NEW ORLEANS – Negligence appears to be behind the diesel fuel spilled from a S&WB plant into the 17th Street Canal.

A siphon pump at the Sewerage and Water Board's Carrollton plant was left on when it shouldn't have been and pumped the fuel out of a containment area and into the canal according to NOFD Superintendent Tim McConnell.

McConnell said the siphon pump is meant to maintain the trench that keeps any spilled fuel from getting out of that area, but because it was left on when it shouldn’t have been, it pumped the fuel out of containment.

“It should not have been on and it pumped the diesel into the drain,” McConnell said.

The leak was first reported on Aug. 15 when people who live near pumping station No. 6 reported smelling diesel fuel near the facility, which sits on the Orleans-Jefferson parish border.

MORE: City investigating reports of diesel leak near pumping station

Since then, crews from the NOFD and the Department of Environmental Quality have been cleaning up the “slow leak” of diesel fuel from the canal.

“One thing I want to emphasis is no diesel reached Lake Pontchartrain,” McConnell said. “So, from an environmental perspective, the lake was protected.”

McConnell said that all of the spilled diesel has been recovered, but out of an abundance of caution, they will continue to monitor the water.

Neither the DEQ nor the NOFD can determine how much diesel fuel was spilled as of yet.

MORE: Crews continue to clean up fuel after leak at S&WB plant

“We have taken some samples and sent them to labs to help us trace down exactly where the leak came from, exactly what the source was. But, we do know it came from that Carrollton plant, McConnell said. “If I can't pinpoint the source, I can't pinpoint the quantity at this point.”