Code of Colorado Regulations
400 - Department of Natural Resources
402 - Division of Water Resources
2 CCR 402-2 - RULES AND REGULATIONS FOR WATER WELL CONSTRUCTION, PUMP INSTALLATION, CISTERN INSTALLATION, AND MONITORING AND OBSERVATION HOLE/WELL CONSTRUCTION
5 - DEFINITIONS

5.2.1 "Annular space," or "annulus" means the space surrounding a cylindrical object within a cylinder, such as the space between the drill pipe or casing and the borehole wall. For example, a borehole with a 10-inch diameter, and a 7-inch outer-diameter casing, will have a 11/2-inch annular space. See Figure 1, below.

FIGURE 1 ANNULAR SPACE

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Figure 1: "Annular Space" is the distance marked "x"

5.2.2 "Aquifer" means a hydrogeologic unit or interval of consolidated and/or unconsolidated geologic material that is capable of storing and transmitting water. "Aquifer" includes both the saturated and unsaturated interval but does not include the confining layer that separates aquifers. These rules provide different construction requirements for three general classifications of aquifers (Types I-III) and one particular aquifer (Laramie-Fox Hills).

5.2.3 "Authorized individual" means a professional engineer registered in Colorado, a professional geologist as defined in section 23-41-208(b), C.R.S., or a person directly employed by or under the supervision of a registered professional engineer or professional geologist. Alternately, an individual may be designated an Authorized Individual by the Board upon presentation and approval of qualifications. "Professional geologist" is defined in section 23-41-208(b), C.R.S. as "a person engaged in the practice of geology who is a graduate of an institution of higher education which is accredited by a regional or national accrediting agency, with a minimum of thirty semester (forty-five quarter) hours of undergraduate or graduate work in a field of geology and whose post baccalaureate training has been in the field of geology with a specific record of an additional five years of geological experience to include no more than two years of graduate work."

5.2.4 "Bedrock" means consolidated crystalline or sedimentary rock.

5.2.5 "Board" means the state Board of Examiners of Water Well Construction and Pump Installation Contractors created by section 37-91-103. § 37-91-102(3), C.R.S.

5.2.6 "Borehole" means a cylindrical 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.

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

5.2.8 "Centralizer" means a device attached to the outside of casing for the purpose of centering it within a borehole or outer casing.

5.2.9 "Cistern" means an enclosed, unpressurized reservoir or tank for storing water as part of a water well supply system.

5.2.10 "Completion of pump installation" means that the production equipment has been installed in a well, all necessary equipment has been connected, the well has been disinfected, the production equipment has been tested, and the well is ready to be placed into service.

5.2.11 "Completion of well construction" means that the well has been cased, developed, tested for yield, cleaned, disinfected, and is ready for the installation of the production equipment.

5.2.12 "Confining layer" means a geologic zone that, because of its impermeability or low permeability, separates and inhibits the flow of groundwater between distinct or administratively-defined aquifers (aquifers identified in permits issued by the State Engineer).

5.2.13 "Construction of wells" means "any act undertaken at the well site for the establishment or modification of a well, including, without limitation, the location of the well and the excavation or fracturing thereof but not including surveying or other acts preparatory thereto, site preparation and modification or site modification, or the installation of pumping equipment." § 37-91-102(4), C.R.S.

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

5.2.15 "Contamination" means the introduction of contaminants.

5.2.16 "Contracting" means undertaking, offering, bartering, or bargaining to undertake for another any activity regulated by the Board under these Rules by any person, firm, corporation, partnership, association, or other organization.

5.2.17 "Contractor" means any person authorized to perform an activity regulated by the Board under these Rules.

5.2.18 "Dewatering system" means a permanent well, drain, sump or other excavation constructed for the purpose of keeping the water table below a desired level or elevation where the water produced is not put to beneficial use. Note: A dewatering system is not the same as a "dewatering well" defined by section 37-91-102 (4.5), C.R.S.

5.2.19 "Dewatering well" "includes any excavation that is drilled, cored, bored, washed, fractured, driven, dug, jetted, or otherwise constructed when the intended use of such excavation is for temporary dewatering purposes for construction only." § 37-91-102 (4.5), C.R.S.

5.2.20 "Directly employed" means "engaged in employment where the employer is responsible for and directly controls the performance of the employee, and, where applicable, the employee is covered by workers' compensation and unemployment compensation. 'Directly employed' does not refer to independent contractors or subcontractors." § 37-91-102 (4.7), C.R.S.

5.2.21 "Filter pack", also referred to as "gravel pack", means selected granular materials placed in the annular space between the borehole wall and casing to reduce the amount of solid material entering the perforated casing or screen.

5.2.22 "Groundwater" or "ground water" means "any water not visible on the surface of the ground under natural conditions." § 37-91-102(7), C.R.S. In these Rules, the term "groundwater" has the same meaning as defined at section 37-91-102(7), C.R.S.

5.2.23 "Grout" means any material, approved by the Board, that is used to form a permanent impermeable seal in the annulus between the casing and the borehole wall or between two strings of casing, or that is used in plugging, sealing, and abandoning a borehole or well. See Rule 10.5.1.

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

5.2.25 "Hydraulic fracturing of a water well" means the treatment of a water well by the application of fluid or other substance or fluid additive under pressure that is expressly designed to initiate or propagate fractures in the permitted production interval to enhance the flow or production of water in that interval.

5.2.26 "Installation of pumping equipment" means "the selection, placement, and preparation for operation of pumping equipment, including all construction involved in entering the well and establishing well seals and safeguards to protect groundwater from contamination." § 37-91-102(8), C.R.S.

5.2.27 "Laramie-Fox Hills aquifer" is defined above in Rule 5.2.2.4.

5.2.28 "License" means "the document issued by the Board to qualified persons making application therefor, pursuant to section 37-91-105, authorizing such persons to engage in one or more methods of well construction or pump installation or any combination of such methods." § 37-91-102(10), C.R.S.

5.2.29 "Lithologic log" means a written geologic description of the type, color, and character of the soil and rock materials penetrated by the drilling procedure or activity.

5.2.30 "Monitoring and observation hole" means a temporary well constructed for the purpose of repeated observations, measurements, or samplings of groundwater. Temporary wells completed for environmental groundwater investigations are monitoring and observation holes. A monitoring and observation hole may only be constructed upon a notice of intent. See Rules 6.3 & 14.2.1 . A monitoring and observation hole must be plugged, sealed, and abandoned in less than eighteen (18) months from the date it was constructed unless a permit for a monitoring and observation well has been obtained from the State Engineer. See Rule 14.2.1. A monitoring and observation hole is not a test hole (see Rule 5.2.51 for definition of "test hole").

5.2.31 "Monitoring and observation well" "includes any excavation that is drilled, cored, bored, washed, fractured, driven, dug, jetted, or otherwise constructed when the intended use of such excavation is for locating such well, pumping equipment or aquifer testing, monitoring groundwater, or collection of water quality samples." § 37-91-102 (10.5), C.R.S. A monitoring and observation well must be permitted by the State Engineer. See § 37-90-105(1)(d), C.R.S.; § 37-92-602(1)(f), C.R.S.; and Rule 14.2.2.

5.2.32 "Nested well" means the installation of two or more casings in a single borehole or excavation for completion of more than one interval.

5.2.33 "Notice of intent" refers to the forms of the State Engineer titled "Notice of Intent to Construct a Monitoring Hole(s)," and "Notice of Intent to Construct Dewatering Wells," which requires no less than seventy-two (72) hours' notice, including one business day, for construction of certain types of structures. See Rule 6.3.

5.2.34 "Person" means "an individual, a partnership, a corporation, a municipality, the state, the United States, or any other legal entity, public or private." § 37-91-102 (11.5), C.R.S.

5.2.35 "Piezometer hole" means a small-diameter monitoring and observation hole or well that is constructed for the sole purpose of monitoring or measuring water pressure or water level elevation.

5.2.36 "Pitless adapter" means a device that is designed to attach to well casing in order to permit water service pipes to pass through the wall of a well casing but prevent entrance of contaminants into the well or water supply.

5.2.37 "Pitless unit" means a commercially-manufactured assembly, or other unit approved by the Board, designed to be attached to the well casing with an integral mechanical seal below ground level, that will permit water service pipes to be connected to the well but will prevent the entry of contaminants into the well or the water supply.

5.2.38 "Plugged, sealed, and abandoned well" means a well that has been filled and grouted to (1) prevent the entry of contaminants from the surface into the well, (2) prevent the movement of fluids between aquifers through the borehole, (3) maintain natural protection against pollution of water-bearing formations, and (4) exclude known sources of contamination, as required by section 37-91-110(1)(a)(III), C.R.S.

5.2.39 "Positive displacement" means a procedure whereby a material such as grout is first introduced at the bottom of an interval and is pumped or placed upward through the interval, displacing fluids within the interval.

5.2.40 "Private driller" means "any individual, corporation, partnership, association, political subdivision, or public agency, that uses equipment owned by it to dig, drill, redrill, case, recase, deepen, or excavate a well entirely for its own use upon property owned by it." § 37-91-102(12), C.R.S. Private Driller typically refers to a well owner who uses his or her own equipment (not rented, leased, or hired) to construct or repair a well located on land he or she owns (not rented or leased).

5.2.41 "Private pump installer" means "any individual, corporation, partnership, association, political subdivision, or public agency that uses equipment owned by it to install pumping equipment on a well entirely for its own use on property owned by it." § 37-91-102 (12.5), C.R.S.

5.2.42 "Producing aquifer," or "production zone" means that portion of the permitted or authorized aquifer (as stated on the well permit) that consists of permeable geologic material.

5.2.43 "Pumping equipment" means "any pump or related equipment used or intended for use in withdrawing or obtaining ground water, including, but not limited to, well seals, pitless adapters, and other safeguards to protect the ground water from contamination and any waterlines up to and including the pressure tank and any coupling appurtenant thereto." § 37-91-102(13), C.R.S.

5.2.44 "Pump installation contractor" means "any person licensed to install, remove, modify, or repair pumping equipment for compensation." § 37-91-102(14), C.R.S.

5.2.45 "PVC casing" means polyvinyl chloride casing as specified in ASTM Standard F480-14 (2014, Thermoplastic Well Casing Pipe) that is clearly marked by the manufacturer as "well casing".

5.2.46 "Recovery well" means a well which is constructed specifically for aquifer remediation, or for the removal of contaminants from an aquifer.

5.2.47 "Repair" means "any change, replacement, or other alteration of any well or pumping equipment which requires a breaking or opening of the well seal or any waterlines up to and including the pressure tank and any coupling appurtenant thereto." § 37-91-102(15), C.R.S.

5.2.48 "Replacement well" means "a new well which replaces an existing well and which shall be limited to the yield of the original well and shall take the date of priority of the original well, which shall be abandoned upon completion of the new well." § 37-90-103(13), C.R.S. All replacement wells must be properly permitted by the State Engineer.

5.2.49 "Static water level" means the water level in a well when there is less than one (1) foot difference between two (2) consecutive water level measurements taken at least sixty (60) minutes apart.

5.2.50 "Supervision" means "personal and continuous on-the-site direction by a licensed well construction contractor or licensed pump installation contractor, unless the licensed contractor has applied for and received from the board an exemption from continuous on-the-site direction for a specific task." § 37-91-102 (15.5), C.R.S.

5.2.51 "Test hole" "includes any excavation that is drilled, cored, bored, washed, fractured, driven, dug, jetted, or otherwise constructed when the intended use of such excavation is for geotechnical, geophysical, or geologic investigation or soil- or rock-sampling." § 37-91-102 (15.7), C.R.S. Test holes must be properly plugged, sealed, and abandoned upon the completion of the geotechnical, geophysical, or geologic investigation or soil- or rock-sampling. Any test hole that penetrates through a confining layer between two distinct aquifers must be constructed by a licensed contractor pursuant to a Notice of Intent filed with the State Engineer. See Rule 6.3.

Any borehole constructed or used for environmental groundwater investigations, or repeated groundwater observations, measurements, or samplings, is a monitoring and observation hole or well (5.2.30 or 5.2.31), not a test hole, and may only be constructed under a notice of intent or well permit. See Rules 6.3 & 14.2.1.

5.2.52 "Type I aquifer" is defined above at Rule 5.2.2.1.

5.2.53 "Type II aquifer" is defined above at Rule 5.2.2.2.

5.2.54 "Type III aquifer" is defined above at Rule 5.2.2.3.

5.2.55 "Valid permit" means a well permit issued by the State Engineer that has not been cancelled and for which (1) when issued in accordance with section 37-92-602, C.R.S. (exempt wells) the completion of well construction is accomplished prior to the permit expiration date; or, (2) for all other wells (non-exempt wells), the completion of well construction or pump installation is accomplished on or before the permit expiration date. The State Engineer has the exclusive administrative authority to determine whether or not a well permit is valid.

5.2.56 "Water well supply system" includes all components of a groundwater well, pump, drop pipe, pitless adapters or units, other pumping equipment, storage tanks or cisterns, and piping and connections between the well and its point of discharge from the pressure tank, if such a tank is installed.

5.2.57 "Watertight" means a condition that does not allow the entrance, passage, or flow of water under normal operating conditions.

5.2.58 "Well" as used in these Rules, "means any test hole or other excavation that is drilled, cored, bored, washed, fractured, driven, dug, jetted, or otherwise constructed for the purpose of location, monitoring, dewatering, observation, diversion, artificial recharge, or acquisition of ground water for beneficial use or for conducting pumping equipment or aquifer tests." § 37-91-102(16)(a), C.R.S.

5.2.59 "Well construction contractor" means "any person licensed pursuant to this article and responsible for the construction, test-pumping, or development of wells, either by contract or for hire or for any consideration whatsoever." § 37-91-102(17), C.R.S.

5.2.60 "Well owner" means any person or his or her agent who holds the title or other property rights in or to a well.

5.2.61 "Well seal" means "an approved arrangement or device used to cover a well or to establish and maintain a junction between the casing or curbing of a well and the piping or equipment installed therein, the purpose or function of which is to prevent contaminated water or other material from entering the well at the upper terminal." § 37-91-102(18), C.R.S. (2014).

5.2.62 "Well vault" means an underground structure or pit in which the well casing terminates below ground surface.

5.2.63 "Well yield estimate" means a procedure designed to accurately estimate stabilized well production rate. Acceptable procedures include, but are not limited to, air-lifting or bailing.

5.2.64 "Well yield test" means a procedure conducted to determine a stabilized drawdown and production rate of a well.