NR 812.152(3)(c)2.2. Setting a temporary casing to the bottom of the drillhole, or to the top of bedrock. NR 812.152(4)(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: NR 812.152(4)(a)1.1. Sixty feet or 20 feet below the static water level when the static water level is greater than 40 feet. NR 812.152(4)(a)2.2. 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. NR 812.152(4)(b)1.1. Sixty feet or to the depth of bedrock when the top of bedrock is more than 60 feet below ground surface. NR 812.152(4)(b)2.2. 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. NR 812.152(5)(5) Grouting. The grouting of an annular space shall be accomplished according to all of the following requirements: NR 812.152(5)(b)(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. NR 812.152(5)(c)(c) Any temporary casing used during the construction of the upper enlarged drillhole shall be removed. NR 812.152(6)(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. NR 812.152(7)(7) Screens. Screens shall meet all of the following requirements: NR 812.152(7)(a)(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. NR 812.152(7)(b)(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. NR 812.152(8)(8) Gravel packs. Gravel packs shall be placed according to the requirements specified in s. NR 812.16. NR 812.152(9)(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: NR 812.152(9)(b)(b) High capacity potable wells when required by an approval issued by the department. NR 812.152 HistoryHistory: CR 18-095: r. and recr. Register June 2020 No. 774, eff. 7-1-20. NR 812.16(1)(1) Conditions. A well driller or a well constructor may construct a screened well with a gravel pack under any of the following conditions: NR 812.16(1)(a)(a) In an unconsolidated formation well when the natural formation comprising the aquifer is very fine grained or when the aquifer formation is highly variable in size. NR 812.16(1)(b)(b) In loosely cemented sandstone aquifers that require screening to prevent sand pumping conditions. NR 812.16(1)(c)(c) In badly fractured or decomposed crystalline bedrock formations. NR 812.16(2)(2) Material. The gravel or sand used to construct a gravel pack shall meet the requirements specified in s. NR 812.11 (12). NR 812.16(3)(3) Screens. Screens to be placed in gravel pack wells shall have a set of centering guides on the top and bottom of the screen to ensure an even gravel pack. The screen slot openings shall be sized to retain 90% of the gravel pack. Screen types and materials shall meet the requirements specified in s. NR 812.11 (11). The screen may either be permanently welded or threaded onto the bottom of the well casing pipe or may be installed by pushing the screen to the bottom of the casing pipe and then pulling back the casing pipe to expose the screen.