Scheduled maintenance at the Laytonville landfill has led to calls for more rigorous groundwater testing and a long-awaited agreement between state and county agencies and the Cahto tribe, whose rancheria is right next door to the closed dump site.
The Mendocino County-owned landfill was shut down in 1993, amid vigorous environmental protests. It was capped in 1997. In 2002 and 2003, the county received multiple letters from the North Coast Regional Water Quality Control Board, referring to “a breakdown in discussions with the Cahto Tribe for an access agreement necessary for installation of the proposed background wells” to investigate the groundwater.
The Water Board wrote that, “In order to develop a comprehensive monitoring well network, background wells will need to be constructed on Cahto Tribe lands adjacent to the Site.” For that to happen, the Tribe and the county would have to make an access agreement and the project would have to be approved by the Bureau of Indian Affairs.
Last year, the County Department of Transportation issued a request for proposals from contractors to undertake a major renovation of the landfill cap, from fixing up access roads on the seven-acre site to replacing worn-out drainage pipes. The work was put on hold after the Cahto Tribe initiated government-to-government consultations with the California Environmental Protection Agency over its concerns about the landfill.
The county submitted its plans for the cap repair in 2020, the same year as a report showing that one of the wells had detected groundwater contamination. That triggered a requirement that the county step up its monitoring program and submit a feasibility study for corrective action.
Since then, there’s been a flurry of correspondence involving the Tribe, the Water Board, the Bureau of Indian Affairs, the US and California Environmental Protective Agencies, county supervisors, community activists, and the Laytonville County Water District.
The Tribe has now signed memorandums of understanding with the county and CalEPA to work together to monitor the site based on cultural relevance, with tribal input. Howard Dashiell, the head of the Mendocino County Department of Transportation, says the new request for proposals will formalize the county’s obligation to work with the Tribe.
“The new RFP will be roughly the same as the old one, except it will inform the consultant that they need to put in their scope of work, time for public meetings in the Laytonville community, at least one, and then with the tribal government, at least two, and to work with the tribal government’s technical representative as they develop the design,” Dashiell explained.
That would be Dr. Dietrick McGinnis, a Nevada-based environmental consultant who started monitoring the groundwater on the Cahto Rancheria about five years ago.
“I”ve worked for Tribes for about 22 years, in Nevada and California,” he said. “It’s the first time I’ve seen a county and a Tribe come together for an MOU regarding an environmental concern. The county was directed to do this by the Water Board, and we’re really happy to see it…And to see the state ask for it, I think, is very respectful of tribal sovereignty. Going forward, I hope we can work together. Just synchronizing sampling events between the landfill and the Tribe increases the quality of the data we produce — or the quality of the interpretation from that data.”
He shared some details about his work, which is still in the assessment phase.
“Over the last few years, we’ve put in remote sensing equipment, and done regular analysis on surface water and groundwater,” he reported. “We’ve found some releases, most likely from the landfill, coming into shallow groundwater, and some hints of volatile organic compounds in surface water that originates from the landfill itself…we’re picking up little bits of acetone, some plasticizers, things that indicate origins at the landfill, but are not in concentrations that have been terribly remarkable. But we’re doing an assessment right now, so we’re just simply following those hints to see how bad the problem is…Unfortunately, we see a lot of this in Indian Country, where these types of sites end up adjacent to tribal trust property. In this case, we have what is essentially rural residential property with an industrial site next door…this isn’t where landfills are supposed to go. They’re supposed to be far away from homes and people and children. And this is doubled down on when we look at these in Indian Country, because the Tribe wants to utilize their natural resources to reflect their cultural values. Harvesting the fish, the plants. And when they collect these things and consume them, they're getting an increased exposure to what’s released by sites like this. So it’s almost like doubling down on the bad. It should have never been located here, because the Tribe was here before the landfill. And these homes, many of them were here before the landfill. And then it deprived the Tribe of the opportunity to harvest some of these things on their own property.”
McGinnis is planning to put in a half dozen more monitoring wells, using state and federal funds. “I’ve got three 20-foot wells, and two of them are showing signs of being negatively affected by the landfill,” he said. “The third not being negatively affected actually provides me with a bit of a control. The depth (of the new wells) will actually be dependent on what we find as we drill. It wouldn’t surprise me if we end up going anywhere between 50 and 100 feet.” McGinnis added that the Tribe is open to working with the state, county or federal government to achieve a complete assessment. “And a complete assessment will require wells all around the site, to complement those that already exist,” he said. “The Tribe’s a little bit ahead, because I do have a few monitoring wells I’ve been able to work with. So I can design over here today. But hopefully we can design for the rest of the community soon. And encourage them to put in a system that will provide a complete picture of groundwater conditions around the landfill.”
In the non-tribal areas, county supervisors and the Laytonville County Water District have asked CalEPA to review the existing studies, and conduct further testing if any contaminants have been overlooked.