As California ramps up efforts to thin out forests and landscapes overgrown from a century of fire suppression, agencies are grappling with the question of what to do with the tens of millions of tons of dead trees, brush and other vegetation to be removed in the coming years.
This month, Marin County launched one of five pilot studies taking place throughout the state to explore opportunities to reuse this biomass through new types of businesses as well as ways to capture or reduce greenhouse gas emissions. Potential options include composting, mulching, energy production, hydrogen production, soil carbon sequestration and wood products, among others.
“In this case, we’re dealing with stuff that is easy to label as waste, but waste is an old-economy way of thinking,” said Chad White, manager for the Marin Biomass Project. “These are bioresources that help us regenerate Marin.”
The $500,000 study, funded by the Governor’s Office of Planning and Research and led by the Marin Resource Conservation District, will work to create an inventory of the current and projected biomass in the county. From there, the project will examine existing and potential new uses of biomass, the costs required for these options and the potential greenhouse gas emissions and sequestration before creating a list of recommended projects.
“We could be producing renewable energy, we could be selling it to the county. We could be producing biochar, which is a byproduct of combusting it down slowly,” said Bruce Goines, a project steering committee member and president of the Marin Wildfire Prevention Authority. “There is a range of products that could be made. So the question is, do we have enough material, what are the economics, what are the environmental consequences, what are the siting opportunities? And hopefully, we are going to be able to maybe develop some new business here.”
The 18-month study will work with a variety of agencies and organizations throughout the county, from fire departments to land managers to waste haulers to local governments.
The state has about 47 million dry tons of biomass, according to the California Energy Commission. Biomass is not limited to forest fuels, but is any plant material from agricultural, industrial and municipal wastes such as food scraps, paper, yard trimmings and cardboard.
With the recent passage of Measure C, of a countywide parcel tax for wildfire prevention efforts, significantly more wood and vegetation are expected to be generated as part of the county’s work to clear out defensible space and thin overgrown forests.
Adding pressure to this inflow of green waste is a state law, Senate Bill 1383, that requires 75% of organic waste to be diverted from landfills by 2025 to reduce the production of methane, a potent greenhouse gas.
“Municipalities and the county need to assure that their biomass collection systems can meet this state goal and identify markets for these materials,” said Belle Cole, chair of the project steering committee.
Waste management businesses such as Marin Sanitary Service, Waste Management Inc., Recology and West Marin Compost process green waste in a variety of ways, from creating wood chips, composting, mulching and exporting plant material to biomass energy plants in the state.
Marin Sanitary Service, based in San Rafael, ships three to four truckloads of ground woody plant material each night to two biomass facilities in Woodland and Stockton, generating greenhouse gas.
“The woodier material and branches and stumps and even the smaller branches and twigs are not really ideal for composting,” said Justin Wilcock, the company’s director of general operations. “It takes a lot longer to compost it.”
Wilcock said San Rafael has already permitted the service to build a 2-megawatt biomass energy plant at its site. The option has been evaluated for the past seven years, Wilcock said, with the passage of Measure C and the expected additional wood material heightening efforts to evaluate this option.
MCE, the electricity provider formerly known as Marin Clean Energy, has been interested in adding biomass power to its portfolio. While biomass energy production does produce carbon dioxide emissions, they are significantly less than from burning the material or allowing it to decompose, said MCE spokeswoman Jenna Tenney.
“Really what we’re hoping we can do is to build some facilities in our service area so you’re not expending as much greenhouse gas emissions trucking it out and letting it sit there,” she said.
Tenney said MCE is waiting for the California Public Utilities Commission to open proceedings to provide guidance on how community choice aggregation energy providers such as MCE are able to integrate biomass power into their energy portfolio.
Larry Minikes, a Marin Conservation League board member and project steering committee member, said the idea is to keep everything local as long as the option fits with the county. Equity issues will need to be taken into account for projects such as biomass plants, he said.
“We have been discussing this because the obvious siting location is Marin Sanitary,” Minikes said, “but if you’re having something putting out any sort of effluent of any kind, there are concerns about local neighborhoods. We are also looking at that and looking at doing this in an ecologically sound way that minimizes any source of pollution.”
The study is set to be completed in 2024 and will be published in a report.
More information on the Marin Biomass Project can be found at marinrcd.org/marinbiomassproject.
