Mass. Gen. Laws ch. 21O § 2
As used in sections 3 through 9, the following terms shall have the following meanings:
"CERCLA", the Comprehensive Environmental Response Compensation and Liability Act of nineteen hundred and eighty, 12 U.S.C. section 9601 et seq., as may be amended from time to time.
"Department", the department of environmental protection.
"Guarantor", any person, other than a person liable pursuant to section five of chapter twenty-one E, who provides evidence of financial responsibility pursuant to this chapter.
"Regulated Substance", (a) any substance defined in section 101(4) of the Comprehensive Environmental Response Compensation and Liability Act of nineteen hundred and eighty, including waste oil but not including any other substance regulated as a hazardous waste under chapter twenty-one C, and (b) petroleum, including crude oil or any fraction thereof which is liquid at standard conditions of temperature and pressure (sixty degrees Fahrenheit and 14.7 pounds per square inch absolute).
"Operator", (1) in the case of an underground storage tank in use on November eighth, nineteen hundred and eighty-four, or brought into use after that date, any person in control of, or having responsibility for, the daily operation of an underground storage tank used for the storage, use, or dispensing of regulated substances or (2) in the case of any underground storage tank in use before November eighth, nineteen hundred and eighty-four, but not in use at any time on or after that date, any person who owns the land on or in which such tank is or was located.
"Owner", (1) in the case of an underground storage tank in use on November eighth, nineteen hundred and eighty-four, or brought into use after that date, any person who owns an underground storage tank used for the storage, use, or dispensing of regulated substances or (2) in the case of any underground storage tank in use before November eighth, nineteen hundred and eighty-four, but not in use at any time on or after that date, any person who owned such tank immediately before the discontinuance of such use.
"Person", any individual, trust, firm, joint stock company, corporation (including a government corporation), partnership, association, the United States Government, state, municipality, commission, political subdivision of a state, interstate body, consortium, joint venture, commercial entity.
"RCRA", the Solid Waste Disposal Act, as revised by the Resource Conservation and Recovery Act, as may be further amended from time to time.
"Release", any spilling, leaking, emitting, discharging, escaping, leaching, or disposing from an underground storage tank into the ground water, surface water or subsurface soil.
"Head of Fire Department" the chief executive officer of the fire department in a city, town or fire district having such an office otherwise the fire commissioner, board of fire commissioners or fire engineers and, in towns not having a fire department the chief engineer, if any, otherwise the chairman of the board of selectmen.
"Trade Secret", anything tangible which constitutes, represents, evidences, or records a secret scientific, technical, merchandising, production or management information, design, process, procedure, formula, invention, or improvement.
"Underground storage tank", any one or combination of tanks, including, without limitation, underground pipes connected thereto, used to contain an accumulation of regulated substance and the volume of which, including the volume of underground pipes connected thereto, is ten percent or more beneath the surface of the ground. The term shall not include any of the following or any pipes connected to any of the following: (1) any septic tank; or (2) any pipeline facility, including gathering lines, which is regulated under (a) the Natural Gas Pipeline Safety Act of nineteen hundred and sixty-eight; or (b) the Hazardous Liquid Pipeline Safety Act of nineteen hundred and seventy-nine; or (3) any surface impoundment pit, pond, or lagoon; or (4) any storm water or waste water collection system; or (5) any flow through process tank; or (6) any liquid trap or associated gathering lines directly related to oil or gas production and gathering operations; or (7) any storage tank situated in an underground area, including without limitation, a basement, cellar, or mineworking driff, shaft or tunnel, if the storage tank is situated upon or above the surface of the floor, and all sides are accessible and visible.
Mass. Gen. Laws ch. 21O, § 2