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. NR 812.16(4)(4) Placement. Gravel packs shall be placed in accordance with all of the following requirements: NR 812.16(4)(a)(a) The gravel pack shall be placed through a tremie pipe placed in the annular space. NR 812.16(4)(b)(b) The gravel pack shall surround the entire screen and shall extend at least 2 feet above the top of the screen. NR 812.16(4)(c)(c) At least a 2-foot sand seal shall be placed upon the top of the gravel pack to prevent the required annular space sealing material from entering the gravel pack. NR 812.16(4)(d)(d) For potable wells, the gravel pack may not extend closer to the ground surface than the minimum depth for the upper enlarged drillhole specified in s. NR 812.152 (3). NR 812.16(4)(e)(e) For nonpotable high capacity wells, the gravel pack may not extend more than 20 feet above the top of the screen. NR 812.16(5)(5) Thickness. The diameter of the upper enlarged drillhole shall be sized to accommodate the thickness of the gravel pack. The gravel pack shall be at least 2 inches greater than the nominal radius of the screen. NR 812.16 HistoryHistory: CR 18-095: r. and recr. Register June 2020 No. 774, eff. 7-1-20. NR 812.18NR 812.18 Welding procedures. Plain end well casing pipe shall be welded watertight using welding procedures for plain end well casing pipe in accordance with the specifications in the American Welding Society manual AWS D10.12, “Guide for Welding Mild Steel Pipe.” Well casing pipe to be welded shall conform to the specifications in s. NR 812.11 (6). Pitless adapter connections to well casing pipe shall be made watertight in accordance with welding procedures in the American Welding Society manual AWS D1.1, “Structural Welding Code-Steel.” NR 812.18 NoteNote: Copies of AWS manuals may be obtained directly from the American Welding Society’s website at www.aws.org. Copies are also on file at the offices of the department and the legislative reference bureau.