58 Pa. Stat. § 452
The following words and phrases when used in this act shall have, unless the context clearly indicates otherwise, the meanings given to them in this section:
"Commodity" or "stored commodity." Either in a liquid or gaseous state natural and artificial gas.
"Department." The Department of Labor and Industry.
"Underground storage facility." A natural or man-made cavern used for the storage of a commodity. Excluded are storage facilities which are not natural or man-made caverns and which are registered with the department for the storage of liquified petroleum gas pursuant to the act of December 27, 1951 (P.L. 1793, No. 475), referred to as the Liquified Petroleum Gas Act and all underground storage facilities subject to the act of November 30, 1955 (P.L. 756, No. 225), known as the "Gas Operations, Well-Drilling, Petroleum and Coal Mining Act" and further excluding underground storage facilities and operations certificated or authorized by the Federal Energy Regulatory Commission (FERC) or its predecessor under the Natural Gas Act (15 U.S.C. § 717 et seq.)
"User." Any person, firm, corporation, partnership or other entity including the Commonwealth and its political subdivisions.
58 P.S. § 452