Ecology releases update on 2023 Walla Walla gasoline leak cleanup
By Dan Thesman on Wednesday, June 18th, 2025 in Columbia Basin News More Top Stories
WALLA WALLA – The Washington State Department of Ecology’s contractor, NWFF Environmental, has set up daily operations at Stillwater Holdings Chevron, 7 E. Rose St., in Walla Walla.
NWFF Environmental is actively monitoring water levels in the sumps at the Marcus Whitman Hotel, plus the building at 106 N. Second Ave., better known as the 106 building. The contractor removes sump water from the Marcus Whitman four times a week. It takes about 30 minutes to pump from the hotel and about 30 minutes to discharge at Stillwater Holdings Chevron, where the remediation equipment is located behind the recently installed security fencing.
Ecology reports Clean Harbors has cleared its remaining equipment from the 106 building parking lot and is finishing their demobilization tasks, which include cleaning and painting areas of the 106 building affected by their operations. The company also addressing damage from flooding in the basement of the 106 building.
GeoEngineers has completed another round of groundwater sampling at the Stillwater Holdings Chevron, 106 building and Marcus Whitman Hotel properties, with results indicating that overall gasoline and its breakdown contaminants are decreasing or stable. However, some pollutants exceeded safety levels specifically in the Marcus Whitman Hotel sump. Only benzene exceeds safety levels in the 106 Building.
The 2025-2027 capital budget approved $3.5 million to support ongoing cleanup efforts. Ecology said it is pursuing recovering costs from Stillwater Holdings Chevron.
The emergency response and cleanup began in September 2023 after gasoline odors were detected from the basement of the Marcus Whitman Hotel. This led to evacuations. Vapors were also detected in two nearby buildings – the 106 building and the Walla Walla Post Office.
Ecology said based on sampling results, Stillwater Holdings Chevron was identified as the source of the gasoline leak. Contamination from the leak continues to impact the Marcus Whitman Hotel and the 106 building.
March 2025 photo shows 106 building and Stillwater Holdings Chevron with installed remediation equipment. MyCB photo by Dan Thesman
