GRAETTINGER - Less than 2,000 gallons of ethanol leaked into Jack Creek as the last three derailed tanker cars were pulled from the creek March 13 south of Graettinger.
All three cars had some ethanol in them. The first car was pulled from the creek without leaking. About 1,500 gallons of ethanol were released as the second tanker was removed about 10:40 a.m. Monday and another estimated 100 gallons leaked as the third car was pulled at 12:30 p.m.
Water monitoring showed normal dissolved oxygen levels of between 11 and 12 parts per million at three locations downstream of the accident site Monday afternoon.
"This is consistent with what we've seen since the accident occurred on Friday," said Amber Wolf, DNR environmental specialist. "The flow is extremely high in the creek and where Jack Creek flows into the Des Moines River about four miles downstream."
As ethanol decomposes in the water it can cause oxygen levels to dip.
"Levels of 5 ppm (parts per million) of oxygen or less could affect fish," she said. "We saw no evidence of that."
The three tankers remained after 20 cars were derailed in Palo Alto County south of Graettinger about 1 a.m. Friday. Ethanol in the tankers caught fire Friday and burned until Sunday.
The DNR will continue to monitor cleanup efforts and will consider appropriate enforcement action.