It likely will take crews another week to finish scraping oil-contaminated dirt and rocks from Salt Wash, a dry streambed on public land 12 miles south of Green River that was filled with thousands of barrels of an oil-water mix when an oil well failed last week.

Heavy rainfall Friday night breached the emergency dams erected to contain the oil, and a small amount flowed into the Green River, said an on-scene coordinator for the Environmental Protection Agency.

Curtis Kimbel, from the EPA’s Region 8 office in Denver, said he arrived Saturday after crews had stopped the flow into the river.

He was told by those working to contain the spill that only a small amount — a matter of gallons, rather than barrels — reached the river, which is running high with the spring runoff, he said.

“The important thing is once it was discovered, modifications were put into place to make sure no more got into the river,” Kimbel said Wednesday. “We’re confident the material is now contained in the wash.”

Beth Ransel, Moab field manager for the Bureau of Land Management, said BLM technicians are inspecting the river banks, and the National Park Service plans to float the river to inspect it for any residue in the water or along the banks.

While it’s unknown how much oil made it into the river, she said, those on site believe it was small because there were only small pools of oil and oil-coated rocks left when the severe rains hit.

The conclusion that only a small amount reached the river is being challenged by at least one area resident, Jim Collar, a software developer based in Moab who was camping on the rim above the Green River Friday night.

Collar shot photos of what he and his friends believe was oil film from the rim of Labyrinth Canyon at the Bow Knot, a famous bend on the Green River.

“On Saturday morning when I got up, I took my camera to the canyon rim to take some pictures. I was startled to find this oil sheen on the river,” which was about 1,000 feet below, he said. “It was very visible. It was river wide, wall to wall. It was there when we left the next day.”

The spot is 15 to 20 river miles downstream from where Salt Wash enters the Green.

John Weisheit, conservation director of Living Rivers and the Colorado Riverkeeper, said, “This pollution is unacceptable,” and called it a sign that oil companies and their regulators are not doing their jobs.

The Green River joins the Colorado River downstream from the spill, flows into Lake Powell, through the Grand Canyon, into Lake Mead and onto the farms of California’s Imperial Valley and into the taps of millions of people in Phoenix, Los Angeles and San Diego, he said.

“Is this a drinking water system or not? It is. Start acting like it,” he said. “Protect our watersheds. The people downstream need to know that.”

Kimbel said it’s not clear how much oil and water escaped after the rupture, which was discovered May 21. The 45-year-old well belongs to SW Energy of Salt Lake City. The company did not immediately return a phone call left at its office on Wednesday.

According to the BLM, an estimated 80 to 100 barrels of the oil-water mixture streamed, each hour, into the Salt Wash about four miles from where it reaches the Green River. The flow continued for 30 hours before crews were able to dump in several truckloads of a high-density mud to seal the well Thursday afternoon.

Based on those estimates, the spill could have been 2,560 to 3,000 barrels, or up to 126,000 gallons of the oil-water mixture. Ransel at the BLM, however, cautioned against such a conclusion. “There are a lot of unknowns about the amount coming out of the well,” she said.

The well operator had used vacuum trucks to suck up much of the spilled oil-water mixture by Thursday, and built berms and placed absorbent materials in the wash to prevent the oil from reaching the Green River.

Heavy rain Friday night, however, breached the dams closest to the river. Rainwater rushed over the oil-coated rocks and picked up small pools of oil that were in the wash about a mile or so from the river, according to Ransel and the BLM’s updates about the spill on its website. The BLM oversees the oil lease and the surrounding land.

New dams stopped the flow Saturday, and those did not fail during rainstorms that night, Kimbel said.

Kimbel said he and representatives from SW Energy, the BLM and the Utah Division of Oil, Gas and Mining “walked the entire area several times” and came up with a strategy to remove all contaminated material from the wash.

There are no culinary wells in the area, he said.

A number of pieces of heavy equipment are now working in the wash to remove rock, sand and dirt, which will be taken to a landfill certified to take such contaminated material.