2023 Sewer Rehabilitation

On March 21, 2023, Maggiora and Ghilotti, Inc., was awarded a $1.8M construction contract to complete numerous repairs, replacements, and improvements to Mill Valley’s sewer system’s infrastructure. This sewer improvement work is funded from the City’s Capital Infrastructure Project (CIP) sewer collection system account and paid by Mill Valley residents and business owners from collected monthly sewer billings and fees.    

Update as of October 19, 2023:

Sewer improvement work started this May and is scheduled to be completed by October 2023. This sewer system improvement project title is called “Frontage Road Force Main Replacement” and is comprised of three major project work elements. Project Element #1 is 100% complete and Project Element #3 is 96% complete. Project Element #2 is currently 100% complete. 

Project Element #1: Hauke Park

Project Element #1 involvehauke_park_birdseye (JPG)d replacing old clay gravity sewer pipe with new plastic pipe by the open trench method. In addition, new concrete manholes along Hamilton Drive and through Hauke Park’s soccer field were provided. This sewer system improvement work was completed on June 23, 2023. 

Projresidential sewer workect Element #2: Residential Areas

Project Element #2 involves replacing old clay gravity sewer pipe with new plastic pipe by the open trench method plus rehabilitating existing concrete manholes along Glenn Drive, Heather Way, Cascade Longfellow Drive.  The pipe replacement was completed in May and the road surface work was completed in June. The new manhole installation in Sycamore Park was completed in August. A planned Sycamore Park Field Restoration Project, to be performed by City Parks Maintenance staff, is scheduled to start late October. 

The Cured-In-Place Pipe (CIPP) sewer rehabilitation work at Sycamore Park was completed on October 16th, for Buena Vista Avenue on October 10th, and for Miller Avenue on October 11th.  CIPP involves inserting a flexible liner inside the existing pipe, inflating the liner, and exposing it to steam pressure to harden the liner inside the pipe. The liner forms a smooth surface inside the existing pipe, restoring it to near-new condition and extending the life of the sewer pipe for 50+ years. 


Sycamore Park Work: This sewer trunk line is a critical component in the SASM collection system which transports over 70% of City of Mill Valley’s sewage flow to SASM’s Wastewater Treatment Plant (WWTP) for processing.  This 30-inch diameter gravity sewer pipeline built in the 1950’s era extends from Miller Avenue through Sycamore Park to Sycamore Avenue under the Arroyo Corte Madera del Presidio creek.  This improvement will minimize the risk of failure and potential environmental impact. 

Project Element #3: Hahamilton drive sewer workmilton Drive

Project Element #3 involves replacing the old cast iron force main sewer pipe with new High Density Polyethylene (HDPE) pipe along Hamilton Drive from Shelter Bay Avenue to the Redwood Frontage Road.  A force main is a pipe that uses continual pumping from a lower elevation to force the fluids to a higher elevation before it can get to its destination.  The high pressure system requires additional care and planning with the use of a temporary by-pass system.  This improvement work, aka, “Frontage Road Force Main Replacement” is scheduled to occur from July - September.  During that construction period of trenching, pipe installation, and road resurfacing, the Public should expect one-lane closures along Hamilton Drive and Frontage Road.  

The remaining contract work includes traffic striping along Hamilton Drive, from Shelter Bay Road to Frontage Road, and is scheduled for October 25. 

 The contract work progress for all three project elements is 96% complete and remains on schedule.  

For any questions or comments, please contact:

Tom Levin, Project Manager