Supervisors approved revisions to county septic system regulations on Tuesday, overriding concerns from a Forest Knolls resident and the nonprofit Turtle Island Restoration Network about failing systems and water setbacks. The decision sends the plan to the Regional Water Quality Control Board for review.
The county’s plan will not affect septic systems that are working; rather, it applies to new systems, replacement systems or failing systems. It tweaks current rules, such as by adding a new mandate for septic pumpers to report failures to the county.
Yet compared to statewide regulations, the plan eases setbacks from impaired waters such that significantly fewer homes in West Marin will need to install expensive pretreatment systems when they get a new or replacement septic.
The plan, called the Local Agency Management Plan, or LAMP, is a requirement imposed by the California legislature, which in 2013 approve statewide septic regulations through AB 885. Counties have until May 13—tomorrow—to send plans tailored to local conditions to the water board, which must approve them. Counties that do not provide their own regulations must abide by the state rules.
For Marin, with an estimated 8,000 septic systems, Environmental Health Services said it would be virtually impossible to follow the state rules because they do not account for the county’s tricky terrain, including high water tables and clay soils.
A county staff report says that implementing the LAMP will increase staff workloads through additional monitoring and reporting. The Community Development Agency may increase septic system permitting fees to recoup new costs.
In large part, the regulations consist of the county’s current septic standards. But the LAMP makes a few notable changes: it will approve more types of pretreatment systems, slightly increase the amount of nitrogen allowed in effluent, increase the number of septic systems subject to an operating permit and require septic pumpers to report failures to the county.
Armando Alegria, an environmental scientist with Environmental Health Services, said that many systems, like redwood box septics, were built before the establishment of modern rules. As long as they work, they will be left alone. If the county learns about failures, it could mandate repairs or, if the system cannot meet requirements such as water setbacks, a new system with pretreatment.
The requirement to report failures could be a significant concern for homeowners, since, depending on site conditions, a replacement system could require pre-treatment, which can be pricey.
Septic failures in the county are a major concern for Turtle Island, the Forest Knolls environmental advocacy group said in a comment letter received by the county on the morning of the hearing.
Rebecca Ng, deputy director of Environmental Health, said the county would also start mapping reported failures. If a certain area suffers high rates of failure, the issue could be addressed in a LAMP update, since the plans will be reviewed every five years.
Brady Wedman, a Pilates instructor in Forest Knolls who in the past objected to a neighbor’s proposed septic, wrote in a letter that the regulations are not based on science and expressed concerns about vertical and horizontal setbacks to water. Ms. Ng, after summarizing the letter, countered that the LAMP is based on county regulations that the water board has reviewed in the past. “We believe it’s based in science,” she said.
A central part of the presentation on Tuesday focused on setbacks from water bodies that the federal government has declared impaired for pathogens or nitrogen.
Federally impaired water bodies are supposed to have a plan for limiting the problematic contaminant, called a Total Maximum Daily Load plan. But so far, Tomales Bay is the only water body in Marin with a T.M.D.L., for pathogens. (The plans for other impaired waters, such as Lagunitas Creek and Bolinas Beach, are supposed to be finished in coming years. Tributaries will be affected by the main body’s load plan, the state board has said.)
Impaired waters without load plans must abide either by the state’s regulations, which establishes a 600-foot setback for septics, or a county LAMP. For properties entirely within a setback, new systems will generally be subject to pre-treatment and an operating permit.
Given the large number of parcels that could be impacted, the county’s LAMP proposes a smaller setback, of 200 feet. That significantly cuts the number of parcels in Marin that could be affected. Countywide, a 200-foot setback affects 571 parcels, where as a 600-foot setback effects 1,171, according to Environmental Health. Specifically, along Lagunitas Creek the smaller buffer reduces the number of affected parcels from 142 to 96; at Bolinas Beach from 116 to just 30; along Walker Creek from 97 to 41; and along San Geronimo Creek from 691 to 371.
Near the end of the meeting, Ms. Ng noted that the county will soon sign a contract for an environmental impact report on a potential community wastewater system in Woodacre, which could take about 300 homes off septic systems and instead send effluent into a community wastewater system. Supporters say the system could reduce the number a failing septics contaminating Lagunitas Creek. Ms. Ng estimated that once underway, the E.I.R. could take about two years.