Current through Register No. 40, October 3, 2024
(a) A bedrock
well shall have no less than 20 feet of casing.
(b) A well casing for a bedrock well shall:
(1) Extend above the ground surface:
a. A minimum of 8 inches or, in areas prone
to flooding, to a greater height sufficient to prevent entrance of surface
water into the well; or
b. For a
well that is part of a public water system as defined in
RSA
485:1-a, XV, a minimum of 18
inches.
(2) Have a
secure cover with an o-ring, gasket, or other seal to prevent the entrance of
insects or other foreign matter into the well; and
(3) Be placed to create a seal which prevents
ground water or contaminants from entering the well at the bottom or anywhere
along the length of the casing.
(c) The following techniques shall apply to
well casing placement:
(1) A hole shall be
drilled into the bedrock to a depth sufficient to allow the casing to be
installed to a minimum depth of 10 feet into competent bedrock or to a greater
depth, if necessary to accept the casing and provide a seat for the drive shoe
on the end of the casing;
(2) A
well casing shall be installed to a minimum depth of 10 feet into competent
bedrock;
(3) A drive shoe shall be
used to assist in sealing the casing into the bedrock when steel casing is
used;
(4) When plastic casing is
used the seal shall be created by using a "Jaswell" type seal tip, shale packer
or equal;
(5) A "Jaswell" type seal
tip, shale packer or functionally equivalent equipment may be used on steel
casing if the casing is placed in an open hole cased with a larger diameter
temporary casing to bedrock;
(6)
For a well that requires additional casing, as specified in
We
602.14 and We 602.16, a water well contractor using
cable tool drilling methods may use a "Jaswell" type seal tip, shale packer, or
functionally equivalent equipment;
(7) When cable tool drilling methods are
used, a drive shoe shall not be required if a tapered hole with ledge drillings
is used or the casing is grouted as specified in
We
602.05;
(8) The void area outside the casing shall be
filled with cement grout, bentonite or ledge drillings or cuttings;
and
(9) For a well constructed on a
known active hazardous waste remediation site, petroleum spill remediation
site, or a site with unlined solid waste landfill, as identified in the
department's remediation and initial response spill sites database, the void
area outside the casing shall be filled with cement grout, bentonite grout, or
a cement-bentonite grout mixture to prevent surface water from migrating along
the well casing.
(d) The
above requirements shall not preclude the use of additional protective
measures.
(e) A "Jaswell" type seal
tip, shale packer or functionally equivalent equipment shall not be used to
remedy a failed drive shoe seal, or to remedy an inadequately cased well, in
new well construction.
(f) When
drilling water wells in bedrock using air rotary drilling methods, water shall
be injected into the well on a continuous basis at a rate sufficient to clean
the well and prevent dust production during the drilling process.
(g) Overflow discharge water lines installed
to vent flowing artesian wells shall meet the following standards:
(1) Overflow discharge water lines shall be
equipped with a swing type check valve;
(2) The end of the water line shall be
equipped with a 1/4 inch mesh screen, or woven hardware cloth;
(3) The end of the water line shall be
terminated with an air gap, if practicable. If termination with an air gap is
not practicable, the water line may be terminated in a bed of 3/4 inch or
1 1/2 inch crushed stone; and
(4) Overflow discharge water lines shall not
terminate directly into any surface water of the state.
(h) For wells constructed as part of a public
water system as defined by
RSA
485:1-a, XV, the void area
outside the casing shall grouted in accordance with
We
602.05 to prevent surface water from channeling along
the well casing.
