Current through Register Vol. 56, No. 18, September 16, 2024
(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.