N.J. Admin. Code § 7:9D-2.5

Current through Register Vol. 56, No. 21, November 4, 2024

Section 7:9D-2.5 - Requirements for the installation of Category 5, 6, and 7 wells

(a) In addition to the well permitting requirements in N.J.A.C. 7:9D-1 and the well construction requirements in N.J.A.C. 7:9D-2.2, the following requirements apply to all Category 5 vertical closed loop geothermal wells:

1. The vertical closed loop geothermal well shall be constructed using a borehole with sufficient diameter to allow for proper grouting;

2. The tremie or grout pipe shall be installed to the total drilled depth upon completion of the borehole. The entire annular space between the closed loop and the uncased borehole shall be tremie pressure grouted in accordance with N.J.A.C. 7:9D-2.9 and 2.10 using the following materials:

i. Sodium-based bentonite, cement-based geothermal grout in accordance with Table 4 at Appendix A, bentonite-based geothermal grout mixed in accordance with Table 5 at Appendix A and incorporated herein by reference or equal for wells constructed into unconsolidated formations; and

ii. Cement-based geothermal grout or bentonite-based geothermal grout containing a minimum silica sand content of 200 pounds per 50 pounds of bentonite for wells constructed into consolidated formations;

3. The circulating fluids utilized in the closed loop system shall be potable water or an appropriate mixture of potable water with one of the following antifreeze solutions:

i. Calcium Chloride;

ii. Ethanol;

iii. Potassium Acetate;

iv. Potassium Carbonate;

v. Propylene Glycol; or

vi. Sodium Chloride;

4. Pipe material for the underground buried portion of the heat exchanger shall be polyethylene pipe as specified below:

i. 160 psi Polyethylene - All material shall maintain a 1600 psi hydrostatic design basis at 73.4 degrees F per ASTMD-2837-11, and shall be listed in PPI TR4 as a PE3408 piping formulation. The material shall be a high density, polyethylene extrusion compound having a cell classification of PE345434C or PE355434C with a UV stabilizer of C, D or E as specified in ASTM D-3350-10A with the following exception: this material shall exhibit zero failures (FO) when tested for 192 or more hours under ASTM D-1693-08, condition C, as required in ASTM D-3350-10A, incorporated herein by reference, as amended and supplemented;

ii. PEXa crosslinked high density polyethylene piping manufactured in accordance with ASTM F-876 to a Standard Dimension Ratio (SDR) of 9 and rated at 160 psi at 73.4 degrees Fahrenheit per ASTM D-2837, incorporated herein by reference, as amended and supplemented.

5. Buried pipe systems shall be joined so that the resultant assembly is leak-proof using one of the following methods:

i. The heat fusion process in accordance with the pipe manufacturer's specifications;

ii. Those joined using the International Ground Source Heat Pump Association (IGSHPA) approved mechanical stab fittings; or

iii. Polymer electro-fusion fittings and cold-expansion compression-sleeve fittings for the joining of PEXa piping in accordance with IGSHPA and the manufacturer's specifications.

(b) In addition to the well permitting requirements in N.J.A.C. 7:9D-1 and the well construction standards in N.J.A.C. 7:9D-2.2, the following requirements shall apply to all Category 6 dewatering wells or dewatering wellpoints:

1. Any dewatering well or dewatering wellpoint installed pursuant to 7:9D-1.11(g) or that requires an individual or site-wide well permit shall be installed by a New Jersey licensed well driller of the proper class;

2. A dewatering well which penetrates a confined aquifer shall be installed by a New Jersey licensed master, journeyman or journeyman (Class B) well driller and constructed in accordance with the requirements in N.J.A.C. 7:9D-2.2;

3. The owner of the project requiring a dewatering system is responsible for obtaining all other necessary permits and for the hiring of a licensed dewatering well driller or a New Jersey licensed well driller of the proper class to install and properly decommission all dewatering wells or dewatering wellpoints;

4. A permit is required prior to the installation of any dewatering well or dewatering wellpoint in accordance with N.J.A.C. 7:9D-1;

5. The location and construction specifications for dewatering wells shall be as follows:

i. A dewatering well shall be located to facilitate temporary dewatering operations and shall be constructed and maintained to prevent surface flow or any other source of pollution from entering the well;

ii. Temporary erosion control measures shall be employed to reduce erosion caused by groundwater diversion including, but not limited to, berms, dikes, drains, soil stabilization matting, diversion channels, baled hay or straw, silt fences or sedimentation basins. All soil erosion control shall be in accordance with Standards for Soil Erosion and Sediment Control in New Jersey (see 2:90-1.3 );

iii. The owner of the project where dewatering is taking place shall be responsible for the repair or replacement of any potable water well system which becomes contaminated, damaged, has reduced capacity, reduced water quality or is otherwise rendered unusable as a potable water well system as a result of the dewatering operation. All work shall be in accordance with this subchapter and N.J.A.C. 7:10-12, or N.J.A.C. 7:10-11; and

6. The requirements for the installation of dewatering well casings and screens are as follows:

i. The wall thickness of the dewatering well casing shall be selected to withstand the forces exerted on the well casing during both installation and removal;

ii. The dewatering well casing shall extend not less than 12 inches above the working grade of the well, except where the operation is under a vacuum and closed piping is maintained to prevent surface contamination from entering the well;

iii. The top of the dewatering well casing shall be capped with either a sanitary well seal, a metal plate welded into place or a threaded cap from date of installation until it is taken out of service and properly decommissioned. The device shall be constructed so as to prevent pollution or physical injury;

iv. The material used between the borehole and the dewatering well casing shall be clean and free of harmful material. Above grade, the material shall be placed around the well casing in a mound to divert surface waters away from the well casing;

v. When a gravel pack is not used, any annular space between the well casing and the wall of the borehole shall be sealed from the top of the screen or base of the casing pursuant to 7:9D-2.9 and 2.10;

vi. Dewatering well screens shall be sufficiently strong and durable to ensure that they may be removed intact from the dewatering well; and

vii. The screening of a dewatering well in more than one aquifer is prohibited.

(c) In addition to the general well drilling and well permitting requirements in N.J.A.C. 7:9D-1 and 2.2, the construction of all Category 7 wells and boreholes shall be in accordance with the New Jersey Department of Community Affairs, Division of Codes and Standards, Uniform Construction Code at N.J.A.C. 5:23 and the American Society of Mechanical Engineers, Safety Code for Elevators and Escalators at A17.1, and shall meet the following requirements:

1. Wells constructed or boreholes drilled for the installation of elevator shafts or hydraulic cylinders shall be cased, sealed and maintained in a manner to prevent the vertical movement of water as a source of contamination to any aquifer;

2. Casing shall either be driven into an undersized borehole or installed using the oversized borehole method. If the oversized borehole method is used, the borehole shall be at least four inches larger than the casing to be installed;

3. The annular space between the casing and the oversized borehole shall be sealed in accordance with the requirements set forth in 7:9D-2.9 and 2.10; and

4. To prevent any contaminants from entering the groundwater at the bottom of the casing, the bottom of the casing shall be:

i. Permanently capped prior to installation; or

ii. A neat cement plug at least two feet thick shall be installed at the bottom of the casing in accordance with 7:9D-2.9 after it is installed.

N.J. Admin. Code § 7:9D-2.5

Amended by 50 N.J.R. 171(a), effective 1/2/2018