(h) Street elbow method.
As depicted in figure 18, a small diameter hole is cut through the wall of the well casing pipe near the bottom of the string of well casing pipe. A street elbow is welded watertight through this hole. The male end of the street elbow extends out into the annular space. A ball check valve is threaded into the female end of the street elbow inside the well casing pipe. The top threads on the check valve are "left-handed". A string of conductor (tremie) pipe is threaded into the top of the check valve. The entire string of well casing pipe and conductor pipe are set to the bottom of the upper enlarged drillhole. The grout is pumped down through the conductor pipe and up into the annular space. The grout must flow at the surface with the same consistency as the grout entering the conductor pipe. Immediately following grouting, the conductor pipe is screwed out of the left-hand thread of the check valve and removed. The check valve prevents the grout from moving back inside the well casing pipe. After the grout has set, the drill stem is lowered to the bottom of the inside of the well casing pipe to knock the street elbow off the well casing pipe before well construction continues.
(4) Sodium bentonite water slurry placement methods.
When neat cement grout is not required in Tables I to IV and is not to be used, the annular space between any upper enlarged drillhole and the well casing pipe shall be sealed as follows:
When percussion methods are used, following completion of the driving of the well casing pipe, a clay or sodium bentonite and cuttings slurry with a mud weight of at least 11 pounds per gallon shall be placed to permanently fill and seal the annular space. Any subsidence shall be made up. If the upper enlarged drillhole extends below the 40-foot depth, the slurry shall be placed with a conductor pipe.
When rotary methods are used, after the upper enlarged drillhole has been completed by circulating drilling mud, the slurry coming out the top of the annular space shall have a mud weight of at least 11 pounds per gallon before the well casing pipe is set in the drillhole. Any subsidence of the drilling mud and cuttings in the annular space shall be made up. The annular space shall remain filled and sealed up to the ground surface. The rotary method of circulating drilling mud during construction described in this paragraph is an approved pressure method for placing sodium bentonite slurry or drilling mud and cuttings and shall be used when required in Tables I to IV and ss. NR 812.13
NR 812.20 History
Cr. Register, January, 1991, No. 421
, eff. 2-1-91; am. (3) (c), (4) (a) and (b), Register, September, 1994, No. 465
, eff. 10-1-94.
Only new steel or thermoplastic well casing pipe as specified in s. NR 812.17
may be used for liner pipe.
(1) Liners installed to correct contaminated water supplies, to line-off the vertical zone of contamination, or to prevent cross-migration between aquifers.
Liner pipe installed in a well with water containing contaminant levels exceeding the drinking water standards of s. NR 812.06
, except turbidity, may be either steel or thermoplastic pipe and shall meet the specifications of s. NR 812.17
and have a nominal diameter at least 2 inches smaller than the nominal diameter of the permanent well casing pipe or the diameter of the drillhole. If the liner pipe has threaded and coupled joints the outside diameter of the couplings shall be 2 inches smaller in diameter than the nominal diameter of the original well casing pipe or the diameter of the drillhole.
The liner pipe shall have a set of at least 3 centering guides at least every 40 feet and they shall be installed so as to not restrict the flow of grout sealing material. A minimum of 2 sets of guides shall be provided, one at the top and one at the bottom of the liner.
When the liner pipe does not extend to the bottom of the well, a flange or approved packer shall be provided at the bottom of the liner between the outside of the liner and the inside of the drillhole or the inside of the well casing pipe, or the liner shall rest on backfill material to be later drilled or bailed out.
The liner pipe should extend to the ground surface but shall extend at least to the bottom of the pitless adapter when one is used.
The liner pipe shall be completely sealed in place from the bottom of the liner to the top of the liner with neat cement grout using an approved pressure method according to the grouting requirements of s. NR 812.20
. If the liner pipe is thermoplastic, the cement grout thickness may not exceed 1-1/2 inches. The liner shall be supported until the grout has set.
Sealing a drillhole with neat cement grout or concrete and subsequently drilling through this material may not be used to reconstruct a well with water containing contaminate levels exceeding the drinking water standards of s. NR 812.06
, except turbidity.
Liners may only be used to reconstruct existing wells cased with stove pipe casing if:
The stove pipe casing is removed and the drillhole is maintained at full diameter before the liner pipe is set and grouted in place, or
The existing stove pipe casing and drillhole is completely clear of obstructions to the depth of liner pipe setting.
(2) Liners installed for caving or sloughing protection, for a non-health-related water quality problem or for a turbidity problem. NR 812.21(2)(a)(a)
A liner pipe shall be installed when the following conditions exist:
A caving or sloughing formation is encountered in drilling or subsequent to well completion and causes interference with the proper functioning of the well or pumping equipment; or
The well produces turbid water or pumps sand after unsuccessful attempts at redevelopment.
Liner pipe used only to seal off a caving or sloughing zone, for a non-health-related water quality problem or to prevent turbid water may be either steel or thermoplastic meeting the requirements of s. NR 812.17
. Steel liner pipe may have a lesser wall thickness than is required in Table V for the diameter of well casing pipe but shall have a wall thickness of at least 0.216 inches. When thermoplastic pipe is used and is sealed in place with cement grout, the grout thickness may not exceed 1-1/2 inches.
Liner pipe installed for the reasons cited in par. (b)
may have the largest practical diameter allowing installation in the well.
The liner pipe shall extend at least 10 feet above the static water level or packers shall be installed far enough above and below the caving zone to prevent further entrance of material into the well. When the liner pipe does not extend to the bottom of the well, the liner pipe shall be supported on the bottom and top with a pipe flange or packer installed between the outside of the liner and the inside of the drillhole.
Sealing a drillhole with neat cement grout or concrete grout and subsequently drilling through the hardened grout may be used to reconstruct a well with water containing contaminant levels not exceeding the drinking water standards of s. NR 812.06
for non-health-related water quality problems or for turbidity problems.
NR 812.21 History
Cr. Register, January, 1991, No. 421
, eff. 2-1-91; am. (intro), (1) (d), (2) (b), (c) and (e), Register, September, 1994, No. 465
, eff. 10-1-94.
All wells shall be developed until the water is practicably clear and free of sand by one of, or a combination or modification of, the following methods:
(a) Mechanical surging.
A valved or solid plunger surge block may be used to create a surging action in the well. Accumulated material shall be removed periodically. A bailer may be used as the surge block but is usually not as effective.
(b) Air surging.
An air compressor and piping may be used to create the surging and jetting action in the well. Water in the well shall be alternately brought to the surface by air lift pumping and allowed to drop back down the well to static condition by shutting the air off. This may be performed with an air-rotary drilling rig and drill stem.
Continuous overpumping at a rate of at least 1 and 1/2 times the design capacity of the well or interrupted overpumping in conjunction with water line drainback to the well in 5-minute cycles may be used. Overpumping alone without a drainback provision or other surging method may not be used to develop screened wells.
(d) Hydraulic jetting.
A nozzled jetting tool may be used to deliver water at high pressure and velocity to the zone being developed in conjunction with pumping the well.
Use the same technique as hydraulic jetting described in par. (d)
except with the use of air rather than water.
NR 812.22(2)(a)(a) Redevelopment.
The methods described for development in sub. (1)
may be used to redevelop a well.
Noncontinuous chemical treatment of a well, except for batch chlorination, shall be conducted under the supervision of a licensed well driller or a Wisconsin registered professional engineer. Acidation of a well shall be done with approved materials 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.
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 in subd. 1.
(c) Physical conditioning.
Wells may be physically conditioned by:
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. The work shall be performed under the supervision of a well driller by a blaster certified by department of safety and professional services according to the requirements of ch. SPS 307
. The well driller shall submit a report of results of the blasting within 30 days following blasting on a well construction report form.
Hydraulic fracturing or hydrofracturing of an aquifer by injecting potable chlorinated water into a crystalline bedrock formation well under high pressures great enough to separate the aquifer along bedding planes, joints and fractures 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 may only be performed under the supervision of a 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 in limestone or dolomite formations may be undertaken only with prior department notification. The well driller shall submit a report on a well construction report form to the department of the results of the hydrofracturing within 30 days following completion.
(3) Well pump test.
The well driller or well constructor shall conduct a pump test using the well driller's, the well constructor's or the well owner's pump for each new or reconstructed well to determine the stable yield in gallons per minute, and the water level drawdown. A pump test may be conducted using air-rotary equipment. For flowing wells, the flow rate may be measured using an orifice plate with manometer or equivalent. The static water level and drawdown shall be measured in a stilling pipe when the flow is not adequate for user needs.
NR 812.22 Note
Note: A stable pumping water level may not be possible in wells completed in crystalline bedrock.
(4) Well disinfection and batch chlorination.
Wells shall be thoroughly disinfected following completion of construction or reconstruction using a chlorine solution such as a sodium or calcium hypochlorite solution. Chlorine compounds having special additives shall not be used.
The disinfectant shall be dispersed throughout the entire water column in the well. The disinfectant shall also be brought into contact with the inside of the well casing pipe above the static water level.
The disinfectant shall remain in the well for at least 2 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.
A chlorine solution with a minimum of 100 mg/l of chlorine shall be used to disinfect wells and well drilling equipment.
For batch chlorination, the entire water system shall be thoroughly disinfected with a chlorine solution having a concentration of at least 500 mg/1 prepared according to Table B. The volume of chlorine solution shall be equal to or greater than the volume of water standing in the well. The chlorine solution shall be brought into contact with the entire inside of the well casing pipe by continuous circulation from the water system. A contact time of at least 12 hours shall be provided for the disinfectant.
Wells shall be thoroughly flushed after disinfection. Flushing and disinfection procedures may be performed simultaneously except for batch chlorination procedures when they shall be done separately.
The well driller or his or her agent or the well constructor of a driven point well shall collect a water sample using the well driller's, well constructor's or well owner's pump, air-lift equipment or with a bailer from any new or newly reconstructed, redeveloped or reconditioned potable well. If the well driller uses the well owner as an agent to collect the water sample, the well driller shall provide the owner with an appropriate sample bottle and laboratory form. A sample shall also be collected following any repair work that involves entry of the well for the purpose of installing, replacing or repairing equipment located within the well. The sample shall be collected for coliform bacteriological analysis within 30 days following completion of the well or following completion of rehabilitation or repair. The well is completed when all operations that require the use of drilling, driving or annular space sealing equipment have been completed. If the well driller or well constructor is also the pump installer, the water sample may be collected following completion, disinfection and flushing of the pump installation. A well driller or well constructor does not have to be licensed as a pump installer to install a test pump for well development and sampling.
The water sample shall be submitted to the Wisconsin state laboratory of hygiene or to a laboratory certified by the department of agriculture, trade and consumer protection under ch. ATCP 77
to do coliform bacteriological examination of water providing the laboratory has an agreement with the department for sending water sample reports to the department within 30 days after completion of the analysis. The department recommends that the sample also be analyzed for nitrate. The certified laboratory shall send a copy of each water sample analysis report to the department on a form prescribed by the department.
The well driller, well constructor or pump installer shall provide the well owner or the owner's agent with a copy of the laboratory bacteriological analysis report within 10 days of the well driller's, well constructor's or pump installer's receipt of the laboratory bacteriological analysis report.
The well driller who contracted to construct the well, the well driller who actually constructed the well, or the well constructor shall submit an original well construction report to the department and to the owner within 30 days following the day the well was completed or reconstructed. A well construction report shall be submitted for any well deepening. A well is completed when all operations that require the use of drilling, driving or annular space sealing equipment have been completed. A well construction report is not required for well screen replacement if the screen is set to a depth not exceeding 5 feet above or below the original screen depth setting. A well construction report is also not required for blasting or hydrofracturing when done within 30 days after original completion of the well construction. Such work shall be reported on the original well construction report or on a copy of the original report. An accurate and complete well construction report shall be submitted on a form prescribed by the department to:
NR 812.22 Note
Note: The department's address is P.O. Box 7921, Madison, WI 53707
Well construction reports returned to the well driller or well constructor for completion or when compliance with the construction requirements of this chapter is questionable shall be resubmitted to the department within 15 days of receipt. The original well construction report shall be resubmitted. Dry drillholes or unsuccessful wells drilled in conjunction with well construction and not immediately abandoned shall be reported on a well construction report and on a well abandonment report form. The well driller or well constructor shall ensure proper abandonment according to s. NR 812.26
, of any drillhole constructed by the well driller or well constructor that is not intended to provide water.
(8) Well conditioning reports.
The well driller, well constructor or project supervisor shall, within 30 days following any well blasting, hydrofracturing or chemical treatment operation conducted under an approval, submit a report to the department detailing the methods used and results achieved.
NR 812.22 History
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
Driven point (sand point) wells.
Driven point wells are typically constructed in sandy soil areas with a high water table. Groundwater in these areas is very susceptible to contamination. Driven point wells shall be constructed to meet the following requirements:
The well shall be located on the highest point on the premises consistent with the general layout and surroundings, if reasonably possible, as specified in s. NR 812.08 (1) (b)
and as far removed as possible from all potential contamination sources, but at least as far as the minimum separating distances required in s. NR 812.08
Well casing pipe used for driven point wells shall meet the requirements of s. NR 812.17
The well drive pipe shall extend 12 inches above the established ground surface, pump house or building floor, or above any concrete or asphalt platform surrounding the well at or above the established ground surface. In a floodfringe, the top of the well drive pipe shall terminate at least 2 feet above the regional flood elevation. Driven point wells may not be constructed in a floodway.
The diameter of the driven point well shall be selected and the expected depth considered so that the pump installation will meet the requirements of this chapter. For static water levels deeper than the lift of a shallow well pump, approximately 20 feet, a well drive pipe diameter sufficient to accommodate the packer-jet assembly in the well shall be selected to allow pumping with a deep well pump. When the requirements of sub. (5)
are met and when the use of a shallow well pump is possible the minimum diameter of the driven point well is 1-¼ inches.
The well drive pipe, not including the screen, of a driven point well shall extend to a depth of 25 feet or to a depth 10 feet below the static water level in the well, whichever is greater.
Driven point wells, when protected against freezing, may be installed with a protective outer sleeve below frost depth as shown in figure 18a. When installed in this manner, the top of the annular space between the well and the protective sleeve shall be sealed watertight with a sanitary well seal.
When a well drive pipe is removed to replace a well screen, the replacement is new well construction and shall meet all the requirements of this chapter.
Screen selection for driven point wells is optional, except that screens having any lead content may not be used.
Starter drillholes not exceeding 10 feet deep may be constructed to facilitate driving the pipe. If a starter drillhole is constructed the annular space shall be sealed according to the percussion drilling methods specified in s. NR 812.13 (2)
following completion. An attempt shall be made to remove any temporary outer casing. If possible, the temporary outer casing shall be removed.
NR 812.23 History
Cr. Register, January, 1991, No. 421
, eff. 2-1-91; am. (4) and (6), Register, September, 1994, No. 465
, eff. 10-1-94.
Dug type well design and construction.
Because dug wells often pose a safety hazard and a threat to groundwater quality, the department discourages their construction. Dug wells may not be constructed without written approval. When approved, they shall be constructed to meet the following requirements:
(1) Curbing wall.
The curbing wall of a dug well shall be concrete or steel and watertight to a depth of at least 2 feet below the vertical zone of contamination, but not less than 25 feet below the established ground surface. The curbing wall through the intake area shall be of adequate strength to withstand any external pressure to which it may be subjected and shall be seated firmly enough to prevent settling.
(a) Concrete curbing wall.
The curbing wall shall be circular and at least 6 inches thick with concrete placed so as to be free from voids. The concrete mixture shall conform to provisions of s. NR 812.20 (1)
. The curbing wall shall be reinforced vertically and horizontally with 3/8-inch rods on 12-inch centers. Rods shall lap 12 inches and be staggered, but the lap may not occur at construction joints. The curbing wall should be poured in one operation. There may not be a construction joint within 10 feet of the ground surface. Construction joints shall be left rough and shall be washed and brushed with neat cement grout before pouring of concrete is continued, if possible.
- See PDF for diagram
Figure 18a. Hand pump installation protected from frost with outer casing and drainback mechanism.
(b) Steel curbing wall.
A steel curbing wall shall have a thickness of at least 1/4 inch thick and assembled with welded joints.
(c) Curbing wall installation.
The curbing wall shall be constructed at the surface and carried down by excavating from the interior. If wood forms are used on the exterior of a concrete curbing wall, they shall be removed before the curbing is lowered. Exterior wood forms may not be used below the ground surface. Metal forms may be left in place.
(d) Annular opening.
The opening between the face of the excavation and the curbing wall through the vertical zone of contamination shall be filled with clean clay slurry.
(e) Upper terminal.
The curbing wall shall extend at least 12 inches above the established ground surface. The ground shall be graded up around the curbing wall to a height of at least 6 inches above the ground surface so surface water will flow away from the well.
(2) Dug well cover.
The cover of the well curbing shall be made of reinforced watertight concrete at least 5 inches thick and of a diameter large enough to overlap the curbing wall by at least 2 inches. A drip groove shall be provided within one inch of the outer edge of the underside of the cover. The cover shall be free from joints. A pump installation access sleeve comprising a section of steel well casing pipe conforming to s. NR 812.17 (2)
shall be installed in the cover at the time of pouring the concrete to fabricate the cover and shall terminate at least 12 inches above the top of the cover. The top of the cover shall be sloped to drain away from the access sleeve. A manhole, if installed, shall be provided with a 4-inch high metal curb which shall be equipped with an overlapping metal cover, the sides of which extend downward at least 1-1/2 inches. A tight joint shall be provided between the top of the curbing and the cover using a nontoxic plastic sealing compound. The manhole cover shall be locked or bolted in place to prevent entrance of water and to be safe from vandalism and accidents.
(3) Equipment location.
All pump piping, including the pump discharge or suction pipe, shall extend watertight through an access sleeve in the dug well cover.
NR 812.24 History
Cr. Register, January, 1991, No. 421
, eff. 2-1-91.
The unprotected nature of springs subjects them to wide fluctuations in water quality. The department discourages their use as a source of potable water.
Springs vary from the standpoint of sources, locations, surrounding land uses and elevation. Each spring considered for use as a source of potable water shall be evaluated by the department prior to use as a potable source. Development of a spring as a source of potable water will be approved only after a department evaluation and approval. The placement or driving of a casing pipe into an undeveloped spring in a location easily accessible to the public regardless of the intended use of the spring water is prohibited.
Water supplies using springs as a source of water shall meet the following requirements:
The area surrounding the spring to a distance of at least 100 feet laterally and 50 feet downgrade and the area immediately upslope from the spring to a point beyond the crest of the slope or to a distance of at least 200 feet upslope from the spring, may not be used for any activity, including human habitation, which may contaminate the spring.