Section NR 812.152 - Construction requirements for potable high capacity wells, potable school wells, and wastewater treatment plant wells Potable high capacity wells, potable school wells, and wastewater treatment plant wells shall be planned and constructed according to the location, approval, and general requirements speecified in ss. NR 812.08 to NR 812.12, and according to all of the following requirements:
(1) MINIMUM DIAMETER. The minimum casing and lower drillhole diameter for potable high capacity wells, potable school wells and wastewater treatment plant shall meet the following requirements: (a) Four inches for wells completed in unconsolidated formations.(b) Six inches for wells completed in bedrock formations.(2) CASING MATERIAL. Only steel well casing pipe meeting the requirements of s. NR 812.11(6) may be used.(3) UPPER ENLARGED DRILLHOLE. An upper enlarged drillhole is required for all wells. An upper enlarged drillhole shall be constructed according to the following requirements: (a) An upper enlarged drillhole shall be a minimum of 3 inches larger than the outside diameter of welded casing pipe, or 3 inches larger than the diameter of the casing couplings, when couplings are used.(b) The upper enlarged drillhole shall be constructed to at least the minimum casing depth requirements specified in sub. (4).(c) The upper enlarged drillhole shall be maintained at full diameter for the entire depth by any of the following methods:1. Circulating bentonite drilling mud.2. Setting a temporary casing to the bottom of the drillhole, or to the top of bedrock.(4) CASING DEPTH. Minimum casing depths are measured from the ground surface. All wells shall be constructed with casing that extends to the minimum depth for the geologic formation they are completed in according to the all of the following requirements: (a)Wells completed in unconsolidated formations.1. Sixty feet or 20 feet below the static water level when the static water level is greater than 40 feet.2. One hundred feet, or 20 feet below the static water level when the static water level is greater than 80 feet, when the well is to supply water for a wastewater treatment plant and there is a treatment pond or lagoon or sludge beds on the property.(b)Wells completed in bedrock.1. Sixty feet or to the depth of bedrock when the top of bedrock is more than 60 feet below ground surface.2. One hundred feet when the well is to supply water for a wastewater treatment plant and there is a treatment pond or lagoon or sludge beds on the property.(5) GROUTING. The grouting of an annular space shall be accomplished according to all of the following requirements:(a) Only neat cement grout meeting the specification under s. NR 812.11(15) (b) shall be used.(b) Grout shall be placed using an approved pressure grouting method as specified in s. NR 812.20(3), except that the grout shall be allowed to set for a minimum of 24 hours before drilling is resumed.(c) Any temporary casing used during the construction of the upper enlarged drillhole shall be removed.(6) DRIVING OR ADVANCING CASING. Casing may be placed to the bottom of an upper enlarged drillhole meeting the requirements specified in sub. (3) and driven or advanced through unconsolidated material to the final casing depth or to the top of bedrock.(7) SCREENS. Screens shall meet all of the following requirements:(a) Screens shall be continuous-slot screen, v-shaped or wire-wrap on a rod base type and composed of stainless steel or lead-free brass.(b) Screens may be permanently attached to the casing or riser pipe, or the screen may be placed using the bail-down method or by pushing the screen to the bottom of the casing and pulling it back to expose the screen.(8) GRAVEL PACKS. Gravel packs shall be placed according to the requirements specified in s. NR 812.16.(9) GEOLOGIC SAMPLES. Geologic samples shall be collected and submitted according to the requirements specified in s. NR 812.12(11) (b) from all of the following:(a) All potable school wells.(b) High capacity potable wells when required by an approval issued by the department.Wis. Admin. Code Department of Natural Resources § NR 812.152
Adopted by, CR 18-095: r. and recr. Register June 2020 No. 774, eff. 7/1/2020