Mill Valley Sewer Project Triggers Foul Odor

MILL VALLEY, CA — A Mill Valley project that aims to extend the life of an aging septic tank has left local residents holding their noses.

The Waste Water Treatment Plant Rehabilitation Project involves the rehabilitation of a 40-year-old, 50-foot diameter digester tank at 450 Sycamore Avenue.

The tank is designed to reduce the volume of sewage sludge and make it suitable for subsequent use.

After the repairs were completed, the tank was gradually refilled and is undergoing a natural process of re-establishing its biological environment to facilitate further breakdown of the organic matter.

It is heated to approximately 98 degrees Fahrenheit and is designed to maintain this temperature (works similarly to our own bellies).

The progression of this biological process consists of several stages that may produce various gases that cause unpleasant odors.

“We expect that this should change within a week or so,” city officials said.

“We are testing the output and its levels are well within regulations, but we realize that odors are very unpleasant and may cause concerns in the community.

“We are working hard to accelerate this process and appreciate your patience.”