In 20 AAC 25.1000 - 20 AAC 25.1900, the following definitions apply:

1. (1) "abandoned well" means a well whose use has been permanently discontinued, or which is in a state of disrepair such that it cannot be used for its intended purpose or for observation purposes;
2. (2) "aquifer" has the meaning given in 20 AAC 25.990;
3. (3) "area of review" means the area surrounding a storage facility where underground sources of drinking water may be endangered by the injection activity; and is delineated using computational modeling that accounts for the physical and chemical properties of all phases of the injected carbon dioxide stream and displaced fluid, and is based on available site characterization, monitoring and operational data under 20 AAC 25.1070;
4. (4) "carbon dioxide" has the meaning given in AS 41.06.210;
5. (5) "carbon dioxide plume" means the extent underground, in three dimensions of an injected carbon dioxide stream;
6. (6) "carbon dioxide stream" means carbon dioxide that has been captured from an emission source, such as a power plant, plus incidental associated substances derived from source materials and the capture process, and any substances added to the stream to enable or improve the injection process; "carbon dioxide stream" does not apply to any carbon dioxide stream that meets the definition of hazardous waste under 40 C.F.R. part 261;
7. (7) "carbon storage" has the meaning given in AS 41.06.210; and includes "geologic sequestration," as defined in 40 C.F.R. 146.81, Part H, Applicability, effective January 10, 2011 and adopted by reference;
8. (8) "casing" means a pipe or tubing of appropriate material, of varying diameter and weight, which is installed into a well to maintain the structural integrity of a well, to prevent the loss of drilling mud into porous ground, or to prevent water, gas, or other fluid from entering or leaving the hole;
9. (9) "cementing" means the operation whereby a cement slurry is pumped into a drilled hole and forced behind the casing;

10. (10) "Class VI well" means a well

    1. (A) that is not experimental in nature that is used for geologic sequestration of carbon dioxide beneath the lowermost formation containing underground sources of drinking water; for the purpose of this subparagraph, "experimental" means use of a technology that has not been proven feasible under the conditions in which it is being tested;
    2. (B) used for geologic sequestration of carbon dioxide that has been granted a waiver of the injection depth requirements under 20 AAC 25.1270; or
    3. (C) used for geologic sequestration of carbon dioxide that has received an expansion to the areal extent of an existing Class II well under 20 AAC 25.442
11. (11) "closure period" means the period from cessation of carbon dioxide injection until the commission issues a certificate of completion under AS 41.06.170 and applicable regulation;
12. (12) "commission" has the meaning given in 20 AAC 25.990;
13. (13) "confining zone" means a geological formation, group of formations, or part of a formation stratigraphically overlying the injection zone that acts as a barrier to fluid movement; for a Class VI well operating under an injection depth waiver under 20 AAC 25.1270, confining zone means a geologic formation, group of formations, or part of a formation stratigraphically overlying and underlying the injection zone;
14. (14) "contaminant" means any physical, chemical, biological, or radiological substance or matter in water;
15. (15) "corrective action" means commission-approved methods to ensure that wells within the area of review do not serve as conduits for the movement of fluid into underground sources of drinking water;
16. (16) "draft permit" means a document prepared under 20 AAC 25.1080 indicating the commission's tentative decision to issue or deny a storage facility permit, or modify, revoke and reissue, or terminate an existing storage facility permit; "draft permit" does not include a denial by the commission of a request for modification, revocation and reissuance, or terminate an existing storage facility permit;
17. (17) "enhanced oil or gas recovery" has the meaning given in AS 41.06.210;
18. (18) "Environmental Protection Agency" or "EPA" means the United States Environmental Protection Agency;
19. (19) "exempted aquifer" has the meaning given in 20 AAC 25.990;
20. (20) "fault" means a surface or zone of rock fracture along which there has been displacement;
21. (21) "fluid" means any material or substance that flows or moves whether in a semisolid, liquid, sludge, gas, or any other form or state;
22. (22) "flow rate" means the volume per time unit given to the flow of gases or other fluid substances which emerges from an orifice, pump, turbine or passes along a conduit or channel;
23. (23) "formation" means a body of consolidated or unconsolidated rock characterized by a degree of lithologic homogeneity which is prevailingly, but not necessarily, tabular and is mappable on the earth's surface or traceable in the subsurface;
24. (24) "formation fluid" means fluid present in a formation under natural conditions as opposed to introduced fluid, such as drilling mud;
25. (25) "injection zone" means a geological formation, group of formations, or part of a formation that is of sufficient areal extent, thickness, porosity, and permeability to receive carbon dioxide through a well or wells associated with a storage facility;
26. (26) "lithology" means the description of rocks on the basis of their physical and chemical characteristics;
27. (27) "mechanical integrity" means the absence of significant leakage within an injection well's tubing, casing, or packer, or outside of the casing;
28. (28) "operator" means the person recognized as responsible for the well, site, storage facility, or storage facility covered by 20 AAC 25.1000 - 20 AAC 25.1900, and includes the storage operator as defined in AS 41.06.210; the operator can, but need not be, the owner of the storage facility;
29. (29) "owner" means the person that owns the well, site, or storage facility, and includes the "storage operator" as defined in AS 41.06.210; the owner may be, but is not always, the operator of the well, site, facility, or activity governed under 20 AAC 25.1000 - 20 AAC 25.1900;
30. (30) "packer" means a device lowered into a well to produce a fluid tight seal;
31. (31) "permit" means a storage facility permit under 20 AAC 25.1170, but does not include a permit which has not yet been the subject of final commission action, such as a draft permit;
32. (32) "person" means an individual, association, partnership, corporation, joint venture, protected series, or other legal or commercial entity, estate, trust, trustee, receiver, executor, administrator, fiduciary, municipality, state, federal, or tribal agency, or an agency or employee thereof;
33. (33) "plugging" or "well plugging" means the act or process of stopping the flow of water, oil or gas into or out of a formation through a borehole or well penetrating that formation;
34. (34) "pressure" means the total load or force per unit area acting on a surface;
35. (35) "post injection site care" means appropriate monitoring and other actions, including corrective action, needed following cessation of injection of carbon dioxide to ensure that underground sources of drinking water are not endangered, as required by 20 AAC 25.1310;
36. (36) "pressure front" means the zone of elevated pressure that is created by the injection of carbon dioxide into the subsurface; the pressure front of a carbon dioxide plume refers to a zone where there is a pressure differential sufficient to cause the movement of injected fluid or formation fluid into underground sources of drinking water;
37. (37) "site" means the land or water area where any storage facility or activity is physically located or conducted, including adjacent land used in connection with the facility or activity;
38. (38) "site closure" means the point or time, as determined by the commission through a certificate of completion under 20 AAC 25.1320, at which the storage operator is released from post-injection site care responsibilities;

39. (39) "stimulation" includes "well stimulation" and means several processes used to clean the well bore, enlarge channels, and increase pore space in the interval to be injected thus making it possible for wastewater to move more readily into the formation, and includes

    1. (A) surging,
    2. (B) jetting,
    3. (C) blasting,
    4. (D) acidizing,
    5. (E) hydraulic fracturing;
40. (40) "storage facility" has the meaning given in AS 41.06.210, and includes a "geologic sequestration project," as defined in 40 C.F.R. 146.81;
41. (41) "surface casing" has the meaning given in 20 AAC 25.990;
42. (42) "transmissive fault or fracture" means a fault or fracture that has sufficient permeability and vertical extent to allow fluid to move between formations;

43. (43) "tribe" or "Indian tribe" means a

    1. (A) tribe that is recognized by the United States Secretary of the Interior to exist as an Indian tribe under 25 U.S.C. 5131 (Federally Recognized Indian Tribe List Act of 1994);
    2. (B) includes any subdivision, subsidiary, or business enterprise wholly owned by a federally recognized tribe;
44. (44) "underground sources of drinking water" or "USDW" has the meaning given in 20 AAC 25.990
45. (45) "well" has the meaning given in AS 41.06.210, a "well" may include an injection well;
46. (46) "well injection" or "underground injection" means the subsurface emplacement of fluid through a well;
47. (47) "well monitoring" means the measurement, by on-site instruments or laboratory methods, of the quality of water in a well;
48. (48) "well plug" means a watertight and gastight seal installed in a borehole or well to prevent movement of fluid.