(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.
The spring outlet shall be at least 2 feet above the regional flood water level.
The spring water shall flow from an underground source having enough overburden so that a horizontal plane extending back into the slope of the hill 100 feet will be at least 25 feet below the ground surface.
The spring shall meet the distance separation requirements from potential contamination sources as specified in s. NR 812.08
The spring outlet shall be completely protected against the entrance of surface water runoff, insects, rodents and contaminants.
As depicted in figure 19, a poured concrete box structure reinforced with 3/8 inch bars each way shall be constructed to house the spring outlet. This spring box shall meet the following minimum construction requirements:
Five-inch thick walls and roof with no cracks or holes, except for the overflow pipe in the wall and the access openings in the roof,
A 20-inch diameter round, or a 20-inch square access opening in the roof with a 4-inch thick concrete curbing wall that extends 8 inches above the roof,
An overlapping, tight-fitting, shoebox-type cover with 4-inch high skirted sides, constructed from welded sheet steel, to cover the access opening,
A 4-inch diameter or larger steel pipe sleeve, comprising a section of well casing pipe conforming to s. NR 812.17 (2)
extending through the roof to a point at least 12 inches above the roof for the passage of the pump suction and discharge pipe or a service pipe from a pressure tank. The steel pipe sleeve shall be provided with a one-piece top plate sanitary well seal, and
An overflow pipe with a screened outlet that terminates at least 2 pipe diameters above the maximum water level at its discharge point.
Buried discharge pipe from the spring, from a pump or any service pipes from a pressure tank shall be maintained under positive gauge pressure at all times.
When the pump, pressure tank, or both, are installed above the spring outlet box, an insulated housing shall be provided for frost protection.
The spring shall be capable of producing water that is continuously free from coliform bacterial contamination and free of contaminants in excess of the drinking water standards in s. NR 812.06
NR 812.25 History
Cr. Register, January, 1991, No. 421
, eff. 2-1-91; am. (1) and (2) (a) 1., Register, September, 1994, No. 465
, eff. 10-1-94.
Well and drillhole abandonment. NR 812.26(1)(1)
The permanent abandonment of unused or contaminated wells or drillholes and noncomplying water systems is an important step in the protection of the local groundwater quality. Wells, especially those with structural defects, may act as conduits for the vertical movement of contamination from or near the ground surface to the groundwater or from one aquifer to another.
The owner shall permanently abandon a well or a drillhole under any of the following conditions unless the department approves the continued use of the well or drillhole:
The well water is contaminated with biological agents, bacteriological, viral or parasitic, and 3 attempts at batch chlorination fail to eliminate the problem,
The well or drillhole construction or well location does not comply with the minimum standards of this chapter, or
The well or drillhole has been taken out of service or has not been used for 3 or more years and is not needed by the owner in the immediate future as a source of water for human consumption, sanitary purposes, commercial use or for stock watering. As an alternative, the owner may temporarily abandon the well according to sub. (4)
The department may require the owner to abandon a well or drillhole under the following conditions:
The well water is contaminated with a substance in exceedence of the drinking water standards specified in s. NR 812.06
The well was not constructed by the well owner or by a licensed well driller, or
A well driller or well constructor shall abandon a well or drillhole, which he or she constructed or reconstructed, under the following conditions except when the department approves the continued use of the well or drillhole:
The well construction or well location does not comply with the minimum standards of this chapter at the time the well was constructed, or
The drillhole is an unsuccessful attempt to construct or reconstruct a well.
The department may require any person who has abandoned a well not in compliance with this section to return and take corrective action so that the well is abandoned by him or her in a complying manner.
(3) Requirements for wells removed from service.
Any well or drillhole removed from service shall be properly abandoned according to the criteria and procedures in this section except as exempted by s. NR 123.23 (3) (c)
or by the department. Any well or drillhole removed from service shall be properly abandoned prior to any demolition or construction work on the property. A well driller or well constructor who removes a well from service shall inform the well owner that the department requires that any well removed from service be permanently abandoned according to the requirements of this section. A well driller or well constructor shall report any well he or she removes from service on the well construction report for any replacement well he or she constructs on the property.
(4) Temporary abandonment requirements.
Any well to be temporarily abandoned shall meet the minimum requirements of this chapter and shall be able to produce a bacteriological safe water sample if the well is potable. When a well is temporarily abandoned, the owner shall notify the department. To temporarily abandon a well, the top of the well casing pipe shall be sealed with a watertight cap threaded onto the top of the well casing pipe or drive pipe or with a steel plate welded watertight to the top of the well casing pipe. If the pump or well seal is watertight, the pump may be left in place.
(5) Well or drillhole casing pipe.
The well casing pipe or drillhole casing pipe shall be left in place when a well or drillhole is permanently abandoned, except under par. (a)
and only if the well or drillhole is sealed as the well casing pipe is pulled; and if any concrete or neat cement grout that settles in the drillhole is replaced.
The well casing pipe may be removed from a dry drillhole and reinstalled in a well on the same property within 30 days of original drillhole construction,
The well casing pipe may be removed from a well or drillhole as part of reconstruction ordered or requested by the department. The well casing pipe may only be reinstalled on the same property if the reconstruction takes place within 120 days of the original construction,
The well casing pipe may be removed from a dewatering well or a drillhole. Such well casing pipe may only be reused for dewatering wells.
The well casing pipe may be removed from a recently constructed well or drillhole and reused if the well casing pipe is inspected and approved for reuse by a department representative.
The well casing pipe may be removed from a well or a drillhole if the well or drillhole is completely filled with the abandonment material before the well casing pipe is pulled.
All debris, pumps, piping, ungrouted liner pipe and any other obstruction known to be in the well or drillhole shall be removed if possible before the well or drillhole is permanently abandoned.
In a badly fractured or highly permeable geologic formation sodium bentonite drilling mud may be circulated in the drillhole or in the well prior to permanent abandonment procedures are undertaken.
The sealing material to be used in permanently abandoning a well or drillhole between 2-½ inches and 30 inches in diameter shall be placed through a conductor (tremie) pipe or by means of a dump bailer except when approved chipped bentonite is used. Conductor (tremie) pipe used shall be any of the following:
Rubber-covered hose reinforced with braided fiber or steel and rated for at least 300 psi, or
For use at depths less than 100 feet, thermoplastic pipe rated for at least 100 psi including:
The bottom end of the conductor pipe shall be submerged in the sealing material at all times. A conductor pipe shall also be used for wells or drillholes greater than 30 inches in diameter if water remains trapped above the sealing material as it is applied.
The flow from a flowing well or drillhole shall be reduced as much as possible with a packer, by extending the well casing pipe, or by other approved means including those depicted in figures 20 to 22 before it is permanently abandoned.
Abandonment of wells or drillholes with inadequate grouting or sealing of the annular space outside the well casing pipe shall be performed to ensure complete sealing of the annular space. Techniques are situation dependent and may include reaming a new annular space outside the well casing pipe, use of pressure grouting methods or perforation of the well casing pipe.
The well casing pipe and abandonment material may be terminated as much as 3 feet below the ground surface or to a depth below any future building foundation at the time of permanent abandonment.
(7) Permanent abandonment methods and materials. NR 812.26(7)(a)(a) Methods.
Once obstructions have been removed from a well or a drillhole, it shall be permanently abandoned by filling, from the bottom up, with the materials specified in this paragraph and Table C with the use of a conductor (tremie) pipe, except where the use of a conductor pipe is specifically exempted, by using one of the following methods:
Drilled wells and drillholes or driven-point wells 2-1/2 inches or larger in diameter in unconsolidated formations shall be filled with neat cement grout, concrete (sand-cement) grout, concrete, or with clay or a sodium bentonite-water-sand slurry with a mud weight of at least 11 pounds per gallon or as in subd. 3.
When clay or sodium bentonite-water-sand slurry is used, the slurry shall have a sand content of at least 10%, but not more than 25% by volume of the slurry and at least the top 5 feet shall be filled with neat cement grout, concrete (sand-cement) grout, concrete or approved chipped bentonite.
Driven-point wells and drillholes less than or equal to 2-½ inches in diameter completed in unconsolidated formations shall be filled with neat cement grout which may be poured or pumped down the drive pipe or drillhole. The use of a conductor pipe is not required. The drive pipe and screen may be removed before placement of the grout if the total well depth is 25 feet or less.
2. `Filling wells and drillholes'.
Wells and drillholes completed in bedrock formations shall be completely filled from the bottom up with neat cement grout, concrete grout, concrete or approved bentonite chips as provided in subd. 3.
As an alternative for uncontaminated bedrock wells and drillholes deeper than 250 feet, chlorinated, sand-free pea gravel may be used to fill the well or drillhole from the bottom up to the 250-foot depth provided that for wells or drillholes extending through more than one geologic formation, a neat cement grout, concrete or bentonite chip plug at least 40 feet thick is placed at the contact surface between the adjacent geologic formations. When pea gravel is used for this alternative, it may be poured without the use of a conductor pipe provided the well is sounded at 50-foot intervals to ensure that bridging of the gravel in the well does not occur.
3. `Use of bentonite chips'.
Approved slow-hydrating bentonite chips may be used to fill both unconsolidated formation and bedrock wells and drillholes by using instructions provided by the department with the following restrictions:
For wells and drillholes 4-inch diameter and larger the total depth may not be deeper than 500 feet and the number of feet of standing water in the well or drillhole may not be more than 350 feet. As an alternative for uncontaminated wells and drillholes deeper than 250 feet, chlorinated, sand-free pea gravel may be used to fill the well or drillhole from the bottom up to the 250-foot depth provided that for wells or drillholes extending through more than one geologic formation, a bentonite chip plug at least 40 feet thick is placed at the contact surfaces between the adjacent geologic formations. When pea gravel is used for this alternative, it may be poured without the use of a conductor pipe provided the well is sounded at 50-foot intervals to ensure that bridging of the gravel in the well does not occur.
Not allowed for any well or drillhole filled with drilling mud or bentonite slurry.
Dug or bored wells shall have the cover removed and the top 5 feet of curbing or concrete wall removed. Rock curbing may be caved into the drillhole as the well is being sealed only if done in a manner to prevent bridging. The well shall be filled using clean clay or silt, clean native soil, approved chipped bentonite, concrete, concrete (sand-cement) grout or neat cement grout if constructed in unconsolidated formations.
Dug wells and drillholes constructed partially or completely into bedrock shall be filled with neat cement grout, concrete (sand-cement) grout, concrete or approved chipped bentonite to a point at least 2 feet above the top of the bedrock. The remainder of the well or drillhole may be abandoned using any of the materials listed in subd. 4. a.
Dug or bored wells 18 inches in diameter and smaller shall be filled by means of a conductor (tremie) pipe, except when bentonite chips are used as specified in subd. 3.
or when clean clay or silt or clean native soil is used and the dug or bored well is 25 feet deep or less.
5. `Well pits'.
When a well terminating in a pit is abandoned, the pit shall also be abandoned except when the pit is a subsurface pumproom (alcove) adjoining a basement. Pits shall be abandoned by perforating the floor, knocking out one wall and filling the pit with clean native soil less permeable than the soil surrounding the pit.
6. `Non-pressure conduits'.
When wells having non-pressure conduits are abandoned and filled, the basement end of the conduit shall be permanently sealed with a watertight cap or seal.
- See PDF for diagram
Figure 20. Inflatable packer method for permanently abandoning a flowing well.
- See PDF for diagram
Figure 21. Method for reducing flow in a flowing well by extending the well casing pipe before permanently abandoning the well.
- See PDF for diagram
Figure 22. Method for reducing flow in a flowing well by first adding gravel to the bottom before permanently abandoning the well.