State Well Codes

Required to drill any hole greater than 20 ft. deep to locate, monitor, extract, or exchange.

Casing to extend at least 12 in. above floor. Pump house over well to be passively drained.

(a) Gravel pack shall be well rounded particles, 95% siliceous material, that are smooth and uniform, free of foreign material, properly sized, washed and then disinfected immediately prior to or during placement.
(b) Gravel pack shall be placed in one uniform continuous operation. (c) Gravel refill pipes, when used, shall be Schedule 40 steel pipe incorporated within the pump foundation and terminated with screwed or welded caps at least 12 inches above the pump house floor or concrete apron.
(d) Gravel refill pipes located in the grouted annular opening shall be surrounded by a minimum of 1 ½ inches of grout.
(e) Protection from leakage of grout or fine grained formation materials into the
gravel pack or screen shall be provided for.
(f) Permanent casings shall meet requirements of Subpart 12.4.10.
(g) Minimum casing and grouted depth shall be acceptable to the Secretary

All wells to be adequately chlorinated following completion of well construction, servicing, repair, or pump installation.

To be equipped w/ drive shoe when driven. To have circumferential welds or threaded coupling joints. To meet AWWA, ASTM, or API standards.

To be terminated w/ packer or secured to bore hole. It may be slotted, screened or perforated to permit the movement or storage of water. When a liner is set to control water movement or contamination, it shall be adequately grouted and water tight.

Drilled bedrock wells to be cased to min of 10 ft. into unweathered competent bedrock. Min of 20 ft. of casing to be installed in all bedrock. Driven casing to have drive shoe or equivalent.

To be water-tight, non-corrodible, & vented. Each cap must have a screened 40 mesh vent designed to shed water and snow. Caps for testing flowing wells shall include a pressure gauge sensitive enough to calculate static water level to the nearest tenth of a foot.

Casing to extend at least 12 in. above ground or concrete floor. Area around the well shall be graded to divert surfacewater away from the well.

Test for bacterial contamination & yield.

To be of stainless steel, plastic, or other suitable materials.

Construction permit must be obtained from the commissioner.

50 ft.

50 ft--50 ft for Class III A or B wells, 100 ft for Class III C of IV wells.

50 ft. (e.g. septic tank, aerobic unit, etc.)

50 ft.

50 ft.

Annular space to be at least 1.5 in. on all sides, 3 in. for bored wells. If grouting depth does not exceed 20 ft., it may be poured. Outer casing to be pulled simultaneously w/ grouting operation. To be brought to surface & flared to provide 1-ft. radius around casing at least 6 in. thick. To be installed by means of grout pump or tremie pipe from bottom of annular space upward in one continuous motion.

All wells to be grouted.

Gravel to be uniformly graded, cleaned, washed, & disinfected.

May not exceed 80% of its RHCP. Where geologic conditions are subject to collapse or shifting, or where heavy clay or unstable backfill materials occur, plastic well casings may not exceed 50% of the RHCP rating.

Driven wells to be cased to min depth of 20 ft. or terminated no < 1 ft. in bedrock when bedrock is encountered at < 20 ft. Driven wells to be cased to water bearing strata & no < 10 ft. Driven wells shall be grouted to a minimum depth of five feet by excavating an oversize hole at least four inches in diameter larger than the casing and pouring an approved grout mixture into the annular space.

Where annular space is grouted to min depth of 20 ft., well to be cased at least 100 ft. Casings shall be steel, stainless steel or plastic.

To be watertight.

Wells > 8 in. in diameter to be provided w/ watertight overlapping cover made of steel or reinforced concrete.

Casing material may be salvaged. Obstructions to be removed from well. Remainder of well to be filled w/ grout or clay slurry. Temporarily abandoned well to be sealed w/ watertight cap or well head seal. Top of sand or gravel fill to be at least 5 ft. below top of consolidated rock & at least 20 ft. below surface. Well to be chlorinated prior to plugging. Wells constructed in collapsing material to be filled w/ grout or clay slurry through pipe. A 1 ft thick cement or bentonite grout plug to completely fill the bore hole shall be placed a minimum of 5 ft from ground surface, remaining space filled w/clean fill mounded a minimum of 1 ft above the ground surface. Bored wells w/no water source found and casing not placed may be abandoned by backfilling with bore spoils to at least 5 ft below ground surface. 2 ft thick bentonite grout plug to be placed at minimum 5 ft from ground surface, and remainder of hole filled with bore spoils.

If a well requires venting, it must terminate in a down-turned position at least 18-inches above ground (land) level, at or above the top of the casing or pitless unit and be covered with a 24 mesh corrosion-resistant screen.

To be sanitary & watertight.

No Standard Specified.

An above-grade connection into the top or side of a well casing shall be at least 18 inches above the land surface and shall be constructed so as to exclude dirt or other foreign matter by at least one of the following methods, as may be applicable: threaded, welded, expansion sealer, bolted flanges w/rubber gaskets, overlapping well cap or if pump is mounted or sealed on a concrete pedestal, casing shall extend at lest to the top of the pedestal and at least 18 inches above land surface.

Packers shall be of a material that will not impart taste, odor, toxic substances or bacterial contamination to the water in the well.

Locations listed on Driller's Start Card.

Granular or powdered bentonite not to be placed under water by gravity feeding from the surface. May be used in construction of well seals above depth of 50 ft. May be placed below 50 ft. when placed inside annulus of 2 casings, when using tremie pipe, or other approved methods. Must be free of organic polymers and other contamination, and be designed for well sealing w/in industry tolerances. Must be placed to result in a seal free of voids or bridges. Sounding or tamping tool to be run in sealing interval during pouring. Not to be used for surface seal if surface casing is left in place.

annular space between the 2 casings to be filled w/ grout, bentonite, or mechanical packer. Grout to be placed in 2 in. annular space to min of 30 ft & at least 5 ft. into confining unit above water bearing formation. Unperforated casing to extend from ground surface to at least 30 ft. & to bottom of confining unit.

Drilling fluids, cuttings, chips, or puddling clay not to be used to fill or partially fill well. Hydrated sealing materials to be placed by tremie pipe, pumping, or pressure from bottom of seal upwards when placed below depth of 30 ft or placed below static groundwater level. To be of neat cement, sand cement, unhydrated bentonite, or bentonite grout.

To contain at least 20% solids by weight of bentonite & have fluid weight of 9.5 lb./gal and specifically designed for purpose of drilling. To have ability to gel & have hydraulic conductivity or permeability value of 10^7 cm/s or less. Bentonite drilling fluid (drilling mud), dry drilling bentonite, or drill cuttings are not an acceptable sealing material. Grout shall not contain toxic, polluting, develop odor or color changes, or promote bacterial growth. All additives to be certified by certification authority as NSF and approved by state engineer.

Hydraulic fracturing to be sent through drill string & not be transmitted through casing. Intervals to be at least 20 ft. below bottom of permanent casing. All equipment must be thoroughly disinfected to 100 ppm free chlorine solution prior to use. Not to allow commingling of waters in well bore, clean sand or other materials (propping agents) approved by the Division may be injected into well when pressure is removed.

Only water from municipal system to be used. If not possible, water to be treated w/ 100 ppm free chlorine residual. Upon well completion, deepening, renovation, rehabilitation, cleaning or other work on a well, to be disinfected to give 100 ppm free chlorine residual equally distributed in well from static level to bottom of well. Chlorine solution should be designed for potable use prepared with either calcium hypochlorite (powdered, granular or tablet form) or sodium hypochlorite in liquid form. Off-the-shelf chlorine compounds intended for home laundry use, pool or fountain use should not be used if they contain additives such as antifungal agents, silica ("ultra" brands), scents, etc. Products must be approved for use by ANSI/NSF Standard 60 or 61, ASTM, AWWA or ANSI.

If check valve or foot valve is not part of a pump, check valve or back-siphon prevention device shall be installed on the pump discharge line within the well or beyond well.

To be in new or like-new condition. To meet ASTM, ANSI, or AWWA standards.

Plastic casing & screen including PVC, SR, or ABS to conform to ANSI or ASTM F 480-95, NSF standard 61. Other types of plastic casings and screens may be installed if manufacturer certifies they meet or exceed described standards and upon state engineer approval. Casing w/nominal diameter >4 inches shall meet min. wall thickness of ASTM standard F480-95 SDR 17 or Schedule 80. Depth to be placed shall conform to ASTM standard F 480-95 and manuf. recommendations.

May be installed if well owner gives permission. To meet ANSI/NSF 61.

Type to be determined by well driller.

To equip every well.

Casing to terminate a min of 12 in. above ground. For plastic casing, except for PVC or pitless adapter, a concrete slab or sealing block to be placed above cement slurry.

To be watertight.

50 ft. Exceptions 1) If well is located in groundwater conservation district, and district's rules regulate well spacing, 2) Well located on property that has restrictions regulating well spacing and on-site sewage systems, 3) Public wastewater treatment is provided and utilized by owner. Alternative Siting Methods-A well is cemented with positive displacement technique to a minimum of 100 ft to surface or the well is tremie pressure filled to the depth of 100 ft to the surface provided the annular space is 3 inches larger than the casing may encroach up to 5 ft of the property line. For wells less than 100 ft deep, the cement slurry, bentonite grout, or bentonite column shall be placed to the top of the producing layer. In areas of shallow, unconfined groundwater aquifers having artesian head, the cement slurry, bentonite grout, or bentonite column need not be placed below the top of the water production zone.

100 ft.

Cement or bentonite mixed with water, or a combination of bentonite and cement mixed with water and/or department-approved additives.

Cross connection prohibited. When aquifers or zones of lesser quality are overlying the production aquifer or zone, the borehole annulus shall be pressure grouted with bentonite or cement from the top of the production zone back to the surface unless formations make total grouting impossible or impractical. In this case the entire borehole annulus which is groutable shall be grouted and sealed including proper surface annular grouting and completion.