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The Marin Biomass Study: Pathways to Improved Utilization and a Regenerative Biomass Economy

The Marin Biomass Project offers the first comprehensive study of biomass flows generated in Marin and pathways that can grow a regenerative biomass economy.

Executive Summary

Marin County faces a growing challenge. Its steps to improve wildfire safety are contributing flows of biomass into Marin’s economy without ways to make productive use of them. Vegetation management around residences, schools, civic spaces, and places of commerce is increasing flows of biomass like foliage, branches, and trunks of smaller-diameter trees. Vegetation management on Marin’s forested lands is likewise increasing flows of woody biomass. Currently, this biomass is largely being directed into waste management supply chains. Along with biomass from Marin’s cities and towns, a majority of this biomass is being sent to landfills for disposal or transported over one hundred miles to power plants in the Central Valley. These options are  expensive, offer little meaningful local benefit, increase Marin’s environmental footprint, and fail to contribute to its long-term resilience.

There is an alternative. Marin has the opportunity to develop an economy for its biomass that helps achieve both wildfire safety and State and local goals to divert organic materials from landfill. This economy is focused on creating local, value-added products that make wildfire safety and landfill diversion more cost-effective over time. It prioritizes options that reduce the greenhouse gases driving climate change and our wildfire crisis and that support regeneration of the ecological resources that make Marin special.

The Marin Biomass Study offers a roadmap for this new biomass economy. Its findings and recommendations are based on a detailed assessment of Marin’s biomass flows and a detailed evaluation of utilization “pathways” that can put them to productive use. The Study identifies the set of pathways that best supports Marin’s needs and goals, and it offers detailed greenhouse gas and economic analyses that demonstrate their individual viability and synergistic potential. 

Key Findings

• Marin’s Current System Is Inefficient and Insufficient. More than half of Marin’s discarded biomass is being landfilled or exported — an inefficient and insufficient outcome based on this Study’s criteria. This does not position Marin well for growth, given that Marin is expected to generate 30% more green materials in the next decade. Its composting system, while robust, is not prepared to absorb them. In addition, only a small fraction of Marin’s usable biomass is being directed into pathways that generate local, renewable electricity.
• Alternative Pathways Can Boost Marin’s Biomass Economy. Marin could put its biomass to significantly better use, as well as reap meaningful economic and environmental benefits, with better planning, better coordination, and targeted investments in the following pathways: 
  • • Bioenergy and Green Electricity. Local gasification of woody debris and non- reusable construction materials can create a local supply of renewable electricity, even when the sun is down and the wind is not blowing. Alternatively, the syngas produced by gasification might be upgraded to create renewable fuels like biomethane, green hydrogen, or other biofuels — as markets for such products strengthen.
    • Soil Amendments. Expanded composting will provide Marin with a sustainable management option for its flow of green materials, as well as provide significant opportunities to reduce its greenhouse gas footprint. LIkewise, producing biochar from woody biomass from wildfire prevention with digestate (aka “biosolids”) from wastewater treatment plants can be done in a joint pyrolysis unit, and the biochar can be used to enhance soil health, sequester carbon, and support local agriculture.
    • Local Wood Products. Small-scale milling can convert logs and branches into dimensional lumber, posts, poles, and artisanal wood products. This could create local jobs while reducing greenhouse gas emissions.
• Coordination Can Create Meaningful Synergies. Building a better biomass economy requires both physical infrastructure and coordinated institutional support. Representatives from wildfire agencies, wastewater districts, energy providers, and waste haulers, as well as planners, agricultural agencies, and municipal staff have jointly reviewed and discussed this Study throughout its development.  These conversations are showing real opportunities for increased collaboration and system efficiency. By working together to improve the biomass economy, these groups can also advance Marin’s transition to a green energy economy and development of green job opportunities.
• Better Pathways Can Reduce Greenhouse Gas and Environmental Impacts. In addition to economic support for wildfire safety and resource regeneration, redirecting organic materials from landfills and from far-away power plants into local energy and resource pathways offers substantial GHG reductions. For example, expanded composting and local gasification each have the potential to reduce at least 11,000 metric tons of carbon dioxide equivalent (MTCO2e) emissions per year. Local milling of logs and local biochar production can reduce several thousand more metric tons of greenhouse gases per year. Implementing all the biomass pathways proposed in this Study could reduce Marin’s countywide GHG emissions for the waste sector by almost three-quarters. This amount is equal to about three percent of Marin’s overall greenhouse gas emissions, and its reduction represents a tangible and achievable step toward the countywide goal of net zero emissions.

Key Recommendations

• Develop Renewable Energy Projects. Gasification and co-digestion projects have the potential to provide significant local, renewable electricity that increases power reliability on the electrical grid. These projects should be encouraged, and public investment should be provided. Funding of $16M will spur development by reducing startup operational risks. It will also drive long-term GHG reductions and increase Marin’s energy resilience.
• Expand Composting Capacity. Green materials are predicted to grow in the next decade and require additional composting capacity. Efforts now to expand local composting will help ensure infrastructure needed for SB 1383 compliance, as well as deliver significant GHG reductions,soil carbon sequestration, and agricultural resilience benefits. For these reasons, supportive funding on the order of $7.5M should be invested to expand local infrastructure.
• Develop Biochar Production: Biochar production offers a missing economic pathway for both woody biomass from wildfire safety programs and for digestate (biosolids) from wastewater treatment plants. As a product, biochar can be used for a variety of industrial and agricultural purposes that reduce Marin’s carbon footprint. The public entities considering this project need supportive funding on the order of $5M to reduce risk and secure the capital needed to move this project forward.
• Reinvest in Local Uses for Wood: Small-scale milling is a better alternative for larger-diameter logs. Milling can turn them into lumber and artisanal slabs for local use. In addition to reducing transportation-related greenhouse gases, milling preserves carbon already sequestered in wood. Redevelopment of this pathway can be done with a modest supportive investment of $0.5M.
• Identify and Address Regulatory Barriers. The development of better biomass pathways can run into a variety of non-financial, regulatory barriers. The County, cities and towns, and agencies in the county should consider and advocate for changes in zoning, permitting, procurement, and rates, with the goal of working together to bring about improved pathways for their discarded biomass. 
• Support Institutional Integration: The Marin Biomass Project has undertaken analyses and provided a forum for providing insights and sharing understanding about Marin’s biomass system. Ongoing engagement among stakeholders is needed to explore how business objectives, operating procedures, contracts, and capital plans can be synergized and lift ideas off the page. This ongoing institutional coordination and systems integration should be encouraged. It is needed to achieve the multiple benefits of a more regenerative biomass economy.

The chapters in this Study offer analyses that build toward these recommendations and the unifying vision of a regenerative economy. Chapter 1 consolidates data about discarded biomass from across Marin to estimate the magnitude of these flows, to offer a composite picture of Marin’s current biomass management system, and to identify what may be underutilized. Chapter 2 assesses a range of processing technologies and output products (i.e., what are called “pathways” in this Study) and identifies a set with the potential to put underutilized biomass to higher and better use. Chapter 3 offers a detailed comparison of Marin’s current system and the alternative set identified in Chapter 3 to estimate the difference in greenhouse gas emissions and carbon sequestration potential between the two. Chapter 4 dives into the economics of the alternative set of pathways to identify their financial viability and supportive funding that could aid their development. These analyses roll up into a summary at the start of Chapter 5 before thirteen recommendations are offered for building a better biomass system in Marin.

Call to Action

Meeting the challenges of this century requires ingenuity, courage, and grit. Most of all, it requires a system that brings out the best in all of us. The Marin Biomass Study offers a framework for a biomass economy that brings parties together in an effort that manages surplus and discarded biomass not as waste but as a resource used to create value-added products. This shift in approach is meant to grow a biomass economy that, in the long run, offers affordable, sustainable ways to support wildfire safety, to reduce greenhouse gas emissions, and to increase Marin’s energy resilience. The pathways analysis in this report lays out the building blocks of this regenerative biomass economy. This includes supportive funding — likely in the form of modest, near-term public investments — along with institutional collaboration and governance.

These pathways have the potential to position Marin as a model for other wildfire-prone, urban and suburban counties in California — demonstrating not just Marin’s capacity to develop a more environmentally-conscious economy, but also how cross-sector collaboration and strategic infrastructure investments can scale solutions. Such leadership is needed to meet state wildfire safety and greenhouse gas reduction goals. Marin received funding for this work because of its potential  to lead on climate, and it is the goal of the Study to deliver on this promise, both in Marin and beyond.

The Marin Biomass Study is contains the following five chapters:

Chapter 1: Marin’s Current Biomass Pathways

Chapter 2: Promising Alternative Pathways

Chapter 3: Greenhouse Gas Reduction and Sequestration Opportunities

Chapter 4: Economic Viability and Investment Opportunities

Chapter 5: Findings & Recommendations