Plans for a new wastewater system on the property at the mouth of Tomales Bay where the Lawson family has operated a campground since the 1950s were approved by the California Coastal Commission last week. The milestone decision marks an end to the family’s decades-long effort to permit its operations and satisfy the Environmental Action Committee of West Marin, which has played the watchdog to protect the site’s sensitive dune habitat.

Over the past decade, the Lawsons have tailored their operations to meet the terms of a coastal development permit they obtained in 2011, which required reducing and consolidating campsites, phasing out 170 residential trailers, implementing a series of conservation projects and developing a new wastewater system. The family proposed plans for the wastewater system several times without success, facing hurdles related to the fact that much of the 960-acre property qualifies as an environmentally sensitive habitat area, or ESHA.

Mike Lawson, who grew up on the property and now serves as the president of the campground business, Lawson’s Landing, said negotiations with the county, the coastal commission staff and representatives from the E.A.C. pushed into the 11th hour before the commission’s hearing last Friday. He expressed relief that an agreement was reached.

“We’ve spent the last 10 years following the lead from the C.C.C., working extensively, cooperating and doing everything that they wanted,” Mr. Lawson said. “I think we’ve done a good job and proved how serious we are with all the effort and money and things we’ve done to change Lawson’s Landing.”

Under the approved plans, the Lawsons will build an entirely new wastewater treatment and disposal facility, abandoning the existing leach fields. Besides serving seven employee houses, the system will allow the Lawsons to build new bathroom facilities for the 350 existing tent and R.V. campsites, which are today serviced by portable toilets, and to proceed with a plan approved in 2011 to build up to 20 guest cottages.

The wastewater system’s design and location are formalized in an amendment to the Lawsons’ 2011 coastal development permit, along with several other changes. These include plans for a new administrative office that will double as an emergency response center in times of need, a mobile food trailer, additional boat storage, a new barn to support agricultural uses, and a beach restoration project in an area where a pier was recently taken down. At the request of Marin County Fire, the family will make some emergency access improvements.

Mr. Lawson did not have a cost estimate for the work ahead, though he said the wastewater system alone could cost up to $2 million. Since he took the helm as president 25 years ago, his family has spent around $5 million in its effort to obtain permits, including funding for a scientific review panel with representatives recommended by the E.A.C.

The Lawsons’ 2011 permit allowed for the sale of a $5.5 million conservation easement to the Natural Resource Conservation Service on 465 acres of the property, a move that helped the family stay afloat in the face of high expenses. To fund the wastewater system, Mr. Lawson says he plans to apply for a loan from a federal program of the Department of Energy.

The improvements to the property over the last decade garnered the applause of Marin County Supervisor Katie Rice, who also serves as a coastal commissioner. She made the motion to approve the permit amendment last week. 

“I’m someone who grew up heading out to Lawson’s Landing and Dillon Beach and, seeing it now, it’s a much different place than it was 50 years ago. It’s more beautiful, cleaner, restored in so many ways and our approval today will just take that further,” she said. “It’s a spectacular place and I commend the Lawsons’ work to date on this and the push of the E.A.C. and commission staff.”

Catherine Caufield, an Inverness resident who served as the executive director of the E.A.C. between 1999 and 2006, has continued to lead the organization’s participation in the Lawsons’ permitting process. Last Friday, she also voiced her approval of the permit amendment—and of the importance of its conservation objectives.

“As this long process comes to an end, I’d like to reflect—briefly—on the big picture,” she told commissioners. “[You] see a spectacular, nearly 1,000-acre coastal site, home to mobile dunes, dune scrub, dune prairie, and the richest collection of seasonal dune wetlands on the central coast—the Tomales dunes and wetland complex. It is one of only four sites in the entire country with gegenwalle, [or] sand ridges that form as mobile dunes migrate downwind and new wetlands are formed in their shadow.”

Ms. Caufield said the site supports at least nine listed species and other locally important species, and provides crucial habitat for the dozens of bird species that depend on Tomales Bay. “And despite the encroachment of the aggressive, alien European beachgrass, it is one of the few dune systems in California that still has a vital population of native dune grasses, including one recently discovered and still-undescribed native grass,” she said.

Ms. Caufield’s involvement in the future of Lawson’s Landing began in 1999, when she appealed a county permit that allowed camping on 83 acres, as opposed to the 18 acres permitted today. The E.A.C. has been involved since its founding in the ‘70s.

The commission has had to approach permitting through a lens of compromise, seeking to balance two of the key mandates of the Coastal Act: preserving the coastline’s significant natural resources and providing public access. Lawson’s is the only campground on Marin’s shores, and offers a rare affordable option for staying at the coast. Campsite prices range from $35 to $60 per night.

Legalizing operations has been a marathon for the Lawson family, which has owned the property for almost a century. Mike Lawson partners with his cousin Willy Vogler to helm the family business; it was their great-grandfather, Sylvester Lawson, who purchased the land and turned it into a summer destination campground. The state became involved in 1960 as it sought to permit the operation, beginning what would become a lifetime of work for the younger generations.