Section NR 812.22 - Well rehabilitation and batch chlorination(1) REHABILITATION. All of the following requirements apply to the rehabilitation of a well by a well driller or well constructor: (a)Redevelopment. The methods described for development under s. NR 812.12(15) may be used to redevelop a well.(b)Chemical conditioning.1. Noncontinuous chemical treatment of a well, except for batch chlorination, shall be conducted under the supervision of a licensed water well driller or a Wisconsin registered professional engineer. Acidation of a well shall be done with materials approved for use under s. NR 812.091 and in a manner to prevent damage to the well or pump and to prevent any hazard to humans or property. The acid shall be inhibited and shall be neutralized upon removal from the well.2. Noncontinuous chemical treatment of pumps or pump intake screens shall be conducted under the supervision of a licensed pump installer or a Wisconsin registered professional engineer. Acidation of a pump or pump intake screen shall be done in a manner described under subd. 1.(c)Physical conditioning. Wells may be physically conditioned using any of the following methods: 1. `Blasting.' When using explosives to increase or recover the yield of a well, the explosive charge shall be set at least 10 feet below the bottom of the well casing pipe, which shall be filled with water or sand. A licensed water well driller shall supervise blasting work, which shall be performed by a blaster certified by the department of safety and professional services according to the requirements specified in ch. SPS 307. The well driller shall submit a report of results of the blasting within 30 days following the work on a well construction report form.2. `Hydrofracturing or hydroflushing.' Hydrofracturing or hydroflushing of an aquifer by injecting potable chlorinated water into a crystalline bedrock formation well under high pressure is allowed. Clean washed inert, nontoxic material such as sand may be added to the water for the purpose of holding the joints and fractures open after the pressure is reduced. Hydrofracturing or hydroflushing may only be performed under the supervision of a licensed water well driller. The upper packer may not extend up into the bottom of the well casing pipe nor higher than 40 feet below the ground surface. Hydrofracturing or hydroflushing in limestone or dolomite formations may be undertaken only after prior department notification. The well driller shall submit a report of the results of the hydrofracturing or hydroflushing no later than 30 days after completion of the work on a form specified by the department.3. `Mechanical brushing.' A well may be mechanically brushed to loosen material attached to the inside of a casing, screen, or open drillhole.(2) BATCH CHLORINATION. All of the following requirements apply to the batch chlorination of a water system by a well driller or well constructor: (a) The entire water system shall be thoroughly disinfected with a chlorine solution having a concentration of at least 100 mg/L, prepared according to Table D.(b) The volume of chlorine solution shall be equal to or greater than the volume of water standing in the well.(c) The chlorine solution shall be brought into contact with the entire inside of the well casing pipe by continuous circulation from the water system.(d) A contact time of at least 12 hours shall be provided for the disinfectant.(e) The well and water system shall be thoroughly flushed.Wis. Admin. Code Department of Natural Resources NR 812.22
Cr. Register, January, 1991, No. 421, eff. 2-1-91; am. (2) (b) 1., (4) (a) and (b), (5), (6) (a) and (7) (a) (intro.), cr. (4) (e), Register, September, 1994, No. 465, eff. 10-1-94; correction in (2) (c) 1. made under s. 13.93(2m) (b) 7, Stats., Register, September, 1996, No. 489; correction in (2) (c) 1. made under s. 13.93(2m) (b) 7, Stats., Register, May, 2000, No. 533; correction in (6) (b) made under s. 13.92(4) (b) 7, Stats., Register July 2010 No. 655; correction in (2) (c) 1., (6) (b) made under s. 13.92(4) (b) 6, 7., Stats., Register December 2011 No. 672; CR 13-096: am. (7) (title), (a) (intro.), (b), cr. (8m), CR 13-099: am. (7) (b), cr. (9), (10) Register September 2014 No. 705, eff. 10-1-14; correction in numbering in (8m) made under s. 13.92(4) (b) 1, Stats., Register September 2014 No. 705.Amended by, correction in s. 13.92(4) (b) or 35.17(2), 2015 Wis. Act 197 s. 46 Register April 2016 No. 724, eff.5/1/2016Amended by, CR 18-095: r. and recr. Register June 2020 No. 774, eff. 7/1/2020