COFFEYVILLE, Kan. (AP) _ An oil spill that damaged hundreds of homes during flooding four weeks ago began when the valve on a refinery storage tank was left open, state health officials said. The open valve allowed oil to continue flowing into a tank until it spilled into the floodwaters July 1, the Department of Health and Environment told the Wichita Eagle for a story published Sunday.
But department officials don't know why the valve was left open, said spokesman Joe Blubaugh.
``That would be a question to ask the company,'' he said.
The refinery's owner, Coffeyville Resources, has long acknowledged that a storage tank overflowed as the refinery was swamped by floodwaters from the Verdigris River. An estimated 71,000 gallons of crude oil escaped and flowed into neighborhoods.
But refinery officials said they are still awaiting findings of their own inspection and declined to comment on the department's report.
``The cause is not a relatively simple error,'' said company spokesman Steve Eames. ``It's caused by an act of God ... a massive flood.''
Refineries facing floods typically partially fill oil tanks to keep them from floating away, something Coffeyville Resources said it was trying to do.
A storage tank sitting at a higher elevation continued to pour oil into a main storage tank at a lower level, the Kansas Division of Emergency Management said.
It was the lower tank that overflowed, said Sharon Watson, spokeswoman for the Kansas adjutant general's department.
Refinery staff made ``heroic efforts'' to shut down the plant as water flowed over river levees, Eames said. Securing the plant usually takes 24 hours, but employees had only five or six hours before the flood forced evacuations, he said.
``This was not an orderly shutdown like we would like to do,'' he said.
The U.S. Environmental Protection Agency, which is overseeing the environmental fallout, said it is awaiting final results of the refinery's own investigation before deciding whether further inquiry is needed.