It was business as usual Monday afternoon at the Marathon Minit Mart on Russellville Road in Bowling Green.
But steps behind the gas station, trucks and emergency responders sprawled around a plunging pit of copper clay where, days earlier, an oil storage tank leaked an estimated 640 gallons of gasoline.
Suspected vandals apparently drilled a hole into an aboveground storage tank at Marathon on Wednesday and left the contents to spill into surrounding soil, according to the Kentucky Energy and Environment Cabinet, which is overseeing the investigation and cleanup.
To contain the spill, regional environmental emergency responders coordinated an excavation to remove all contaminated soil and haul it to a processing facility. By Monday, the team approached bedrock as it dug nearly 18 feet below the surface.
The state has been monitoring air quality, nearby dry wells and Jennings Creek – the closest surface water source, where responders proactively placed oil-absorbent pads – to determine if the oil has traveled beyond the soil.
The gas station is just a few hundred yards from the greater Lost River Cave karst, an underground limestone network with features connecting surface water and groundwater.
“There is a concern that it could hit the karst system and it could start to move,” said Matt Powell, environmental manager for the city of Bowling Green.
So far, there has been “no indication of impact,” said Robin Hartman, spokeswoman for the Kentucky Energy and Environment Cabinet, but the state will continue to closely monitor the situation.
After completing the excavation, the state will direct the cleanup and monitoring effort to the Superfund Branch “petroleum section,” which oversees non-underground storage tank petroleum releases and their corresponding investigations, remediation and contaminated site management.
“Then they’ll make recommendations,” Hartman said.
Gas stations store fuel in underground or aboveground storage tanks. Earlier this year, an underground storage tank released an unknown amount of gasoline into the greater Lost River Cave system. That investigation is ongoing.
Gasoline exposure poses significant hazards to people. Nozzles dripping onto the ground or even open gas tanks can cause vapors to leak into the air, seep into the soil or discharge into waterways, contributing to air, soil and water pollution, according to the National Institutes of Health.
If the highly flammable oil seeps far enough into the soil, it could contaminate groundwater and, consequently, local well water.
The Marathon spill was reported about 9:30 a.m. Wednesday to the Kentucky Energy and Environment Cabinet, according to Hartman.
Neither the Bowling Green Police Department nor the Bowling Green Fire Department were alerted about the spill last week, according to representatives of both agencies.
EnSafe, Southern Environmental Services and Appalachian Environmental Services are assisting with the cleanup response effort.
– Follow reporter Caroline Eggers on Twitter @eggers dailynews or visit bgdaily news.com.