Subsurface Trespass in the Restatement (Fourth) of Property

Abstract

Building on the scholarly work of leading property theorists Henry Smith and Thomas Merrill, the recently approved Fourth Tentative Draft of the Restatement (Fourth) of Property prescribes treating all entries below ground as ordinary trespasses. That includes entries in the shallow subsurface by tree roots, building foundations, and utility lines, as well as invasions in the deep subsurface by mining shafts, oil and gas wells, and substances injected for disposal and storage. The Restatement comes at an important time in the development of subsurface trespass law, as developers, courts, and policymakers grapple with the growing use of subsurface technologies for horizontal drilling, hydraulic fracturing, and injection of fluids including for carbon dioxide capture and storage (CCS). 

The standard model of trespass, in which harm to the plaintiff is presumed from the mere fact of a physical entry into the plaintiff's close, works well for entries that occur near the surface and nonmigratory entries into solid, stationary mineral deposits in the deep subsurface. These parts of the subsurface are capable of effective, exclusive control and the case law applies the standard tort in those cases accordingly. Ordinary trespass has, however, proven an awkward fit for invasions involving resources that are not capable of exclusive control, like oil and gas and interconnected "pore space" where fluids are injected and stored. Accordingly, the case law generally does not support the Restatement's application of ordinary trespass to invasions of fluid and nonexclusive resources. 

A modified account of subsurface trespass to fluid minerals and interconnected space, requiring actual harm in addition to a physical invasion, better fits the case law. The harm-based account has roots in well-established oil and gas jurisprudence, which recognizes that property rights in common reservoirs are nonexclusive and correlative in nature. The harm-based account also advances the broader goals of Merrill and Smith's scholarship and the Restatement itself, in furnishing workable guidance to owners and developers of subsurface resources and in providing a superior baseline from which legislation and administrative regulation can address typical common pool problems.