Standards for Construction of Water Wells

PURPOSE: This rule describes the minimum construction standards for water wells. PUBLISHER’S NOTE: The secretary of state has determined that publication of the entire text of the material that is incorporated by reference as a portion of this rule would be unduly cumbersome or expensive. This material as incorporated by reference in this rule shall be maintained by the agency at its headquarters and shall be made available to the public for inspection and copying at no more than the actual cost of reproduction. This note applies only to the reference material. The entire text of the rule is printed here. (1) Domestic Water Wells and Pilot Holes. (A) Casing. 1. Steel well casing. The minimum standards for steel casing are found in Table 3.2. RESOURCES Table 3.2 Minimum standards for steel casing. Nominal Pipe Outside Diameter Wall Thickness (Inches) (Inches) (Inches) (Weight (lbs.)/Foot) 4 4 1⁄2 0.188 9 5 5 1⁄2 0.188 10 6 6 5⁄8 0.188 13 8 8 5⁄8 0.188 17 10 10 3⁄4 0.188 21 12 12 3⁄4 0.188 25 14 14 0.188 28 16 16 0.188 32 A. Joints. Joints shall be welded or threaded and be watertight. Recessed or reamed and drifted couplings shall be used on threaded casing. Other couplings may be used provided the design, taper, and type of thread of the coupling matches that of the pipe. Casing extension material shall be of similar material to the original casing. Other types of joints or devices used to join dissimilar casing extension materials may be used upon receiving prior written approval from the department. B. Standards. Casing shall be new, which includes used casing that was salvaged from a water supply well within ninety (90) days of installation and is decontaminated. Casing shall meet one (1) of the following requirements: (I) Grade A or B of the American Society for Testing and Materials (ASTM) A53-A53M-20 Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless. This standard is incorporated by reference as published July 15, 2020, by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959 and does not incorporate any subsequent amendments or additions; (II) Grade A or B of ASTM A500/A500M-21 Standard Specification for Cold-Formed Welded and Seamless Carbon Steel Structural Tubing in Rounds and Shapes. This standard is incorporated by reference as published January 21, 2021, by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959 and does not incorporate any subsequent amendments or additions; (III) ASTM A589-A589M-06 Standard Specification for Seamless and Welded Carbon Steel Water-Well Pipe. This standard is incorporated by reference as published October 2, 2018, by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959 and does not incorporate any subsequent amendments or additions; or (IV) Any other new pipe having a quality equal to or greater than those specified above. C. Drive shoe. (I) In areas where steel casing is required, equip the well casing with a drive shoe or similar protective device to prevent damage to the well casing during construction of the well. (II) If no drive shoe is used, follow the minimum grout cure times in Table 3.3. Table 3.3 Minimum cure times for grout. Grout Type Minimum Cure Time (hours) Hi early cement 12 Portland Type I cement 72 Chipped Bentonite 4 High Solids Bentonite Slurry * *Follow manufacturer’s guidelines. Cure time will vary based on additives. D. Installation. Install and centralize casing within the borehole for even distribution of grout material. 2. Plastic well casing. The minimum standards for plastic well casing are found in Table 3.4. Table 3.4 Minimum standards for plastic casing. Nominal Pipe Outside Diameter Standard Dimension Ratio Schedule (Inches) (Inches) (SDR) (SCH) 4 4 1⁄2 26 40 5 5 1⁄2 26 40 6 6 5⁄8 26 40 A. Joints. Well casing joints shall be watertight and joined by solvent weld (glued) or mechanical. Casing extension material shall be of similar material to the original casing. Other types of joints or devices used to join dissimilar casing extension materials may be used upon receiving prior written approval from the department. B. Standards. Casing shall be new and meet ASTM F48014 Standard Specification for Thermoplastic Well Casing Pipe and Couplings Made in Standard Dimension Ratios (SDR), SCH 40 and SCH 80. This standard is incorporated by reference as published March 1, 2014, by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959 and does not incorporate any subsequent amendments or additions. Used casing is considered new when salvaged from a water supply well within ninety (90) days of installation and decontaminated. C. Packers. A packer, coupling, or inverted bell shall be secured at the bottom of the casing and hold the grout in place while drilling continues. No packer, coupling, or inverted bell is needed if grout is allowed to cure following minimum cure times in Table 3.3. D. Installation. Casings shall be installed and centralized within the borehole for even distribution of grout material. 3. Concrete and fiberglass well casing— A. May be used for unconsolidated wells greater than eighteen inches (18") in diameter; B. Shall be composed of non-toxic durable material designed for use in potable water wells; and C. Shall be installed and centralized within the borehole for even distribution of grout material. 4. Other materials may be used upon receiving prior written approval from the department. (B) Borehole. For borehole size see 10 CSR 23-3.090. (C) Grouting. It is the responsibility of the well installation contractor to ensure that the annular space is sealed and that the casing does not leak. This responsibility ends three (3) years after the approval date by the department unless it can be proven that the annular seal has been damaged by other persons. 1. Grouting installation methods. A. Gravity method. (I) Bentonite granules or bentonite slurry shall not be poured through standing water greater than one hundred feet (>100'). (II) Table 3.5 states the maximum depth that grout can be gravity-fed into the well annulus. Table 3.5 Maximum gravity grouting depths. Annular Space Gravity Feed Depth (inches) (feet) 1 100 1 1/16 106 1 1⁄8 112 1 3/16 119 1 1⁄4 125 1 5/16 131 1 3⁄8 137 1 7/16 144 1 1⁄2 150 1 9/16 156 1 5⁄8 162 1 11/16 169 1 3⁄4 175 1 13/16 181 1 7⁄8 187 1 15/16 193 2 200 (III) Gravity grouting greater than two hundred feet (200') in a four inch (4") annulus is not allowed. B. Tremie method. Tremie pipes shall be— (I) Placed into the annulus and extend to no less than five feet (5') from the bottom of the interval to be grouted; (II) Gradually withdrawn as the grouting material is emplaced; and (III) No greater than ten feet (10') above the emplaced grouting material during the entire grouting process. C. Tremie pressure method. The tremie pipe shall remain submerged in the grouting material during the entire grout pumping process. D. Pressure method. E. Open-hole method. (I) Non-slurry bentonite may be poured from the surface and allowed to completely hydrate before the casing is installed. (II) Bentonite slurry may be used in wells with more than one hundred feet (>100') of standing water only if the grout is emplaced by one (1) of the tremie grouting methods. F. Positive displacement method. (I) Bentonite slurry or cement slurry may be used in wells with more than one hundred feet (>100') of standing water only if the grout is emplaced by one (1) of the tremie grouting methods. G. Other grouting methods may be used upon receiving prior written approval from the department. 2. Grout materials. A. Cement slurry. B. Bentonite slurry. C. Bentonite non-slurry. If there is no water in the annular space, the bentonite shall be hydrated. D. Other grout types may be used upon receiving prior written approval from the department. (D) Driving Casing. 1. When geologic conditions require the casing to be driven, the casing may be driven to the casing depth without adding grout. 2. When it is necessary to drive multiple strings of smaller diameter casing through the primary casing, each succeeding smaller diameter casing shall extend into the preceding casing at least twenty feet (20'). 3. Once the casing is set, install liner pursuant to 10 CSR 23-3.080(3)(C). 4. In addition to the liner, a top annular casing seal, at least ten feet (10') deep is required below the pitless connection. 5. A liner and top annular seal are not required when the open hole method or positive displacement grouting method is used. (E) Wellhead Completion. Follow well casing seal and connection installation pursuant to 10 CSR 23-3.050(6). (2) Multifamily Wells. (A) Multifamily wells shall have no more than eight (8) connections, fewer than twenty-five (25) individuals, and have a pumping capacity of less than seventy gallons per minute (<70 gpm). (B) Multifamily wells may be used to serve a charitable or benevolent organization pursuant to section 640.116, RSMo. (C) Casing. 1. Follow 10 CSR 23-3.090 for minimum casing depths by Drilling Area for domestic water wells. 2. Install new casing that meets the requirements listed in 10 CSR 23-3.030(1)(A)1. or new Standard Dimension Ratio 21, or SCH 80 plastic casing meeting the requirements of 10 CSR 23-3.030(1)(A)2.B. 3. Other casing design or materials may be used upon receiving prior written approval from the department. 4. Liners are not a substitute for casing. (D) Joints. 1. Steel well casing joints shall be welded or threaded and be watertight. Other types of joints may be used upon receiving advanced written approval by the department. Recessed or reamed and drifted couplings shall be used on threaded casing; other couplings may be used provided the design, taper, and thread type is compatible with the pipe. 2. Plastic well casing joints shall be watertight and joined by solvent weld (glued) or mechanically. 3. Casing extension material shall be of similar material to the original casing. Other types of joints or devices used to join dissimilar casing extension materials may be used upon receiving prior written approval from the department. (E) Drive shoe. For drive shoe requirements see 10 CSR 233.030(1)(A)1.C. (F) Packers. For packer requirements see 10 CSR 23-3.030(1) (A)2.C. (G) Installation. Casings shall be installed and centralized within the borehole for even distribution of grout material. (H) Borehole. The borehole must be a minimum of four inches (4") larger in diameter than casing. (I) Grouting. Grout the annular space of the well full length. RESOURCES It is the responsibility of the well installation contractor to ensure that the annular space is sealed and that the casing does not leak. This responsibility ends three (3) years after the date of approval by the department unless it can be proven that the well seal has been damaged by another person. 1. Grouting installation methods. A. Tremie method pursuant to 10 CSR 23-3.030(1)(C)1.B. B. Tremie pressure method pursuant to 10 CSR 23-3.030(1) (C)1.C. C. Pressure method pursuant to 10 CSR 23-3.030(1)(C)1.D. 2. Grout materials. A. Grout types pursuant to 10 CSR 23-3.030(1)(C)2. may be used except powdered or granular non-slurry bentonite. B. Other grout types may be used upon receiving prior written approval from the department. (J) Wellhead Completion. The wellhead shall be completed pursuant to 10 CSR 23-3.050(6). (3) High yield bedrock wells or high yield unconsolidated wells two hundred feet (200') or more in depth. (A) Casing. 1. The minimum amount of casing shall be determined by the department in advance. 2. Install new steel casing that meets the minimum standards specified in Table 3.6 for size and weight. 3. In lieu of steel casing, unconsolidated wells two hundred feet (200') or more in depth may use Schedule 80 or Standard Dimension Ratio 21 (SDR 21) plastic casing. 4. Liners are not a substitute for casing. 5. Other design or materials may be used upon receiving prior written approval from the department. Table 3.6 Minimum steel casing requirements for high yield bedrock wells and high yield unconsolidated wells two hundred feet (200') or more in depth. Nominal Pipe Outside Diameter Wall Thickness (inches) (inches) (inches) Weight per foot (lbs.) 6 6 5⁄8 0.280 19 8 8 5⁄8 0.322 29 10 10 3⁄4 0.365 40 12 12 3⁄4 0.375 50 14 14 0.375 55 16 16 0.375 63 18 18 0.375 71 20 20 0.375 79 22 22 0.500 115 24 24 0.500 125 26 26 0.500 136 28 28 0.500 147 30 30 0.500 158 32 32 0.500 168 34 34 0.500 179 36 36 0.500 190 (B) Joints, Standards, Drive Shoe, Borehole, and Wellhead Completion shall be followed pursuant to 10 CSR 23-3.030(2). (C) Grouting. 1. Grout the annular space of the well full-length with neat cement. It is the responsibility of the well installation contractor to ensure that the annular space is sealed and that the casing does not leak. This responsibility ends three (3) years after the date of approval by the department unless it can be proven that the well seal has been damaged by another person. 2. Grouting installation methods. A. Tremie method pursuant to 10 CSR 23-3.030(1)(C)1.B. B. Tremie pressure method pursuant to 10 CSR 23-3.030(1) (C)1.C. C. Pressure method pursuant to 10 CSR 23-3.030(1)(C)1.D. (4) High yield unconsolidated wells less than two hundred feet (<200'). (A) Casing. 1. Install a minimum of twenty feet (20') of casing. 2. Install new steel or plastic casing that meets the minimum standards specified in Table 3.2 or Table 3.4, respectively. 3. Install and centralize casing within the borehole for even distribution of grout material. 4. Other design or materials may be used upon receiving prior written approval from the department. (B) Borehole. Construct the borehole pursuant to 10 CSR 233.030(2)(H). (C) Grouting. Install a ten foot (10') minimum top grout seal. It is the responsibility of the well installation contractor to ensure that the annular space is sealed and that the casing does not leak. This responsibility ends three (3) years after the date of approval by the department unless it can be proven that the annular seal has been damaged by another person. 1. Grouting installation methods. A. Gravity method pursuant to 10 CSR 23-3.030(1)(C)1.A. B. Tremie method pursuant to 10 CSR 23-3.030(1)(C)1.B. C. Tremie pressure method pursuant to 10 CSR 233.030(1)(C)1.C. D. Pressure method pursuant to 10 CSR 23-3.030(1)(C)1.D. 2. Grout materials. A. Cement slurry. B. Non-slurry bentonite. C. Other grout types may be used upon receiving prior written approval from the department. (D) Gravel Pack. All gravel placed into the well shall be clean, washed, and disinfected prior to placement or provisions made for disinfection in place. (E) Wellhead Completion. Follow well casing seal and connection installation pursuant to 10 CSR 23-3.050(6). (F) Major water users are subject to requirements pursuant to section 256.410, RSMo. (5) Public Water Supply Wells. (A) Wells that serve a public water system shall not be constructed or altered without authorization pursuant to 10 CSR 60-3. (6) Oil and Gas Zones. (A) Report oil or gas encounters and the conversion of water wells to oil or gas wells pursuant to section 256.614, RSMo. (B) Any water well that encounters oil and/or gas shall have an annular or open hole grout plug from fifty feet (50') below the oil and/or gas bearing zone to fifty feet (50') above the oil and/or gas bearing zone. (C) The grout plug shall be composed of cement slurry with a two to six percent (2–6%) bentonite additive. (D) The grout plug shall be placed via one (1) of the tremie methods. AUTHORITY: sections 256.606, 256.614, 256.615, and 256.626, RSMo 2016.* Original rule filed April 2, 1987, effective July 27, 1987. Emergency amendment filed Nov. 16, 1993, effective Dec. 11, 1993, expired April 9, 1994. Amended: Filed Aug. 17, 1993, effective March 10, 1994. Amended: Filed July 13, 1994, effective Jan. 29, 1995. Amended: Filed Nov. 1, 1995, effective June 30, 1996. Amended: Filed June 27, 2018, effective Feb. 28, 2019. Amended: Filed March 20, 2024, effective Nov. 30, 2024. *Original authority: 256.606, RSMo 1991; 256.614, RSMo 1985, amended 1991; 256.615, RSMo 1991; and 256.626, RSMo 1985, amended 1991.