Administrative Rules of Montana › Department 36 - NATURAL RESOURCES AND CONSERVATION › Chapter 36.22 - OIL AND GAS CONSERVATION › Subchapter 36.22.14 - Underground Injection Control › Rule 36.22.1401 - DEFINITIONS

Current through Register Vol. 13, July 5, 2024
For the purposes of this subchapter the following are
				  defined:
(1) "Area of review" means
				the area surrounding an injection well to a radius calculated according to the
				criteria set forth in ARM
				36.22.1425 or a fixed radius of
				one quarter mile, or for an area project, plus the project area plus a radius
				calculated according to the criteria set forth in ARM 36.22.1425, or the
				project area plus a circumscribing area the width of which is one quarter
				mile.
(2) "Confining zone" means
				the geological formation or formations, or the portion of a formation that is
				capable of limiting fluid movement out of the injection zone.
(3) "Corrective action" means the reworking,
				repair, replugging, or other activity taken for the purposes of preventing
				migration of injected fluids into underground sources of drinking water through
				any existing wellbore that penetrates the injection zone within the area of
				review.
(4) "Class II injection
				well" means a well that:
(a) injects fluids
				brought to the surface in conjunction with conventional oil and gas production
				and may be commingled with waste waters from gas plants which are an integral
				part of production operations, unless those waters are classified as a
				hazardous waste at the time of injection;
(b) is used to inject brines or other fluids
				brought to the surface in connection with oil or gas production or gas storage
				operations;
(c) is used to inject
				brines or other fluids described in (4)(b) which, prior to injection, have
				been:
(i) used onsite for purposes integrally
				associated with oil and gas production or storage;
(ii) chemically treated or altered to the
				extent necessary to make them useable for purposes integrally related to oil
				and gas production or storage; or
(iii) commingled with fluid wastes resulting
				from the treatment described in (4)(c)(ii), so long as they do not constitute a
				hazardous waste;
(d) is
				used to inject freshwater (i.e., water containing less than 10,000 mg/L total
				dissolved solids) from groundwater or surface water sources, added to or
				substituted for the brine may also be injected, as long as the only use of the
				water is for purposes integrally associated with oil and gas production or
				storage;
(e) is used to inject
				fluids for the enhanced recovery of oil or gas;
(f) is used to inject fluids for storage of
				hydrocarbons that are liquid under standard conditions of temperature and
				pressure; or
(g) is used to inject
				exempt waste fluids associated with oil or natural gas exploration and
				production as long as their physical state allows it, including produced fluid,
				drilling fluids, drill cuttings, rigwash, well completion fluids, workover
				wastes, gas plant dehydration wastes, gas plant sweetening wastes, spent
				filters and backwash, packing fluids, produced sand, production tank bottoms,
				gathering line pigging wastes, hydrocarbon-bearing soil, and waste crude oil
				from primary field sites.