Wyoming Administrative Code
Agency 020 - Environmental Quality, Dept. of
Sub-Agency 0011 - Water Quality
Chapter 13 - CLASS I HW & NON-HW WELLS UNDERGROUND INJECTION CONTROL PROGRAM
Section 13-2 - Definitions

(a) "Aquifer" means a zone, stratum or group of strata that can store and transmit water in sufficient quantities for a specific use.

(b) "Area of review" means the area for which information and analyses shall be submitted as part of an underground injection control permit application, and reviewed for issuance of a permit.

(c) "Background" means the constituents or parameters and the concentrations or measurements which describe water quality and water quality variability prior to the subsurface discharge.

(d) "Bore/casing annulus" means the space between the well bore and the well casing.

(e) "Casing/tubing annulus" means the space between the well casing and the tubing.

(f) "Cementing" means to seal the annular space around the outside of a casing string using a specially formulated portland cement mixture or other hydraulic cement mixture to hold the casing in place and prevent any movement of fluid in this annular space. Cementing also includes operations to seal the well at the time of abandonment.

(g) "Class I well" means a well used to inject hazardous or non-hazardous industrial, commercial or municipal waste beneath the lowermost formation containing, within one-quarter (1/4) mile of the well bore, an underground source of drinking water. Class I wells are regulated under this chapter.

(h) "Class II well" means a well regulated by the Wyoming Oil and Gas Conservation Commission, other than a Class II commercial disposal well, which injects fluids:

(i) "Class III well" means a well used for in situ mining which njects or extraction of minerals, or products, or recovers recovery fluids, minerals or products, including a well used in:

(j) "Class IV well" means a well used to dispose of hazardous waste or radioactive waste into or above a formation which contains, within one-quarter (1/4) mile of the well bore, an underground source of drinking water. Class IV wells are prohibited by Chapter XIII, Water Quality Rules and Regulations.

Except that a well is not class IV if it is used to inject contaminated groundwater that has been treated and reinjected into the same formation from which it is drawn for the purpose of aquifer remediation where the ultimate cleanup criteria is protective of groundwater standards of these regulations. These wells are regulated as a class V well, type 5X26 under these regulations.

(k) "Class V well" means any injection well not included in Classes I, II, III, or IV.

(l) "Cone of influence" means that area around a well within which increased discharge zone pressures caused by the injection would be sufficient to force fluids into an under ground source of drinking water.

(m) "Confining zone" means the zone in the well designated in the permit application to provide hydrologic separation between the receiver and any underground source of drinking water.

(n) "Draft permit" means a document indicating the tentative decision by the Department to issue or deny, modify, revoke, or terminate a permit or license. A notice of intent to terminate a permit and a notice of intent to deny a permit are types of draft permits. A denial of a request for modification, revocation and reissuance, or termination is not a draft permit. A draft permit for issuance shall contain all conditions and content, compliance schedules and monitoring requirements required by this Chapter.

(o) "Duly authorized representative" means a specific individual or a position having responsibility for the overall operation of the regulated facility or activity. The authorization shall be made in writing by a responsible corporate officer and shall be submitted to the administrator.

(p) "Endangerment" means exposure to actions or activities which could pollute groundwaters of the State.

(q) "Fact Sheet" means a document briefly setting forth the principal facts and the significant factual, legal, methodological and policy questions considered in preparing the draft permit. Fact sheets for class I wells are incorporated into the public notice.

(r) "Fluid" means any material which flows or moves, whether semisolid, liquid, sludge, gas or any other form or state.

(s) "Groundwater" means subsurface water that fills available openings in rock or soil materials such that they may be considered water saturated under hydrostatic pressure.

(t) "Groundwaters of the State" are all bodies of underground water which are wholly or partially within the boundaries of the State.

(u) "Hazardous waste" means a hazardous waste as defined in 40 CFR 261.3.

(v) "Lithology" means the description of rocks on the basis of their physical and chemical characteristics.

(w) "Long string casing" means a casing which is continuous from at least the top of the injection interval to the surface and which is cemented in place.

(x) "Log" means to make a written record progressively describing the strata and geologic and hydrologic character thereof to include electrical, radioactivity, radioactive tracer, temperature, cement bond and similar surveys, a lithologic description of all cores, and test data.

(y) "Radioactive Waste" means any waste which contains radioactive material in concentrations which exceed those listed in 10 CFR Part 20, Appendix B, Table II, Column 2.

(z) "Mechanical integrity" means the sound and unimpaired condition of all components of the well or facility or system for control of a subsurface discharge and associated activities.

(aa) "Permit" means a Wyoming Underground Injection Control permit, unless otherwise specified.

(bb) "Permittee" means the named permit holder.

(cc) "Receiver" means any zone, interval, formation or unit in the subsurface into which fluids and pollutants are discharged.

(dd) "Responsible corporate officer" means a president, secretary, treasurer, or vice president of the corporation in charge of a principal business function, or any other person who performs similar policy- or decision-making functions for the corporation.

(ee) "Subsurface discharge" means a discharge into a receiver.

(ff) "Underground source of drinking water" means those aquifers or portions thereof that have been classified as either Class I, II, III, IV(a), or Special (A), pursuant to Chapter VIII, Quality Standards for Wyoming Groundwaters, Water Quality Rules and Regulations.

(gg) "Well" means an opening, excavation, shaft or hole in the ground allowing or used for an underground injection or for the purpose of extracting a fluid, mineral, product or pollutant from the subsurface or for monitoring.

(hh) "Workover" means to pull the tubing, packer, or any downhole hardware from the well and inspect, replace, or refurbish it prior to placing that hardware back in service, or to enter the hole with any drilling tool.