A mysterious milky white liquid that is draining from under a Stow shopping plaza’s parking lots is under investigation by the Ohio Environmental Protection Agency.
The leachate or liquid runoff is hazardous, but there is no evidence that the runoff from the Stow Community Shopping Center off Kent Road (state Route 59) has affected wildlife or humans, the agency said.
The liquid is draining from under the plaza parking lots to a stormwater retention basin that drains via a ditch to nearby Fish Creek, a Cuyahoga River tributary.
The shopping plaza owner, Beachwood-based DDR Corp., was cited by the EPA on March 25 for the illegal discharge of a hazardous waste, said EPA spokeswoman Lindey Amer.
The company has been ordered to end the discharge and to clean up the precipitate that has built up along the ditch, she said.
The company has hired contractors to correct the leachate problem and to devise a long-term solution.
“We are working diligently with the EPA along with our consultants and engineers to identify and understand any areas of concern at the property. We have taken steps to immediately address the issues identified by the EPA,” said spokesman Matt Schuler.
The problem was discovered on March 19 by Stow resident Dave Laube. He described the liquid as light-colored, similar to poorly made coffee. There was no odor, he said.
He notified a passing Stow firefighter. The city initially investigated. It contacted Stow-based EnviroScience Inc., thinking the problem might be an illegal discharge.
The Summit County Hazmat team then contacted the EPA.
The agency determined that the whitish runoff was coming from multiple storm inlets draining the plaza’s parking lots in an area near the Giant Eagle, Kohl’s, Target and Hobby Lobby stores.
The liquid runoff appears to have picked up precipitate from slag used as fill material under the plaza’s parking lots, the EPA said. It is possible that the dirt and slag were also treated with lime before the parking lots were built and that caused the problem, the parties said in a report.
Those storm inlets drain to a stormwater retention basin between the Giant Eagle and Hobby Lobby stores.
The result was stormwater with a pH of 14, the EPA said.
A pH of greater than 12.5 is characteristic of hazardous waste for being overly corrosive, the agency said.
The basin also drains via an east-flowing ditch behind the Hobby Lobby store to Fish Creek.
The pH was about 10 where the east-flowing ditch emptied into Fish Creek, the EPA said.
There was flocculate or solid material that has collected in the ditch, the agency said.
The initial remedy is to pump the water from the ditch and the drainage pond, treat it to reduce the pH to less than 9 to reduce corrosivity, and then discharge the treated water to the sanitary sewer system for additional treatment, Amer said.
The ditch has been dammed to keep the flow away from the creek.
Plastic sheeting has been secured along the entire length of the drainage channel to prevent new stormwater from coming into contact with the underlying contaminated sediments until they can be cleaned up, the EPA said.
Three tanks, each capable of holding 20,000 gallons of liquid, have been moved to the Stow site.
DDR could be required to limit public access to the site and to haze waterfowl to keep them away and safe, EPA staffer Kurt Kollar said in a report.
The 75-year-old Laube, for his part, is not convinced by the explanation.
Over the last few months, the ditch appears to have more liquids on Mondays and less later in the week, as if someone were dumping tankers of liquids on weekends behind the Hobby Lobby store, he said.
He frequently eats lunch behind Hobby Lobby while working part time at a nearby auto parts store.
Reporter Paula Schleis contributed to this report. Bob Downing can be reached at 330-996-3745 or bdowning@thebeaconjournal.com.