A flash flood shortly after a late May oil spill in a remote section of eastern Utah hampered cleanup and spill assessment. The accident apparently unleashed thousands of gallons of an oil and water mixed-fluid into a wash on land controlled by the U.S. Bureau of Land Management.

The fluid is a water and oil mixture at a 2-to-1 ratio, according to Beth Ransel, Moab field manager for the BLM.

On May 21, the Bureau of Land Management says, its Moab, Utah, field office was notified by SW Energy and the Utah Division of Oil, Gas and Mining of a leaking oil well in the Salt Wash approximately 12 miles southeast of Green River, Utah. The Green River joins the Colorado River downstream from the spill and flows into Lake Powell.

Lisa Bryant of the BLM blamed the leak on a faulty below-grade valve that had been inspected recently. Utah placed an oil, gas and mining division inspector on site the same afternoon the spill was reported. By then, Bryant says, well owner SW Energy had hired a cleanup contractor to construct containment and back-up berms and remove fluid with vacuum trucks. BLM said the well was capped at 1:20 p.m.

An unexpected weather event hit the area the next day, however, and the original containment areas were overwhelmed, Ransel said. "Some of that fluid had been mobilized and moved into the (Green) River," she added.

BLM constructed a new underflow containment structure in Salt Wash on May 24 that has prevented outflows during rainstorms since then, Ransel says.

However, Jim Collar, a Moab man camping on the Green, took photos that showed what looks like a mid-current oil slick below the spill site. BLM and state personnel subsequently took river samples. Ransel said they identified some sheening.

Zach Frankel of the Utah Rivers Council said that regulators and the owner have very little detail on a spill that might have exceeded 100,000 gallons.

"It has been seven days and we have no data. We have only opinions," he said.

Ransel said results from water samples taken May 30 will be available by mid-June and that cleanup efforts in the Salt Wash are expected to be completed the first week in June.