This rule has been repealed.

This rule has been repealed.

(2) Before any person (as above defined) shall be issued a water well contractor's or driller's license or shall be in the lawful possession and use of such license, he shall first have met the requirements for licensure as established by sections 37-43-303 and 37-43-305 , MCA. No person shall be licensed to engage in the business of a water well contractor or driller by inheritance, purchase, transfer, or by any means other than direct licensure from the board in the manner stated above.

(1) Each rig shall have a sign showing the company or contractor name and license number in letters three inches high.

(2) Each firm must have a licensed and bonded water well contractor who is financially responsible for that firm and in charge of drilling operations.

(2) Firm name and address changes shall be submitted to the board office within ten days after the change occurs.

(3) Changes in name and address must be accompanied by the fee set out in the fee schedule.

(2) When a change in contractor occurs, in addition to the requirements of ARM 36.21.407, a new license will be issued to the driller containing the same information as listed above. A fee will be charged for the new license.

(2) The driller shall notify the board office in writing of change in responsible contractor within five days of new employment.

(3) A water well contractor shall notify the board office in writing within ten days of new hirings of any driller or apprentice.

(1) The examination is given by appointment in the board office in Helena, Montana, on any work day, Monday through Friday. The examination must be started prior to 2:00 p.m.

(2) Examinations may also be given at the Department of Natural Resources and Conservation Water Resources Regional offices in Billings, Bozeman, Glasgow, Kalispell, Lewistown, Havre, and Missoula. Applications must be approved by the board office prior to setting for the exam at a regional office.

(3) The examination fees may be found at ARM 36.21.415.

(4) Examinations given in regional offices shall be written.

(5) A grade of 80 percent is necessary to pass the examination. Grading will be completed by the board or its designee.

(6) Oral examinations may be given in the Helena board office with specific board approval on a case-by-case basis.

(7) Applicants for licensure by reciprocity will be required to pass the examination with a score of 80 percent.

(8) Applicants may not use notes or reference materials for the exam.

(9) Any applicant who is determined by the board to be cheating on an examination or using inappropriate material during an examination will fail and be required to wait at least one year before reapplying for a license.

(10) An applicant shall have one year from the date of board approval to take the examination for which the application was approved. If the examination is not taken within that one-year period, the applicant will be required to submit a new application with written verification, and pay the applicable fees.

(11) An applicant who fails to take an examination within 18 months from the date of the last examination that was failed will be required to submit a new application, provide written verification, and pay the applicable fees.

(2) A contractor shall list with the board office the names of all apprentices employed on a permanent or reasonably continuous basis, except that a contractor need not list persons employed whose duties are not directly related to the drilling of a water well.

(3) Apprentices while employed shall be under the personal supervision, as defined in ARM 36.21.409 of this chapter, of a licensed water well contractor or driller.

(4) One year's apprenticeship as required by section 37-43-305 (1) (h) , MCA, shall consist of 12 months of full-time employment in drilling water wells under the direct supervision of a licensed water well contractor, which experience shall have occurred during the three years immediately preceding the date of application, or suitable vocational training approved by the board.

(5) The board may, upon application and request, approve equivalent experience under a nonlicensed water well contractor or driller, if the experience was in a state other than Montana and if the board is satisfied that the experience was the equivalent of working under a licensed water well contractor in Montana. The board may approve other experience as equivalent as it finds appropriate.

(6) It is necessary to provide documentation of actual experience in water well construction during the past three years. This should include the number of wells constructed, the approximate dates, and any other information that would be helpful in evaluating experience.

(7) A statement from the licensing agency for water well contractors in another state relative to the experience is also required.

This rule has been repealed.

(2) The training may include, but is not limited to:

(a) National Water Well Association;

(b) Montana Water Well Drillers Association;

(c) board sponsored workshops; or

(d) other board approved training, relating to the specific area of licensure.

(3) The training must have prior board approval to count towards the training requirement. A course outline must be submitted, along with the instructor's name(s), length of the training, and an explanation of how it relates to the area of licensure.

(4) Credit may be requested for training classes that a licensee has completed without prior board approval, provided the licensee can supply:

(a) verification of actual attendance;

(b) a course outline; and

(c) an explanation as to why prior approval was not obtained. These courses will be approved on a case-by-case basis.

(5) A new licensee will not be required to obtain the training until the second renewal year following issuance of his license.

(6) Separate training is required for apprentices.

(1) Application and examination

(a) Contractors                                                      $575

(b) Drillers                                                             $475

(c) Monitoring well constructor                              $575

(2) Re-examination

(a) Water well contractor                                       $175

(b) Water well driller                                              $150

(c) Monitoring well constructor                              $175

(3) Renewal

(a) Contractor                                                        $575

(b) Driller                                                                $475

(c) Monitoring well constructor                               $575

(d) Monitoring well constructor/water well driller    $575

(e) Renewal - inactive (all licenses)                       $250

(4) Late renewal                                                     $150

(a) In addition to the renewal fee, a fee will be charged for any license not renewed prior to July 10.

(5) Duplicate license                                               $50

(6) Copies of law and rules--per book                    $10

(a) Licensed drillers and contractors are exempt from the fee.

(7) Exemption permits                                            $100

(8) Construction standard variance inspection/follow-up      $100

This rule has been repealed.

This rule has been repealed.

This rule has been repealed.

This rule has been repealed.

This rule has been repealed.

This rule has been repealed.

This rule has been repealed.

This rule has been repealed.

This rule has been repealed.

This rule has been repealed.

For purposes of this chapter, the following terms shall apply.

(1) "Abandoned water well":

(a) "permanent" means a well whose use has been permanently discontinued; and

(b) "temporary" means a well from which a drilling rig has been removed from the well site prior to completing or altering the well.

(2) "Access port" means an opening in the upper terminus of a well casing in the form of a tapped hole and plug or a capped pipe welded onto the casing to permit entry of water-level measuring devices into the well.

(3) "Annular space" or "annulus" means the space between a drill hole and a casing pipe, or between two well casings.

(4) "Aquifer" means any geological formation which is capable of yielding water or is capable of recharge.

(a) Any discrete water bearing unit with a specific water chemistry, temperature, or hydrostatic head shall be considered a separate aquifer.

(5) "Artesian well" means a well in which the water level rises above the point at which it was first encountered. This term includes both flowing and non-flowing wells.

(6) "Bentonite" means a highly plastic, highly absorbent, colloidal clay composed primarily of swelling sodium montmorillonite.

(7) "Board" means the Montana Board of Water Well Contractors.

(8) "Capped well" means a well that is not in use and has a permanent seal or locked cap installed on top of the casing.

(9) "Casing":

(a) "inner" means the inner tubing, pipe, or conduit installed inside the well casing or lower well drill hole, which is used to protect against caving formations or to seal out polluted or mineralized water zones; and

(b) "outer" means an impervious durable pipe placed in a well to:

(i) prevent the walls from caving;

(ii) seal off surface drainage or undesirable water, gas, or other fluids to prevent their entering the well; and

(iii) prevent the waste of groundwater.

(10) "Casing seal" means the watertight seal established in the drill hole between the well casing and the drill hole wall to prevent the inflow and movement of surface water or shallow ground water in the well annulus, or to prevent the outflow or movement of water under artesian or hydrostatic pressures.

(11) "Clay" means a fine-grained, inorganic material having plastic properties and with a predominant grain size of less than 0.005 mm (0.0002 inches).

(12) "Community water system" means any public water supply system which

serves at least 15 service connections used by year-round residents or regularly serves at least 25 year-round residents.

(13) "Concrete" means a mixture of not more than two parts sand and one part cement, and not more than six gallons of clear water per 94-pound bag of Portland cement. Up to five percent, by weight, of bentonite clay may be used to improve flow and reduce shrinkage. 

(14) "Confining formation" means a body of impermeable or distinctly less permeable material adjacent to one or more aquifers.

(15) "Consolidated formation" means any geologic formation in which the earth materials have become firm and coherent through natural rock forming processes, including, but is not limited to basalt, granite, sandstone, shale, conglomerate, and limestone.

(16) "Construction of water wells" means all acts necessary to obtain groundwater by wells, including:

(a) the contracting for, and excavation of the well;

(b) installation of casing, sealing material, and screens; and

(c) developing and testing, whether in the installation of a new well or the alteration of an existing well. The term does not include the installation of permanent pumps and pumping equipment.

(17) "Contamination" means an impairment of water quality by chemicals, radionuclides, heat, or biologic life to a degree that may or may not affect the potential or intended use of water.

(18) "Department" means the Department of Natural Resources and Conservation.

(19) "Disinfection" means the introduction of chlorine or other disinfecting agents using a method approved by the board, in a sufficient concentration and followed by an adequate exposure contact time so as to inactivate coliform or other indicator organisms.

(20) "Drawdown" means the extent of lowering of the water level in a well when pumping is in progress or when water is discharging from a flowing well. Drawdown is the difference between the static water level and the pumping level.

(21) "Gravel pack":

(a) "artificial gravel pack" means placement of gravel in the annular space around the well casing or screen. A gravel pack is frequently used to:

(i) prevent the movement of finer material into the well casing;

(ii) increase the ability of the well to yield water; and

(iii) lend lateral support to screens in unstable formations; and

(b) "natural gravel pack" means a gravel pack which leaves the coarser, naturally occurring gravels around the screen. The finer sands are removed from the formation by development.

(22) "Monitoring well" means a well that will be used for pollutant recovery or monitoring of groundwater quality, groundwater levels, or flow direction but whose primary purpose is not withdrawal or acquisition of groundwater.

(23) "Montana Bureau of Mines and Geology (MBMG)" means the Montana Bureau of Mines and Geology located in Butte, Montana.

(24) "Multiple-user water supply system" means a nonpublic water supply system designed to provide water for human consumption. In estimating the population served, the reviewing authority shall multiply the number of living units based on the most recent census data. The supply system shall provide water for:

(a) 3 through 14 living units; or

(b) 3 through 14 commercial units. The total people served shall not exceed 24.  

(25) "Noncommunity water system" means any public water supply system which is not a community water system.

(26) "Pitless adapter or pitless unit" means a commercially manufactured unit or device designed for attachment to a well casing which permits buried pump discharge from the well and allows access to the interior of the well casing for installation or removal of the pump or pump appurtenances, while preventing the entrance of contaminants from surface or near surface sources from entering the well.

(27) "Pollution" means a serious impairment of water quality by chemicals, radionuclides, heat, biologic organisms, or other extraneous matter to the degree that impairs the potential or intended use of water or creates a hazard to the public health and safety.

(28) "Potable water" means water which is safe for human consumption in that it is free from impurities in amounts sufficient to cause disease or harmful physiological effects.

(29) "Public water supply system" means a system for the provision of water for human consumption from any community well, water hauler for cisterns, water bottling plant, water dispenser, or other water supply that has at least 15 service connections or that regularly serves at least 25 persons daily for any period of 60 days or more in a calendar year.

(30) "Pump test" means the procedure used to determine the yield characteristics of a water well by installing and operating a pump for an extended period of time.

(31) "Pumps" and "pumping equipment" mean any equipment or materials utilized or intended for use, including seals and tanks, together with fittings and controls, in withdrawing or obtaining groundwater for any use.

(32) "Sand" means a detrital material having a prevalent grain size ranging from 2 millimeters to 0.06 millimeters (0.08 inch to 0.002 inch).

(33) "Sanitary well seal" means a manufactured seal installed at the top of the well casing which, when installed, creates a watertight seal to prevent contaminated or polluted water from gaining access to the ground water supply.

(34) "Sealing material" means neat cement, bentonite water slurry or grout, or bentonite chips or pellets. Bentonite water slurry shall be mixed according to the manufacturer's instructions as a sealing material, and shall contain no less than 1.5 pounds of bentonite per gallon of freshwater. The mixed slurry shall weigh no less than nine pounds per gallon. 

(a) "Bentonite clay grout" means a mixture consisting of not less than one-half pound of commercial bentonite clay to one gallon of clear water.

(b) "Neat cement grout" means a mixture of not more than six gallons of clear water per 94-pound bag of Portland cement. Up to five percent, by weight, of bentonite clay may be used to improve flow and reduce shrinkage. No sand or gravel is to be used in cement grout.

(c) Any slurry or cement shall be pumped from the bottom up. Chip or pellet placement may be gravity fed at a controlled rate that equals or is slower than the manufacturer's recommendation, and in such a manner that will prevent bridging.

(35) "Sewage lagoon" means any holding or detention pond that is used for treatment or storage of water-carried waste products from residences, public buildings, institutions, or other buildings, including discharge from human beings or animals, together with ground water infiltration and surface water present. For purposes of this rule, the term includes concentrated animal feeding operations but does not include storm water facilities or subsurface wastewater treatment systems.

(36) "Silt" means an unconsolidated clastic sediment composed predominantly of particles between 0.06 and 0.005 mm (0.002 inch to 0.0002 inch) in diameter.

(37) "Static water level" means the vertical distance from the surface of the ground to the water level in a well when no water is being taken from the aquifer, either by pumping or by free flow.

(38) "Transient noncommunity water system" means a public water supply system that is not a community water system and that does not regularly serve at least 25 of the same persons for at least six months per year.

(39) "Unconsolidated formation" means naturally occurring, noncemented materials including, but not limited to clay, sand, silt, and gravel.

(40) "Water table" means the upper surface of an unconfined water body, the surface of which is at atmospheric pressure and fluctuates seasonally.

(41) "Well drilling machine" means any power-driven machine used in the construction or alteration of water wells, including, but not limited to percussion, jetting, rotary, boring, digging, or augering machines.

(42) "Well log report" means DNRC Form No. 603 (see ARM 36.12.102). The water well driller/contractor shall record the well information on the wells constructed and file the report as required by ARM 36.21.639 and 85-2-516 and 85-2-527, MCA.

(1) All wells for public, community, noncommunity public, and multiple-user water supply system use are governed by those construction standards set forth in the Department of Environmental Quality rules (ARM Title 17, chapters 30, 36, and 38). Copies of those rules may be obtained by contacting DEQ.

(2) The minimum construction standards set by the Board of Water Well Contractors in this subchapter shall apply to all wells in Montana. However, for the above-stated wells, DEQ may adopt more specific or stringent standards.

(2) The drilling agreement, if used, should contain, but not be limited to the following items:

(a) name and address of the well owner and the contractor;

(b) legal description of the property on which the well is to be drilled;

(c) site protection;

(d) depth at which well owner requests drilling operations cease and contract be renegotiated (in cases of lack of sufficient water) ;

(e) size and type of casing to be used;

(f) disinfection responsibility;

(g) excessive pressures (flowing wells) ;

(h) applicable warranties and guarantees;

(i) abandonment responsibilities, if it becomes necessary to abandon the well for any reason;

(j) itemized price list, including cost per foot of drill hole; and

(k) date, signatures of well owner and water well contractor.

(3) Copies of all drilling agreements should be maintained by the water well contractor for a period of 3 years.

(4) As part of a disciplinary action, the board may require a licensee to make use of written drilling agreements.

(2) Cleanup and restoration of site should be covered by a drilling agreement.

(3) The well shall be protected by the contractor from pollution during construction.

(1) At a minimum, unless contamination risk is evident, water wells shall not be located within:

(a) 50 feet of septic tanks, and underground storage tanks and associated lines; or

(b) 100 feet of drainfields, seepage pits or cesspools, unregulated sewage lagoons, or other site treatment systems; or

(c) 1,000 feet of regulated sewage lagoons; wells less than 1,000 feet setback must be in compliance with the Department of Environmental Quality under ARM 17.30.1702.

(2) Water wells should not be located within:

(a) 10 feet of property lines unless properly protected by easement or agreement;

(b) 10 feet of sewer lines with permanent watertight joints; or

(c) 50 feet of other sewer lines.

(3) Contractors should contact local flood plain administrators for rules pertaining to wells in flood plain areas.

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(1) Licensed Montana water well contractors/drillers shall prepare a well log report form for each well drilled. The contractors/drillers shall file each well log report (Form No. 603) with the Ground Water Information Center (GWIC) of the MBMG within 60 days of completing the well. The contractors/drillers shall also provide copies of each well log, within 60 days of completing the well, to:

(a) the water well owner; and

(b) other such agencies as required by 85-2-516 and 85-2-517, MCA.

(2) The contractors/drillers must maintain copies of each well log report in their own files.

(1) All casing installed, other than plastic casing as set forth in ARM 36.21.641 and 36.21.645, shall be steel, in new or like new condition, being free of pits, breaks, or contamination, and shall meet minimum American Society of Testing Materials (ASTM) A53 specifications for line pipe for the following sizes:

Table 1 - Minimum specifications for steel well casing.

Nominal Size (inches)	Outside Diameter (inches)	Wall Thickness (inches)	Weight Per Foot (pounds)
2	2.375	0.154	3.56
2	2.875	0.203	5.79
3	3.500	0.216	7.58
3	4.000	0.226	9.11
4	4.500	0.237	10.79
5	5.563	0.244	13.70
6	6.625	0.250	17.02
8	8.625	0.250	22.36
10	10.750	0.250	28.04
12	12.750	0.312	41.45
14	14.000	0.312	45.68
16	16.000	0.312	52.27
18	18.000	0.375	70.59
20	20.000	0.375	78.60

(2) All casing having a diameter larger than 20 inches shall have a wall thickness of at least 0.375 inch.

(3) Well casing installed in a well greater than a nominal diameter of ten inches, may have a wall thickness of 0.250 inch as long as it otherwise meets ASTM A53 specifications and does not exceed the following depth limitations:

Table 2 – Diameter and depth limitations.

Diameter	Maximum Depth
12 inches	250 feet
14-16 inches	150 feet
18-20 inches	100 feet

(4) Casings of other specifications may be considered under the provisions of variances ARM 36.21.680.

(2) In the event inner casing must be driven, it must meet the specifications of ARM 36.21.640.

(1) All plastic casing shall be installed only in an oversized drill hole without driving. Wells cased with plastic shall have steel casing extending a minimum of 25 feet below the surface and 18 inches above the ground surface. Plastic casing to be used must be specifically designed for water well construction and bear NSF approval. Methods of installation shall be:

(a) installing a larger size steel casing on the outside of the plastic casing with a minimum of four feet of overlap (see Figure 6A at the end of this subchapter); or

(b) attaching directly to the plastic casing a threaded plastic to steel coupling (Figure 6B).

(2) Thermoplastic well casing shall conform with ASTM Specification F480-81, or its latest revision, as follows:

(a) minimum standards dimension ratio shall be 26 for inner casing in bedrock applications;

(b) minimum standards dimension ratio shall be 21 for unconsolidated formations greater than 125 feet;

(c) minimum pipe stiffness shall be 224 foot-pounds/in² [kiloneutron (meter meter)] when tested according to section 5.4.1 of ASTM Specification F480;

(d) all casing five inches (12.7 centimeters) and larger shall be tested for impact resistance and shall meet or exceed IC-1 impact classification according to section 6.5 and Table 6 of ASTM Specification F480; and

(e) carry the seal of the national sanitation foundation.

(3) All casing shall have additional thickness and weight if standard thickness is not capable of withstanding forces to which it is subject.

(4) The well casing must be clearly marked by the manufacturer showing: nominal size, type plastic material, standard dimension ratio (SDR), ASTM designation, and National Sanitation Foundation seal of certified approval.

(5) The use of plastic well casing in connection with a pitless adaptor is not acceptable.

(a) All pitless adaptors must be installed according to manufacturers specifications.

(2) In no case shall holes be cut in the casing wall for the purpose of lifting or lowering casing into the well bore, unless such holes are properly welded closed and watertight prior to placement into the well bore.

(1) Well casing to be sealed into an oversize drill hole should be equipped with centering guides to ensure the proper centering of a casing. In all events, casings shall be centered in the sealed interval. Guides should be of steel, at least 1/4 inch in thickness, evenly spaced in groups of 3 or 4 in 20 foot intervals or less. (See Figure 1.)

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(a) in-place perforations with star, mills knife, similar type perforators, millslotted, sawed, or drilled;

(b) perforated inner casing, either torch-cut, millslotted or punched. Such inner casing may be of steel, plastic or other suitable corrosion-resistant material, but if other than steel, a full evaluation of the structural stability of the inner casing must be made prior to its placement. They may be used in a natural development or gravel packed type of construction. Where appropriate, the top of the inner casing shall be fitted with suitable packers or sealing material and sealed to the well casing.

(2) Casing perforations that allow the well casing to act as a conduit for deleterious interflow between aquifers shall not be permitted. (That is, interflow where waters of different heads, temperatures, or quality mix causing deleterious effects.)

(3) Perforations shall not be placed to allow cascading water within the well casing during static conditions.

(4) Perforations shall not be placed to allow upward artesian flow from one aquifer to another.

(a) The choice of material should be selected on the basis of chemical analysis of the water or prior knowledge of the water quality.

(2) The well screen aperture openings, screen length and diameter should be selected to have sufficient open area to transmit the desired yield, at aperture entrance velocities of 0.1 feet per second or less.

(3) Where appropriate, suitable neoprene packers or cement grout shall be fitted to the top of the well screen assembly.

(1) In constructing, developing, redeveloping, or conditioning a well, care shall be taken to preserve the natural barriers to groundwater movement between aquifers and to seal aquifers or strata penetrated during drilling operations which might impair water quality or result in cascading water.

(a) All sealing shall be permanent and prevent possible downward movement of surface waters in the annular space around the well casing.

(b) Sealing shall be accomplished to prevent the upward movement of artesian waters within the annular space around the well casing that could result in the waste of groundwater.

(c) The sealing shall restrict the movement of groundwater either upward or downward from zones that have been cased out of the well because of poor quality.

(d) When cement grout is used in sealing, it shall be set in place 72 hours before additional drilling takes place, unless special additives are mixed with the sealing material that will cause it to adequately set in a shorter period of time.

(e) All sealing shall be performed by adding the mixture from the bottom of the space to be sealed toward the surface in one continuous operation. The minimum sealing material thickness shall be three inches. A minimum thickness of 1.5 inches of sealing material shall be applied around the outside of the casing.

(2) When casing diameter is reduced, a minimum of four feet of overlap shall be required, except when a deleterious case may occur.

(3) All new wells shall be sealed to a minimum depth of 25 feet with appropriate sealing material with the exception of those wells addressed in (4) of this rule.

(4) For wells drilled with a cable tool or other driven methods through unconsolidated formations, when the drilling and driving is a continuous operation, bentonite shall be fed continuously along the outside of the casing as the well is being driven. However, it is required that fresh, clean, pure bentonite be used.

(5) For wells drilled through formations that need special sealing techniques to protect aquifers, ARM 36.21.655 through 36.21.660 suggest alternative procedures that may be required and are intended as examples that can be modified to protect the aquifer.

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(1) The following special sealing methods may be required in situations where different techniques are necessary to protect aquifers.

(a) In drilled wells that penetrate an aquifer either within a consolidated or confining formation, sealing of the casing shall conform with one of the following procedures:

(i) an upper drill hole, at least three inches greater in diameter than the nominal size of the permanent well casing, shall extend from land surface to at least three feet into sound, consolidated formation. In no instance shall said upper drill hole extend less than 25 feet below land surface; and

(ii) unperforated permanent casing shall be installed to extend to this same depth, and the lower part of the casing shall be sealed into the rock formation with cement grout. The remainder of the annular space to land surface shall be filled with an appropriate sealing material (see Figure 2A at the end of this subchapter).

(2) If temporary surface casing is used in either of the above procedures, this casing shall be of sufficient diameter to conform to the upper drill hole specifications. Withdrawal of the temporary casing shall take place simultaneously with proper sealing of the annular space to land surface.

(1) The following special sealing methods may be required in situations where different techniques are necessary to protect aquifers.

(a) In drilled wells that penetrate an aquifer overlain by unconsolidated formations such as sand and gravel without significant clay beds, an unperforated well casing shall extend to at least one foot below the known seasonal low water table. An upper drill hole having a diameter at least three inches greater than the nominal size of the permanent casing shall extend to at least 25 feet below land surface.

(b) The annular space between the upper drill hole and the well casing shall be kept at least one-half full with bentonite slurry throughout the driving of the permanent casing into the aquifer. After the permanent casing is set in its final position, the remaining annular space shall be filled to land surface with appropriate sealing material (see Figure 3A at the end of this subchapter).

(c) If the oversized drill hole is extended to the same depth as the permanent casing, a suitable bridge shall be installed between the casing and the drill hole at a position directly above the production aquifer. The remaining annular space shall be completely filled and sealed to land surface with appropriate sealing material (see Figure 3B at the end of this subchapter).

(d) A suitable bridge is one that prevents the sealing material from dropping into the producing formations and reducing the output of the well.

(e) If temporary casing is used to maintain the oversized drill hole, the annular space shall be kept full with appropriate sealing material as the temporary casing is being withdrawn.

(2) For drilling with cable tool rigs, see ARM 36.21.654.

(2) In drilled wells that penetrate an aquifer overlain by clay or other unconsolidated deposits such as sand and gravel in which significant (at least 6 feet thick) interbeds of clay are present, the well casing may be terminated in such clay strata, provided that the casing be sealed in substantially the same manner as is required in the case of consolidated formations (see ARM 36.21.655 and Figure 3C at the end of this subchapter) .

(1) When flowing water is encountered in the well, an unperforated well casing shall extend into the confining stratum overlying the artesian zone. The casing shall be adequately sealed into the confining stratum so as to prevent surface and subsurface leakage from the artesian zone.

(2) If the well flows at land surface, it shall be equipped with a control valve so that the flow can be completely stopped.

(3) The well shall be completed with packers or appropriate sealing material that will eliminate leakage around the well casing.

(4) The driller is responsible to use all reasonable methods and care to prevent leakage around the well casing within a reasonable time frame or until the board is satisfied that the leakage is controlled.

(1) The following special sealing methods may be required in situations where different techniques are necessary to protect aquifers.

(a) An upper drill hole having a diameter of at least three inches greater than the outside diameter of the production casing shall be drilled to extend from land surface into a clay or other formation of low permeability overlying the water-bearing zone.

(b) The annular space to this depth shall be filled with sealing material. If the clay or other impermeable formation is at or near land surface, the upper drill hole and unperforated production casing shall extend to a minimum depth of 25 feet below land surface, provided that the casing does not pass through the impermeable zone.

(c) A suitable bridge shall be installed in the annular space between the gravel pack and the sealing material. A gravel fill pipe may be installed for injecting gravel prior to sealing the top of the gravel pack (see ARM 36.21.656(5) for definition of a suitable bridge).  

(d) Special care shall be taken to ensure that the seal is watertight around the injection pipe. The injection pipe shall be capped with a watertight seal or plug (see Figure 4A at the end of this subchapter).

(1) The following special sealing methods may be required in situations where different techniques are necessary to protect aquifers.

(a) When permanent surface casing is installed, the well bore shall have a diameter of at least three inches greater than the surface casing for the introduction of sealing materials.

(b) A watertight seal shall be installed at the top of the gravel pack between the permanent surface and production casing.

(c) Sealing procedures and installation of gravel fill pipes are substantially the same as in ARM 36.21.659.

(d) If a temporary casing is used to maintain the oversized drill hole, the annular space to be sealed under conditions of ARM 36.21.659 and 36.21.660 shall be kept full with cement grout or bentonite clay grout as the temporary casing is withdrawn (see Figure 4B at the end of this subchapter).

(2) If a clay layer or other formation of low permeability is not encountered before reaching the top of the water-bearing zone, the upper drill hole and unperforated production casing shall extend to a minimum depth of 25 feet below land surface. Sealing procedures, installation of gravel fill pipes, and temporary casing are substantially the same as in ARM 36.21.659 and 36.21.660.

(1) At all times during the progress of the work, the�well driller�shall protect the well in such a manner as to effectively prevent either tampering with the well or the entrance of foreign matter into it. Upon its completion, the well driller shall provide and set a�sanitary well cap�or welded cap.

(2) Any well to be temporarily removed from service, temporarily abandoned due to a recess in construction, or any well to be temporarily abandoned before commencing service, shall be capped with a sanitary well cap,�watertight seal, watertight welded steel cap, or threaded cap.�

(3) Temporarily abandoned wells shall be grouted and sealed to comply with ARM 36.21.654 before the drill rig is removed from the site.

(4) Temporarily abandoned wells shall have an access port as per ARM 36.21.665.

(5)�Hydrants, frost-free hydrants, faucets, hose attachments, or discharge hardware that allow siphoning into a well cannot be directly attached to the well casing, pitless adapter, or well cap.�Hand pumps, windmills, or other manually operated discharge hardware that have hose connections or attachments and that attach directly to the well casing shall use a vacuum breaker or an anti-siphoning device. �Flowing wells shall be capped and sealed to comply with ARM 36.21.658.

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(2) The responsibility for the chlorination of the well shall be agreed upon in writing by the parties to the drilling agreement.

(3) The contractor shall clean and disinfect the drilling equipment after drilling in an area of known or suspected contamination or areas of iron bacteria problems.

(2) The contractor shall extend to the purchaser, factory guarantees on pumps and accessories sold and installed by him.

(3) The warranty or guarantee period shall be a minimum of one year from the date of completion of the well.

(a) static water level immediately before testing begins;

(b) pump rate and means of discharge (i.e., bailing, airlift, pumping) ;

(c) pumping level after one hour;

(d) recovery level and time of recovery; and

(e) for public community, non-community public and multi-family water supply wells, the testing requirements set out in ARM Title 17, chapters 30, 36 and 38 shall apply.

(2) In the event that pump test data is required for 100 gpm or more or as required by the board, pump test data to be recorded on the well log report form shall be:

(a) static water level immediately before testing begins;

(b) depth at which pump is set for test;

(c) the pumping rate;

(d) the maximum drawdown during the test;

(e) the duration of the test, including both:

(i) the pumping time; and

(ii) recovery time;

(f) recovery water levels and the respective times after cessation of pumping that the recovery water level data was taken;

(g) All depth measurements shall be from the top of the well casing unless otherwise specified.

(3) Flowing wells must be flow tested at least one hour.

(4) Wells intended to yield 100 gpm or more shall be tested for a period of eight hours or more. The test shall follow development of the well, and shall be conducted continuously at a constant discharge which is at least as great as the intended appropriation.   As a minimum, water level data shall be collected and recorded on the schedule shown on the department's "well test data sheet". If possible, it is recommended that drawdown data instead be collected on a logarithmic schedule (see, for instance, Johnson's "Ground Water and Wells") throughout the test. The height above ground of the point from which water levels are measured shall also be recorded. The above information and any additional aquifer testing data shall be attached to the driller's log and submitted to the department.

(1) All wells shall be equipped with an access port 1/2 inch minimum that will allow for the unobstructed measurement of the depth to water surface or a pressure gauge that will indicate the shut-in pressure of a flowing well (see Figure 5 at the end of this subchapter) . � The access ports and pressure gauges or other openings in the cover shall be sealed or capped to prevent entrance of surface water or foreign material into the well.

(2) Removable caps are acceptable as access ports.

(1) In gravel packed wells, the gravel mixture shall be placed around the screen so that bridging or size separation will not occur. The gravel pack shall be clean, chemically stable, and composed of reasonably uniform grains. All gravel and water used shall be disinfected in at least 50 ppm chlorine.

(2) Gravel packing shall be placed from the bottom of the screen upwards to 2 to 3 feet above the screen.

(a) one sample at the beginning of each change in material encountered; and

(b) samples should be taken in the water-bearing aquifer(s) .

(2) Sampling methods used shall assure securing the required representative sample. Care shall be taken to accurately determine the depth of the material sampled.

(3) Materials encountered during the sampling shall be so indicated on the well log report form.

(a) The sample shall be clearly marked with the location of the well, the date and time taken, and the depth of the strata from which the water was taken.

(2) To determine the bacteriological quality of a water supply, the water in all wells should be sampled after construction is complete and the system has been disinfected.

(a) The sample shall be collected after chlorinating solution has been dissipated or been flushed from the system.

(3) The contractor/driller should inform the well owner of the importance of having the water analyzed and coliform tests performed.

(4) Local health offices and the department of environmental quality can be contacted for lists of certified labs who can perform these tests.

(1) Wells requiring permanent abandonment include, but are not limited to those:

(a) whose use has been permanently discontinued, or

(b) in such disrepair that its continued use for obtaining groundwater is impractical or may be a health hazard, or

(c) whose existence allows intermixing of waters which cause deleterius effects upon temperatures, qualities, or pressures, or

(d) a well in the process of being drilled which is rendered unusable because of driller error and for which drilling must be discontinued.

(2) The well owner is responsible for abandonment of wells described in (1) (a) , (b) , and (c) .

(3) The well driller is responsible for abandonment of wells described in (1) (d) . These types of wells shall be permanently abandoned by the driller within 60 days after drilling is discontinued.

(4) The driller should advise well owner of this requirement that abandoned wells must be permanently abandoned.

(5) The board may order the driller to permanently abandon an unusable well that may be a danger to the aquifer.

(2) Abandoned wells must be completely filled with sealing material to within 3 feet of the surface. Any remaining hole shall be filled with naturally occurring soils.

(3) The abandoned well shall not produce water nor serve as a channel for movement of groundwater.

(4) In no instance shall abandoned wells be used for disposal of sewage, household waters or other contaminated material.

(5) Land surface shall be restored to a like condition, safe to livestock and humans.

(6) Where possible, all casings or liners shall be removed. In the event that the casing cannot be removed, it shall be cut off or driven downward so that the top of the casing is at least 3 feet below the ground surface.

(2) Flowing wells should be made static before plugging with cement if they are not contained by casing. If unable to make the well static with heavy mud, heavy weight cement should be pumped into the hole from the bottom up at a brisk rate. Cement mix should be at least twice the volume needed to plug the well. The first cement pumped out will be diluted and should be discarded.

(3) If the flowing well is controlled by the casing, a pressure reading should be taken and sufficient cement should be pumped in the casing from the top so that the cement will enter the aquifer.

(1) If the casing of a well is removed during abandonment, the well shall be plugged and sealed in accordance with ARM

(1) Concrete or cement grout used as a sealing material in abandonment operations shall be introduced at the bottom of the well or required sealing interval. All cement sealing materials shall be placed to avoid segregation or dilution of the sealing materials.

(1) A water well log report, Form No. 603, fully describing all abandonment procedures, shall be submitted to the Ground Water Information Center (GWIC) of the MBMG within 60 days of abandoning the well.

(1) Water wells which have been constructed and do not provide an adequate supply of water for the use for which they were drilled (dry hole) are not to be considered completed until the well driller either:

(a) removes the casing and fills the hole with cement grout, concrete, or bentonite clay grout; or

(b) constructs the well in accordance with minimum well construction standards and welds a 0.25-inch thick steel plate fully covering the top of the casing providing a watertight seal.

(2) A water well log report must be completed and filed with each dry hole, as per ARM 36.21.639, after moving the drilling equipment from the drill site.

(a) the purpose of the well construction;

(b) the location of the well;

(c) name and address of the owner;

(d) distance to the nearest well, septic tank, drainfield, or other hazardous wastes--surface or subsurface;

(e) the unusual conditions existing at the well site;

(f) the reasons that compliance with the rules for minimum standards will not result in a satisfactory well;

(g) the proposed standards that the water well contractor believes will be adequate for his particular well; and

(h) a drawing with written explanation showing the pertinent features of the proposed well design and construction.

(2) If the board finds that special circumstances beyond the control of the contractor make compliance with existing standards impossible or otherwise unreasonably difficult, and finds that the proposed variance will adequately protect the public and the ground water RESOURCES, the board may approve the proposed construction by prescribing a variance for the particular well under consideration.

(3) The board shall act in writing on any requests for variances within 30 days after receipt of the request.

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(a) a listing of monitoring well work performed in the past 4 years including:

(i) location of job site and name and address of company for whom the monitoring work was performed,

(ii) description of the work,

(iii) length of work,

(iv) other details which will assist in verifying the work;

(b) three professional references other than persons within the firm by whom you are employed.

(a) college course work or equivalent professional education classes equal to or exceeding 9 semester credits at an accredited college or university, directly pertaining to groundwater or well installation technology and 6 months experience;

(b) other combinations of education and experience, as approved on a case by case basis.

(1) Applications accompanied by proper verification and fees will be reviewed and acted upon in a timely manner.

(2) After approval, applicants may take the examinations at the board office in Helena or the Department of Natural Resources and Conservation Water Resources Regional offices in Billings, Bozeman, Glasgow, Havre, Kalispell, Lewistown, or Missoula.

(3) The examination fees may be found at ARM 36.21.415.

(4) A grade of 80 percent is necessary to pass the examination.

(5) Any applicant determined by the board to be cheating on an examination or using inappropriate material during an examination will fail and be required to wait at least one year before reapplying for license.

(6) An applicant shall have one year from the date of board approval to take the examination for which the application was approved. If the examination is not taken within that one-year period, the applicant will be required to submit a new application with written verification and pay the applicable fees.

(7) An applicant who fails to take an examination within 18 months from the date of the last examination that was failed will be required to submit a new application, provide written verification, and pay the applicable fees.

(2) Firm name and address changes shall be submitted to the board office within 10 days after the change occurs.

(3) Changes in name and address must be accompanied by the fee prescribed in ARM 36.21.415.

The following definitions shall apply for monitoring well construction:

(1) "Abandoned well" means a well whose use has been permanently discontinued.

(2) "Annular space" or "annulus" means the space between two concentric tubes or casings, or between the casing and the borehole wall.

(3) "Aquifer" means any geological formation which is capable of yielding water or is capable of recharge.

(4) "Artesian" means a condition in an aquifer wherein groundwater is confined under pressure by an overlying geologic unit of relatively lower permeability.

(5) "Bentonite" means a highly plastic, highly absorbent colloidal clay composed primarily of swelling sodium montmorillonite.

(6) "Board" means the Montana Board of Water Well Contractors.

(7) "Borehole" means an open or cased subsurface hole created by drilling.

(8) "Casing" means tubing which is installed to counteract caving and isolate the zone being monitored of a drilled hole.

(9) "Casing " means tubing which is installed to counteract caving and isolate the zone being monitored of a drilled hole:

(a) "protective" means a section of pipe or tubing that is placed over the well casing at the surface to provide structural protection to the well and restrict unauthorized entrance into the well; and

(b) "surface" means a single section of tubing used to stabilize a borehole near the surface during, and following the drilling of the hole.

(10) "Cement" means Portland cement, usually furnished in 94-pound bags.

(11) "Confined groundwater" means groundwater within a geologic unit(s) that is under pressure significantly greater than atmospheric pressure; the upper limit of the geologic unit being the bottom of a zone of distinctly lower hydraulic conductivity than that of the geologic unit(s) in which the confined water occurs.

(12) "Confining bed" means a layer of geologic materials having very low hydraulic conductivity that hampers the movement of water into and out of an aquifer.

(13) "Contamination" means the degradation of natural water quality as a result of human activities. There is no indication of specific limits, since the degree of permissible contamination depends upon the intended use(s) of the water.

(14) "Cuttings" means fragments or particles of soil or rock, with or without free water, created during the drilling of a borehole.

(15) "Deionized water" means water that contains less than 50 milligrams per liter of dissolved solids.

(16) "Drilling fluid" means a liquid or gas which may be used in the drilling operation to remove cuttings from the borehole, to clean and cool the bit, to reduce friction between the drill stem and the borehole wall, and to seal the borehole to prevent loss of drilling fluids.

(17) "Flowing well" means a well from which water flows from the casing top under natural hydro-dynamic pressure.

(18) "Gravel pack" means the principal filter pack of a well or monitoring device.

(19) "Groundwater" means water encountered below ground surface.

(20) "Hazardous" means a condition where materials or fluids contain sufficient types and amounts of biological, chemical, or physical (including radiological) agents which are likely to cause human illness, disorders, or disability. These include, but are not limited to pathogenic viruses, bacteria, parasites, toxic chemicals, and radioactive isotopes.

(21) "Hydraulic conductivity" means a property of the geological material expressing the relative ease with which water flows through the geological material in response to a differential in total hydraulic head.

(22) "Hydraulic gradient" means the rate of change in total head per unit of distance of flow in a given direction.

(23) "Injection well" means a well utilized for injecting fluids or gases into geologic materials.

(24) "Leachate" means contaminated water resulting from the passage of direct precipitation, surface water, or groundwater through waste.

(25) "Lysimeter" means a device used to obtain soil moisture samples above the water table.

(26) "Monitoring well" means a well that is used for monitoring groundwater quality or flow direction, but is not used for withdrawing groundwater for purposes other than water quality sampling or pump testing.

(27) "Monitoring Well Log Report Form" means DNRC Form No. 603, Well Log Report. The monitor well constructor shall record the well information on the wells constructed and file the report as required by ARM 36.21.639 and 85-2-516 and 85-2-527, MCA.

(28) "Montana Bureau of Mines and Geology (MBMG)" means the Montana Bureau of Mines and Geology located in Butte, Montana.

(29) "Neutron tube" means tubing installed in a borehole for the purpose of measuring soil-water content by neutron moderation techniques. Neutron tubes are constructed of a variety of materials, including plastic, fiberglass, fluorocarbons, or metal.

(30) "Nonbiodegradable fluidizing admixtures" means grout additives that provide temporary reduction of gel strength by dispersing the clay particles. Nonbiodegradable limits the use to only those additives not subject to biological decomposition. Natural polymers are biodegradable and may not be used. Totally synthetic polymers must be used with care, and only after determining that they are chemically acceptable can they be introduced into freshwater systems.

(31) "Nonhydrologic geotechnical" means the purpose of the hole is not to collect hydrologic information. Geotechnical is information on geological, geochemical, and geophysical conditions.

(32) "Observation well" is a well designed to measure the exact depth to the water table. An observation well is often screened or perforated across the water table.

(33) "Packer" means a transient or dedicated device placed in a well, which plugs or seals a portion of the well or well annulus at a specific level.

(34) "Permeability" means a measure of relative ease with which a porous medium can transmit a liquid under a potential gradient. It is a property of the medium that is dependent upon the shape, size, and degree of interconnection of the pores.

(35) "Piezometer" is a well device or instrument designed to measure the hydraulic potential (water level elevation) at a specific point in the subsurface.

(36) "Radius of influence" means the radial distance from the center of a pumped well to the point where there is no lowering of the water table or potentiometric surface (the edge of the cone of depression).

(37) "Recovery well" means a well installed to recover contaminates that have been introduced into the groundwater table, but is not used for monitoring groundwater quality or flow direction.

(38) "Saline seep" means an artificially created groundwater system of poor quality, created by a change in the land use, which generally occurs in materials of very low transmissivity.

(a) "Saline seep well" means a well used for recharge area identification and for monitoring water table levels.

(39) "Sealing" means the operation by which seal material is placed in the borehole.

(40) "Sealing material" means an impervious or low permeable inorganic material used for the purpose of preventing interaquifer contamination and/or surface water infiltration. Types of sealing material include:

(a) asphaltic concrete, which is a mixture of dense graded sand or sand and gravel and asphalt cement with less than eight percent air voids;

(b) bentonite clay grout, which is a mixture of at least 1.5 pounds of bentonite clay per gallon of potable water;

(c) bentonite pellets and chips, which are particles of bentonite passing a 0.75-inch sieve and retained on a #4 sieve;

(d) compacted clay cuttings, which are uncontaminated cuttings, a sample of which can be rolled into a thread of 0.125 inch in diameter or smaller, and compacted to a density of at least equal to the formation from which they were cut. Bentonite powder passing a #200 sieve may be mixed with the cuttings. When attempting to roll the thread, particles of sand and gravel larger than a #40 sieve may be removed.

(e) cuttings slurry grout, which is a mixture of uncontaminated water and a minimum of 15 percent solids by weight consisting of uncontaminated clay or shale cuttings, and a minimum of ten percent bentonite by weight. The mixture shall have a unit weight of at least 9.00 pounds per gallon;

(f) granular bentonite, which is bentonite sand size particles, most of which passes a #4 sieve, and most of which are retained on a #200 sieve;

(g) neat cement grout, which is a mixture of not more than six gallons of potable water per 94-pound sack of Portland cement. Up to five pounds of bentonite clay per sack of cement may be added. When bentonite is added, the quantity of water may be increased 0.1 gallon for each pound of bentonite per sack of cement. Commercial fly ash may be substituted on a weight basis for up to half of the Portland cement; and

(h) Portland cement concrete, which is a mixture of sand, Portland cement, potable water, and four to eight percent air. The mixture may contain gravel, and fly ash may be substituted for up to 25 percent of the Portland cement. It shall contain at least six sacks of cement per cubic yard and have a 28-day compressive strength of at least 4000 psi.

(41) "Static water level" means the elevation of the top of a column of water in a well, which is no longer influenced by effects of installation, pumping, or other temporary conditions. Static water levels are transitory and therefore will change due to temporal and seasonal effects. 

(42) "Surfactants" mean synthetic detergents.

(43) "Transmissivity" means the rate at which water of prevailing kinematic viscosity is transmitted through a unit width of an aquifer under a unit hydraulic gradient.

(44) "Tremie pipe" means a pipe or tube that is used to transport grout or other material from above ground surface into a borehole annulus of a monitoring well or other groundwater monitoring device.

(45) "Unconfined aquifer" means an aquifer in which hydrostatic pressures at the water table are equal to atmospheric pressure. In unconfined aquifers, the water table is exposed to the atmosphere through openings in the overlying materials.

(46) "Vapor detection well" means a well or borehole used to obtain soil-gas samples above the water table.

(47) "Water cement ratio" means the proportion of the weight of mixing water to the weight of cement.

(48) "Water table" means the surface in an unconfined aquifer at which the pressure is atmospheric. This level is determined at a location by the static water level in a monitoring well or piezometer screened across the top of the zone of saturation.

(49) "Well screen" means pipe or cylindrical tubing with slots of a uniform width, orientation, and spacing.

(50) "Zone of saturation" means a hydrologic zone below the water table in which the interstices are filled with groundwater.

(1) recovery wells;

(2) all wells less than 10 feet deep;

(3) vapor detection wells that do not penetrate the water table;

(4) lysimeters;

(5) neutron tubes;

(6) injection wells for the oil and gas industry;

(7) holes drilled for non-hydrologic geotechnical information;

(8) piezometers and observation wells in dams;

(9) monitoring wells installed under the authority of another governmental agency where the construction standards of that agency are more stringent than these rules; and

(10) special cases, with prior approval of the board.

(1) A well used for monitoring purposes may not be converted to a water supply well, unless it:

(a) meets minimum water well construction standards;

(b) has board approval; and

(c) complies with the Department of Natural Resources and Conservation's water rights statutes (Title 85, chapter 2, MCA).

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(2) Drilling fluids which will contaminate the aquifer shall not be used.

(3) In areas of known contamination, materials which will not corrode in the environment in which they are placed shall be used.

(4) The well screen and well casing shall be new and be of sufficient structural strength to protect the integrity of the well.

(2) Acceptable seals for rotary or dug holes [air, fluid, auger (solid and hollowstem) , backhoe] include:

(a) above the water table:

(i) neat cement grout or Portland cement concrete,

(ii) bentonite clay grout,

(iii) cuttings slurry grout,

(iv) compacted clay cuttings,

(v) pre-wetted granular or powdered bentonite,

(vi) compacted asphaltic concrete,

(vii) other materials or methods with board approval;

(b) below the water table:

(i) neat cement grout, tremied or pumped,

(ii) bentonite clay grout, tremied or pumped,

(iii) cuttings slurry grout, tremied or pumped,

(iv) bentonite pellets or chips,

(v) other materials or methods with board approval.

(3) For driven wells acceptable seals are granular or powdered bentonite.

(4) Jetted methods are not allowed for monitoring well use without board approval.

(2) The minimum sealing material thickness shall be 1 1/2 inches around the outside of the casing on all sides, except for driven wells.

(3) For driven wells, granular or powdered bentonite shall be fed alongside the casing.

(4) Seal material shall extend down to within five feet of the zone being monitored. In sand and gravel formations, a minimum of 10 feet of surface seal shall be used, except when the zone of monitoring is higher.

(5) If the borehole will be advanced through a confining bed immediately below a contaminated aquifer, a casing shall be sealed into the top of the confining bed prior to advancing the borehole through the confining bed. All contaminated tools, drilling fluids, and down-hole equipment shall be cleaned or treated prior to advancing the borehole through the confining bed.

(6) A monitoring well encountering an artesian condition shall be sealed and controlled in the same manner as an artesian water well (ARM 36.21.658) .

(1) Preventive measures shall be performed to ensure against contamination from equipment used to install or sample monitoring wells. Particular care must be exercised when equipment used to install or sample monitoring wells in contaminated environments is subsequently used to install production wells for domestic use.

(2) When practicable or feasible, monitoring well installation should proceed from areas with no or low levels of contamination to areas with higher levels of contamination.

(3) If contamination is detected during installation of a monitoring well, down-hole equipment should be decontaminated before use on another well or at another site. Appropriate methods of cleaning or decontamination will depend upon the level and type of contaminants, but may include steam cleaning, rinsing with uncontaminated water, or thorough cleaning with surfactants and deionized water.

(4) Contamination of down-hole equipment on the drill rig itself by hazardous materials requires thorough cleaning to prevent transport of hazardous contaminants to other locations. On-site decontamination may be necessary under particularly hazardous conditions.

(1) The top of the well shall be fitted with a tight fitting slip cap, threaded plug or cap, or locking cap. Monitoring wells within the radius of influence of a well used as a domestic supply well and hydraulically connected to the aquifer from which the well is drawing water shall have a locking cap or be surrounded by a fenced controlled enclosure.

(2) The following are suggested methods for site protection:

(a) If the well is cased with metal and completed above the ground surface, a lockable watertight cap may be welded to the top of the casing.

(b) If the well is not cased with metal and completed above the ground surface, a metal protective casing may be installed around the well. The protective casing may extend at least six inches above the top of the well casing and at least two feet into the ground. A lockable cap may be welded to the top of the protective casing.

(c) If the well is completed below ground surface, a lockable "water-meter cover," or equivalent, may be installed around the well. The cover must be designed to withstand the maximum expected loadings. A watertight seal on the casing itself shall be installed to prevent the inflow of surface water. Drains may be provided, when feasible, to keep water out of the well and below the well cap.

(3) The well(s) completed above ground may be protected from damage by one of the following suggested methods:

(a) Three metal posts at least three inches in diameter may be installed in a triangular array around the casing. Each post may extend at least three feet above and below the ground surface.

(b) A reinforced concrete pad may be installed to prevent freeze/thaw cracking of the surface seal. When a concrete pad is used, the annular seal shall be contiguous to the concrete pad.

(c) Other methods agreed upon by the well owner and the monitoring well constructor may be used.

(4) The final surface should be sloped away from the monitoring well. If slabs or pavements prevent this, the surface should be sealed with at least four inches of Portland cement or asphaltic concrete. A surface condition which allows surface runoff to run down the side of the casing or borehole is unacceptable and shall be repaired.

(a) the water well owner; and

(b) other such agencies as required by 85-2-516 and 85-2-517, MCA.

(2) The monitoring well constructors must maintain copies of each well log report in their own files.

(1) Wells which have not been monitored for more than three years shall be deemed abandoned unless written permission is obtained from the board to maintain the well.

(2) Monitoring wells that have outlived their useful purpose shall be abandoned by one of the following methods:

(a) if the casing and screen are left in place, the casing and screen shall be sealed from the bottom up by the following methods:

(i) using a pump and hose or tremie pipe to conduct the sealing material to the bottom of the well; or

(ii) by filling the casing and screen with bentonite pellets or chips placed in a manner that will prevent bridging. Metal casings shall be cut off three feet below the ground surface and the last three feet backfilled with naturally occurring soils;

(b) the department recommends that the casing be removed in all possible instances. If the casing and/or screen are removed, the hole shall be filled with sealing material, concrete, or bentonite pellets or chips from the bottom up, as the casing and/or screen is removed. From six to three feet from the surface, bentonite shall be added to the well. The last three feet shall be filled with naturally occurring soils;

(c) the sealing material shall be bentonite pellets or chips, bentonite clay grout, neat cement grout, or concrete. The material may contain nonbiodegradeable fluidizing admixtures, provided they will not contaminate the groundwater. Sealing materials which settle shall be topped to provide a continuous column of grout to within three feet of the surface; or

(d) other methods for abandonment with prior board approval.

(3) For flowing wells, the abandonment procedures outlined in ARM 36.21.671 shall apply.

(4) A properly abandoned well shall not produce water nor serve as a channel for movement of water.

(5) A water well log report, fully describing all abandonment procedures, shall be submitted to the Ground Water Information Center (GWIC) of the MBMG within 60 days of abandoning the well.