$640.15
Carbon credits for climate change mitigation. Delivery year: 2026. Currently available: 881.00 metric tons.
CREW Carbon is a carbon removal company utilizing a technology known as Wastewater Alkalinity Enhancement (WAE) to permanently sequester carbon dioxide using existing wastewater infrastructure. By integrating into wastewater treatment plants (WWTPs), CREW repurposes these facilities into “carbon removal hubs,” leveraging the natural biological processes occurring within them to capture CO2 and store it safely in the ocean. This approach allows for rapid deployment and high measurability, offering a scalable solution that simultaneously improves the efficiency of water treatment operations.
CREW’s technology is a specialized form of enhanced weathering that takes place within the controlled environment of a treatment plant. The process capitalizes on the fact that wastewater treatment inherently produces large amounts of biogenic CO2 as microbes break down organic waste. The system operates through the following steps:
Dosing: CREW adds alkaline minerals, primarily crushed limestone (calcium carbonate), directly into the treatment tanks. This material is abundant, safe, and globally available.
Reaction: The added minerals react with the high concentration of CO2 produced by the microbes. This reaction dissolves the limestone and converts the dissolved carbon dioxide into stable bicarbonate ions.
Storage: The bicarbonate ions remain dissolved in the treated water, which is eventually discharged into rivers or oceans. Once in the ocean, the carbon is permanently stored for tens of thousands of years, contributing to ocean alkalinity without increasing acidity.
Measurement: Because the reaction occurs within a “closed” engineered system, CREW can utilize sensors at the inlet and outlet of the facility to precisely measure the inputs and the amount of carbon captured. This provides a level of verification often difficult to achieve in open-field weathering projects.
CREW Carbon’s solution is designed to benefit both the climate and the utility operators. For wastewater plants, the addition of alkaline minerals acts as a direct replacement for the caustic, hazardous, and expensive chemicals typically used to manage pH levels. This not only lowers operational costs but also improves the stability and safety of the treatment process.
The company has already demonstrated commercial viability, delivering verified carbon removal credits from its operational project at the East Shore Water Pollution Abatement Facility in New Haven, Connecticut. By retrofitting existing infrastructure rather than building new standalone facilities, CREW can deploy projects in months rather than years.
With approximately 100,000 wastewater treatment plants in operation worldwide, CREW Carbon estimates its technology could scale to remove nearly 500 million tons of CO2 annually. The approach utilizes standard industrial equipment and readily available minerals, creating a clear pathway to low-cost carbon removal. By transforming a necessary public utility into a climate solution, CREW aims to achieve gigaton-scale impact while modernizing critical water infrastructure.