Ecology releases new data on Chevron gasoline leak

WALLA WALLA – The Washington State Department of Ecology has released new data on how much and for how long gasoline leaked from an underground storage tank at Stillwater Holdings Chevron, 7 East Rose Street.

In a letter sent Monday to the gas station’s owners, Ecology said the leak appears to have begun during the last week of June and continued until gasoline and gasoline vapors were detected in the basement of the Marcus Whitman Hotel on Sept. 14.

Based on analysis, an estimated 2,500 to 3,000 gallons of gasoline leaked at a rate of one gallon per hour from the regular gasoline underground storage tank. The premium gasoline and diesel fuel underground storage tanks do not appear to be leaking.

Ecology is trying to determine why a statistical continuous automatic leak detection test for detecting leaks from the Stillwater Holdings Chevron’s underground storage tanks failed to detect a leak for three months while tank inventory logs flagged a potential problem. It is Ecology’s recommendation that additional tests be performed on the current on-site leak detection system to rule out other potential problems.

It is also Ecology’s understanding that the probe and sensors installed specifically inside the regular gasoline underground storage tank failed sometime in mid-September.

Photo via Ecology shows testing lines/tanks at the Stillwater Holdings Chevron

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Elkhorn Media Group

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