CREW Carbon

A rock, a pipe, and a quietly radical idea

Somewhere in Connecticut, wastewater is flowing through a tank that has no business being interesting. CREW Carbon made it interesting anyway.

The water arrives the way it always has: used, treated, on its way back to a river. But before it leaves, CREW doses it with finely ground alkaline minerals. The minerals do what minerals have done for hundreds of millions of years - they react with dissolved CO2 and lock it into stable bicarbonate. The difference is the clock. In nature this weathering takes millennia. CREW compresses it into the time the water spends in the tank.

The result is two things from one act. The plant runs better - steadier pH, easier nutrient removal, lower operating costs. And the carbon is gone, permanently, measured on the way in and counted on the way out. CREW sells the first benefit to the utility and the second to companies like Google and JPMorgan Chase. Same tank. Two customers. One of them is the atmosphere.

Two scientists, one closed system

CREW was spun out of Yale in 2022 by Dr. Joachim Katchinoff, a biogeochemist who had spent more than a decade studying how the planet naturally stores carbon, and Prof. Noah Planavsky, an earth scientist whose research underpins the chemistry. Their bet was specific and a little contrarian: stop fighting the measurement problem in the wild, and move the entire reaction indoors.

Inside a wastewater plant, a weathering reaction stops being a leap of faith. The water comes in through one pipe and leaves through another. Put instruments on both ends, model the chemistry in between, and you get something the open-ocean and open-field approaches struggle to produce: a number you can defend. The closed system isn't a constraint. It's the whole pitch.

The founders also understood something about adoption that pure climate plays often miss. A utility manager does not wake up wanting to save the planet on a tight municipal budget. They wake up wanting cleaner effluent and lower costs. CREW leads with that. The carbon removal rides along, which is exactly how you get conservative public infrastructure to try something new.

The receipts, itemized

Climate startups are easy to admire and hard to verify. CREW's argument is that the numbers do the talking. Roughly ten facilities are running its process across two continents. Corporate buyers have committed about $33 million to its removals through Frontier, the advance-market-commitment vehicle backed by some of the most demanding carbon buyers on earth. And the Series A was oversubscribed.

The customer list reads like a who's-who of buyers who hate being wrong: Google, JPMorgan Chase, Autodesk, Stripe, Shopify, Salesforce, Workday, Watershed and H&M Group on the carbon side; utilities like the Hampton Roads Sanitation District on the water side. The investor roster - Burnt Island Ventures, AP Ventures, Sony Innovation Fund, Builders Vision, Idemitsu Ventures and New York Ventures - leans toward people who price climate risk for a living.

Back to the tank

Return to that wastewater plant in Connecticut. Nothing about it looks like the future. The water still arrives used and leaves clean. The smell has not improved. From the road, it is the least photogenic climate solution you could invent.

But the carbon that left in that water is not coming back. It is bicarbonate now, and it will still be bicarbonate when everyone reading this is gone.

That is the quiet bet CREW Carbon is making - that the most durable way to fix the climate is not to build something new and heroic, but to add one missing step to something the world already runs by the thousands. A rock, a pipe, and a number you can actually trust. The plant looks exactly the same. The atmosphere does not.