A sheen of transmission fluid on the Clark Fork River near the Higgins Avenue Bridge late Tuesday afternoon probably came from a leaking vehicle a block away, according to Missoula City-County Health Department officials.
The leak, later determined to be about a gallon total, was reported at about 4 p.m. Tuesday after passers-by saw it spreading from a stormwater drainpipe by the Missoulian newspaper building. The pipe runs under the building and connects to storm drains along Higgins Avenue.
Missoula city firefighters found fluid dripping into a drain at the corner of South Third Street West and Higgins, but no nearby car or truck that could have been the source of the leak. They placed absorbent pads along the curb and drain to keep more fuel from reaching the river.
Travis Ross of the Health Department's Water Quality District said about 70 percent of the city's storm drains are "injection wells" that simply diffuse runoff water into the surrounding soil. But the remainder - including the one at Third and Higgins - flow into an old network of pipes that empty into surface water like the Clark Fork.
Firefighters placed a fuel-absorbent boom around the mouth of the drainpipe where it emptied into the river upstream of the bridge. They also used absorbent pads to soak up other fuel that was collecting along the riverbank and in a nearby irrigation ditch.
Reporter Rob Chaney can be reached at 523-5382 or at email@example.com.