This series highlights the companies Carbon Drawdown Initiative has invested in.
There are more than 16,000 publicly-owned wastewater treatment plants in the United States and over 100,000 worldwide. Each one continuously produces COâ‚‚ inside the same enclosed reactors where alkalinity enhancement can take place. That makes wastewater treatment one of the most practical platforms for durable carbon removal.
CREW Carbon integrates alkalinity enhancement directly into wastewater treatment plants to improve plant performance, while removing COâ‚‚. Instead of building new carbon-removal infrastructure, the company optimizes the wastewater treatment process that already operates at massive scale in cities around the world.
Born out of research at Yale by co-founders Dr. Joachim Katchinoff and Professor Noah Planavsky, CREW applies alkalinity enhancement inside controlled wastewater reactors — enabling measurable, verifiable carbon removal alongside cleaner water and more efficient treatment facilities. By embedding carbon removal into essential infrastructure, CREW creates a scalable pathway that aligns climate impact with utility performance.
How It Works
Wastewater treatment plants grow trillions of microbes that digest organic waste. The process produces COâ‚‚ inside large, controlled reactors. CREW enhances alkalinity within the treatment process, converting biologically produced COâ‚‚ into stable dissolved forms, before it can return to the atmosphere, storing it in the water on a geological timescale.
Because wastewater facilities already:
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Continuously process biogenic carbon
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Operate in closed, monitored systems
CREW’s carbon removal is measurable and verifiable by design. At the same time, CREW’s patented wastewater alkalinity enhancement improves treatment efficiency and reduces pollution discharged into waterways — delivering operational benefits to utilities and ratepayers.
CREW’s model:
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Leverages existing infrastructure
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Avoids time- and capital-intensive projects
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Integrates into regulated public systems
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Generates co-benefits beyond CO2 removal
If even a small fraction of global wastewater plants adopt this approach, the impact scales quickly.
Key Milestones
CREW has already delivered the world’s first verified CO₂ removals from wastewater treatment facilities under the wastewater alkalinity enhancement protocol.
Since launching commercial operations in 2024, CREW has:
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Deployed at wastewater treatment facilities across the US and Europe, including leading utilities like HRSD (Hampton Roads Sanitation District)
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Delivered measurable performance improvements at wastewater treatment facilities, with one utility considering deferring $400 million in planned capital upgrades
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Secured $33M+ in carbon removal offtake agreements
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Captured 2,000+ tons of CO2 faster and more cost effectively than other carbon removal credit suppliers
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Won a $2.3 million award from the Colorado Energy Office as part of the state’s Clean Air Program
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Developed proprietary measurement, reporting, and verification (MRV) capabilities that enable high-confidence carbon removal quantification
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Raised $25M of funding across equity and non-dilutive capital sources in 2026
This is not a lab concept. CREW is operating inside real infrastructure.
Scaling Ahead
CREW plans to expand to a global network of wastewater partnerships — each capable of removing thousands of tons of CO₂ annually. The company is also expanding its MRV (Measurement, Reporting, and Verification) platform to ensure removals remain trusted, traceable, and audit-ready as scale increases. International expansion is already underway, with growing interest from Europe and Asia. Since closing its oversubscribed Series A round, CREW is adding to the talent on the team. Some of the high-priority roles to fill in 2026 include:
Why We Back CREW
At Carbon Drawdown Initiative, we prioritize solutions that combine:
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Strong scientific foundations
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Clear and credible MRV
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Realistic scaling potential
CREW meets all three criteria. The science builds on leading enhanced weathering research. The MRV is embedded in wastewater chemistry. The scaling pathway is replication across utilities — not reinvention. Carbon removal will only reach climate-relevant scale if it integrates into systems that already exist.
CREW does exactly that. And that is why we are proud to support them.
