Pore Space Rights - U.S. Overview

By: Ruth Ivory-Moore, Global CCS Institute (May 2022)

This paper discusses the intricate issue of pore space ownership, a crucial factor in sequestering carbon dioxide (CO2) in subsurface geological formations in the United States. It underscores the distinction between surface and mineral estates, with the former encompassing all aboveground elements and the latter referring to underground resources. Ownership of pore space, the voids within geologic formations where CO2 can be stored, is often unclear, creating significant legal uncertainty.

In the US, most states adhere to the "American rule", under which the surface owner holds the rights to the geologic pore space and storage. However, the rule mandates that the mineral estate holder (who only owns the minerals) must first deplete the resources before the surface owner can lease the pore space. The paper highlights that this area of property law remains unsettled and recommends rigorous research into local property rights laws for anyone considering CO2 sequestration.