Sewer sludge spill creates stinky traffic mess near Cotati

A truck hauling sewer sludge crashed Tuesday morning on a rural Sonoma County highway, dumping about 10 tons of smelly waste byproduct and causing traffic issues, according to the CHP.

The 8:10 a.m. crash occurred on Highway 116 near Blank Road, northwest of Cotati.

The driver apparently lost control and the vehicle spun into a tree. The driver, working for Poncia Fertilizer of Cotati, wasn’t injured. But the impact tipped the load, said CHP Officer Jon Sloat.

Sludge slopped across the highway lane and drivers traveling into the mess began spinning out, according to multiple 911 callers to the CHP.

It wasn’t clear at first what the black, slippery stuff was. Callers suggested wet concrete, asphalt or mud.

Sloat said officers determined it was sewer sludge to be sprayed on a field as fertilizer.

Sebastopol resident Paul Derkos and his son, Dylan, pulling a trailer, were on their way to a drilling job in Sonoma when they came upon the spill soon after it happened.

First it looked like uncompacted asphalt, perhaps left over from nighttime highway work. But that didn’t square with what was happening to the cars - slipping around like a winter day on black ice, Paul Derkos said. “We realized this isn’t asphalt, it was like Tahoe, cars sliding, going sideways.”

“After I realized it wasn’t asphalt I thought it was cow hooey. There was a lot,” he said. He pulled far to the right and slowly got around it without incident.

He later learned from news reports what it was and said he’d give his vehicle and trailer a good scrubbing.

Officers closed the highway lane for the cleanup and drivers were routed to Roblar and Stony Point roads until 12:45 p.m., Sloat said.

The detours backed up traffic extensively and officers reported numerous drivers were making illegal turns to get out of the traffic jam, according to the CHP.