Six monitoring wells drilled, gasoline investigation continues in Walla Walla
By Dan Thesman on Monday, September 25th, 2023 in Columbia Basin News More Top Stories
News release from city of Walla Walla
WALLA WALLA – Over the weekend, GeoEngineers, guided by the Washington State Department of Ecology and Clean Harbors, drilled more wells along 2nd Avenue and Rose Street, and around the Walla Walla Post Office and the building at 106 N. 2nd Ave. Overall, the team drilled six monitoring wells (which are lined and capped) and five boring sites (which are capped but not lined). Readings performed at two of the monitoring wells revealed significant levels of contamination.
Preliminary testing of the gasoline samples taken from the sump at 106 N. 2nd Ave. indicated the gasoline is modern fuel, meaning it did not come from a decommissioned storage tank in the area. These samples are now undergoing “fingerprint analysis” testing to determine their specific additives and chemical makeup. Fingerprint analysis is also being performed on samples taken from the gasoline tanks at the Chevron and Circle K stations.
The investigation team expects to receive the results of these fingerprint analyses by Thursday, Sept. 28.
Testing of the gasoline tanks and lines at the Chevron and Circle K stations will be performed on Tuesday, Sept. 26, under the direction of the Department of Ecology.
Investigators will analyze the results of the fingerprint analyses, tank and line testing, and locations of contaminated monitoring wells. This combined evidence is expected to reveal the source of the gasoline. Once the source is identified, the response will shift from investigation to ending the contamination and cleaning up its effects.
Clean Harbors is continuing to pump out the sump at 106 N. 2nd, which continues to collect contaminants.
A representative from Washington State Labor and Industries’ Consultation Program has arrived and will be working with hotel management to create a plan for reopening.
WWFD continues to perform regular air quality monitoring at buildings around the area, with no changes detected.
The response team appreciates the flexibility of the community as we learn more about the situation and adjust our approach to changing conditions.
City staff will continue to provide these updates on the City website (https://www.wallawallawa.gov/gasoline) as the situation changes.
In response to a question from a resident, City staff checked with our contact at USPS to confirm the time the College Place Post Office closes. That office closes at 5 p.m., which differs from most recent information we had been provided. We have updated our current Post Office information to reflect this, and have added the hours the PO boxes and lobby are open and when the last mail collection occurs each day.
Please note: When City staff have posted these updates on the City website, we had been using the title “Marcus Whitman update xx,” since our public communication around the incident began when the hotel was evacuated, and because “Marcus Whitman” is the official name of the incident response.
However, the situation at the hotel has since been stabilized, and the response has expanded to include additional structures and the surrounding area. To reflect the wider spread of the investigation, we will be using the title “Gasoline investigation update xx” going forward. The updates posted on the website from Sept. 18 (when the Walla Walla Post Office closed due to volatile organic compounds detected in its basement) until now have been renamed with the new title to indicate these updates include information about the expanded investigation.
Photo shows pump moving contaminants pulled from the basement sump at 106 N. 2nd Ave.
