Vaulted Deep deal with Microsoft will turn biomass waste into carbon storage

Biomass waste destined for landfill or incineration will instead be locked away underground under a deal announced between US waste management firm Vaulted Deep and Microsoft.

The agreement will see Vaulted Deep remove up to 4.9 million tonnes of carbon dioxide from the atmosphere over the next 12 years by processing and permanently storing organic waste, which the company collects from farms, cities and industries.

Vaulted Deep’s method involves diverting sludgy organic materials such as biosolids, manure, paper sludge and food or agricultural residues — which would otherwise release methane or other greenhouse gases — and injecting them deep underground into stable geological formations.

The process both removes carbon from the atmosphere and prevents contaminants like PFAS from leaching into soils and waterways.

The company already operates permitted sites in multiple US states, working with municipalities and farmers to manage problematic biomass waste.

Its first site in Los Angeles has handled 20 per cent of the city’s biosolids for 15 years, while its Kansas facility manages 75 per cent of Derby’s biosolids and excess manure from local farms.

Julia Reichelstein, co-founder and chief executive of Vaulted Deep, said: “As carbon removal moves beyond pilots and prototypes, there is growing demand for solutions that can scale safely and address real-world problems. Vaulted offers a dual solution: it meets urgent waste management needs and drives measurable climate and public health improvements.”

To date, the company has removed nearly 18,000 tonnes of CO₂ and diverted more than 69,000 tonnes of organic waste from surface disposal or burning.

Its methodology is certified by carbon registry Isometric to ensure durability for over a thousand years.

Brian Marrs, senior director of energy and carbon removal at Microsoft, said: “Vaulted Deep provides a differentiated, scalable approach to permanent carbon removal with low technology risk. Its work delivers immediate climate benefits while stimulating local economies and addressing long-standing environmental challenges.”

The 12-year offtake agreement runs through 2038 and is expected to help Vaulted expand its operations to new sites across the United States.