Montana Administrative Code

36.21.637 PROTECTION OF SITE The contractor shall remove from the site all unused materials. Water pumped from the well shall be conducted to a place where it will be possible to dispose of the water without damage to property or the creation of a nuisance. Cleanup and restoratio…

36.21.638 LOCATION OF WELLS At a minimum, unless contamination risk is evident, water wells shall not be located within: 50 feet of septic tanks, and underground storage tanks and associated lines; or 100 feet of drainfields, seepage pits or cesspools, unregulated sewage lagoons,…

36.21.639 WELL LOG REPORTS 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 da…

36.21.640 WELL CASING 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 s…

36.21.641 INNER CASING Inner casing installed through caving formations, or for sealing out water of poor quality, and installed without driving, may be of lighter weight than specified by the table under ARM 36.21.640. Such lightweight pipe shall have a wall thickness equal to o…

36.21.641A CASING DEPTH All wells shall be completely cased to the bottom of the usable drill hole and sealed in accordance with ARM 36.21.654. Authorizing statute(s): 37-43-202(3), MCA Implementing statute(s): 37-43-202(3), MCA History: NEW, 1986 MAR p. 1699, Eff. 10/17/86; AMD,…

36.21.642 STEEL CASING JOINTS All casing joints shall be welded or screw coupled and shall be watertight. If welded casing joints are used, the weld shall be a full penetrating weld at least equal in thickness to the wall thickness of the casing. Welded casing joints shall have a…

36.21.643 TEMPORARY CASING Temporary outer surface casing used in the construction of a well shall be withdrawn as sealing material is placed. Authorizing statute(s): 37-43-202(3), MCA Implementing statute(s): 37-43-202(3), MCA History: NEW, 1986 MAR p. 1699, Eff. 10/17/86.

36.21.644 CASING SHOE In all drilled wells, permanent well casing that is driven should be equipped with a standard drive shoe at its lower end, welded or threaded onto the lower end of the string of casing. The shoe shall have a beveled cutting edge of metal forged, cast, or fab…

36.21.645 PLASTIC CASING 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…

36.21.646 PLASTIC CASING JOINTS All casing joints shall be watertight. Either "bell" type or coupling hubs or threaded couplings are approved. Hub couplings shall be of material meeting the specifications for plastic casings as stipulated in ARM 36.21.645. Solvent cemented joints…

36.21.647 TOP TERMINAL HEIGHT The casing head or pitless unit of any water well shall extend not less than 18 inches above the finished ground surface or pump house floor, and not less than 18 inches above the local surface runoff level. No casing shall be cut off below land surf…

36.21.648 CASING OPENINGS There shall be no opening in the casing wall between the top of the casing and the bottom of the required casing seal except for pitless adapters, screened vents (inverted u-construction) , measurement access ports, and grout nipples installed in conform…

36.21.649 CASING CENTRALIZERS 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…

36.21.650 CASING PERFORATIONS Perforations above the lowest expected static water level shall not be permitted. Wells may be completed with perforations as follows: in-place perforations with star, mills knife, similar type perforators, millslotted, sawed, or drilled; perforated …

36.21.651 MOVEMENT OF CASING AFTER SEALING In no case shall the permanent well casing be moved or driven following the placement and initial set of the cement grout. Authorizing statute(s): 37-43-202(3), MCA Implementing statute(s): 37-43-202(3), MCA History: NEW, 1986 MAR p. 169…

36.21.652 WELL SCREENS Well screens shall be constructed of one type of corrosion-resistant material. The choice of material should be selected on the basis of chemical analysis of the water or prior knowledge of the water quality. The well screen aperture openings, screen length…

36.21.653 WELL DEVELOPMENT PROCEDURES Upon completion of the well and before conducting the yield and drawdown tests, the contractor shall surge and develop the well to remove all fines, drill cuttings, mud, drilling fluids, and additives. The method of developing and length of t…

36.21.654 SEALING OF CASING - GENERAL 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 …

36.21.655 CONSOLIDATED FORMATIONS The following special sealing methods may be required in situations where different techniques are necessary to protect aquifers. In drilled wells that penetrate an aquifer either within a consolidated or confining formation, sealing of the casin…

36.21.656 UNCONSOLIDATED FORMATIONS WITHOUT SIGNIFICANT CLAY BEDS The following special sealing methods may be required in situations where different techniques are necessary to protect aquifers. In drilled wells that penetrate an aquifer overlain by unconsolidated formations suc…

36.21.657 UNCONSOLIDATED FORMATIONS WITH CLAY BEDS The following special sealing methods may be required in situations where different techniques are necessary to protect aquifers. In drilled wells that penetrate an aquifer overlain by clay or other unconsolidated deposits such a…

36.21.658 SPECIAL SEALING STANDARDS FOR FLOWING WELLS 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 …

36.21.659 SEALING OF ARTIFICIAL GRAVEL PACKED WELLS, PERMANENT SURFACE CASING NOT INSTALLED The following special sealing methods may be required in situations where different techniques are necessary to protect aquifers. An upper drill hole having a diameter of at least three in…

36.21.660 SEALING OF ARTIFICIAL GRAVEL PACKED WELLS, PERMANENT SURFACE CASING INSTALLED The following special sealing methods may be required in situations where different techniques are necessary to protect aquifers. When permanent surface casing is installed, the well bore shal…

36.21.661 CAPPING At all times during the progress of the work, thewell drillershall 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…

36.21.662 DISINFECTION Sand and gravel used in filter pack wells shall be thoroughly hosed or sluiced with water, and shall be disinfected with a solution containing at least 50 parts per million chlorine before being placed in the well. All water introduced into a well during co…

36.21.663 WARRANTY AND GUARANTEES The contractor warrants and guarantees to the well owner that all materials and equipment shall be new unless otherwise specified and that all work shall be of good quality and free from faults or defects and in accordance with the requirements o…

36.21.664 TESTS FOR YIELD AND DRAWDOWN Every well shall be tested for yield and drawdown for a period of not less than 1 hour either by bailing, pumping, or air testing. During testing, discharge rate shall be as uniform as possible. The minimum data to be entered on the well log…

36.21.665 ACCESS PORT 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 sub…

36.21.666 ARTIFICIAL GRAVEL PACKED WELLS - GENERAL 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 gr…

36.21.667 SAMPLING OF FORMATIONS The contractor shall secure representative samples of all materials encountered in the formations drilled in the well. These samples shall be taken as required by the following: one sample at the beginning of each change in material encountered; a…

36.21.668 WATER SAMPLES To determine the chemical quality of ground water which will be available from each well and its suitability for intended uses, the water in all wells should be sampled during or immediately following construction and development. The sample shall be clear…

36.21.669 PLUMBNESS AND ALIGNMENT TEST The completed well shall be sufficiently plumb and straight so that there will be no interference with installation, alignment, operation or future removal of the permanent pump. Authorizing statute(s): 37-43-202(3), MCA Implementing statute…

36.21.669A TYPES OF WELLS REQUIRING ABANDONMENT Wells requiring permanent abandonment include, but are not limited to those: whose use has been permanently discontinued, or in such disrepair that its continued use for obtaining groundwater is impractical or may be a health hazard…

36.21.670 PERMANENT ABANDONMENT Any well that is to be permanently abandoned shall be completely filled in such a manner that vertical movement of water within the well bore, including vertical movement of water within the annular space surrounding the well casing, is effectively…

36.21.671 ABANDONMENT OF FLOWING WELLS The flow of flowing wells to be abandoned shall be confined or restricted by cement grout applied under pressure, or by the use of a suitable well packer, or a wooden or cast plug placed at the bottom of the confining formation immediately a…

36.21.672 ABANDONMENT OF FILTER PACK WELLS Appropriate methods of abandonment of filter pack or gravel enveloped wells, or other wells in which coarse material has been added around the inner casing should be determined individually by the responsible water well contractor. Appro…

36.21.673 REMOVAL OF WELL CASING DURING ABANDONMENT If the casing of a well is removed during abandonment, the well shall be plugged and sealed in accordance with ARM 36.21.670 and shall be filled with sealing materials as the casing is removed. Authorizing statute(s): 37-43-202(…

36.21.674 OBSTRUCTIONS All obstructions or debris which may interfere with effective sealing operations shall be removed from the well to be abandoned. Authorizing statute(s): 37-43-202(3), MCA Implementing statute(s): 37-43-202(3), MCA History: NEW, 1986 MAR p. 1699, Eff. 10/17/…

36.21.675 CEMENT GROUT Cement grout for use in abandonment operations shall conform to the requirements of ARM 36.21.634(33) (b) . Authorizing statute(s): 37-43-202(3), MCA Implementing statute(s): 37-43-202(3), MCA History: NEW, 1986 MAR p. 1699, Eff. 10/17/86.

36.21.676 CONCRETE Concrete for use in abandonment operations shall conform to the requirements of ARM 36.21.634 (13) . Authorizing statute(s): 37-43-202(3), MCA Implementing statute(s): 37-43-202(3), MCA History: NEW, 1986 MAR p. 1699, Eff. 10/17/86.

36.21.677 METHOD OF PLACEMENT OF CONCRETE OR CEMENT GROUT 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…

36.21.678 WATER WELL LOG REPORT 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. Authorizing statute(s): 37-43-202(3), MCA Implem…

36.21.679 DRY OR INADEOUATE WELL HOLES 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: removes the casing and fills the hole…

36.21.680 VARIANCES When, due to special circumstances beyond the control of the contractor, compliance with these minimum construction standards is impossible or otherwise unreasonably difficult, a variance may be requested from the board of water well CONTRACTORS prior to begin…

36.21.701 VERIFICATION OF EXPERIENCE Verification of 1 year of experience shall consist of: a listing of monitoring well work performed in the past 4 years including: location of job site and name and address of company for whom the monitoring work was performed, description of t…

36.21.701A VERIFICATION OF EQUIVALENT EDUCATION AND EXPERIENCE Equivalent education pursuant to section 37-43-305 (4) (f) , MCA, shall be: college course work or equivalent professional education classes equal to or exceeding 9 semester credits at an accredited college or univers…

36.21.702 APPLICATION APPROVAL AND EXAMINATION Applications accompanied by proper verification and fees will be reviewed and acted upon in a timely manner. After approval, applicants may take the examinations at the board office in Helena or the Department of Natural Resources an…

36.21.703 CONTENTS OF LICENSE Each monitoring well constructor's license shall show on its face the name of the constructor, his firm name and address, the license number, and the date issued. Firm name and address changes shall be submitted to the board office within 10 days aft…