Ross Valley plans major downtown sewer upgrades in Fairfax to cut stormwater inflows and replace four creek crossings

Ross Valley Sanitary District officials told the Fairfax Town Council on June 3 that the district will begin a multi‑technique sewer rehabilitation this summer to fix chronic inflow and infiltration problems and to replace four creek crossings on Fairfax Creek.

"We are addressing hydraulic deficiencies and reducing the risk of overflows," said Phil Benadetti, identified in the presentation as a senior engineer with Ross Valley Sanitary District. He told the council the work is project number 957 and said it is required under a 2013 cease‑and‑desist order from the California State Water Resources Control Board.

The district plans to rehabilitate about 5,659 linear feet of sewer pipe, using a mix of methods: approximately 2,300 feet of open trench; about 2,100 feet of pipe bursting (a trenchless replacement technique); roughly 980 feet of guided boring; and about 200 feet installed by horizontal directional drilling (HDD). Work downtown will include open trenching on Pacheco and targeted trenchless installation near Merwin and Bank streets; a downtown segment notice to proceed was scheduled for June 22 with a goal to complete the downtown work before the end of July to reduce overlap with other summer projects.

Benadetti said the district selected alignments and construction methods to minimize public impact and cost to ratepayers. "We chose the shortest route and methods that reduce disruption — pipe bursting where possible and guided boring under the creek — to avoid removing parklets and to keep businesses accessible," he said.

Council members and residents pressed the district on coordination with other projects in town. "We are concerned about multiple simultaneous projects on our limited downtown streets," said a council member, noting ongoing Marin Water work. Benadetti said RVSD is coordinating with the town and other agencies, will issue two‑week and project notices, and will maintain a construction management presence and a 24‑hour service line for sewer‑related problems.

RVSD emphasized that much of the work targets infiltration: cracks, roots and stormwater that enter old pipes and overwhelm system hydraulic capacity during storms. Replacing exposed or vulnerable creek crossings and realigning pipes under or around creeks are intended to reduce the risk of infrastructure damage from debris and scouring during peak flows.

The district described environmental and cultural mitigation measures, including nesting bird surveys, biological and cultural monitors on site, and compliance with CEQA (a Mitigated Negative Declaration is available on the project web page). Benadetti said the district will avoid Bolinus Road where possible and coordinate pavement restoration with Fairfax public works.

Benadetti also said that, while the district's hydraulic model shows the current project resolves local deficiencies, any future new development would be evaluated site‑by‑site and developers may need to pay for required capacity increases. Residents and business groups urged clearer, earlier communications and a shared construction calendar that shows anticipated work zones and parking impacts across all concurrent projects.

The district's presentation materials and an alternatives analysis are posted on the RVSD project page, and the district said it would post real‑time updates during construction.

What happens next: RVSD planned to issue a notice to proceed for the downtown segment in late June and to update the town and businesses as work progresses; the district said it will prioritize rapid, well‑signed work zones and a public phone line for questions and complaints.