Stewards of the Subsurface: Safe, Responsible CO₂ Sequestration

CO₂ sequestration can help stabilize climate—but only if we protect groundwater, ecosystems, and the deep Earth itself. This guide explains how to bury carbon safely for millions of years without side effects.

Lithospheric Ethics

What it is: Choosing rock types that lock CO₂ into minerals without leaching metals or harming underground microbes.

How it works: Mafic rocks (like basalt) and ultramafic rocks (like peridotite) naturally react with CO₂ to form stable carbonates. We test water samples to ensure no toxic elements are released and monitor microbial life that keeps soils and aquifers healthy.

Groundwater Protection

What it is: Keeping drinking water and aquifers safe from CO₂ or contaminants.

How it works: We choose storage sites far from potable aquifers. Wells use triple-layered steel and cement casings to seal off CO₂ pathways. Regular pressure tests and water quality checks confirm no leaks into fresh water.

Pressure & Tectonics

What it is: Balancing subsurface pressure so we don’t trigger earthquakes or rock fractures.

How it works: Injected CO₂ raises pressure in pore spaces. We model the surrounding rock layers and limit injection rates to keep stresses below natural tectonic thresholds. Continuous microseismic monitoring detects any movement long before it becomes significant.

Thermal & Chemical Compatibility

What it is: Ensuring temperature and chemistry changes don’t corrode well casings or create acidic zones.

How it works: CO₂ can cool or heat the rock as it expands or dissolves. We pre-treat injection fluids to buffer pH and use corrosion-resistant alloys for wells. Geochemical models predict fluid-rock reactions, and we sample fluids at depth to validate safety.

Post-Project Ecology

What it is: Planning for land use, habitat and water health after injection ends.

How it works: We map nearby ecosystems—surface wetlands, forests and farmlands—and set up long-term monitoring of soil health, groundwater levels and biodiversity. Site closure plans include habitat restoration, public access or new land-use agreements.

Glossary

Mafic & Ultramafic Rocks
Dark volcanic rocks rich in magnesium and iron, ideal for mineralizing CO₂.
Aquifer
A layer of rock or sand that holds groundwater used for drinking and irrigation.
Caprock
An impermeable layer (shale or clay) above a reservoir that traps fluids below it.
Hydromechanical Equilibrium
A balanced state where fluid pressure and rock strength remain stable, preventing fractures.
Carbonate Minerals
Stable solid compounds (like calcite) formed when CO₂ reacts with rock.
pH Buffer
A substance that keeps liquids from becoming too acidic or basic.

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