Cleanup efforts continue at a site along Olequa Creek in Winlock after a diesel fuel spill from a nearby tank contaminated the surrounding area earlier this month.
A spill team with the Washington state Department of Ecology is currently working to contain the spill and remove diesel fuel from Olequa Creek as well as nearby soil and vegetation.
As of Monday, July 28, the team had effectively contained the spill to the origin point. However, a roughly mile-long portion of the stream starting at the spill site and ending downstream at the Hining Road Bridge is still considered to be part of the affected area.
Residents further south of Winlock and in Vader are safe to enter the stream but asked to stay vigilant for any signs of water contamination, including discoloration and oil slick on the surface of the water.
The saga of the local spill began with a report of discoloration and oil slick being spotted on the surface of Olequa Creek near the Winlock City Treatment Plant on Thursday, July 10.
A response and investigation by the state Department of Ecology led to confirmation of a fuel spill the following day. Lewis County first released a public announcement that day, July 11, warning residents of Winlock and Vader against recreating or in any way entering Olequa Creek.
The investigation by the Department of Ecology found 200 gallons of diesel fuel to be missing from an above ground fuel tank located near the creek on Northwest King Road. It also later found the concrete basin below the tank to be cracked. The tank sat on City of Winlock property that is currently used as a bus depot for the Winlock School District.
Since the discovery, a spill team from the state along with a contracted cleanup crew and soil testing team has begun work on the site to address the spill, first removing the fuel from the leaking fuel tank and placing sorbent materials in the creek to absorb remaining diesel fuel. Sorbent materials are often used in fuel and other types of spills for absorbing harmful materials.
Since the initial response, the contracted cleaning crew, Cowlitz Clean Sweep, has removed two fuel tanks — one for diesel and one for gasoline — and identified the diesel tank as the source of the spill, according to a statement from the Washington state Department of Ecology. Both tanks were removed and cut apart to identify the source of the leak. This identified a small hole in the bottom of the large diesel fuel tank.
The team has also demolished the cracked concrete containment structure and began excavating the soil below. The spill team expected to resume excavation on Wednesday while testing for soil contamination and flushing the nearby bank of the creek to remove any remaining fuel from the soil and vegetation.
A continued timeline and footprint of excavation depends on the results of further soil testing as the team as of Wednesday morning had placed sorbent in the recently dug pit to absorb diesel leaking out of the soil.
Despite the significant amount of fuel spilled, the damage seems to be minimal with no reports of humans affected and no reported fish kills, according to a statement from the Department of Ecology spill team.
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