For the purposes of this chapter, unless otherwise indicated, the following terms shall have the meanings respectively ascribed to them by this section:

(1) COMMISSION. The Alabama Environmental Management Commission.

(2) DEPARTMENT. The Alabama Department of Environmental Management.

(3) DIRECTOR. The Director of the Alabama Department of Environmental Management.

(4) OPERATOR. Any person in control of, or having responsibility for, the daily operation of an underground storage tank.

(5) OWNER OF AN UNDERGROUND STORAGE TANK:

a. In the case of an underground storage tank in use on November 8, 1984 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, and

b. In the case of any underground storage tank in use before November 8, 1984 but no longer in use on that date, the present owner of the tank and any person who owned such tank immediately before the discontinuation of its use.

(6) PERSON. Any natural person, any firm, association, partnership, corporation, trust, the state and any agency of the state, governmental entity, the United States and any agency of the United States, a consortium, a joint venture, a commercial entity and any other legal entity.

(7) PETROLEUM. Crude oil or any fraction thereof which is liquid at standard conditions of temperature and pressure (60 degrees Fahrenheit and 14.7 pounds per square inch absolute).

(8) POLLUTION. The presence or discharge of regulated substances in or on the land or in the water of the state.

(9) REGULATED SUBSTANCE:

a. Any substance identified as hazardous in Section 101(14) of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (42 U.S.C. §9601 through 9675). This shall not include any substance regulated as a hazardous waste under the Alabama Hazardous Wastes Management Act of 1978 as amended, Section 22-30-1 et seq. or the regulations promulgated under such act; and

b. Petroleum.

(10) RELEASE. Any spilling, leaking, emitting, discharging, escaping, leaching, or disposing from an underground storage tank into waters or subsurface soils.

(11) UNDERGROUND STORAGE TANK. Any one or combination of tanks (including underground pipes connected thereto) used to contain an accumulation of regulated substances, and the volume of which (including the volume of the underground pipes connected thereto) is 10 percent or more beneath the surface of the ground. Such term does not include any:

a. Farm or residential tank of 1,100 gallons or less capacity used for storing motor fuel for noncommercial purposes;

b. Tank used for storing heating oil for consumptive use on the premises where stored;

c. Septic tank;

d. Pipeline facility (including gathering lines) regulated under:

1. The Natural Gas Pipeline Safety chapter of 1968 (49 U.S.C. App. 1671 et seq.),

2. The Hazardous Liquid Pipeline Safety chapter of 1979 (49 U.S.C. App. 2001 et seq.), or

3. State laws comparable to the provisions of law in subparagraph 1. or 2. above;

e. Surface impoundment, pit, pond, or lagoon;

f. Stormwater or wastewater collection system;

g. Flow-through process tank;

h. Liquid trap or associated gathering lines directly related to oil or gas production and gathering operations;

i. Storage tank situated in an underground area (such as a basement, cellar, mineworking, drift, shaft, or tunnel) if the storage tank is situated upon or above the surface of the floor;

j. Other tanks exempted by the administrator of the United States Environmental Protection Agency; and

k. Piping connected to any of the above exemptions.

(12) WATERS. All waters of any river, stream, watercourse, pond, lake, coastal, ground or surface water, wholly or partially within the state, natural or artificial. This does not include waters which are entirely confined and retained completely upon the property of a single individual, partnership or corporation unless such waters are used in interstate commerce.

(13) WELLHEAD PROTECTION AREA. The surface and subsurface area surrounding a water well or wellfield, supplying a public water system, through which contaminants are reasonably likely to move toward and reach such water well or well field.