State Well Codes

Required. Specific backflow prevention measures are required for drinking water supply wells, as prescribed in Title 17, Public Health.

No Standard Specified.

Standard Specified

Locate outside areas of flooding. Locate wells up gradient from pollutant sources. Wells to be located an adequate horizontal distance from potential or known sources of contamination.

Standard Specified

Standard Specified

clean, inert material

No more than 8% bentonite by dry weight, added water is limited to 0.75 gal. per 94-lb. cement for each 1% bentonite added.

Must obtain a variance - at least 20% solids and density of not less than 9.8 lb/gal.

Must meet standards of the NFPA 70: National Electric Code (2014), subject to
permitting and inspection by the Colorado State Electrical Board.

Developed to remove drill cuttings and fluid

Minimum wall thickness of 0.188 in. and 4.5 inch ID.

Min. 1 ft. above surface and min. of 19 ft. below ground level. Must be sufficiently plumb and straight.

Must not be <2 in. larger than the outside diameter of casing. If grout poured from surface and casing not vibrated, borehole diameter must not be <4 in. larger than outside diameter of casing.

No Standard Specified.

Yield estimate or yield test to determine a stabilized yield for the well and production equipment test to determine the production capacity of the equipment.

No standard for screens.

Required for all wells. Must have check valves, backflow prevention devices or suitable air gap cross-connection controls.

Must have pump license for pump, piping, and pressure tank - all materials and fittings must meet standards of the Rules and Regulations of the
Colorado State Plumbing Board, 3 CCR 720-1.

Permit required prior to construction, repair, replacement, or modification of a well.

Well must be at least 50 ft. from sewer line.

Must comply with the regulations of federal, state, county, municipal, or local governments, in determining the required distance from sources of contaminants, when those regulations are more stringent than the minimum standards of these Rules. Location is determined by the permit. Ex: Some are required to be constructed within 200 ft. of the permitted location and others (rule 6.2.3) can be constructed anywhere on the permitted parcel and the location entered on the construction report.

Must pass NGWA test for applicable category; Pumps: Less than 100 GPM and Over 100 GPM. A general knowledge and category test is required, Colorado rules and regulations and an oral exam before the Board of Examiners. Well Construction: Air Rotary, Mud Rotary, Reverse Circulation, and Cable tool. Then Colorado Rules and Regulations exam and oral exam before the BOE.

1 bag to 6 gal. water, Portland cement ASTM C-150. The water-cement ratio for grout slurries blended with fly ash must not exceed 5 gal. of water per 86 lb. blended cement.

Must be obtained before drilling, repair, development, hydrofracturing, or abandonment of well.

Subject to approval by local health officer.

After installation of pipe, borehole shall be covered with a protective layer of grout at least 1 ft thick and 3 ft in diameter centered over borehole. Salt water resistant grouts shall be used where appropriate. Any additives to the grout other than silica sand and water shall meet NSF/ANSI Standard 60.

Shall conform to State Basic Building Code.

To be performed only by properly registered person.

Shall be equipped with a tightly fixed vented cap or a sanitary seal with an access port with minimum inside diameter of 1/4 inch. Shall be installed and maintained to prevent entrance of water, dust, insects and other foreign material, and permit ready access for water level measurement.

Base plate shall form watertight seal with casing or pump foundation.

No solder containing > 0.2% lead shall be used in making joints & fittings. Well completion report filed within 60 days of completion, copies shared with owner, Department of Consumer Protection, the Department of Environmental Protection, and the local health department or district.

Chlorinate prior to abandonment with 150 ppm of chlorine. Fill & seal with heat cement, sand cement, bentonite clay, sand clay, or bentonite cement grout. Plug to prevent entrance of surface water, circulation of water among producing zones, and contaminants. Prevent voids in grout and dilution of grout with proper grout placement. Seal with watertight cap or seal. Shall be performed by a registered well driller. Shall not be a source of contamination. Top of casing or grout may be terminated at least 4 ft. below ground surface. Top of sand fill to be at least 10 ft. below bottom of casing. Wells in consolidated rock formations may be filled with fine sand.

Well casing shall be strong enough to resist the forces imposed on it during and after installation, and be minimum Schedule 40. Minimum diameter 4 in.

Shall be watertight and joined in accordance with the manufacturer's recommendations. Joints for steel well casing may be electrically welded or threaded. Joints for pvc casing shall be solvent welded or threaded. All couplings and solvents shall meet ANSI/NSF Standard 14, ASTM F480 or similar requirements.

Caps shall be lockable or removable only with tools. If a cap cannot be used, an alternative method for securely covering the well shall be employed.

No Standard Specified.

Avoided whenever practical, if used shall be large enough to permit access, be watertight or suitably drained to insure dryness. Every conduit or similar connection shall be watertight. If constructed in impervious soil, no porous material shall be used as a base under pit floor. If fill required, it shall be clean, impervious earth, well tamped.

Every well in which the drawdown is 10 ft. or more shall be fitted with an adequate air vent, extended at least 12 in. above high water level, and shall be shielded and screened to permit the entrance of air but keep out foreign matter.

Shall be equipped with a tightly fixed vented cap or a sanitary seal with an access port with minimum inside diameter of 1/4 inch. Shall be installed and maintained to prevent entrance of water, dust, insects and other foreign material, and permit ready access for water level measurement.

No Standard Specified.

Wells shall be located at least 50 ft. from holding tanks.

Wells shall be located at least 50 ft. from any sewer line. The minimum distance may be decreased to 10 ft. where the sewer line is constructed in a confined aquifer or if cased and grouted to a minimum of 100 ft. below ground surface.

100 feet from identifiable potential or existing sources of contamination. Exceptions are addressed in subsections 5.1.1.2, 5.1.1.3, 5.1.1.4, 5.1.1.5, 5.1.1.6, and 5.1.1.8. The Department requires that all wells be placed the maximum distance possible from lands where federally regulated chemicals have been applied. Pesticides that have been applied in accordance with their respective pesticide product label and are not associated with any known contamination are exempt.

All wells shall be constructed by a well driller licensed in the State of Delaware. Well drillers must be 18 years old, have two years experience, and pass written exam. The construction, repair, modification, or sealing of wells shall be performed by or under the direct on-site supervision of a licensed well driller or well driver. The installation of well pumps and pumping equipment shall be performed by or under the direct on-site supervision of a licensed pump installer, plumber or well driller.

All wells shall be grouted from the top of the gravel pack to the ground surface unless specifically exempted in subsection 5.8.7 or otherwise approved by the Department, and within 24 hrs after casing has been set. Wells 40 ft or less in depth constructed in unconfined aquifers may be grouted by pouring chipped or pelletized bentonite into the annulus. For wells deeper than 40 ft in depth, the annulus shall be pressure grouted from top of the gravel pack to ground surface. Single-cased wells confined aquifers shall be pressure grouted from the top of gravel pack to ground surface. If rapid loss of grout material occurs during emplacement, clean fill material such as sand, gravel, crushed stone, or cement additives manufactured for lost circulation may be used in the zone where the loss is occurring. All water used for grouting shall be treated to achieve a minimum pH of 8.0 with soda ash (sodium carbonate (Na2C03) or other industry recognized products. The top of grout shall be at the base of the well’s discharge line for wells equipped with pitless adapters, pitless well unit, or plumbing “Tees”.

Bentonite grout is a sodium based bentonite with a ratio of not less than 2 lb of bentonite per 1 gal water. Bentonite clay without additives shall not be used where it comes in contact with groundwater with a pH less than 5 or TDS content greater than 1,000 mg/L without Department approval. Thermally enhanced bentonite grout is a sodium-based bentonite silica sand mixture with a ratio of not less than 1.5 lb of bentonite per 1 gal. of water containing no more than 300 lbs of sand per 50 lbs of bentonite. Sand shall be "000" well gravel or range between 50 and 70 mesh containing a minimum of 95% silica having a uniformity coefficient not greater than 1.7.

No Standard Specified.

Disinfection of all newly constructed or repaired wells is required. After repair or maintenance to well, pumping equipment or piping, and entire plumbing system shall be disinfected. Disinfection shall be repeated until bacteriological test results meet standards. Calcium hypochlorite must be NSF/ANSI Standard 60 Drinking Water grade or equivalent shall be used for disinfection unless otherwise approved by the Department. Continuous disinfection directly into a well while in service is prohibited. The Department may require specific disinfection procedures for deep wells with a higher pH, turbidity, lower temperatures, iron, organic matter, ammonia, or other chemical constituents that interfere with disinfection. See Disinfection Procedures section 7.2.

See \"Upper Terminus\"