City of Walla Walla looks to relocate filtration equipment, reopen Second Avenue

By on Monday, October 16th, 2023 in Columbia Basin News More Top Stories

News release from city of Walla Walla

WALLA WALLA – Staff from Washington Department of Ecology, the City of Walla Walla, Walla Walla Fire Department, Clean Harbors, and Aspect Consulting met this morning to discuss the ongoing response, including Ecology’s current Incident Action Plan covering the period of Oct. 16-23. Ecology, Clean Harbors, and Aspect are collaborating on each team’s individual Health & Safety Plan to ensure a consistent overall approach.

In addition to supporting the investigation and recovery efforts, the City’s priority is to reopen 2nd Avenue to traffic as soon as possible. City staff are working with Ecology and Aspect to determine the most efficient way to fund the lease of a property adjacent to the Chevron station, so the filtration equipment can be moved there and 2nd Avenue reopened this week.

An abandoned stormwater lift station at the southwest corner of the Marcus Whitman Hotel appeared to show a sheen and gasoline odor, so crews constantly pumped it over the weekend to remove any contaminated material present. 

Crews continue to monitor Mill Creek where it daylights near this location to identify any sheen on the water surface, which could indicate the presence of gasoline. Two boom systems continue to be present on the creek (one just west of 3rd Avenue and one at 9th Avenue, each consisting of a hard and a soft boom) to prevent any potential contamination from traveling downstream. 

Testing of water samples taken from within the booms, and the continued visual observation of the creek, have not detected the presence of any sheen or volatile organic compounds in the waterway.

Clean Harbors continues to recover contaminated groundwater from two of the monitoring wells (a third well used for recovery is pumped on Fridays). Pumping operations also continue from the sumps of the hotel and building 106. Ventilation continues to mitigate VOCs from the impacted structures. Dual exhausts have been directed above the hotel, while a single exhaust vent terminates above building 106.

Filtered water is constantly being discharged to Walla Walla’s wastewater treatment system at a rate of about 15 gallons per minute. The discharged water is being metered, and totaled just over 86,200 gallons as of Sunday afternoon.

Additional wells will be drilled this week in the area. Drilling operations will likely require two days of road or lane closures on Rose Street, beginning Tuesday.

This update is based on information provided by Washington Department of Ecology and City of Walla Walla Public Works staff. City staff will continue to provide these updates on the City website (https://www.wallawallawa.gov/gasoline) as we receive additional details.

We will be titling these updates “Walla Walla Gasoline Release 2023 update ##” going forward to match Ecology’s new name for its incident response.

Photo via Washington Department of Ecology shows components of the pumping system on 2nd Avenue