A company's neglect to report a spill has allowed up to 18,480 gallons of oil to stagnate uncleaned in the wetlands of Iberville Parish for at least six months, regulators said Wednesday.

An Office of Conservation inspector noticed the crude oil leak at a Metairie Energy site during a routine inspection on Aug. 29, said Department of Natural Resources spokesman Patrick Courreges.

The next month, the agency sent a formal order to clean the site. However, the work was never done properly, and Metairie Energy did not notify other regulatory agencies as required, representatives of the Department of Environmental Quality and Louisiana Oil Spill Coordinator's Office said.

State Police Maj. Doug Cain said his agency only found out about the spill in late January after the Department of Natural Resources contacted it.

"It was still pretty much a mess when we eventually got there," said DEQ spokesman Greg Langley.

The company had made some attempts to clean the oil with detergents but did not follow generally-accepted practices, he continued.

Company officials did not return a call for comment.

Now, authorities are looking into "a number of issues" with the "potential for multiple violations," said spill response specialist Chris Viator. He declined to provide more specific information, and regulators said no penalties have been assessed yet.

Metairie Energy has told officials that the spill occurred in August, the same month it was discovered. The told officials crude oil leaked out of a holding tank in the Bayou Choctaw area, possibly due to a faulty valve.

It is unclear exactly how much oil was released, though officials are operating under the assumption that the tank, which holds 440 barrels — or 18,480 gallons — was fully drained. Courreges said one early report indicated the affected tank was no longer in use, though that information was incorrect.

The oil may have spread during the August flood but is now believed to be contained to an area of about 10 acres in what's been described as non-navigable wetlands off La. 1148. The area is near, though not part of, the Strategic Petroleum Reserve.

The Strategic Petroleum Reserve is a U.S. government complex of four sites with deep underground storage caverns created in salt domes in Texas and Louisiana — including caverns along Bayou Choctaw — that store emergency supplies of crude oil owned by the U.S. Government, according to a U.S. Department of Energy website.

Viator said there is no threat to the public from the Iberville Parish oil spill.

Agencies are using sound cannons to try to keep wildlife away from the site while crews can vaccuum the oil from the water and excavate any soil which may be contaminated. Cleanup began Feb. 1 and will take at least several more weeks, Viator said.

The specialist emphasized that while a state inspector became aware of the spill last year, it is the company's legal responsibility to notify agencies including the state police and National Response Center of an incident the size of the one in Iberville Parish.

Local lawmen were also caught off-guard.

Sheriff Brett Stassi said Wednesday he wasn't aware there had been an incident until last month when his office started receiving calls from residents in the area complaining about the loud booms they were hearing from the cannon firings.

"They were asking, 'What's that noise coming from back there?' That's how we learned Wildlife and Fisheries was firing the cannons to keep the wildlife away," Stassi said.

The five-month delay in notification doesn't sit too well with Stassi. He believes his office should have been put on notice immediately after the spill.

"That way we could have given our residents a warning about what was going on rather than them calling us and hearing about it on the back end," he said.

Editor's note: This article was changed on Thursday, February 16, to note that State Police Maj. Doug Cain said his agency only leaned of the oil spill in late January after it was contacted by the state Department of Natural Resources.

Follow Steve Hardy on Twitter, @SteveRHardy.