Oct. 25—Sensors for the underground tanks at a Kokomo gas station indicate gasoline was leaking for more than a month before the business owner officially notified the Indiana Department of Environmental Management, inspection reports from the state agency show.

According to an IDEM inspection report, the automatic tank gauge systems installed on the underground storage tanks at the Marathon gas station and convenience store, located at 2105 S. Washington St., indicated a leak rate of 0.15 gallons per hour on Aug. 15. That was followed by "several failed tests" and an "increasing leak rate in excess of 0.2 gph" between Aug. 16 and Sept. 19.

However, IDEM did not become aware of the possible leak until Sept. 23, contrary to Indiana Administrative Code, which states that the owner(s) of the leaking underground storage tank must be reported within 24 hours. A formal report was filed with the state agency on Sept. 24.

According to IDEM, their emergency response team was called to the gas station Sept. 23 for a report of a "strong" smell of gasoline.

The next day, underground storage tank contractor M&M Mid-Valley Service and Supply's initial assessment indicated that the 6,000-gallon premium gasoline underground storage tank could be the source of the leak, according to an abatement report filed Oct. 13 by Indianapolis remediation company SESCO.

Concurrently, testing by an IDEM Emergency Response team reported gas vapor present in nearby storm sewer lines and three nearby residences on West Boulevard, prompting the temporary closure of the road and the removal of the fuel from the gas station's underground storage tanks. The removal was completed Sept. 26.

According to IDEM, one nearby homeowner was mandated to temporarily evacuate on orders from the Kokomo Fire Department. Other nearby residents also voluntarily evacuated, IDEM said.

According to the abatement report, gas-related vapors have reportedly dissipated from the three affected residences. The IDEM ER team and M&M did not detect leaked gasoline in the nearby groundwater wells, though an additional soil, groundwater and vapor investigation will be undertaken, according to the abatement report.

On Oct. 3-4, a tightness test was conducted on the property's three underground storage tanks. According to the testing results, two of the three tanks passed, while the premium tank did not. A tightness test is a means of determining whether a storage tank is leaking.

According to the IDEM inspection report, the leak rate of the premium gas underground storage tank was 0.8 gallons per hour.

When reached for comment, Robinpreet Singh, the gas station's owner, denied the tank was leaking on Aug. 15. He added that he had the tank tested for a leak at the end of August and said he was told the positive reading may have been a false positive because of the low amount of premium fuel in the tank at the time and to have the tank tested again at the end of September.

"Hopefully it's not too contaminated down there," Singh said.

An email seeking comment to the land owner, Don Good of Winamac-based Good Oil Company Inc., was not returned.

The gas station was cited for numerous violations by IDEM, including failing to provide documentation showing the three underground storage tanks — all installed in 1970 and now more than 50 years old — were rated to hold fuel with ethanol in it. The gas station must show proof that the tanks are compatible for fuel with ethanol, upgrade the storage tanks or switch to a product that is compatible.

"The normal operational lifespan of a UST before failing is 25 to 30 years," the inspection report reads. "The three main product tanks are at least 52 years old and were never rated to hold any amount of ethanol blended fuels."

Currently, the gas station's fuel pumps are inactive and will remain that way until "compliance is restored," IDEM told the Tribune.

This is not the first time a gasoline leak has been reported by the gas station.

In 1998, gasoline leaked from the station's fuel lines during a removal process. Tests for elevated levels of petroleum hydrocarbons (TPH) and benzene and other harmful chemicals were not above detection limits.

In 2003, a gasoline leak was reported. Only four bores were drilled by Alt & Witzig Engineering as the company struggled due to hitting slag material. Of the soil and groundwater samples collected, no levels of TPH and other harmful chemicals were above detection limits.

The property has a long history as a gas station/auto repair service dating before 1934, according to SESCO's abatement report.

In 1956, Vern Rethlake and his partner John Schanbacher, two Coca-Cola employees, decided to leave their jobs and open the Southside Marathon gas station and auto mechanic shop. Quickly, the business became a Kokomo staple.

In 1978, Mike Rethlake stepped in to run the business with his father, Vern, after Schanbacher retired. In 1993, Vern Rethlake died and Mike Rethlake took over the business, gaining a reputation as one of the town's most accommodating business owners.

In 2019, he sold the property to Good Oil Company Inc. The old building and repair shop were torn down and replaced with a new, more modern building.

Tyler Juranovich can be reached at 765-454-8577, by email at tyler.juranovich@kokomotribune.com or on Twitter at @tylerjuranovich.