County water crews stopped a sewage leak Monday after it had spilled about 12,000 gallons of raw waste into Sonoma Creek. A broken pipe under the creek at the Madrone Road bridge, creating “a small fountain” of sewage bubbling up through the fresh water, was reported at about 12:30 p.m. by a neighbor.
Crews arrived about an hour later, and the leak had been isolated and stopped by about 5 p.m.
The steel pipe carries waste from the Glen Ellen area to the treatment plant on 8th Street, said Brad Sherwood of the Sonoma County Water Agency. He said the pipe, which was probably 20 to 30 years old, had become exposed out of its concrete casing beneath the water.
The pipe should normally have lasted about 50 years, he said.
The pipe was one of two running along the creek bed. Crews were able to divert the sewage flow into the second, secure pipe to stop the spillage into the creek.
Workers then installed a portable dam around the site, on the eastern side of the creek next to the bridge foundation. After the temporary barrier isolated the spot, four pumps were deployed to drain the area to give workers access to the broken pipe.
Once there is full and dry access to the pipe, repair work was to begin immediately. Sherwood said the affected pipe may be able to be re-lined, but it would need to be replaced if there is more serious damage
“We’ll decide what to do when we get a good look,” he said.
Signs warning not to wade, swim or drink creek water were posted on all bridges down through Maxwell Park, Sherwood said. Neighbors in the immediate vicinity of the spill were warned as well.
Kevin Dillon, who lives five houses downstream for the bridge, was having coffee in his backyard at about 10:30 a.m. when he noticed a strange odor. At the time, it smelled like someone doing laundry, he said.
As the smell intensified and the creek grew cloudy, Dillon walked to the site and saw a “small fountain” bubbling up through the creek flow. He then made the 12:30 p.m. call to the county.
Water quality was at acceptable levels by Tuesday afternoon, Smith said. Testing showed oxygen levels significantly above distress levels and a visual inspection downstream of the bridge showed no impact to wildlife.
There was enough moving water in the creek to help dilute the waste, he said.
Experts from the Sonoma Ecology Center are also monitoring the situation.
