C05_Attach 5 - Water Well Regulations 1 (1).pdf

DEPARTMENT OF NATURAL RESOURCES

Division of Water Resources

Board of Examiners of Water Well Construction and Pump Installation Contractors Rules and Regulations for Water Well Construction, Pump Installation, Cistern Installation, and Monitoring and Observation Hole/Well Construction

2 CCR 402-2

Rule 1 Title

1.1 The title of these rules and regulations is “Rules and Regulations for Water Well Construction, Pump Installation, Cistern Installation and Monitoring and Observation Hole/Well Construction.” The short title for these rules and regulations is “Construction Rules” and they may be referred to herein collectively as the “Rules” or individually as a “Rule.”

Rule 2 Authority

2.1 These Rules are promulgated pursuant to the authority granted the State Board of Examiners of Water Well Construction and Pump Installation Contractors (the “Board” or “Board of Examiners”) in sections 37-91-104(1)(b), (c), (j) & (k); 37-91-106(3) & (4); 37- 91-109(1) & (2); and 37-91- 110(1) & (2), C.R.S.

Rule 3 Scope of Rules

Basis and Purpose: The statutory authority for this Rule is found in sections 37-91-101(1); 37- 91-102; 37- 91-104(1)(c), (j), & (k); 37-91-106(3) & (4); and 37-91-110(2), C.R.S. The purpose of this Rule is to identify the activities and individuals to which these Rules apply.

3.1 These Rules apply to the construction and repair of water wells, test holes, dewatering wells, monitoring and observation holes and wells; well plugging, sealing, and abandonment; and pump and cistern installation and repair, as those terms are defined by these Rules and section 37-91- 102, C.R.S.

3.2 These Rules do not apply to excavations made for the purpose of obtaining or prospecting for minerals or to those wells subject to the jurisdiction of the Oil and Gas Conservation Commission as provided in Article 60 of Title 34, C.R.S., or to those wells subject to the jurisdiction of the Mined Land Reclamation Board as provided in Article 32 of Title 34, C.R.S. (Minerals), and Article 33 of Title 34, C.R.S. (Coal). See section 37- 91-102(16)(b)(I), C.R.S.

3.3 These Rules apply to licensed well construction and pump installation contractors, private drillers, private pump installers, authorized individuals, any persons who undertake any activity described in Rule 3.1 or otherwise described by these Rules, and any persons excluded from the licensing requirements as described in section 37-91- 106, C.R.S. See sections 37-91-102, 37-91-104(j) & (k), and 37-91-106, C.R.S

3.4 Reference Materials - Information on examining or acquiring reference materials referred to in these rules, including American Society for Testing and Materials (ASTM) Designation: F480-14(2022) Standard Specification for Thermoplastic Well Casing Pipe and Couplings Made in Standard Dimension Ratios (SDR), SCH 40 and SCH 80;

Department of Agriculture, Colorado Chemigation Act, Article 11 of Title 35, C.R.S.;

National Fire Protection Association standard number 70, hereafter known as the NFPA 70 National Electrical Code, 2023 Edition; Examining Board of Plumbers Rules and Regulations, 3 CCR 720-1 (April 2025); and National Ground Water Association ANSI/NGWA-01-14 Water Well Construction Standard (May 2014), Code of Federal Regulations, Title 40 Protection of the Environment Subpart H (2010); NSF/ANSI 60- 2024: Drinking Water Chemicals Health Effects. Rules Governing New Withdrawals of Ground Water in Water Division 3 Affecting the Rate or Direction of Movement of Water in the Confined Aquifer System (Confined Aquifer New Use Rules for Division 3) may be obtained from the Division of Water Resources, 1313 Sherman Street, Denver Colorado, 80203. Any Rule that incorporates any of these reference materials does not include later amendments to or editions of the incorporated material. See § 24-4-103(12.5), C.R.S.

3.5 These Rules shall not be construed to establish or alter the jurisdiction of either the State of Colorado or the Southern Ute Indian Tribe over the construction and repair of water wells, test holes, dewatering wells, monitoring and observation holes and wells; well plugging, sealing, and abandonment; and pump and cistern installation and repair within the boundaries of the Southern Ute Indian Reservation as recognized in Pub. L. No. 98- 290, S 3, 98 Stat. 201 (1984)

Rule 4 Purpose of Rules

Basis and Purpose: The statutory authority for this Rule is found in sections 37-91-104(1)(c), (j), & (k); 37- 91-106(3) & (4); and 37-91-110(2), C.R.S. The purpose of this Rule is to identify the broad purposes for the Rules.

4.1 To enable the Board to carry out the provisions of Article 91 of Title 37, C.R.S.

4.2 To safeguard the public health of the people of the State of Colorado and to protect the groundwater resources of the State of Colorado.

4.3 To set minimum standards for the construction, repair, plugging, sealing, and abandonment of all wells, test holes, monitoring and observation holes and wells, and dewatering wells.

4.4 To allow certain types of monitoring and observation holes, monitoring and observation wells, temporary dewatering wells, and test holes to be constructed, utilized, plugged, sealed, and abandoned by persons other than a licensed well construction contractor.

4.5 To set minimum standards for the installation and repair of pumping equipment and cisterns.

4.6 To set minimum standards for the reporting, testing, sampling, measuring, and disinfection of all wells and associated water well supply systems, to the extent such standards are required for the proper construction and repair of water wells.

Rule 5 Definitions

Basis and Purpose: The statutory authority for this Rule is found in sections 37-91-101(1); 37- 91-102; 37- 91-104(1)(c), (j), & (k); 37-91-106(3) & (4); and 37-91-110(2), C.R.S. The purpose of this Rule is to identify the terms used throughout the Rules.

5.1 Statutory Definitions - Certain terms used in these Rules have the identical meaning as provided in section 37-91-102, C.R.S., as quoted and cited in Rule 5.2.

5.2 Specific Definitions - Unless expressly stated otherwise, the following terms when used in these Rules have the meaning indicated in this Rule. Terms used in the singular include the plural.

5.2.1 “Administrative Denver Basin” means the geographic area including the Denver Basin Aquifers as defined in 2 CCR 402-6, 1985 and on Figure 1). For the purposes of these Rules, the Boulder Complex Area is not within the “Administrative Denver Basin.”

5.2.2 “Annular space,” or “annulus” means the space surrounding a cylindrical object within a cylinder, such as the space between the outermost drill pipe or casing and the borehole wall. It also means the space between the outside of an inner string of casing and the inside of an outer string of overlapping casing. For example, a borehole with a 10-inch diameter, and a 7-inch outer-diameter casing, will have a 1½-inch annular space. See Figure 2, below.

5.2.3 “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 unit that separates aquifers.

5.2.3.1 “Administratively-defined aquifer” means a hydrogeologic unit that has been defined in rules promulgated by the State Engineer, identified in a well permit, identified in a decree, or included in a list of aquifers approved by the Board.

5.2.3.2 “Type 1 aquifer” means an aquifer that is overlain by a confining unit of relatively impermeable geologic material. A Type 1 Aquifer may also be known as a confined aquifer, but the water level could potentially be lower than the top of the aquifer.

5.2.3.3 “Type 2 aquifer” means an aquifer consisting of consolidated geologic material or crystalline rock that is not overlain by a confining unit. A Type 2 Aquifer may also be known as an unconfined bedrock aquifer. Type 2 aquifers can be identified on geologic maps as outcropping or subcropping below unconsolidated units at the well location.

5.2.3.4 “Type 3 aquifer” means an aquifer that consists of unconsolidated geologic material including alluvial, colluvial or other unconsolidated materials. Type 3 aquifers may contain localized impermeable layers that do not act as hydraulic boundaries between distinct aquifers. A common example of a Type 3 aquifer is an alluvial aquifer.

5.2.3.5 “Laramie-Fox Hills aquifer” means that aquifer found below the shales of the Laramie Formation and above the Pierre Shale, including the basal sandstone units of the Laramie Formation and the siltstones and sandstones of the Fox Hills Sandstone. The Laramie-Fox Hills aquifer exists both inside and outside the Administrative Denver Basin boundary (Rule 5.2.1).

5.2.3.6 “Unconfined San Luis Valley aquifer” means the aquifer underlying portions of Water Division No. 3 consisting in part of unconsolidated clays, silts, sands, gravels, and cobbles. The Unconfined San Luis Valley aquifer, an administratively-defined aquifer, is found above the Blue Clay (confining layer) and is also identified as Layer 1 in the RGDSS Groundwater Model, https://cdss.colorado.gov/rgdss-modeling-data. The Unconfined San Luis Valley aquifer shall be considered as a Type 3 aquifer for the purposes of well construction and abandonment.

5.2.3.7 “Confined San Luis Valley aquifer” means the formations, groups of formations, or parts of formations underlying portions of Water Division 3 consisting in part of unconsolidated clays, silts, sands, gravels, and interbedded volcanic rock. The Confined San Luis Valley aquifer, an administratively-defined aquifer, is found below the Blue Clay (confining layer) and is also identified as Layer 2, 3, 4, and 5 in the RGDSS Groundwater Model, https://cdss.colorado.gov/rgdss-modeling-data.

5.2.3.8 “High Plains aquifer” means the Ogallala and White River aquifers. The High Plains aquifer is a Type 2 aquifer. Within the Northern High Plains Designated Basin (see Figure 3) the alluvium and the High Plains aquifers are an administratively-defined aquifer and a single hydrogeologic unit. Therefore, within the Northern High Plains Designated Basin, wells completed in the alluvium and the High Plains aquifers shall be considered as a Type 2 aquifer for the purposes of well construction and abandonment. Wells completed solely within the alluvium within the Northern High Plains Designated Basin shall be considered as constructed within a Type 3 aquifer for the purposes of well construction and abandonment.

5.2.3.9 “Southern High Plains aquifer” is an administratively-defined aquifer and includes the Alluvial, Ogallala, Dakota, Cheyenne, and Dockum aquifers within the Southern High Plains Designated Basin. See Figure 3. The Southern High Plains Aquifer is a Type 2 aquifer within the Southern High Plains Designated Basin. Wells completed solely within the alluvium within the Southern High Plains Designated Basin shall be considered as constructed within a Type 3 aquifer for the purposes of well construction and abandonment.

5.2.4 “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. Alternatively, 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.”

https://cdss.colorado.gov/rgdss-modeling-data https://cdss.colorado.gov/rgdss-modeling-data

Figure 1 Administrative Denver Basin

Figure 1. Administrative Denver Basin and Denver Basin Aquifer Extents. Note Boulder Complex Area is in the Administrative Denver Basin but are not considered Denver Basin Aquifers.

Figure 2. Annular Space” is the distance marked “x”

Figure 3. Boundaries of the High Plains Aquifer, the Northern High Plains Designated Basin, and the Southern High Plains Designated Basin

5.2.5 “Bedrock” means consolidated crystalline or sedimentary rock.

5.2.6 “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.

5.2.7 “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.

5.2.8 “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.

5.2.8.1 “Temporary Surface Casing” is the outermost, temporary string of casing used to hold back zones of shallow, unconsolidated, or unstable materials from the borehole to facilitate drilling and placement of other strings of casing.

Temporary surface casing may be PVC or steel and is differentiated from Surface Casing and Production Casing in that it is not considered a permanent part of the well construction, must be removed prior to completing grouting in any required grouted intervals and thus is not documented on the well construction report.

5.2.8.2 “Surface Casing” is one or more strings of nonperforated, steel casing typically set to isolate or protect the borehole and other subsequent strings of casing from shallow, unconsolidated, or unstable materials, though surface casing may extend to significant depths. Surface casing can be placed in a drilled borehole or driven into place.

5.2.8.3 “Production Casing” is a string of casing that is typically set through the production zone. The production casing may extend to the ground surface and could be the only casing string if no surface casing is used, or could be a liner that extends up and into the surface casing but not necessarily to the ground surface. Production casing can be nonperforated, perforated, PVC or steel casing depending on its position within the well and the Aquifer type.

5.2.9 “Centralizer” means a device attached to the outside of casing for the purpose of centering it within a borehole or outer casing.

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

5.2.11 “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.

5.2.12 “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.

5.2.13 “Confining unit” means a geologic formation, group of formations, or part of a formation that separates or inhibits the flow of groundwater into, out of, or between distinct or administratively-defined aquifers because it is impermeable or distinctly less permeable than adjacent hydrogeologic units. Some confining units may contain geologic materials or intervals capable of yielding small amounts of water to wells.

5.2.14 “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.

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

5.2.16 “Contamination” means the introduction of contaminants.

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

5.2.18 “Development” means the act of repairing damage to the formation resulting from the drilling process and enhancing the permeability of the materials surrounding the intake portion of the well.

5.2.19 “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.

A dewatering system is not the same as a “dewatering well” defined by section 37-91-102(4.5), C.R.S.

5.2.20 “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.

5.2.21 “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.

5.2.22 “Dry Hole” means a borehole that does not produce enough water for the permitted use(s). Dry hole reports must be submitted in lieu of well construction reports in order to continue to attempt to drill a successful well under the original permit.

Dry holes constructed under a valid well permit are not Test Holes as defined in Rule 5.2.57.

5.2.23 “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.

5.2.24 “Gallery Well or Infiltration Galleries” means a shallow depth groundwater collection device comprising solid and perforated pipes, rings, boxes, or casing.

These systems are not constructed using conventional drilling methods, are typically excavated, and may only be constructed after a variance has been issued in accordance with Rule 10.4.13. A gallery well or infiltration gallery does not include a spring box or other spring collection structure as defined by Rule 5.2.64.2.

5.2.25 “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.

5.2.26 “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.

5.2.27 “Grouting” means the process by which grout is placed in the borehole or casing.

5.2.28 “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.

5.2.29 “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.

5.2.30 “Laramie-Fox Hills aquifer” is defined above in Rule 5.2.3.5

5.2.31 “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.

5.2.32 “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.

5.2.33 “Monitoring and observation hole” means a temporary well constructed for the purpose of repeated observations of groundwater, repeated measurements of groundwater, any sampling of groundwater, or any remediation 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 5.2.57 for definition of “test hole”).

5.2.34 “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.

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

5.2.36 “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 three days notice, including one business day, for construction of certain types of structures. See Rule 6.3.

5.2.37 “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.

5.2.38 “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.

5.2.39 “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.

5.2.40 “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.

5.2.41 “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.

5.2.42 “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.

5.2.43 “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 refers to a well owner or their direct employee(s) who use the owner’s equipment (not rented, leased, or hired) to construct or repair a well located on land they own (not rent or lease).

5.2.44 “Private driller assessment” means an online, open-book assessment meant to aid the private driller in understanding their responsibilities pursuant to § 37- 91-110, C.R.S., and to assist them in complying with all applicable well construction standards and the rules of the Board.

5.2.45 “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. Private pump installer refers to a well owner or their direct employee(s) who use the owner’s equipment (not rented, leased or hired) to install pumping equipment in a well on land they own (not rent or lease).

5.2.46 “Private pump installer assessment” means an online, open-book assessment meant to aid the private driller in understanding their responsibilities pursuant to § 37-91-110, C.R.S., and to assist them in complying with all applicable pump installation standards and the rules of the Board.

5.2.47 “Production zone” means that portion of the permitted or administratively-defined aquifer that consists of permeable geologic material.

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

5.2.48.1 “Pumping equipment” also includes cisterns or other water storage tanks connected to a water well supply system between the wellhead and the pressure tank or downstream of the wellhead if no pressure tank is utilized.

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

5.2.50 “PVC casing” means polyvinyl chloride casing as specified in ASTM Standard F480-14 (2022), Thermoplastic Well Casing Pipe and Couplings Made in Standard Dimension Ratios (SDR), SCH 40 and SCH 80 that is clearly marked by the manufacturer as “well casing”.

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

5.2.52 “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.

5.2.53 “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.

5.2.54 “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.

5.2.55 “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.

5.2.56 “Surface Water” means any and all surface waters which are contained in or flow in or through this State, but does not include waters in sewage systems, waters in treatment works of disposal systems, waters in potable water distribution systems, and all water withdrawn for use until use and treatment have been completed (5 CCR 1002-61).

5.2.57 “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 unit must be constructed by a licensed contractor pursuant to a Notice of Intent filed with the State Engineer. See Rules

6.3 and 14.6.

A “dry hole” or borehole not completed for its intended use as a production water well constructed pursuant to an issued well permit is not a Test hole. See Rule 5.2.22.

Inclinometers and soil vapor extraction wells, or air sparge structures that do not encounter the water table are considered test holes with the exception that any borehole constructed or used for environmental groundwater investigations, repeated groundwater observations, repeated groundwater measurements, or any groundwater samplings, is a monitoring and observation hole or well (5.2.33 or 5.2.34), not a test hole, and may only be constructed under a notice of intent or well permit. See Rules 6.3 & 14.2.1.

5.2.58 “Type 1 aquifer” is defined above at Rule 5.2.3.2.

5.2.59 “Type 2 aquifer” is defined above at Rule 5.2.3.3.

5.2.60 “Type 3 aquifer” is defined above at Rule 5.2.3.4.

5.2.61 “Valid permit” means a well permit issued by the State Engineer that has not been canceled or revoked 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.

5.2.62 “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.

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

5.2.64 “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 groundwater for beneficial use or for conducting pumping equipment or aquifer tests.” § 37-91-102(16)(a), C.R.S.

5.2.64.1 “Well”, as used in these Rules, does not include: “an excavation made for the purpose of obtaining or prospecting for minerals or those wells subject to the jurisdiction of the Energy and Carbon Management Commission, as provided in article 60 of title 34, C.R.S. or article 90.5 of title 37, C.R.S., or those wells subject to the jurisdiction of the office of mined land reclamation, as provided in article 32-34 of title 34, C.R.S.” § 37-91- 102(16)(b)(I), C.R.S.

5.2.64.2 “Well”, as used in these Rules, “does not include a naturally flowing spring or springs where the natural spring discharge is captured or concentrated by installation of a near-surface structure or device less than ten feet in depth located at or within fifty feet of the spring or springs’ natural discharge point and the water is conveyed directly by gravity flow or into a separate sump or storage, if the owner obtains a water right for such structure or device as a spring pursuant to article 92 of this title.” § 37-91- 102(16)(b)(II), C.R.S.

5.2.64.3 “Well”, as used in these Rules, does not include wells constructed specifically for cathodic protection, a technique to prevent corrosion of a metal surface by making that surface the cathode of an electrochemical cell

(7 CCR 1101-14).

5.2.64.4 “Well”, as used in these Rules, does not include recharge basins, or infiltration basins that are constructed in such a manner that the intent of their design is to remain above the groundwater level.

5.2.64.5 “Well” as used in these Rules, does not include injection wells used to emplace a carbon dioxide or wells used for geologic sequestration of carbon dioxide as allowed by 40 CFR 146 Subpart H - Criteria and Standards Applicable to Class VI Wells (2010).

5.2.64.6 “Well” as used in these Rules does not include wells associated with Deep Geothermal Operations. Deep geothermal operations means any exploration for or production of allocated geothermal resources or geothermal resources that are deeper than two thousand five hundred feet below the surface. Deep geothermal operations do not include any exploration or production activities associated with the groundwater in the Denver Basin Aquifers. Deep Geothermal Operations Wells are regulated by the Energy and Carbon Management Commission (§37-90.5-103. C.R.S., 2023).

5.2.65 “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.

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

5.2.67 “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.

5.2.68 “Well vault” means an underground structure or pit in which the well casing terminates below ground surface.

5.2.69 “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.

5.2.70 “Well yield test” means a procedure conducted to determine a stabilized drawdown and production rate of a well, also known as a pumping test or aquifer test.

5.3 Other Definitions All other words used herein must be given their usual, customary, and accepted meaning. Terms not defined in Rule 5.2 that are defined in other rules promulgated by the State Engineer must use the meaning given therein. All words of a technical nature specific to the water well construction industry must be given the meaning generally accepted in that industry.

Rule 6 General Rules

Basis and Purpose: The statutory authority for this Rule is found in sections 37-91-101(1); 37- 91-102; 37- 91-104(1)(c), (j), & (k); 37-91-106(3); and 37-91-110(2), C.R.S. The purpose of this Rule is to implement general statutory provisions that apply to well construction and the installation of pumping equipment.

6.1 The process for obtaining and maintaining a license for the construction of wells or the installation of pumping equipment or cisterns, or any special licenses issued pursuant to the Board’s authority in section 37-91-105(2.5), C.R.S., is codified in the Board’s Rules and Regulations for Administration of Licensing, Financial Responsibility, Continuing Education and Remedial Action, 2 CCR 402-14.

6.1.1 Private drillers must complete the private driller assessment prior to constructing or repairing a well on their property.

6.1.2 Private pump installers must complete the private pump installer assessment prior to installing or repairing pumping equipment in wells on their property.

6.2 Compliance with Well Permits

6.2.1 No well may be constructed, repaired, replaced, or modified, unless the well is associated with a valid well permit issued by the State Engineer. (See sections 37-90-105(3)(a)(I)(C), 37-90-107, 37-90-108, 37-90-137, 37-90-138(3), 37-92- 602(3)(a), and 38-30-102(3) C.R.S.).

6.2.1.1 A valid well permit is required for:

a. any change, replacement, or other alteration of any well or pumping equipment which requires a breaking or opening of the well seal, or

b. any change, replacement, or other alteration of any waterlines up to and including the pressure tank and any coupling appurtenant thereto.

6.2.1.2 For those wells that are permitted, the State Engineer requires that a new well permit be obtained prior to:

a. changing the production and/or grout interval of an existing well,

b. installing certain dewatering systems as specified by the State Engineer,

c. installing pumping equipment that will allow a sustained production rate in excess of the permitted production rate.

6.2.1.3 The extraction of casing or pumping equipment for the purpose of repair or replacement does not require a new permit if the interval of perforated casing is not altered and the production rate does not exceed the rate specified on the existing valid well permit.

6.2.2 As further defined in Rules 6.2.2.1 and 6.2.2.2, it is the responsibility of the private driller, private pump installer, and all persons licensed to construct or repair wells, or to install, repair, modify, or replace pumping equipment, to determine that a valid permit issued by the State Engineer exists prior to and during all such work.

6.2.2.1 A copy of the well permit must be available and posted at the well site at all times when a contractor is working on a new well or when performing any work that requires a new well permit as specified in Rule 6.2.1.2. All such work must comply with the conditions of approval of the valid well permit, including any applicable condition that the well construction and/or pump installation contractor provide advance notification to the State Engineer prior to well construction, the initial installation of the pump, or installation of a cistern connected to a water well supply system. All work must be completed prior to the expiration of the permit.

6.2.2.2 When performing repairs on an existing well or pumping equipment in accordance with Rule 6.2.2, the private driller, private pump installer, or licensed contractor must make a reasonable effort to comply with the requirements of Rule 6.2.2. If the private driller, private pump installer, or licensed contractor is unable to verify that a valid well permit exists within thirty (30) days of performing the work;

a. The individual must notify the State Engineer of the well on a form prescribed by the State Engineer.

b. If the work performed on the well requires the filing of a well construction report, pump installation report or other report, the individual need not additionally notify the State Engineer pursuant to Rule 6.2.2.2.a.

6.2.3 Where a well has been constructed in accordance with a well permit issued by the State Engineer that authorized construction of the well at any location within a specified tract of land, the well construction contractor must submit the Well Construction and Yield Estimate Report, including the as-built well location by UTM coordinates (NAD83) or latitude/longitude WGS84 (decimal degrees), within sixty (60) days of completion of the well or seven (7) days after the permit expires whichever is sooner.

6.3 Prior Notice of Dewatering Well, Monitoring and Observation Hole, and Test Hole

In accordance with the requirements of the State Engineer, the Division of Water Resources must be provided with a Notice of Intent (see Rule 5.2.36) no less than three

(3) days, including at least one standard business day, prior to the construction of the following:

a. any dewatering well;

b. any monitoring and observation hole; or

c. any test hole that will penetrate through a confining unit between two distinct or administratively defined aquifers.

6.3.1 The State Engineer requires notice to be submitted through the Notice of Intent eForm available on the Division of Water Resources’ website, https://dwr.state.co.us/eforms

6.3.2 Any test hole or monitoring and observation hole that penetrates through a confining unit between two distinct or administratively defined aquifers may only be constructed by a licensed contractor. See Table 1 for a summary of notice, license, and permit requirements.

6.3.3 The authorized individual (see Rules 5.2.4 and 9.1) or the licensed well construction contractor is responsible for providing the necessary notice required for the construction of dewatering wells, test holes, and monitoring and observation holes.

6.3.4 The construction of any test hole penetrating through a confining unit, dewatering well, or monitoring and observation hole for which a Notice of Intent form was provided to the State Engineer pursuant to Rule 6.3 must be completed within ninety (90) days of the notice date.

6.3.5 Construction of a monitoring and observation hole must be completed within 72 hours after drilling the borehole (see Rule 14.2.1.1).

6.4 Emergency Authorization - Pursuant to the procedures of the State Engineer, the State Engineer or their designee may approve the construction of dewatering wells or monitoring and observation holes with less than the required notice upon the State Engineer’s determination that such approval is warranted based on certain conditions, such as public safety, practical difficulties, or unusual hardship.

6.5 Requests for Well Site Information - Upon request by the State Engineer or their staff, all water well construction and pump installation contractors, authorized individuals, private drillers, and private pump installers must identify the permit number or other authorization and the location of any wells, test holes, cisterns connected to a water well supply system, or monitoring and observation holes or wells which that person expects to work on within a specified five (5) day period.

6.6 Compliance with Regulations - All well construction and pump and cistern installation must comply with the minimum standards in these Rules. There may be federal, tribal, state, county, municipal or local government laws, regulations, or codes that are more stringent than these Rules, or contain standards not covered by these Rules then the work must comply with those laws, regulations, codes, or standards. The licensed well construction or pump installation contractor, authorized individual, private driller, or private pump installer is responsible for determining if such laws, regulations, codes, or other requirements exist and apply to the work being performed.

6.7 Products Containing Toxic Materials - Products, such as solder and fluxes that contain any more than 0.20% lead, and materials, such as pipes, fittings, fixtures or pipe joint compounds, that are not considered “lead free” (per 40 CFR 143.12(a) of the Safe Drinking Water Act) are prohibited from being used in the construction, repair, rehabilitation, hydraulic fracturing of a water well, or abandonment of wells and holes.

Known toxic materials must not be used in well construction.

6.8 Disposal of Fluids Resulting from Well Construction, Development and Disinfection - Fluids resulting from well construction, development or disinfection must not be discharged into the surface waters of the state without first obtaining a permit pursuant to the Colorado Discharge Permit System (CDPS) administered by the Colorado Department of Public Health and Environment.

6.8.1 Fluid disposal by land application must not flow into surface waters and must not impact aquatic life or groundwater.

6.8.2 Fluid wastes may be disposed of by other proper means such as off-site transport for treatment and final disposal, evaporation ponds, or pumping to a sanitary sewer system with permission from the appropriate authorities.

6.9 Water Used for Well Construction and Stimulation - All water used during the construction, development, and stimulation, including hydraulic fracturing, of a well must be obtained from an approved public supply.

6.9.1 If water is not readily available from such a public supply, the water may be obtained from a groundwater source or from a flowing surface water supply under the following conditions:

a. water obtained from a groundwater source must be disinfected with a minimum chlorine concentration of twenty-five (25) mg/l (milligrams per liter);

b. in remote mountainous areas, where adequate public or groundwater sources are not readily available, water may be obtained from flowing surface waters, provided that such waters are located upstream from any sewer plant, feedlot, chemical storage area or other known sources of contamination. These surface waters must be disinfected by adding chlorine for a minimum concentration of one-hundred (100) mg/l (Fifty (50) mg/l when polymer or bentonite is used), with a contact time of one (1) hour and a residual concentration of ten (10) mg/l; or

c. for reverse rotary construction, only when public or groundwater sources cannot provide sufficient volumes of drilling water, water may be obtained from flowing surface water supplies provided that such water is disinfected to a minimum chlorine concentration of twenty-five (25) mg/l or the well is disinfected in accordance with the provisions of Rule 6.9.1 (also see Rule 15.7).

6.9.2 Upon completion, all wells must be disinfected in accordance with Rule 15.

6.9.3 The use of water from wetland areas, lakes, ponds, or known contaminated groundwater sources is prohibited.

6.10 Fluids and Additives– The use of fluids and additives must comply with all manufacturers’ safety guidelines and directions, as well as federal, state, and local laws, rules, regulations, and codes.

The individual using the materials is responsible for ensuring that the materials are used properly.

Requests to add fluids, additives, or chemicals must be submitted to the Board in writing with supporting information and be approved prior to use.

6.10.1 Drilling Fluids and Additives: All drilling fluids and drilling fluid additives must be appropriate for the purposes for which the well or hole will be constructed and must be specifically approved for use by the Board. A list of specifically approved drilling fluids and drilling fluid additives is available on the Board’s website.

6.10.2 Grout Additives: All grout additives must be appropriate for the purposes for which the well or hole will be constructed and must be specifically approved for use by the Board. A list of specifically approved grout additives is available on the Board’s website.

6.10.3 Well Development and Rehabilitation Chemicals: All well development and rehabilitation chemicals must be appropriate for the purposes for which the well or hole will be constructed or rehabilitated, and must be specifically approved for use by the Board. A list of specifically approved well development and rehabilitation chemicals is available on the Board’s website.

TABLE 1: SUMMARY OF LICENSING AND CONSTRUCTION AUTHORIZATION

REQUIREMENTS

STRUCTURE WHO MAY CONSTRUCT REQUIRED AUTHORIZATION

Type of Well or Borehole

Licensed

Authorized Individual

Special License

Approved

Well Permit

Approved

Notice of Intent

BOREHOLE DOES NOT PENETRATE THROUGH A CONFINING UNIT*

Water well X X Gallery/infiltration well X X X Monit./observ. well, recovery well, & certain dewatering system

X X X X

Monit./observ. holes & dewatering wells X X X X Test holes X X X

BOREHOLE DOES PENETRATE THROUGH A CONFINING UNIT*

Water well X X Monit./observ. well, recovery well & certain dewatering system

X X X

Monit./observ. hole and dewatering well X X X Test holes X X X

*As defined in Rule 5.2.13

Notes:

1) This table summarizes minimum licensing requirements. A licensed contractor is authorized to construct all of the types of wells or holes indicated above. Special licenses may be obtained for certain types of specialized work or well construction, as allowed in Rule 6.5 of the Board’s Rules and Regulations for Administration of Licensing, Financial Responsibility, Continuing Education and Remedial Action, 2 CCR 402-14. Persons who obtain a special license and authorized individuals are restricted to the type of work for which they are licensed or qualified.

2) Monitoring and observation holes constructed pursuant to notice as provided in Rule 6.3, or under a special license issued by the Board, may not be converted into water wells (see Rule 14). Monitoring and observation holes must be plugged and sealed within eighteen (18) months after being constructed (see Rule 16.5). The requirement to permit a monitoring and observation well also applies to any borehole that will remain in use for more than eighteen (18) months (e.g., long-term piezometers).

3) The requirements for test holes only apply to geotechnical boreholes that are not used for repeated groundwater measurements, repeated groundwater observations, and any samplings of groundwater (see Rules 5.2.57 & 14.6).

Rule 7 Licensing

For rules and regulations concerning the Board’s licensing procedures, see Rules and Regulations for Administration of Licensing, Financial Responsibility, Continuing Education and Remedial Action (BOE Rules) 2 CCR 402-14.

Rule 8 Financial Responsibility

For rules and regulations concerning the Board’s bonding and financial responsibility requirements, see Rules and Regulations for Administration of Licensing, Financial Responsibility, Continuing Education and Remedial Action (BOE Rules) 2 CCR 402-14.

Rule 9 Wells and Holes Which May Be Constructed by Persons Other Than Licensed Well Construction Contractors

Basis and Purpose: The statutory authority for this rule is found in sections 37-91-101(1); 37-91- 104(1)(c), (j), & (k); 37-91-106(3); and 37-91-110(2), C.R.S.