proposals

Statement of Problem 

Untreated wastewater poses significant risks to both human and ecological health. Climate change, a global concern with far-reaching implications, has a direct impact on wastewater management systems. Variations in temperature, rising sea levels, shifting precipitation patterns, and increased instances of flooding place additional stress on wastewater infrastructure. Extreme weather events influence both the availability and demand for water resources, while elevated temperatures contribute to a higher volume of untreated wastewater. As a result, the need for effective wastewater treatment strategies has become increasingly urgent in the face of accelerating environmental changes.

A critical challenge associated with wastewater treatment is the emission of greenhouse gases (GHGs) such as carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O). These emissions contribute to climate change, further exacerbating existing environmental concerns. Consequently, it is imperative to assess and implement strategies that not only enhance wastewater treatment processes but also align with broader climate change mitigation efforts.

The purpose of this report is to conduct a comprehensive assessment of the East Bay Municipal Utility District’s (EBMUD) existing strategies for addressing climate change within its wastewater treatment operations. Specifically, this report examines EBMUD’s approach to achieving carbon neutrality, the methodologies employed to mitigate GHG emissions, and the current status of EBMUD’s GHG inventory. These key areas of inquiry serve to evaluate the agency’s role in mitigating the impacts of climate change and ensuring the sustainability of wastewater management practices.

Status Quo of Energy and Carbon Emissions  

The global and U.S. economies have historically been carbon-intensive, with crude oil and natural gas making up a significant portion of U.S. energy consumption. Since the Industrial Revolution, fossil fuels—petroleum, natural gas, and coal—have dominated the U.S. energy mix, accounting for an average of 87% of total primary energy use over the past decade (EIA, 2011). While there has been a gradual shift toward renewables, energy consumption remains the primary source of greenhouse gas emissions, contributing 73% globally.  

Since the 1970s, nuclear and renewable energy sources have gained traction, particularly in electricity generation, where renewables now account for 26% of the sector’s energy use. However, transportation lags with only 3.3% renewables (IEA, 2011). Recent trends—such as increasing electric vehicle adoption, solar power installations, and sustainability-focused policies—indicate a shift away from fossil fuels.  

Policy Shifts and Renewable Energy Growth  

Despite challenges from the COVID-19 pandemic, renewable energy set a record in new power capacity in 2020 and was the only energy source to see net growth (Murdock et al., 2021). Policies such as California’s Zero Emissions Vehicle Agreement, the Clean Air Act, and the Cap-and-Trade program have positioned the state as a leader in sustainability, potentially influencing national policies ("California Effect"). The U.S. also rejoined the Paris Agreement in 2021, signaling a renewed commitment to reducing carbon emissions. However, while climate targets have become more ambitious, many countries failed to meet their 2020 goals, and some have yet to establish new ones (Murdock et al., 2021).  

Challenges remain in the renewable energy transition, including slow adoption rates, inadequate innovation, infrastructure limitations, affordability concerns, weak policy enforcement, and ongoing fossil fuel subsidies. COVID-19 recovery investments in fossil fuels were six times greater than those in renewables (Murdock et al., 2021), highlighting the structural barriers to decarbonization.  

Climate Change and Water Industry Impacts  

Carbon emissions have also significantly impacted water systems. Ocean acidification, driven by rising CO₂ levels, is altering marine chemistry and threatening marine life, particularly shell-forming organisms (Doney et al., 2009).  

The wastewater treatment sector is also highly energy-intensive, with emissions dependent on electricity sources, plant capacity, and treatment technologies (Wang et al., 2016). However, energy-efficient wastewater treatment is possible. Some U.S. and German facilities have achieved near-total energy self-sufficiency by integrating energy efficiency measures and biogas recovery.  

EBMUD in California exemplifies a shift toward sustainability, generating renewable energy from food and bio-waste, surpassing its onsite energy needs. This transition aligns with broader environmental goals, reducing carbon emissions in wastewater treatment.  

Forest Management and Carbon Sequestration  

U.S. forest policy has shifted significantly over time. The late 19th and early 20th centuries saw aggressive deforestation, followed by conservation policies like the Organic Administration Act (1897) and the Weeks Law (1911), which established national forests and promoted reforestation. Clearcutting peaked in the post-WWII era but declined in the 1990s due to environmental concerns.  

Globally, deforestation remains a major issue, particularly in developing nations like Brazil. Forests play a crucial role in carbon sequestration, and timely reforestation efforts are essential for maintaining carbon sinks, ecosystems, and biodiversity.  

Emerging Technologies: Soil Carbon Sequestration  

Soil carbon sequestration is gaining attention as a viable climate solution. Research on soil-based carbon storage has expanded significantly, with publications on the topic increasing 18-fold from 2001 to 2020. Soil stores up to five times more carbon than the atmosphere, making it a critical carbon sink. While agricultural workers are most directly affected by soil enrichment practices, research has demonstrated positive outcomes, supporting the pursuit of this technology (Di et al., 2022).  

Proposed solutions

Reforestation

Increasing the planting of diverse tree species on water treatment and wastewater treatment plants is a promising solution. A dedicated committee should oversee on-site plant and tree management. Trees enhance water quality by slowing rainfall, allowing it to infiltrate the soil, and acting as natural sponges that filter and release water into streams and rivers gradually.

As the most effective land cover for maintaining water quality, trees prevent soil erosion, reduce stormwater runoff, and mitigate flood damage. Additionally, trees facilitate the movement of water through transpiration, contributing to cloud formation and precipitation.

Afforestation

Afforestation involves introducing trees and seedlings to previously non-forested areas, either naturally or artificially, distinguishing it from reforestation, which is restorative. This approach is proposed as a means to sequester carbon emissions, given that forests act as natural carbon sinks.

Potential East Bay Municipal Utility District (EBMUD) project sites include Briones and possibly San Pablo Reservoir, with further opportunities in Upper San Leandro, Siesta Valley, and other open areas where collaboration is possible. Native tree species suitable for the East Bay district include Redwood, Coast Live Oak, California Bay, California Buckeye, Pacific Madrone, Western Sycamore, and Big Leaf Maple.

Theoretically, 46 trees are required to neutralize 1 ton of carbon dioxide. In 2021, EBMUD emitted 38,580 tons of CO2, necessitating the planting of 839 trees for full sequestration. With a projected emission goal of 25,000 tons, 543 trees would be required for carbon neutrality.

Geologic Sequestration

Another viable solution is carbon capture and storage (CCS), involving the injection of carbon back into the Earth. However, California has yet to approve any carbon injection projects, which would necessitate extensive monitoring and permitting. Despite these challenges, EBMUD could lead the field and benefit from incentives such as Low Carbon Fuel Standard (LCFS) credits and carbon offset credits.

Regulatory requirements from the U.S. Environmental Protection Agency (EPA), state, and county authorities include habitat conservation plans, waste discharge permits, building and grading permits, fire safety and dust control plans, operational permits, and a monitoring and reporting program.

In 2013, the U.S. Geological Survey (USGS) estimated a national geologic carbon sequestration potential of 3,000 metric gigatons of CO2, though California’s specific geology affects these figures. Investing in sequestration technology could provide economic incentives, as the California Air Resources Board (CARB) allows entities with LCFS credits to monetize them through state-run auctions or private contracts.

Additionally, increasing soil organic carbon storage enhances soil quality by supporting beneficial physical, chemical, and biological processes. Grasslands and rangelands have significant potential to absorb atmospheric CO2. The ability of soil to store organic carbon depends on factors such as clay content. Effective management practices can maximize photosynthetic carbon capture and long-term storage.

One potential project site is an overgrazed area off Bear Creek Road at Briones Reservoir. This site’s depleted soil profile and dominance of non-native grass make it an ideal candidate for carbon sequestration and land restoration efforts

Work plan 

Work Plan for Carbon Sequestration Initiatives

I. Introduction
The implementation of biological (afforestation, reforestation) and geological (carbon capture and sequestration) strategies presents a viable opportunity for significant carbon reduction. To support these initiatives, securing funding through available state rebates and incentives will be a key objective. The California Air Resources Board’s (CARB) Low Carbon Fuel Standard (LCFS) regulation provides credits, which can be monetized through bilateral contracts or state-run auctions, thus offering financial sustainability for the project.

II. Work Plan for Carbon Capture and Geologic Sequestration

Phase 1: Stakeholder Coordination and Biomass Collection

• Engage with the East Bay Regional Park District, which is scheduled to deploy a carbonizer for processing fallen tree debris.

• Utilize the carbon-rich byproduct (biochar) as a soil amendment at designated sequestration sites.

• Estimated Cost: No direct cost associated with procurement.

Phase 2: Material Transport and Site Preparation

• Transport the generated biochar to the Briones site for application.

• Each metric ton of biochar has the potential to sequester approximately 2.35 metric tons of CO2.

• The projected quantity of 4,036.56 cubic yards of biochar is estimated to capture 617.03 metric tons of CO2.

• The Briones site’s clay-rich soil profile enhances long-term carbon retention.

• Estimated Cost: Transportation costs to be determined based on logistics and volume.

Phase 3: Soil Integration

• Utilize rototilling or topsoil application techniques to incorporate biochar into the soil profile.

• Estimated Equipment Cost: Rototiller rental rates range from $250-$1,000 per hour, with an estimated 15 hours required for a 15-acre application.

Phase 4: Monitoring and Performance Assessment

• Conduct periodic soil assessments to evaluate biochar efficacy in carbon sequestration.

• Soil analysis can be conducted utilizing EBMUD’s in-house laboratory resources.

• Estimated Cost: No additional cost, as EBMUD staff and facilities will be utilized.

III. Work Plan for Afforestation and Reforestation

Phase 1: Site Assessment

• Conduct physical and productivity assessments, including soil profile analysis, moisture regime, and nutrient status to determine optimal tree species selection.

• Estimated Cost: No additional cost, as EBMUD’s laboratory resources will be utilized.

Phase 2: Tree Planting Methodology

• Evaluate and select from the following tree planting methods:

  • Bare Root Stock: Seedlings cultivated in nursery seedbeds and transplanted directly.

  • Plug Stock: Seedlings grown in containers and transplanted into the field.

  • Transplants: Seedlings cultivated in a nursery for one year, then transferred to an open field for an additional growth period.

• Estimated Cost: Labor costs will vary based on acreage and selected planting method.

Phase 3: Ongoing Monitoring and Management

• Implement continuous monitoring of tree health and site conditions.

• Conduct periodic assessments for wildfire impact and other environmental risks.

• Decision-making framework to determine whether natural regeneration or continued artificial planting is required.

• Estimated Cost: No additional cost, as park rangers will integrate inspections into their daily responsibilities.

IV. Implementation Timeline
A phased implementation over a 15-year period is proposed to effectively integrate carbon sequestration programs within EBMUD’s infrastructure. Regular performance evaluations will be conducted to ensure alignment with long-term carbon neutrality objectives.

Pilot 

The Carbon TerraVaul initiative, a proposed geologic sequestration project spearheaded by Chevron, aims to sequester over one million metric tons of CO₂ annually—an amount equivalent to removing approximately 200,000 passenger vehicles from circulation—culminating in a total projected sequestration of 48 million metric tons. The West Pearl Queen Field, a decommissioned oil field located in southeastern New Mexico, serves as a potential case study for an analogous pilot project under the jurisdiction of the East Bay Municipal Utility District (EBMUD).

Extensive geological monitoring and site-specific modeling have been undertaken at the West Pearl Queen Field to assess the feasibility and efficacy of long-term carbon sequestration. During a controlled injection period spanning December 20, 2002, to February 11, 2003, approximately 2,090 metric tons of CO₂ were introduced into the subsurface formation. The findings from this study yielded critical insights into the optimal CO₂ injection rate, the rate of subsequent production, and the cumulative production trends observed during the initial three-month venting phase, which were notably lower than anticipated.

Additionally, the stability of biochar remains a key determinant of its effectiveness in mitigating greenhouse gas (GHG) emissions. While it is broadly acknowledged that biochar undergoes eventual decomposition, akin to other organic materials, its degradation rate is significantly slower. A substantial body of peer-reviewed literature indicates that biochar's mean residence time in soil can range from several hundred to several thousand years (Brunn et al., 2008; Cheng et al., 2008; Kuzyakov et al., 2009; Zimmerman, 2010). However, a universal mean residence time does not exist due to environmental variables such as mineralogical composition, moisture levels, and temperature fluctuations. Nevertheless, it is widely recognized that biochar exhibits markedly greater stability compared to uncharred organic matter, reinforcing its viability as a long-term carbon sequestration strategy.

Evaluate and Refine 

In 2013, the United States Geological Survey (USGS) published the first comprehensive, nationwide assessment of geologic carbon sequestration, estimating a mean storage potential of 3,000 metric gigatons of carbon dioxide across the United States. However, the geological characteristics of California necessitate region-specific adjustments to these estimates. Investment in sequestration technologies remains a compelling strategy, particularly in light of available economic incentives and rebate programs.

Reforestation and Afforestation

Scientific estimates indicate that one ton of CO₂ is neutralized by approximately 46 trees. In 2021, the East Bay Municipal Utility District (EBMUD) reported CO₂-equivalent (CO₂e) emissions totaling 38,580 metric tons, necessitating the planting of approximately 839,000 trees to achieve full carbon neutrality. By comparison, the district's 2025 emissions reduction target of 25,000 metric tons CO₂e would require the planting of 543,000 trees for equivalent sequestration.

Despite its potential benefits, large-scale reforestation and afforestation efforts present significant risks. Anthropogenic climate change has increased both the frequency and severity of wildfires, raising concerns about unintended emissions from large-scale vegetation growth. A large wildfire covering 250,000 acres—an event uncommon but not unprecedented in the Bay Area—could release over 3.5 million metric tons of greenhouse gases (GHGs). Even smaller fires, such as the 2022 Eden Fire (58 acres), resulted in 818 metric tons of GHG emissions.

Tree longevity also plays a role in carbon sequestration effectiveness. Native species such as California bay laurel and coast live oak have lifespans exceeding 100 years, while coast redwoods can persist for 500 to 2,000 years. Although this does not pose an immediate concern for emissions offsetting, it remains a factor requiring long-term consideration in sequestration planning.

Geologic Sequestration via Soil Enhancement (Biochar Application)

Biochar presents a promising mechanism for geologic carbon sequestration through soil enhancement. One metric ton of biochar has the capacity to sequester approximately 2.35 metric tons of CO₂. At the Briones site (15 acres), the potential application of 4,036.56 cubic yards of biochar—if sourced through the East Bay Regional Park District—could result in the sequestration of approximately 617.03 metric tons of CO₂.

Beyond sequestration, biochar introduction at the Briones rangeland site could serve as a tool for habitat restoration. The removal of non-native grasses would facilitate the reintroduction of native grass species, including California fescue (Festuca californica) and Melica californica. However, prior studies on biochar implementation in agricultural settings have identified potential operational challenges, including:

• Land loss due to erosion

• Soil compaction during application

• Risk of contamination

• Reduction in soil fertility from crop residue removal

• Decreased earthworm populations

A comprehensive evaluation of these risks is necessary to ensure the efficacy, stability, and sustainability of biochar as a carbon sequestration strategy within EBMUD's jurisdiction.

Recommendation

It is recommended that the East Bay Municipal Utility District (EBMUD) prioritize reforestation and afforestation as primary strategies for carbon sequestration. Forest ecosystems serve as natural carbon sinks with the potential to not only reduce emissions but also contribute to environmental restoration in areas that have experienced extensive deforestation.

Additionally, it is advisable to leverage the East Bay Regional Park District's tree removal project by conducting a pilot biochar enrichment study at the Briones site. This initiative would provide valuable data on the effectiveness of biochar application in enhancing soil carbon retention. Furthermore, identifying and assessing potential sites for afforestation and reforestation projects should be a key component of EBMUD’s carbon management strategy.

Implementing these approaches in tandem has the potential to significantly reduce EBMUD’s annual greenhouse gas (GHG) inventory levels, aligning with long-term sustainability and emissions reduction objectives.