Microsoft buys wastewater-derived removal credits from CREW Carbon
CREW Carbon has announced an offtake agreement with Microsoft covering the delivery of up to 23,602 durable, verified carbon removal units generated by its wastewater alkalinity enhancement technology, extending the company’s contracted order book past $40 million.
The Brooklyn-based water technology firm describes the credits as the world’s first and only verified carbon removals produced through wastewater alkalinity enhancement to date. The technology, developed at and backed by Yale University, retrofits into existing municipal wastewater treatment infrastructure rather than requiring purpose-built facilities, an approach the company says removes the dependence on federal funding and permitting support that other removal pathways typically carry.
The process works by dosing strategically sourced alkaline minerals, principally calcium carbonate, into a treatment plant’s existing process to optimise pH and alkalinity conditions. CREW says this delivers improved biological treatment performance, better settleability, reduced chemical usage and increased plant capacity and efficiency for the operator, while simultaneously locking away carbon dioxide and what the company terms superpollutant emissions in a permanent, measurable form. The dual function is central to the commercial proposition, since the operational benefits give treatment plants a reason to adopt the system independently of carbon revenue.
Measurement rests on a closed-system approach incorporating inlet and outlet monitoring at each site. CREW states that all removals are quantified through plant-level monitoring, tracked using downstream modelling and verified by independent registries. Closed-system quantification has been a persistent obstacle for alkalinity enhancement conducted in open marine environments, where dispersion and uncertain measurement of carbon dioxide uptake have complicated verification and constrained buyer confidence. Conducting the process within engineered infrastructure allows inputs and outputs to be measured directly at defined boundaries.
Phillip Goodman, carbon removal portfolio director at Microsoft, said the agreement supports a novel wastewater-based approach that is highly durable and measurable, and that CREW has demonstrated carbon removal in the wastewater sector to be implementable and scalable with high monitoring, reporting and verification certainty. Joachim Katchinoff, chief executive and co-founder of CREW, described the agreement as a milestone for the company and said it further validates its approach to delivering durable credits while optimising wastewater treatment performance.
The Microsoft deal follows existing long-term agreements CREW holds with JP Morgan, Google, Autodesk and Stripe, contracted through the Frontier advance market commitment. Frontier announced a further $915 million in funding commitments earlier this year, taking its total pledged spending on permanent removal to $1.8 billion and adding Anthropic as a buyer, with a stated strategy of concentrating on suppliers judged to have gigaton-scale potential.
CREW argues its own pathway meets that threshold, noting that the treatment plants it works with globally process billions of gallons daily, which it presents as a clear route toward gigaton-scale removal capacity. The volume in the Microsoft agreement is modest by comparison with the buyer’s larger commitments, which have included a 650,000-tonne bioenergy with carbon capture and storage agreement in Denmark and a 626,000-tonne Canadian BECCS offtake, and reflects the early commercial stage of the wastewater pathway rather than any ceiling on it.
The purchase is also notable for its timing. Reports in April indicated Microsoft had informed suppliers it was pausing new carbon removal purchases, prompting concern across the sector given the company’s position as by far the largest corporate buyer of durable removals. Subsequent agreements, including this one, suggest purchasing has resumed at a more selective cadence, with a visible preference for pathways offering high measurement certainty and existing infrastructure rather than first-of-a-kind capital projects.
