Marin environmental staffers released a draft of revamped regulations for septic systems that must be submitted to the state for approval next month. The new rules include greater setbacks for systems near federally impaired water bodies like Tomales Bay and Lagunitas Creek and a requirement that septic pumpers report failures to the county.

The rules are part of a state effort begun over a decade ago to regulate septic systems, which can contaminate creeks and groundwater if they fail. In 2012, A.B. 885 created a series of tiered rules for septic systems depending on the level of risk they pose. But the law allows each county to create an alternative plan tailored to local conditions—called a Local Agency Management Plan, or LAMP—which the Regional Water Quality Control Board must approve. 

County plans are due May 13, and counties that do not create a LAMP must follow the state guidelines. Supervisors will vote on the LAMP on May 10.

Rebecca Ng, chief of Marin’s Environmental Health Services, said during a Tuesday workshop on the draft that California has extremely variable geology and climate. Marin in particular has tricky terrain because of clayey or rocky soils and high groundwater in many areas.

“The one-size-fits-all regulations are not possible,” Ms. Ng said. “Most areas in Marin County cannot meet the [state] minimum standards.”

For instance, state regulations require a minimum distance of five feet between the septic trench bottoms and groundwater or an impermeable layer; because of its high groundwater, Marin is proposing that distance be three feet, which is more in line with current county regulations.

One of the most significant differences between the state rules and the county’s local plan has to do with setbacks. The state rules prohibit installing new traditional systems within 600 feet of federally impaired water bodies. Since that setback can encompass entire parcels, many property owners who want to develop or add to their property must pay for more expensive, alternative systems that pretreat sewage, such as with sand mounds, and which are usually hooked up to a computer system to detect failures. (Those who are not planning to further develop their properties and have no problem with their systems should not be affected.)

In West Marin, many waters are considered impaired due to either pathogens or nitrogen, or both. These include waters off Lawson’s Landing, the Pacific Ocean at Bolinas Beach, Tomales Bay, Lagunitas Creek and Walker Creek. And the new setback requirement applies not just to the impaired water body itself, but all its tributaries.

Environmental Health Services staffer Armando Alegria warned that the water board’s online tool meant to help homeowners figure out whether they are affected, does not show tributaries, but that tributaries are indeed included. 

Marin’s draft LAMP shrinks the setback to just 200 feet, which the county called “a more reasonable standard.”

“The 600 feet just came out of nowhere, quite honestly,” Mr. Alegria said.

He said they are still determining how many parcels would be impacted by the 200-foot buffer. 

Mr. Alegria also noted that once the water board implements what’s called a Total Maximum Daily Load plan—which regulates pathogens or nutrients going into specific rivers, bays and oceans— for each water body, specific setbacks for those water bodies could change.

In response to skeptical remarks from Supervisor Kate Sears, who wondered if the county’s plan was too weak, staffers noted the Tomales Bay is already under a protective daily load plan limiting pathogens. They also said the LAMP will expand the types of septic systems within the setback that require an operating permit—which involves annual fees and inspections—to some traditional systems, which do not typically need permits. 

Mr. Alegria said that having more systems under operating permits would help the county oversee them, “because that’s an issue with septic systems. Once they meet the code and they’re not alternative, it’s basically up to the landowners to maintain the systems.”

Supervisor Katie Rice supported protections for water, but also worried about compliance—that is, whether additional regulations would push more homeowners to pursue projects without permits—and other impacts to homeowners, given permitting costs. But she also suggested the county consider adding another layer of regulation: requiring inspections when properties are sold.

Brian Crawford, director of the Community Development Agency, said they had considered that rule, but he added, “I think the best way to work with property owners…is to incentivize them.”

Supervisor Steve Kinsey chimed in: “I think in the Wild West, that [requirement] would go very poorly.” 

Other changes in the LAMP include setbacks for public water wells and reservoirs, and the kinds of allowed pretreatment systems. One looming change elicited concern from Supervisor Kinsey: the requirement that septic tank pumpers report failures to the county. 

“I think that we need to have some pretty clear rules for septic tank pumpers,” he said. “Mike Giammona [of City Sewer Pumping] is out there driving in West Marin, and being a friendly guy, and all of a sudden he’s turning everyone in… I encourage staff to think about what we do with that information, and how quickly, and how friendly our letter is when it comes.”