The National Park Service is moving forward with a plan to overhaul its wastewater treatment facility at Stinson Beach, where septic tank leaks have long been suspected to pollute groundwater. The septic system services public bathrooms and showers for park employees and hundreds of thousands of beachgoers. Though the park says it is pursuing the project according a schedule of periodic rehabilitations through the Golden Gate National Recreation Area, sea-level rise is a lingering concern at Stinson Beach, where higher levels and storms exacerbated by climate change not only have the potential to flood the wastewater treatment site but also push up groundwater until it comes into contact with contaminated effluent in the leach fields.
“We’re looking to get our facility away from the ocean and reduce risk for groundwater contamination. Some of the system’s components are near the end of their industry life cycle, and we want to be proactive,” said Howard Levitt, the communications director for the recreation area.
A 30-day public comment period for the plan ends at midnight on Dec. 12.
Among the many proposed changes to the septic system, the park would repair and replace primary treatment tanks at the parking lot and install sewer lines running from the tanks to a large collection tank that would be built at a nearby storage facility. Treated wastewater would then be pumped from the collection tank to a new fenced-off, elevated leach field.
Park representatives say that field would be located on a parcel further away from the beach than where the existing leach field stands, thus helping prevent effluent from mixing with groundwater. “The site conditions are such that the facilities are right next to the coast and we have to design a system to work with those site constraints,” said Steve Ortega, an environmental protection specialist who is managing the project. “Anything we design has to deal with sea rise, and that’s what this project does.”
Stanford researchers in 2010 found wastewater contaminants that have been emanating from septic systems near the beach’s parking lot and polluting groundwater in the area. The park service, however, does not monitor fecal coliform at the beach.
Observers noticed 10 years ago that weeds and algae—an indicator of possible contamination—had begun to grow rapidly along the beach. To Scott Tye, the chairman of the Surfrider Foundation’s Marin Chapter and a former board member for the water district, it was a sign the tanks were leaking.
“We jumped on [the park service] about this problem about 10 years ago, so I’m glad to see this project happening. It’s a good thing they’re doing,” he said.
Others, however, are not so certain the plan will provide a safeguard against future contamination around the bathrooms. “The main concerns are that the plan will be an expensive, ugly, noisy and disruptive construction project that will not create a long-term solution to rising seas since the bathrooms themselves are more at risk from storm surge than the septic systems,” said Stephen Simac, a Stinson Beach resident.
The National Resource Council and Coastal and Ocean Working Group of the California Climate Action Team estimate that by 2050 sea levels could rise anywhere from 7 inches to 35 inches (and by 2100 could rise as high as six feet). Such widely varied projections make planning difficult.
“I think the system will work for another 20 years,” Mr. Tye said. “After that, all bets are off. If the ocean rises six feet, then the area will be under water. Septic systems will be the least of our worries then.”
Other residents feel the park has not done enough to reach out to the community for input on the project.
“For one, I’m requesting the public comment period be extended, since they didn’t even post notifications locally,” Mr. Simac said. “There’s been very little outreach, other than a presentation to the [village association] board. Very few residents are aware of their plans and I only know what they’ve posted online.”
The park estimates the total cost for the project will be $2.55 million, although that amount is expected to change as the process moves forward. Golden Gate National Recreation Area has been working with the California Coastal Commission to bring the project into compliance with federal regulations. Once the project has received approval, Mr. Levitt says construction will last for eight months and will begin in either the fall of 2015 or the spring of 2016.
The schematic design for the rehabilitated system, and a form to submit comments, is available at http://parkplanning.nps.gov/documentsList.cfm?projectID=49543. The Stinson Beach Village Association will be discussing the plan at its regular meeting this Saturday, Dec. 6 at 10 a.m. at the community center.