News Flash


Posted on: August 3, 2021

Sewerage Agency of Southern Marin Wins Major Award for Exemplary Design and Construction

9 men and 1 woman stand in a row in casual attire and suits. The woman holds a large glass award.

9 men and 1 woman stand in a row in casual attire and suits. The woman holds a large glass award.

The Sewerage Agency of Southern Marin (SASM) has won the California Association of Sanitation Agencies (CASA) Award for Excellence for Outstanding Capital Project for the “Headworks Building Biological Odor Control System” project, completed in 2020.

The new $2.2M Bio-Trickling Odor Scrubber Control System employs a unique and innovative dual-vessel, three-story odor control process, using a biologically active process with a scrubbing solution to dissipate and neutralize odors. Despite the numerous construction challenges, including the removal of two 12,000-gallon underground storage tanks and building a deep concrete pad over soft bay-mud conditions, this project was successfully completed on time and within budget. 

The CASA Award for Excellence for Outstanding Capital Project recognizes exemplary wastewater capital projects.

“We are grateful to CASA for recognizing the important and innovative work we are doing at the SASM Wastewater Treatment Plant,” Lew Kious, President of the SASM Board of Commissioners said. CASA grants the award to agencies that have demonstrated unique or innovative design and construction, engineering applications, technical advancements, and difficult challenges of the project.

The SASM Board decided to focus on the odor control and allocate additional funding for its construction in 2016, after conducting a study of odors and emissions from the facility while doing a 5-Year Capital Improvement Program design.  

“This is the first and major step towards improvements of the odor control at the SASM Plant and we plan to do more,” President Kious continued.  

The Wastewater Treatment Plant (WWTP), constructed in 1954 and upgraded in 1981, is located across the street from the Mill Valley Middle School, Harrison Skatepark, and Bayfront Park, a very popular recreation area. Over the years, school officials, parents, and residents have shared complaints about plant odor. 

In 2017, SASM awarded a $17.5M contract to execute Phase I of the WWTP Rehabilitation Project, which consisted of numerous improvements to the plant. To address odor issues, wastewater engineers focused on the source of the issue and constructed the Odor Scrubber Control System for the Headworks Building, where raw sewage enters the plant. 

“We’ll continue to work on odor control improvements at the plant, despite challenges posed by the processing of millions of gallons of wastewater that flow through SASM plant every day,” Mark Grushayev, Wastewater Treatment Plant Director said. “The plant was designed to have treatment processes that are open to the air, which is common throughout the industry. We are exploring new and emerging technologies. We work hard to be a good neighbor and appreciate community support as we improve and modernize the plant.”

About the Sewerage Agency of Southern Marin

The Sewerage Agency of Southern Marin (SASM) is a Joint Powers Agency formed in 1979 to consolidate the wastewater collection, treatment, water reclamation and disposal needs of about 29,500 residents in Southern Marin County.

SASM is made up of six Member Agencies (MAs). They are: the City of Mill Valley, Tamalpais Community Services District, Almonte Sanitary District, Alto Sanitary District, Homestead Valley Sanitary District, and Richardson Bay Sanitary District.  Each Sanitary District has one seat on the SASM Board of Commissioners.  

Each MA owns, operates and maintains a sanitary sewer system.  These sewer systems connect to the main sewer lines owned by SASM which carry the wastewater to the WWTP.

The SASM WWTP in Mill Valley was designed for treatment of 3.6 million gallons per day in dry weather and serves approximately 29000 residents.

Learn More:


Telephone: (415) 388-2402
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