Microsoft has entered into a long-term agreement with Vaulted Deep, a U.S.-based waste management company, to purchase up to 4.9 million tonnes of durable carbon dioxide removal (CDR) through 2038. The deal supports the scaling of Vaulted’s carbon sequestration method, which involves injecting organic waste into deep geological formations for permanent storage.
The agreement is one of the largest to date for carbon removal via deep well injection and is expected to significantly expand Vaulted’s operations across the U.S. The company currently stores organic waste — including biosolids, paper sludge, manure, and food residues — in stable underground formations sealed by impermeable rock. This process prevents the release of methane and other pollutants while locking away atmospheric carbon dioxide.
Vaulted’s method is certified by carbon registry Isometric, which validates the permanence of its removals for over 1,000 years. The company has so far sequestered nearly 18,000 tonnes of CO₂ and diverted more than 69,000 tonnes of organic waste from landfills, incineration, and surface application.
Microsoft, which has committed to becoming carbon negative by 2030, described the approach as a scalable and low-risk solution to both climate and local environmental challenges. “Vaulted Deep offers a differentiated, scalable approach to permanent carbon removal,” said Brian Marrs, Senior Director of Energy and Carbon Removal at Microsoft.
Vaulted’s technology has been in operation since 2008 and is permitted in several U.S. states. In Los Angeles, it has managed 20% of the city’s biosolids for over 15 years. Its Kansas site, active since 2022, currently handles the majority of the City of Derby’s biosolids and supports local agriculture by managing excess manure. The site has also generated economic activity, including 18 full-time jobs and over $5 million in investment.
The company is now seeking additional partners to handle the estimated one billion tonnes of organic waste generated annually in the U.S.
