UPDATE: Heating oil is collecting behind absorbent pads in a northwest Cedar Rapids drainage ditch after a leak was discovered Friday morning.
A hazardous materials team responded to Guppy's on the Go, 235 Edgewood Rd. NW, after a maintenance worker noticed the smell of diesel fuel coming from a drain near the entrance to the car wash around 9 a.m.
Tests confirmed the substance that went into the drains was heating oil, officials said.
Fire Department spokesman Greg Buelow said it appears the oil came from two 300-gallon above-ground tanks behind the gas station, where excavators were working at the site of a former greenhouse. The amount of oil that leaked out is unknown, he said.
"The odor is really strong over in a couple of these manholes," Buelow said.
Buelow said a Marion company was en route to suck up the oil. The Department of Natural Resources has been notified.
Firefighters put absorbent pads in a drainage ditch across Johnson Avenue known as Vinton Ditch, and oil was collecting behind them. The ditch feeds into the Cedar River.
Todd Satterly, the owner of the gas station, said there is a natural spring that runs behind his property where excavation is under way.
"That's what's carrying it," Satterly said.
Satterly said boilers that used the oil were in the basement of the greenhouse that used to be behind the gas station. He said the man who delivered it said they stopped using fuel oil in 1962.
Crews were still investigating to determine if the excavators were responsible for the leak, Buelow said.