In the leading English case of Bernstein v Skyviews & General Ltd, Griffiths J said “I can find no support in authority for the view that a landowner’s rights in the air space above his property extend to an unlimited height”*. The Superior Court of Pennsylvania seems to have gone in the opposite direction both spatially and jurisprudentially.

Briggs owned land in Susquehanna County, Pennsylvania. Southwestern Energy Production Co leased oil and gas rights on an adjoining parcel of land. The company extracted natural gas from below both properties using hydraulic fracturing (“fracking”). Briggs sued the company in the Court of Common Pleas for conversion of natural gas and trespass to land. The Company sought and was granted summary dismissal of the plaintiff’s claim based on the “rule of capture”. The rule of capture says that an owner (or lessee) may extract oil and gas from below ground even when doing so depletes a single reservoir of oil or gas beneath both their own and adjoining land**. The plaintiff appealed.

The Superior Court upheld the appeal and set aside summary judgment. It found that fracking was so different from conventional gas extraction that the rule of capture did not apply –

Traditionally, the rule of capture assumes that oil and gas originate in subsurface reservoirs or pools, and can migrate freely within the reservoir and across property lines, according to changes in pressure. … Unlike oil and gas originating in a common reservoir, natural gas, when trapped in a shale formation, is non-migratory in nature. … Shale gas does not merely “escape” to adjoining land absent the application of an external force. … Instead, the shale must be fractured through the process of hydraulic fracturing; only then may the natural gas contained in the shale move freely

It followed that fracking may be an actionable trespass where subsurface fractures and fracking substances entered the “subsurface estate” of a property and resulted in the extraction of natural gas.  Conceivably this trespass may extend to damage caused by earth tremors if they can be credibly linked to fracking.

Briggs v Southwestern Energy Production Co, 2018 PA Super 79

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* [1978] Q.B. 479 at 487.
** Minard Run Oil Co v US Forest Service, 670 F. 3d 236 at 256 (3d Cir. 2011)