NR 811.12(13)(a)4.4. When a well is to be hydrofractured within 100 feet of any existing bedrock well, the well driller shall notify the existing well owner or owners and the department’s regional drinking water staff person of the forthcoming hydrofracturing operation at least 48 hours prior to the commencement of the hydrofracturing operation.
NR 811.12(13)(a)5.5. The upper packer may not be placed at a depth closer than 20 feet below the bottom of the casing.
NR 811.12(13)(a)6.6. Following the completion of the hydrofracturing procedure, the well shall be thoroughly disinfected, pumped to waste, and safe bacteriological water samples shall be collected according to the requirements of s. NR 810.09 (4).
NR 811.12(13)(a)7.7. The owner or an authorized representative shall submit a written report to the department within 30 days of the date of completion of the hydrofracturing and subsequent pumping of the well that includes the static and pumping water levels, gallon per minute pumping rate and specific capacity of the well both before and after the hydrofracturing, and the results of any testing for chemical or physical properties for which the well may have been hydrofractured, if applicable.
NR 811.12(13)(a)8.8. All material released from the casings, screen, and borehole as part of the rehabilitation shall be removed from the well.
NR 811.12(13)(b)(b) Impulse generation. Impulse generation procedures shall meet the following requirements:
NR 811.12(13)(b)1.1. The department’s regional drinking water staff person shall be given at least 48 hours notice prior to the date and time of the impulse generation work.
NR 811.12(13)(b)2.2. Impulse generation procedures shall be performed by or under the supervision of a licensed well driller.
NR 811.12(13)(b)3.3. A report shall be submitted to the department that identifies the impulse method to be used, the means of generating the impulse, the number of passes, the depths in the open drillhole or well screen that the procedure will be started and stopped, the psi strength of each impulse, and the number of impulses per foot. The report shall also include information on all the gases to be used and details of any chemical addition to be performed along with the impulse generation procedures, including the chemicals to be used, the reason for using the chemicals, the strength of each chemical as applied, the means to be used to inject the chemicals, and how the chemicals will be neutralized and disposed of. All chemicals used shall have NSF/ANSI Standard 60 approved for use in potable water as required per s. NR 810.09 (1) (c).
NR 811.12(13)(b)4.4. Impulse strength shall be maintained low enough to prevent structural damage to well casings, grout, and screens.
NR 811.12(13)(b)5.5. Following the completion of the impulse generation work, the well shall be thoroughly disinfected, pumped to waste, and safe bacteriological water samples shall be collected according to the requirements of s. NR 810.09 (4).
NR 811.12(13)(b)6.6. The owner or an authorized representative shall submit a written report to the department within 30 days of the date of completion of the impulse generation and subsequent pumping of the well that includes the static and pumping water levels, gallon per minute pumping rate and specific capacity of the well both before and after the impulse generation, and the results of any testing for chemical or physical properties for which the well may have been treated with impulse generation, if applicable.
NR 811.12(13)(b)7.7. All material released from the casings, screen, and borehole as part of the rehabilitation shall be removed from the well.
NR 811.12(14)(14)Grouting requirements. The water system owner shall give notice to the department’s regional drinking water staff person at least 48 hours prior to the date and time of the well grouting work. In addition, all of the following requirements shall be met:
NR 811.12(14)(a)(a) Grout types and specifications.
NR 811.12(14)(a)1.1. Neat cement grout shall be labeled as ASTM C150, Type I, ASTM C595, Type IL, or API-10A, Class A Portland cement and water from a known bacteriologically safe and uncontaminated source, with not more than 6 gallons of water per 94-pound sack of cement. A mud balance shall be used to measure the grout density. Additives, including bentonite to increase fluidity, reduce shrinkage, or control time of set may be used only with prior department approval. No more than 4.7 pounds of powdered bentonite, a maximum of 5 percent, may be added to each 94-pound sack of cement. When bentonite is added, the volume of water shall be increased. When bentonite is added, a pressurized mud balance shall be used to measure the grout density. Bentonite mixed with neat cement grout shall comply with Table 2.
- See PDF for table PDF
(Bentonite table information provided by the Halliburton Co.)
NR 811.12(14)(a)2.2. Sand cement grout may be used for annular openings greater than 3 inches. The mixture may not exceed 2 parts by weight of sand to one part of ASTM C150, Type 1 or API-10A, Class A Portland cement and not more than 6 gallons of water from a known bacteriologically safe and uncontaminated source to each 94-pound sack of cement.
NR 811.12(14)(a)3.3. Concrete grout may be used for annular openings greater than 6 inches. The concrete shall contain not less than 6 sacks of cement per cubic yard and not more than 6 gallons of water from a known bacteriologically safe uncontaminated source to each 94-pound sack of cement. The gravel size may not exceed 0.75 inch. The volumetric ratio of either gravel or sand to cement may not exceed 2.5 parts to one part. Wisconsin department of transportation grade A concrete is also acceptable.
NR 811.12(14)(b)(b) Grouting procedures.
NR 811.12(14)(b)1.1. All grout shall be placed from the bottom of the annular opening to the surface in one continuous operation. Grouting methods that involve forcing a measured quantity of grout down the inner casing by a plug, such as the Halliburton method, shall not be used. When a conductor pipe in the annular opening is used, the conductor pipe shall meet the material requirements of subd. 8. and shall be submerged in the grout during the entire operation. For grout depths in excess of 100 feet, a pump shall be used to inject the grout.
NR 811.12(14)(b)2.2. A sufficient annular opening shall be provided to permit a minimum of 1.5 inches of grout around the protective casing, grouted liner pipe, or outer casing when it is intended to grout the outer casing in place, including couplings, if used.
NR 811.12(14)(b)3.3. Any materials used as drilling aids shall be removed from the annular opening prior to grouting.
NR 811.12(14)(b)4.4. Prior to grouting through creviced formations, bentonite or similar approved materials shall be added to the annular opening in the manner indicated for grouting and circulated until the bentonite or other approved material flows to the ground surface.
NR 811.12(14)(b)5.5. Grout shall be allowed to overflow from the annular opening until such time as the density is the same as that of the grout being placed. The specifications shall outline the method to be used to check the grout density and equipment shall be available on site to determine grout density.
NR 811.12(14)(b)6.6. Standby grouting equipment for grouting annular openings, including a backup grout pump and tremie pipe meeting the material requirements of subd. 8., shall be on site during the grouting of all wells.
NR 811.12(14)(b)7.7. The grout level shall be maintained above the bottom of any outer casing during the withdrawal procedure.
NR 811.12(14)(b)8.8. Grout conductor, or tremie, pipes shall be metal pipe or a rubber-covered, fiber or steel braided, reinforced hose with a minimum pressure rating of 300 psi. Plastic pipe, including PVC pipe, shall not be used as a grout conductor pipe.