Code of Colorado Regulations
400 - Department of Natural Resources
402 - Division of Water Resources
2 CCR 402-10 - RULES AND REGULATIONS FOR PERMITTING THE DEVELOPMENT AND THE APPROPRIATION OF GEOTHERMAL RESOURCES THROUGH THE USE OF WELLS
4 - Definitions

Universal Citation: 2 CO Code Regs 402-10 ยง 4

Current through Register Vol. 47, No. 17, September 10, 2024

4.1 Statutory Definitions - The terms listed below are defined by statute and have the identical meaning as in the referenced statutes:

4.1.1 Colorado Geothermal Resources Act, Section 37 90.5 103, C.R.S. (2003): Geothermal By Products, Geothermal Fluid, Geothermal Resource, Hot Dry Rock, and Material Medium.

4.1.2 Section 37 91 102, C.R.S. (2003): Board, Ground Water, Installation of Pumping Equipment, Person, Repair, Well Construction Contractor, and Well Seal.

4.1.3 Colorado Ground Water Management Act, Section 37 90 103, C.R.S. (2003): Nontributary Ground Water, and Waste.

4.2 Specific Definitions - Unless expressly stated otherwise, the following terms shall have the meaning indicated in this Rule.

4.2.1 " Aquifer " means a hydrogeologic unit consisting of an interval, or hydraulically connected intervals, of consolidated and/or unconsolidated rock material that is capable of storing and transmitting water. It includes both the saturated and unsaturated zone but does not include the confining layer that separates aquifers.

4.2.2 " Borehole " means any excavation that is augered, drilled, bored, cored, washed, fractured, driven, dug, jetted, or otherwise constructed to access the subsurface for the purpose of constructing a hole or well under the jurisdiction of these Rules.

4.2.3 " Casing " means the pipe installed to prevent collapse of and provide access to the borehole. The term includes both nonperforated ("solid") pipe, perforated pipe, and screen.

4.2.4 " Certified Individual " means an individual who is certified by the State Engineer to perform/supervise the drilling or grouting in the construction of loop fields in vertical closed-loop geoexchange systems, or to perform/supervise the excavation and backfilling of loop fields in horizontal closed-loop geoexchange systems or submerge loop fields in a body of water.

4.2.5 " Completed Loop Field " means that closed-loop piping has been installed in a borehole, trench or other excavation, or submerged in a body of water; grout has been placed as required by these Rules; and the integrity of the loop field has been tested as required in Rule 8.6.

4.2.6 " Completed Well " means a well that has been drilled to its total depth, has been cased, grouted, and pressure or flow tested as required, has been equipped with production equipment if needed, and is ready to be placed into service.

4.2.7 " Confining Layer " means a geologic zone that, because of its impermeability or low permeability, inhibits the flow of ground water to or from an adjacent aquifer.

4.2.8 " Contaminant " means any chemical or organic material, live organisms, radioactive material or heated or cooled water that will adversely affect the quality of surface or ground water.

4.2.9 " Contamination " means the introduction of contaminants into surface or ground water.

4.2.10 " Designated Agent " when used herein shall mean the representative of an owner of a geothermal well who has been authorized in writing by the owner to act in his behalf.

4.2.11 " Discharge " means the disposal of geothermal fluids after use by a geothermal well owner or operator.

4.2.12 " Field or Geothermal Field " means the general area that is, or appears to be, underlain by a geothermal resource, including hot dry rock. The terms "field" and "reservoir" have the same meaning if only one reservoir is involved; however, "field", unlike "reservoir", may relate to two or more reservoirs.

4.2.13 " Flow Test " means the testing of a geothermal well to determine the geologic and hydrologic parameters of the reservoir, the physical and chemical properties of the geothermal fluids, or the production or reinjection rates for a well.

4.2.14 " Geoexchange System " means a heat pump or heat exchange system having a horizontal or vertical closed-loop portion consisting of pipe buried in trenches, boreholes, or wells (ground-source), or submerged in a body of water (water-source), in which a heat exchange medium (fluid or vapor) is circulated and fully contained within the pipe or tubing. The purpose of the closed loop is to provide for the transfer of heat between the circulating fluid or vapor and the ground or water.

4.2.15 " Geothermal Well " means a well that is constructed for the purpose of exploration, use of a geothermal resource, or reinjection of a geothermal fluid. The term "Geothermal Well" does include loop fields, but does not include a well subject to the provisions of Articles 90 and 92 of Title 37, C.R.S. (2003), wells subject to the jurisdiction of the Oil and Gas Conservation Commission pursuant to Article 60 of Title 34, C.R.S. (2003), or wells subject to the jurisdiction of the Mined Land Reclamation Board pursuant to Articles 32 and 33 of Title 34, C.R.S. (2003).

4.2.16 " Grout " means any material approved by these Rules that is used to form a permanent impermeable seal in the annulus between the closed loop or casing and the borehole wall, between two strings of casing, or that is used in plugging, boreholes, loops or wells.

4.2.17 " Grouting " means the process by which grout is placed in the borehole or casing.

4.2.18 " Loop Field " means any excavation or borehole constructed for the installation of piping to contain a fluid or vapor for circulation in the operation of a closed-loop geoexchange system.

4.2.19 " Mechanical Integrity Test " means a procedure to determine if the casing, tubing, or packers leak or if fluid movement occurs in or adjacent to the well other than in the reservoir.

4.2.20 " Open System " means a system that generally consists of a production well (Type A-OS) to withdraw a geothermal fluid, and a reinjection well for returning the fluid to the aquifer.

4.2.21 " Operator " means the person maintaining or operating a geothermal well, whether or not such person is the owner of the well, and where such person has been designated in writing by the well owner to act on his behalf.

4.2.22 " Plugged Well " means a well that has been plugged to prevent entry of fluids into the well and to isolate subsurface fluids to the formations in which they are encountered in the well.

4.2.23 " Production Equipment " means any pump, fluid circulating system, or other device used or intended for extracting geothermal resources from a well. Production equipment includes well seals, well heads, control devices, and couplings appurtenant thereto.

4.2.24 " Reinjection " means reintroducing geothermal fluids through a well into the same reservoir from which they were produced, whether by pressure at the surface or by gravity flow.

4.2.25 " Replacement Geothermal Well " means a new well constructed to replace an existing geothermal well, or any portion thereof. The repair of an existing geothermal well is excluded from this definition, where such repair does not relocate or expand the structure.

4.2.26 " Reservoir " means a subsurface geologic unit or aquifer that contains a common geothermal source. Each reservoir in a field, which is hydrologically separated from any other reservoir, is covered by the term "reservoir" in these Rules.

4.2.27 " Special Field Rules " shall mean those rules promulgated for and which are limited in their application to geothermal management districts.

4.2.28 " Type A Geothermal Well " means any geothermal well that has a total depth not exceeding two thousand five hundred (2,500) feet or that encounters geothermal fluids having a temperature not exceeding two hundred and twelve (212) degrees Fahrenheit.
4.2.28.1 " Type A-OS Well " means the production well component of an open system to withdraw a geothermal fluid that is utilized for its geothermal properties.

4.2.28.2 " Type A-CLH Well " means loop fields in a horizontal closed-loop geoexchange system that consists of pipe or tubing installed in horizontal trenches (ground-source) or submerged in a body of water (water-source).

4.2.28.3 " Type A-CLV Well " means loop fields in a vertical closed-loop geoexchange system that consists of pipe or tubing installed in drilled boreholes or wells.

4.2.29 " Type B Geothermal Well " means any geothermal well that has a total depth greater than two thousand five hundred (2,500) feet or that expects to encounter geothermal fluids having a temperature greater than two hundred and twelve (212) degrees Fahrenheit.

4.2.30 " Well Construction Operations " means any act undertaken at the well site for the establishment or modification of a geothermal well, including the installation and cementing of casing and the installation of production and well head equipment. Well construction operations do not include surveying actions and site preparations prior to installing construction equipment.

4.2.31 " Well Owner " means any person who holds the title or other property rights in or to a geothermal well.

4.3 Other Definitions - All other words used herein shall be given their usual customary and accepted meanings. All words of a technical nature specific to the well drilling industry shall be given the meaning that is generally accepted in that industry.

4.4 Gender - Words used in the present tense include other tenses; words used in the masculine gender include the feminine and neuter genders.

Disclaimer: These regulations may not be the most recent version. Colorado may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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