Flushes of the toilet in most West Marin homes usually send down mixtures of urine, excrement and water into a personal septic system. But in a few years time, up to 300 homes in the flats of Woodacre and San Geronimo might hook into a community system to handle the human effluent instead.
Such a system might pipe the wastewater to a leachfield northeast of the flats, but an alternative, which would shuttle the wastewater to a proposed pair of ponds on the San Geronimo Golf Course—there to be disinfected and used for irrigation—has lately been the favored subject of discussion.
The county is currently seeking a grant to review those options through an environmental assessment, and while some residents fear a community system will encourage development or be prohibitively expensive for existing homeowners, others say those beliefs result from misunderstandings.
Leaky septic systems, many built before modern codes were in place, pose a problem for water quality in Tomales Bay, which is fed by Lagunitas Creek. According to Liza Crosse, a member of the Tomales Bay Watershed
Council and an aide to Supervisor Steve Kinsey, the creek is the second largest contributor to pathogens in the bay.
The flats of Woodacre are a particular problem because of the high water table, said Christin Anderson with the Woodacre/San Geronimo Wastewater Project Group, which is raising money from homeowners to help fund an environmental impact report. “We primarily became involved because during wintertime when the water table was high and it would rain, you would walk through Woodacre and it would smell like sewage,” she said.
The idea for a community wastewater system had its genesis in a grant received by the watershed council, which funded community meetings in the valley to discuss problematic septic tanks. A feasibility study was completed in 2011, concluding that many septic systems in the flats of Woodacre were not up to par. A sample survey found 73 percent needed high-level repairs to meet modern standards and reduce the potential for waste to make its way into the watershed. The average cost for a high-level upgrade, it said, is $43,500.
That feasibility study assessed three different solutions, including a system that would pipe wastewater to a treatment site near the golf course—where millions of gallons would be disinfected, stored in ponds and used as spray irrigation during the dry months. A hundred and fifty homes could provide 15 percent of the golf course’s irrigation needs.
Though the golf pond system provides a way to recycle the water, it is also the most complex option. Wastewater must be filtered and disinfected to meet stringent state standards, waste must be collected and periodically disposed of, and failsafe systems must be in place so that human wastewater does not make its way into the watershed.
Based on estimates of hooking up 150 homes, capital costs of over $6.7 million, as well as annual maintenance costs, made it the second most expensive option studied. Including more homes would lower the cost per person, but building a proposed second pond to accommodate up to 300 people would add significantly to the bottom line; there is not yet an estimate of just how much.
In response to a recent community survey sent out by the county, opponents raised concerns about the high cost of a complex community system and said modern improvements instead should be made to existing septic systems. One response noted that a community system simply could not force leaky systems to connect: “What is the point of this exercise in futility if the owners with failing systems don’t want to hook up?” it asked.
Brian Staley, a Woodacre resident and critic of a community system, worries about whether such a complex system for a small, capped number of homes would set a precedent for more multi-million dollar projects around the state. He argues that, unlike towns such as Marshall that have set up a community system, Woodacre is not an in immediate emergency. He believes that individual fixes are the better option, perhaps undertaken when homes go through a change in ownership.
The feasibility study evaluated the option of creating a management district that would monitor individual septic systems to ensure failing ones were fixed and that wastewater was contained. That approach could ameliorate many environmental and water quality problems, but it was also ruled the most expensive option, at over $8.3 million, because of the high cost of bringing substandard septic tanks up to code. And homeowners might object because modern mound systems take up space above ground on their small lots.
Robert Turner, a project manager at Marin Environmental Health Services, also questioned whether people would ever support a system that would require visits on private property to inspect septic tanks.
Overall, the feasibility study concluded that a community leachfield would be the best option in terms of cost—but when environmental, water quality and reliability were factored in, the golf ponds were the favored alternative.
The Woodacre homeowner group aspires to fund at least 50 percent of capital costs through grants, Ms. Crosse said, but added that goal is just that: an aspiration.
Ms. Anderson said those who hooked up would likely have to pay about $20,000, which could be delivered over 20 years. But there is no way to know for sure how much it might cost until a final total cost is determined, homeowners commit and grant money is procured.
As for those who may have a difficult time affording to buy in, Ms. Crosse said some lower-income residents might quality for a program to defer payments, or pay back the loan over a longer period of time. But everyone must also pay an annual fee, which would likely be around $1,100 or $1,200. “There’s no way to defer that,” she said.
Apart from economic fears are claims that the elimination of hundreds of local septic systems could spur development. “We are being lied to by people who want larger homes or are too lazy to do the homework to figure out a reasonable fix for their antique septic systems,” said Mr. Staley, in a Facebook in a post positing his concerns.
But supporters of the golf pond system say the opposite: that a community system could limit development.
Homes that utilize septic tanks are subject to regulations that—depending on a number of factors including the parcel size, the size of the septic tank and leachfield, and the number of bedrooms—can limit the square footage of a home. Those limitations disappear if a home hooks into a sewer system.
But there are ways to ensure that development does not spiral out of control. On the recent community survey, the most popular option was a deed restriction on houses that sign up, with limits to either 500 square feet of additional development or however many square feet would bring the home to the average size in the area— 1,371 square feet.
Mr. Staley countered that it is the county and legislators’ jobs, not homeowners, to regulate development. He worries that homebuyers who don’t read the fine print may find themselves surprised with deed restrictions later on.
The environmental impact report itself will cost about $225,000. A mixture of money from the county, Marin Municipal Water District and locals will fund most of it, but the county is also seeking a $75,000 grant from the State Water Resources Control Board’s recycling water program.
The scope of the report was a bone of contention in some community survey responses. One respondent called the golf pond option a “railroad job.” But the county says it would evaluate at least two options: the golf ponds and a community leachfield. Once funding is secured, the community can formally comment on its scope.
And even if the report is funded, a community system cannot be built until the assessment is completed, homeowners vote to go forward and the Board of Supervisors approves the project itself.