Key Takeaways
A Yale spinout’s novel limestone-based water treatment system could save a Virginia utility $400 million in infrastructure costs, using a $2 million installation that also captures thousands of tons of carbon dioxide.
"If there’s an opportunity to save $400 million, we’re moving mountains,” said Charles Bott, technology chief for Hampton Roads Sanitation District, a public utility serving nearly 2 million people in coastal Virginia.
CREW Carbon, which just raised $25 million in a new funding round to expand its 10 projects across the U.S. and Europe, uses ground-up limestone to make wastewater more alkaline. This enhances the removal of nitrogen and phosphorus, helping the utility meet tough water-quality rules for the Chesapeake Bay. The new system is expected to remove several thousand tons of CO2 per year.
The project pits a $2 million operational investment against a $400 million capital upgrade, a compelling economic choice for public utilities facing pressure from population growth and stricter environmental regulations. CREW's business model, which includes selling carbon credits for hundreds of dollars per ton, could offer a new, cheaper path for infrastructure modernization.
Wastewater treatment plants are essentially farms for microorganisms that break down waste, releasing carbon dioxide. CREW's process introduces calcium carbonate (limestone) into the waste pools. The limestone combines with CO2 to produce bicarbonate, which keeps the greenhouse gas out of the atmosphere and makes the water more alkaline.
This increased alkalinity is the key benefit for the Hampton Roads utility. It creates a better environment for the specific microorganisms that remove phosphorus and nitrogen from the water. The utility is under regulatory pressure to reduce these pollutants, which can harm aquatic life.
"The nitrogen cycle, phosphorus cycle, carbon cycle—these fundamental reactions are happening across the globe, but in a wastewater plant it’s happening on steroids,” said CREW cofounder and CEO Joachim Katchinoff, a biogeochemist.
According to Bott, the economics of CREW's system would be compelling even without the revenue from carbon credits. The primary driver is avoiding the massive capital expenditure of a new facility dedicated to removing the pollutants.
The race is now on to complete the installation before summer, as the phosphorus-removing microorganisms are less effective in hotter temperatures, making the season a stress test for the new system.
This article is for informational purposes only and does not constitute investment advice.
