A recent proposal to inject and store millions of tons of carbon dioxide beneath wetlands in Solano County, California marks the latest development in carbon capture and storage (CCS) in the Golden State. Integrating large-scale CCS projects with a clean energy grid is part of California's strategy for reaching net-zero emissions by 2045.
The state is accelerating CCS deployment through legislative efforts (SB 905, 2022; SB 614, 2025), executive actions (E.O. B-55-18, 2018), and policy declarations (AB 1279, 2022). Detractors say (and research supports) that the capacity for CCS deployment is under-proved; CCS perpetuates reliance on fossil fuels, and the focus on mitigation pulls money and attention away from more beneficial climate innovations.
The Montezuma Wetlands are a series of tidal marshes in the San Francisco Bay estuary. Until recently, the area "was treated as expendable." Proximity to the Bay Area, lower population numbers, and agricultural land use meant that "[b]y the end of the 20th century, much of the area functioned less as a marsh and more as a repository for industrial waste," Miranda de Moraes wrote in Grist a few days ago. Over the last two decades, ongoing, large-scale restoration efforts have seen the wetlands make a remarkable recovery. In 2020, tidal flows returned and the marsh resumed providing habitat, flood protection, and other ecosystem services to the region.
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| Montezuma Hills along the Sacramento River Image source: public-domain-image.com (2013) |
Given this history, the newly-proposed NorCal Carbon Sequestration Hub raises the sore issue of Solano County's role as a dumping ground for the Bay Area's toxic waste. The new CCS storage project seeks to "inject CO2, sourced from refineries, hydrogen plants, and power plants" into the saline aquifers a mile or so below the wetlands. The storage site would be located around the small town of Collinsville. According to Grist, project architects hope to be depositing up to 8 million tons of carbon dioxide annually within the next three years.
[UC Berkeley Professor of Civil & Environmental Engineering Jamie] Rector believes the site could store at least 100 million tons [of CO2] over its 40-year lifespan. The site’s compacted mud, silt, and clay, he said, would provide a natural cap that could keep the pollutant locked underground indefinitely, while its location alongside Bay Area industries would reduce carbon transportation costs.
Carbon capture and storage as a climate change mitigation strategy is not a new idea. Carbon capture has been used around the globe since the 1970s, and the projects generally come in two flavors: capturing carbon dioxide at the point of emission (point-source capture) or sucking carbon dioxide out of the ambient atmosphere (direct air capture). Once captured, the gases are pressured into a liquid and transported by truck or – more likely – by pipeline to the storage site.
Researchers and organizations focused on climate change generally agree that some carbon capture and storage will be necessary to reach international climate targets. California may become especially reliant on CCS in order "to eliminate [the] millions of tons of greenhouse gases" needed to meet its carbon-neutrality mandate by 2045. Whether the state can meet these goals without exposing rural communities to localized environmental harms remains to be seen. Thus far, the dozen or so projects awaiting permits occur in largely rural and low-income communities (such as the CarbonTerraVault projects, which are pending permits for multiple carbon capture and storage projects in the San Joaquin and Sacramento Basins).
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| A visual representation of CCS Image Source: CO2GeoNet (Creative Commons license) (2025) |
The extent to which communities will welcome the technology is another question. In western Kern County, CalMatters covered community response to a project designed to capture emissions at Elk Hills Oil and Gas Field and then "inject the gases more than a mile deep into a depleted oil reservoir." Elk Hills sits between the small Central Valley towns of Buttonwillow (pop. 1,2501) and Taft (pop. 7,000), about 30 miles west of Bakersfield. Covering the proposal for CalMatters, Alejandro Lazo writes:
Many residents and environmental justice groups oppose these projects because they allow oilfields, power plants and other industrial operations to keep emitting dangerous air pollutants in their communities. At the Kern County project, emissions of fine particles and gases that form smog would be 'significant and unavoidable,' according to the county’s environmental impact report.
On the other side of the conversation lies Dave Noerr, the mayor of Taft. According to CalMatters, Noerr "sees the technology as a gamechanger for Kern County: a way of hanging on to well-paying, middle class oil and gas jobs as California tackles climate change."
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| Shuttered gas station near Taft, western Kern County © Lisa Pruitt (2024) |
New reporting from Grist and local news outlets suggest that support for the Montezuma project might be harder to come by. Environmental groups oppose the project for its location near sensitive wetlands habitat just beginning to realize the benefits of ecosystem restoration. Public health professionals cite concerns about leaks and continued exposure to polluting industry.
The Montezuma NorCal Carbon Sequestration Hub is currently waiting on a permit from Solano County to build a test well. In its permit application, Montezuma Carbon claims the project will bring jobs, tax revenue, and cleaner air to Solano County. However, as proposed, the 45-mile carbon dioxide transport pipeline would run right by South Vallejo. Recent reporting by the Vallejo Sun highlights California EPA data showing that South Vallejo residents already deal disproportionately with poverty, unemployment, air pollution, and higher rates of asthma.
Opponents frame Montezuma Carbon’s proposal as a question of who controls their land and who absorbs the risks of decarbonization. The county is home to roughly half a million people, including the Bay Area’s largest per capita populations of veterans and residents with disabilities, and it is among the most racially diverse counties in the nation.
Conclusion
In many ways, the Montezuma Carbon project highlights systemic inequities and urban-centric values lurking in the corners of the energy transition. Success of CCS in California appears to depend (almost entirely) on rural counties and communities to host and accommodate these projects, now and forever. Their permanence raises questions about monitoring, the potential for future harms, and meaningful consent. Similar proposals have been shut down due community opposition in the Midwest (previous coverage of one such proposal on the blog), but the fate of many California projects remains to be decided.
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| Montezuma Hills between Suisun and Rio Vista © Lisa Pruitt (2024) |
It will be interesting to see what happens with this project going forward. I think the Solano County project is unique, given that Solano County is facing significant unemployment after recent manufacturing closures. The whole county could use the jobs and tax revenue that would come from this job. This could be an excellent way to boost the economy, but it could also have significant setbacks, as you pointed out.
ReplyDeleteCarbon capture does seem to be a necessary part of any future climate strategy, though the trade-offs and difficulties seem similar to other environmental projects. This at least doesn't have as much of the "NIMBY" problem that solar panels and especially wind turbines seem to cause, but the costs Jillian highlights are definitely something that needs to be addressed.
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