Attorney General Ethel Branch went to Shiprock to look at the tanks a day after farmers voted to reject the water. Branch and Begaye placed their hands inside the area where hoses hook up to the tanks, and their hands came out partially black, according to a video the president's office posted on its Facebook page.

"That is clearly oil," Branch said. "We don't trust the EPA to be here. They need to get out of our nation, send the dollars directly here. Let us take care of these issues ourselves because we care about the health and welfare of our people."

Manus said tribal officials were testing the water from three of the tanks that were being held by tribal police.

The EPA said it would provide an alternate water source from within the reservation but didn't directly address questions regarding the holding tanks. One EPA contractor, Triple S Trucking, said the tanks were cleaned before being delivered to the reservation.

EPA Administrator Gina McCarthy and Begaye spoke Wednesday about water quality in the river and agreed to have EPA cease water deliveries Friday for agricultural use on the reservation, the EPA and Manus said. The agency said it would work with the Navajo Nation on a monitoring plan for the river.

Ben said he wouldn't support a return to using the canals to water crops because not enough is known about the impact to the soil.

Messages left with farm board members in Hogback and Cudeii, two other tribal communities where farmers rely on river water, weren't immediately returned.

"The testing that was done was surface testing, no subsurface testing, also sediment testing," Ben said. "And never any information about the long-term and short-term effects of these toxins in our water."

New Mexico environment officials said Thursday they are planning another water-testing fair for residents next week and the results from previous tests have been mailed to about 570 private well owners.

Those tests didn't focus on heavy metals, but officials said the results of more extensive testing of more than 100 wells in the Animas valley will be released by the EPA in the coming weeks.