Chapter NR 812

NR 812.41(1) (1) Disinfection. When a potable well is entered for the purpose of installing, replacing or repairing equipment located within the well, the well and discharge piping shall be thoroughly disinfected by the pump installer or by the person who installed the pump using sodium hypochlorite or calcium hypochlorite. Chlorine compounds having additives may not be used.

NR 812.41(1)(a) (a) The disinfectant shall be dispersed throughout the entire water column and in the water system.

NR 812.41(1)(b) (b) A chlorine solution with a minimum of 100 mg/l of chlorine shall be used to disinfect wells and water systems.

NR 812.41(1)(c) (c) The disinfectant solution shall be prepared according to Table D and shall remain in the system at least 8 hours, except for emergency situations when water is needed without delay. A contact time of at least 30 minutes shall be provided for emergency situations.

NR 812.41(2) (2) Flushing. The pump installer or his or her agent shall thoroughly flush the system of chlorine after disinfecting and before the pump is placed in normal service.

NR 812.41(3) (3) Water sample collection, analysis, and reporting. The pump installer shall collect water samples, submit them to a certified laboratory for analysis, and provide the test results in compliance with s. NR 812.46.

NR 812.41 History History: Cr. Register, January, 1991, No. 421, eff. 2-1-91; am. (1) (intro.), (3) (a), (c), Register, September, 1994, No. 465, eff. 10-1-94; CR 13-099: r. and recr. (3), cr. (4) Register September 2014 No. 705, eff. 10-1-14; CR 18-095: am. (1) (c), r. and recr. (3), r. (4) Register June 2020 No. 774, eff. 7-1-20.

subch. IV of ch. NR 812 Subchapter IV — Standards for Existing Installations

NR 812.42 NR 812.42 Criteria for evaluation. Each existing water system shall be viewed as an individual unit and its acceptability for use as a source of water shall be determined on the basis of its location, construction, installation, pump discharge piping arrangement, water quality, and sanitary condition. The owner shall provide written documentation verifying the date of construction or installation or both. Existing installations shall meet all of the following requirements:

NR 812.42(1) (1) Location, well construction and water quality.

NR 812.42(1)(a) (a) Location. The well location shall comply with the requirements in effect at the time the well was constructed as shown in Table E, or to the location requirements of s. NR 812.08, whichever is less restrictive. However, if a contamination source was installed after the well was constructed, the well location shall conform to the requirements in effect at the time of installation of the contamination source.

NR 812.42(1)(b) (b) Well construction.

NR 812.42(1)(b)1. 1. The well construction shall comply with the construction requirements in effect at the time the well was constructed or shall be in compliance with any standards or approval issued under ss. NR 812.09 to 812.25, except if the well was constructed prior to April 10, 1953, in which case the well construction shall be in compliance with the standards adopted on April 10, 1953.

NR 812.42(1)(b)2. 2. The well casing pipe shall meet the minimum wall thickness requirements of s. NR 812.11 Table B for its diameter and may not be in a deteriorated condition.

NR 812.42(1)(b)3. 3. For wells in basements or walkout basements, the well casing pipe depth shall be measured from the floor of the basement.

NR 812.42(1)(b)4. 4. Wells completed in unconsolidated formations, including both drilled and driven point wells, shall have minimum well casing pipe depth settings of at least 25 feet below the ground surface, not including the screen; or, if the static water level is deeper than 15 feet, shall have the minimum well casing pipe depth setting at least 10 feet below the static water level.

NR 812.42(1)(b)5. 5. Wells completed in sandstone shall have minimum well casing pipe depth settings below the ground surface as follows:

NR 812.42(1)(b)5.a. a. Twenty-five feet for wells constructed before February 1, 1991.

NR 812.42(1)(b)5.b. b. Thirty feet for wells constructed on or after February 1, 1991.

NR 812.42(1)(b)6. 6. Wells terminating in limestone or dolomite shall have minimum well casing pipe depth settings below the ground surface as follows:

NR 812.42(1)(b)6.a. a. Forty feet for wells constructed before July 1, 2020.

NR 812.42(1)(b)6.b. b. Sixty feet when the depth to bedrock is less than 10 feet below the ground surface and the well was constructed between February 1, 1991 and July 1, 2020.

NR 812.42(1)(b)6.c. c. Sixty feet when the depth to bedrock is less than 20 feet below the ground surface and the well was constructed after July 1, 2020.

NR 812.42(1)(b)7. 7. Wells terminating in bedrock other than sandstone, limestone, or dolomite shall have a minimum of 40 feet of casing pipe below the ground surface.

NR 812.42(1)(c) (c) Water quality. A well shall produce water free from coliform bacteria and free from contaminant levels in excess of the standards of s. NR 812.06. If the standards of s. NR 812.06 are exceeded, the department may require the water system to be upgraded to meet the requirements of this chapter or may require the well to be filled and sealed according to the criteria and requirements of s. NR 812.26.

TABLE E

HISTORIC MINIMUM SEPARATION DISTANCE REQUIREMENTS BETWEEN EXISTING POTABLE OR NONPOTABLE WELLS, RESERVOIRS, AND SPRINGS AND POSSIBLE SOURCES OF CONTAMINATION

NR 812.42(2) (2) Pits and alcoves. Existing well or pressure tank pits and alcoves constructed after April 10, 1953 shall comply with the minimum requirements specified in s. NR 812.36 (2). When a well in a pit is filled and sealed, the pit shall be filled in accordance with s. NR 812.26 (5) (m) unless the pit is a complying valve pit. If a building is constructed over a well pit or alcove, the well shall meet the requirements of a basement well as specified in s. NR 812.42 (9). Pits and alcoves constructed on or before April 10, 1953 shall meet the following minimum requirements:

NR 812.42(2)(a) (a) Construction. The entire pit or alcove, including the roof, shall be constructed of reinforced watertight poured concrete. If the pit or alcove has a history of being continuously dry, walls of concrete block, brick, or stone with mortared joints are allowed. The walls, floor and roof shall be crack-free and watertight. The junction of walls and floors and all openings in the structure shall be sealed watertight. The roof or deck shall be at or above the ground surface. Requirements for existing pits are shown in Figure 10 of ch. NR 812 Appendix. Requirements for existing alcoves are shown in Figure 11 of ch. NR 812 Appendix.

NR 812.42(2)(b) (b) Access. The pit or alcove shall be provided with a manhole opening, having a raised curbing edge at least 4 inches higher than the pit or alcove roof. A structurally substantial, waterproof, overlapping, tight-fitting cover with skirted sides shall be provided for the manhole. A watertight, cast-iron manhole frame and cover bolted in place with a gasket may be substituted for a curbed manhole. An alcove adjoining a basement or a pit not having the manhole centered over the well may have a section of well casing pipe installed directly above the well. This pipe shall be equal in size or larger than the well casing pipe and it shall be sealed with an approved well seal or cap.

NR 812.42(2)(c) (c) Drainage. An alcove adjoining a basement where the basement is subject to flooding shall be discontinued for use as a well pit and the well shall be filled and sealed according to s. NR 812.26. The alcove need not be filled and sealed. A pit or alcove drain or sump pump discharge pipe may not be directly connected to a sewer or other plumbing system. If the alcove drain discharge pipe is discharging to the ground surface, the end of the discharge pipe shall be screened.

NR 812.42(2)(d) (d) Casing height. The well casing pipe shall terminate at least 6 inches above the floor of a pit or alcove and shall be provided with a one-piece sanitary well seal approved for use under s. NR 812.091.

NR 812.42(2)(d)1. 1. If the well casing pipe does not extend at least 6 inches above the floor, the pit or alcove may remain in service only if all of the following apply:

NR 812.42(2)(d)1.a. a. The well location meets the minimum standards of sub. (1) (a).

NR 812.42(2)(d)1.b. b. The well construction meets the minimum standards of sub. (1) (b), verified by measuring the well casing pipe depth in accordance with sub. (7) (c) 3., if no confirmable well construction report can be found for the well. Well details, including location, well casing pipe depth, total well depth, distances to possible contaminant sources and well owner information shall be entered on a form and submitted to the department in accordance with s. NR 812.10 (15).

NR 812.42(2)(d)1.c. c. The pit or alcove structure meets the requirements of this section.

NR 812.42(2)(d)1.d. d. The well casing pipe is extended up and out of the pit or alcove to 12 inches above the outside grade in accordance with sub. (12). For situations where the well would create an obstruction, including in a stoop, sidewalk, breezeway, driveway, garage or patio, making it impractical to raise the well casing pipe up and out of the alcove, the well casing pipe may be raised to a height just below the ceiling of the alcove structure in accordance with sub. (12).

NR 812.42(2)(d)2. 2. If the floor of an alcove is lower than the basement floor, the alcove floor shall be raised to a height at least even with the basement floor by pouring concrete.

NR 812.42(2)(d)3. 3. If the raised alcove floor results in the well casing pipe terminating less than 6 inches above the floor, then the well casing pipe shall be extended as specified in sub. (2) (d) 1. d. and in accordance with sub. (12).

NR 812.42(2)(e) (e) Pit venting. Well pit vent pipes, if used, shall be located in opposite corners. One pipe shall extend to within one foot of the pit floor and the other extend only down through the pit roof. The upper end of each vent pipe shall extend watertight through the pit roof and terminate with a reverse bend and screened outlet.

NR 812.42(3) (3) Noncomplying pits and alcoves.

NR 812.42(3)(a) (a) Noncomplying pit structures. When a pit structure does not meet the minimum construction requirements of sub. (2) or when water gains access to a pit through the floor or walls, the floor and at least one wall of the pit shall be perforated and the pit shall be filled after properly extending the well casing pipe above grade in accordance with sub. (12) or after properly filling and sealing the existing well according to s. NR 812.26. Before the pit is filled, all water system components, including the pressure tank, pump, discharge piping, electrical wiring and conduit, and any treatment equipment shall be removed from the pit.

NR 812.42(3)(b) (b) Noncomplying alcoves. If the pit is an alcove, the alcove does not need to be filled, except when the alcove floor is lower than the basement floor, in which case the floor shall be raised to a height at least even with the basement floor by pouring concrete. To allow for easy removal of the pump for servicing or replacement, this casing extension may be made with the use of a threaded and coupled joint.

NR 812.42(3)(c) (c) Other modifications to pit or alcove. Any other modifications to a pit or alcove allowed under this chapter shall meet the requirements of s. NR 812.36.

NR 812.42(3m) (3m) Valve pits and alcoves. Existing pits and alcoves used only for the housing of valves are exempt from the requirements of this section except that a pit or alcove used for this purpose shall be watertight, may not be connected to a sewer, shall be drained to permeable soil or to the ground surface, and may not be subject to flooding.

NR 812.42(4) (4) Reservoirs.

NR 812.42(4)(a) (a) An existing reservoir shall be constructed of steel or reinforced concrete. If constructed with concrete, the roof shall be watertight, reinforced, poured concrete having a thickness of at least 5 inches. The walls and floor of the reservoir shall be watertight and constructed of reinforced, poured concrete or equivalent watertight construction.

NR 812.42(4)(b) (b) The manhole curbing shall extend at least 12 inches above the established ground grade. If the reservoir roof terminates above the established ground grade, the curbing shall terminate at least 6 inches above the reservoir roof. The manhole shall be provided with a waterproof, tight-fitting, overlapping metal cover with skirted sides.

NR 812.42(4)(c) (c) A reservoir overflow pipe shall be installed watertight just under the roof of the reservoir and entirely above the established ground grade. It shall terminate at a point at least 12 inches above the established ground grade with a screened, downturned elbow. If an existing overflow pipe is totally buried between the reservoir and its outlet, it shall be eliminated by properly sealing the pipe with concrete at the reservoir.

NR 812.42(4)(d) (d) A gravity discharge pipe to the reservoir shall extend entirely above established ground grade and through the roof of the reservoir or manhole curbing. Service pipe connections shall be sealed watertight. A pressurized service pipe may be connected to the reservoir below ground grade provided it is under a continuous pressure which is greater than the ground surface elevation.

NR 812.42(4)(e) (e) The reservoir shall meet the location requirements in effect at the time of its construction.

NR 812.42(4)(f) (f) When a below ground-grade reservoir or a buried pressure tank pit is to be abandoned, it shall be permanently filled and sealed when the well or drillhole is filled and sealed. The reservoir shall be filled according to the filling and sealing requirements specified in s. NR 812.26 (5) (m) for well pits.

NR 812.42(4)(g) (g) The owner shall permanently fill and seal a reservoir if any of the following apply:

NR 812.42(4)(g)1. 1. The location or construction of the reservoir does not meet the requirements of this chapter.

NR 812.42(4)(g)2. 2. It poses a hazard to health or safety.

NR 812.42(4)(g)3. 3. It has been taken out of service or has not been used for 2 or more years.

NR 812.42(4)(h) (h) A reservoir shall be maintained in a clean and sanitary condition and provide water free from coliform bacteria and free from contaminant levels in excess of the standards specified in s. NR 812.06.

NR 812.42(5) (5) Dug wells. An existing dug well may be continued in service only if it produces water free from coliform bacteria and free from contaminant levels in excess of the standards specified in s. NR 812.06. Use of dug wells is not recommended by the department. A dug well may not be reconstructed without approval under s. NR 812.09 (4) (m). Existing dug wells shall meet the following minimum construction requirements:

NR 812.42(5)(a) (a) Curbing. The curbing of every dug well shall be of watertight reinforced poured concrete or at least 3/16 inch thick steel curbing with watertight joints. Fieldstone curbing may not be used. The curbing shall extend above grade at least 8 inches and be protected from flooding. An open annular space may not exist around the dug well curbing.

NR 812.42(5)(b) (b) Depth. If the well was dug after June, 1975, the watertight curbing shall extend to a depth of at least 25 feet below ground surface and the well shall produce water free from coliform bacteria. If the well was dug prior to June, 1975, the watertight curbing shall extend to at least the 15-foot depth and the well shall produce water free from coliform bacteria.

NR 812.42(5)(c) (c) Cover. The dug well cover shall be of watertight, reinforced concrete at least 5 inches thick and wide enough to overlap the curbing by at least 2 inches. It shall provide a tight seal and be free of joints. A steel well casing pipe sleeve meeting the requirement for potable well casing pipe specified in s. NR 812.11 (6) shall extend watertight through the cover to provide access for installing the pump. The steel well casing pipe sleeve shall extend at least 8 inches above the cover and have an approved well cap or a one-piece well seal.

NR 812.42(5)(d) (d) Equipment location. Pumping equipment or attachments may not be installed for a dug well so that access to the interior of the well will be required for maintenance or repair.

NR 812.42(6) (6) Pump and pump discharge installations. Pump installations installed prior to February 1, 1991 shall conform to the following requirements:

NR 812.42(6)(a) (a) Residential up to three families. Installations for water supplies serving a maximum total of 3 families in residential units shall meet the following requirements:

NR 812.42(6)(a)1. 1. The subsurface connection to the well casing pipe may be made with an approved weld-on pitless adapter or with an approved pitless unit provided the adapter or unit is installed according to the requirements of s. NR 812.31.

NR 812.42(6)(a)2. 2.

NR 812.42(6)(a)2.a. a. Any buried suction pipe shall be contained in a sealed pressurized conduit or a nonpressurized conduit, if the nonpressurized conduit was installed before February 1, 1991 (Figures 12 and 13 of ch. NR 812 Appendix). The nonpressurized conduit shall meet the pipe requirements of Table B between the connection to the well casing pipe and a basement, or shall be properly connected to the well with an approved pitless adapter or pitless unit designed for and used with a concentric piping arrangement. Unprotected buried suction lines not enclosed in conduit may not be used.

NR 812.42 Note Note: Unprotected buried suction lines have never been allowed by the Wisconsin Well and Pump Code.

NR 812.42(6)(a)2.b. b. Nonpressurized conduits shall have been welded watertight or threaded watertight to the well casing pipe and shall be at least 4 inches in diameter and shall enter the basement such that the bottom of the conduit is at least 6 inches above the basement floor.

NR 812.42 Note Note: Nonpressurized conduits to protect buried suction lines were only allowed before February 1, 1991 and then only for installations serving three or fewer homes.

NR 812.42(6)(a)2.c. c. A nonpressurized conduit may extend at an angle up through a basement floor, or up through a concrete slab floor of a building having no basement, provided the lowest end of the conduit is at least 6 inches above the floor.

NR 812.42(6)(a)2.d. d. The basement end of a nonpressurized conduit shall be sealed with a watertight seal.

NR 812.42(6)(a)3. 3. Buried submersible pump discharge pipes connected to pitless adapters or pitless units shall conform to the requirements specified in s. NR 812.11 (6) for steel pipe or shall conform to the requirements in the “Pipe and Tubing for water services and private water mains” table in ch. SPS 384. This pipe shall be maintained under system pressure at all times. No check valve may be placed in the pump discharge line between a pitless adapter or unit and a pressure tank or other pressure vessel. The check valve shall be located either at the top of the submersible pump, in that portion of the discharge pipe within the well or on the spool of an approved spool-type pitless unit.

NR 812.42(6)(b) (b) Residential more than three families. Installations for non-community water systems and water systems serving more than 3 families in residential units except high capacity and school wells shall meet all of the following requirements:

NR 812.42(6)(b)1. 1. The subsurface connection to the well casing pipe may be made with a factory-assembled pitless unit provided the unit is approved and installed according to the requirements of s. NR 812.31.

NR 812.42(6)(b)2. 2. All suction pipe for off-set pump installations shall be enclosed in a sealed pressurized conduit between the connection to the well casing pipe and a basement, or shall be connected to the well with an approved factory-assembled pitless unit designed for and having a concentric pressurized piping arrangement. Unprotected buried suction lines or suction lines enclosed in nonpressurized conduits may not be used. The pipe for a pressurized conduit shall meet the requirements of Table B and shall enter the basement such that any pump suction pipe in the basement not enclosed in a pressurized conduit shall be at least 6 inches above the basement floor.

NR 812.42(6)(b)3. 3. Buried submersible pump discharge pipes connected to pitless units shall meet the requirements of sub. (6) (a) 3.

NR 812.42(6)(b)4. 4. When an existing off-set pump installation using a nonpressurized conduit has been or will be converted to a submersible pump installation, the nonpressurized conduit shall be completely eliminated by cutting off the well casing pipe below the nonpressurized conduit, extending the well casing pipe to at least 12 inches above grade in accordance with sub. (12) and installing pressurized discharge piping according to the requirements of ss. NR 812.28, 812.31, and 812.32 (4).

NR 812.42(6)(c) (c) School and high capacity wells. Pump installations for water supplies serving schools, and high capacity wells shall be provided with an above-ground discharge meeting the minimum requirements of s. NR 812.32.

NR 812.42(6)(d) (d) Pit pump location. A pump located in a conforming pit or alcove shall be installed to allow the sealing of the top of the well with an approved one-piece sanitary well seal.

NR 812.42(6)(e) (e) Hand pumps. Hand pumps may be continued in service if the pump base flange is bolted watertight to a well casing pipe flange and has a gasket seal; if the pump is firmly threaded to the well casing pipe; or if the structured base of the pump has recesses and is bolted to the top of the well casing pipe.

NR 812.42(6)(f) (f) Pump connections to reservoirs. If water is pumped to a reservoir, the piping attachment to the pump shall be made with watertight pipe fittings. The discharge pipe from the pump shall enter the reservoir in a watertight manner through that portion of the structure extending above the ground grade, unless a subsurface reservoir supply pipe is connected to the well by an approved pitless adapter and the supply pipe can be maintained under a continuous pressure head which is greater than the ground surface elevation. In such case the supply pipe shall terminate near the bottom of the reservoir. A float control switch or low and high water level electrical pump-control elements may be provided to control the pump. A check valve may be installed only in the portion of the pump discharge pipe located within the well.

NR 812.42(6)(g) (g) Pump installations for flowing wells. Pump installations for flowing wells shall meet the requirements of s. NR 812.32 (9).

NR 812.42(7) (7) Casing height.

NR 812.42(7)(a) (a) When a well is not terminated in a basement, in a walkout basement, in a pit, or in an alcove, the well casing pipe shall extend above grade as follows:

NR 812.42(7)(a)1. 1. Low capacity wells, except school and wastewater treatment plant wells, constructed before February 1, 1991 shall terminate at least 8 inches above established ground grade,

NR 812.42(7)(a)2. 2. High capacity, school and wastewater treatment plant wells shall terminate at least 12 inches above established ground grade, and

NR 812.42(7)(a)3. 3. All wells constructed on or after February 1, 1991 shall terminate at least 12 inches above established ground grade.

NR 812.42(7)(a)4. 4. All wells located in a floodplain shall extend at least 2 feet above the regional flood elevation for the well site.