For purposes of this article, the following definitions apply:

(a) “Annulus” means the space between the outside edge of the injection tube and the well casing.

(b) “State board” means the State Water Resources Control Board.

(c) “Compatibility” means that waste constituents do not react with each other, with the materials constituting the injection well, or with fluids or solid geologic media in the injection zone or confining zone in a manner as to cause leaching, precipitation of solids, gas or pressure buildup, dissolution, or any other effect that will impair the effectiveness of the confining zone or the safe operation of the injection well.

(d) “Confining zone” means the geological formation, or part of a formation, that is intended to be a barrier to prevent the migration of waste constituents from the injection zone.

(e) “Constituent” means an element, chemical, compound, or mixture of compounds that is a component of a hazardous waste or leachate and that has the physical or chemical properties that cause the waste to be identified as hazardous waste by the department pursuant to this chapter.

(f) “Discharge” means to place, inject, dispose of, or store hazardous wastes into, or in, an injection well owned or operated by the person who is conducting the placing, disposal, or storage.

(g) “Drinking water” has the same meaning as “potential source of drinking water,” as defined in subdivision (t) of Section 25208.2.

(h) “Facility” means the structures, appurtenances, and improvements on the land, and all contiguous land, that are associated with an injection well and are used for treating, storing, or disposing of hazardous waste. A facility may consist of several waste management units, including, but not limited to, surface impoundments, landfills, underground or aboveground tanks, sumps, pits, ponds, and lagoons that are associated with an injection well.

(i) “Groundwater” means water, including, but not limited to, drinking water, below the land surface in a zone of saturation.

(j) “Hazardous waste” means any hazardous waste specified as hazardous waste or extremely hazardous waste, as defined in this chapter. Any waste mixture formed by mixing any waste or substance with a hazardous waste shall be considered hazardous waste for the purposes of this article.

(k) “Hazardous waste facilities permit” means a permit issued for an injection well pursuant to Sections 25200 and 25200.6.

(l) “Injection well” or “well” means any bored, drilled, or driven shaft, dug pit, or hole in the ground the depth of which is greater than the circumference of the bored hole and any associated subsurface appurtenances, including, but not limited to, the casing. For the purposes of this article, injection well does not include either of the following:

(1) Wells exempted pursuant to Section 25159.24.

(2) Wells that are regulated by the Division of Oil and Gas in the Department of Conservation pursuant to Division 3 (commencing with Section 3000) of the Public Resources Code and Subpart F (commencing with Section 147.250) of Subchapter D of Chapter 1 of Part 147 of Title 40 of the Code of Federal Regulations and are in compliance with that division and Subpart A (commencing with Section 146.1) of Part 147 of Subchapter D of Chapter 1 of Title 40 of the Code of Federal Regulations.

(m) “Injection zone” means that portion of the receiving formation that has received, is receiving, or is expected to receive, over the lifetime of the well, waste fluid from the injection well. “Injection zone” does not include that portion of the receiving formation that exceeds the horizontal and vertical extent specified pursuant to Section 25159.20.

(n) “Owner” means a person who owns a facility or part of a facility.

(o) “Perched water” means a localized body of groundwater that overlies, and is hydraulically separated from, an underlying body of groundwater.

(p) “pH” means a measure of a sample’s acidity expressed as a negative logarithm of the hydrogen ion concentration.

(q) “Qualified person” means a person who has at least five years of full-time experience in hydrogeology and who is a professional geologist registered pursuant to Section 7850 of the Business and Professions Code, or a registered petroleum engineer registered pursuant to Section 6762 of the Business and Professions Code. “Full-time experience” in hydrogeology may include a combination of postgraduate studies in hydrogeology and work experience, with each year of postgraduate work counted as one year of full-time work experience, except that not more than three years of postgraduate studies may be counted as full-time experience.

(r) “Receiving formation” means the geologic strata that are hydraulically connected to the injection well.

(s) “Regional board” means the California regional water quality control board for the region in which the injection well is located.

(t) “Report” means the hydrogeological assessment report specified in Section 25159.18.

(u) “Safe Drinking Water Act” means Subchapter XII (commencing with Section 300f) of Chapter 6A of Title 42 of the United States Code.

(v) “Strata” means a distinctive layer or series of layers of earth materials.

(w) “Waste management unit” means that portion of a facility used for the discharge of hazardous waste into or onto land, including all containment and monitoring equipment associated with that portion of the facility.

(Amended by Stats. 2006, Ch. 538, Sec. 378. Effective January 1, 2007.)