Today, Isometric issued the world’s first verified Wastewater Alkalinity Enhancement (WAE) carbon dioxide removal (CDR) credits for CREW Carbon. The 104.4 credits mark the first delivery under CREW Carbon’s $32.1 million offtake agreement with Frontier buyers.
This is a significant milestone for scaling carbon removal and demonstrates WAE’s potential as a CDR pathway.
These credits set the standard for all future WAE credit deliveries and correspond to CREW’s project in New Haven, Connecticut—soon to be one of the largest CDR projects on the East Coast of the U.S. The project is integrated into the East Shore Water Pollution Abatement Facility, which processes 40 million gallons of wastewater per day.
In wastewater treatment, microbes break down organic waste, releasing carbon dioxide that would typically enter the atmosphere. WAE enhances this process by introducing finely crushed, soluble alkaline minerals—such as limestone—during treatment. These minerals react with carbon dioxide, converting it into stable bicarbonate ions. These ions remain in the treated wastewater and are ultimately transported to the ocean, where they are safely stored for thousands of years.
WAE is an exciting pathway because of its possibility for scale. With nearly 110,000 municipal wastewater treatment facilities worldwide, estimates suggest that WAE could scale to remove hundreds of millions of tonnes of carbon dioxide annually. It also has several key operational advantages—it integrates with existing infrastructure, leverages existing permits, and utilizes one of the lowest-cost and most abundant minerals on Earth—limestone. WAE can also lower operational costs for wastewater treatment facilities by replacing carbon-intensive and hazardous pH control chemicals with locally sourced, natural minerals.
These credits were certified according to Isometric’s industry-first Wastewater Alkalinity Enhancement Protocol, which takes a rigorous, science-based approach to monitoring, reporting and verification (MRV). The protocol accounts for potential downstream losses—where some of the captured carbon dioxide may be released into the atmosphere—using peer-reviewed river and ocean chemistry models tailored to each site’s specific conditions.
The detailed, transparent data behind each WAE credit is publicly available on the Isometric Registry—which provides a permanent audit trail for all credits issued by Isometric, ensuring that all underlying information can be reviewed and scrutinized.
With scientific rigor, robust MRV and transparency at the core of these first WAE credits, buyers can be confident that every WAE credit from Isometric represents one tonne of carbon dioxide durably removed from the atmosphere.
