Update: Walla Walla Gasoline Leak & Closures

There is currently a near four block closure area in Walla Walla, resulting from fumes and volatile organic compounds being detected in several buildings.

Reporting began on this story late last week when the Marcus Whitman Hotel was temporarily closed due to strange fumes being detected in the building's basement. Since then the story has taken an odd turn, as the source of the fumes continues to confound local authorities.

On Monday Walla Walla Fire Department crews performed an air-quality test of buildings around the Marcus Whitman Hotel, finding a previously unidentified sump in the basement of a vacant building at 106 N. 2nd Ave. (between the Chevron station and the Walla Walla Post Office). Testing within that sump revealed the presence of extremely high concentrations of volatile organic compounds (VOCs) and LELs (lower explosive limits), similar to what was found in the sump of the hotel last Thursday.

Power and gas to the building were immediately shut off and ventilation of the sump and basement began. Over Monday night, a Clean Harbors crew began active ventilation of the basement and pumping of the sump. Initial barrels of material pulled from the sump had the appearance and smell of clean gasoline.

Meanwhile, the Post Office remains closed pending USPS bringing in a team to respond to the elevated VOC levels in its basement.

The USPS collection boxes along Sumach Street on the northern corner of the Post Office property are not available to the public at this time. Mail deposited in the other collection boxes throughout the city is still being collected.

The original culprit for the appearance of the VOCs and gas was thought to be from the nearby Chevron gas station. However, a tightness test on the suspected gasoline storage tank at the Chevron station was performed Monday afternoon. The tank passed the test, indicating that it is not leaking.

A hydrogeologist from the Washington State Department of Ecology has now arrived in Walla Walla, meting with the City's Environmental Engineer to learn about conditions around the hotel. He has since begun an investigation focusing on determining the source of the gasoline and the flow of groundwater in the area, and to identify the route the gasoline might be taking. The DOE will also be leading the investigation of additional fuel storage tanks at the Chevron and at the Circle K station at 315 N. 2nd Ave.

Additionally, there are seven known decommissioned underground fuel storage tanks in the area, but are not currently viewed as probable sources.

We'll bring you more on this story as developments are released.