Current through Register Vol. 48, No. 9, September 27, 2024
The construction of bored wells shall meet the following minimum
requirements:
1. Drilling.
a. The drilling process or use of drilling fluid
additives shall not contaminate any aquifer.
b. Water used in the drilling process shall be
obtained from a source that will not result in chemical or biological contamination
of any aquifer. Water taken directly from ponds, lakes, streams or other surface
water sources shall not be used.
2. Grouting.
a.
The diameter of the borehole shall be large enough to allow for a minimum of 1.5
inches of annular space on all sides of the casing for forced injection of grout
through a tremie pipe.
b. Grout is to be
composed of neat cement, a bentonite cement mixture, or high solids sodium bentonite
grout.
(1) Neat cement grout shall be composed of
Class A, Type I Portland Cement mixed with not more than seven (7) gallons of clean
water per bag (one cubic foot or 94 pounds) of cement with a density of 15 to 16
pounds per gallon, or to manufacturers specifications
(2) Bentonite-cement grout shall be composed of
powdered bentonite (less than 5% by weight) mixed at not more than 8 gallons of
water to the bag, with a density of 14 to 15 pounds per gallon, or to manufacturers
specifications.
(3) High solids sodium
bentonite grout shall have a minimum of 20% solids and be mixed per manufacturers
specifications with water and/or other required additives.
c. When high solids sodium bentonite grouts are
used, a vapor barrier at the land surface made of suitable natural materials as
approved by the Department, such as native soils, gravel, or sand, is
required.
d. Grout shall fill the entire
annular space from a minimum depth of fifteen feet from the land surface at the time
of well completion to ensure that water does not enter the well from the joints in
the well casing. Bored wells shall be greater than 15 feet in depth.
e. Grouting shall be done by forced injection of
grout. When emplacing the grouting material, the tremie pipe shall be lowered to the
bottom of the zone to be grouted. The tremie pipe shall be kept full continuously
from start to finish of the grouting procedure, with the discharge end of the tremie
pipe being continuously submerged in the grout until the zone to be grouted is
completely filled.
f. Grouting shall
take place within five (5) days after borehole completion.
3. Development.
Development shall be complete when the well produces water typical
of the aquifer being utilized.
4. Well Tested for Yield.
If a yield test is conducted, it shall be by a standard method and
accurately measure flow. Results are to be included in the well record to be sent to
the Department.
5. Backflow
Prevention.
Approved backflow prevention devices are required on all wells that
utilize a chemical feed system for any purpose other than water treatment. The
backflow prevention device shall be installed so as to preclude any direct pathway
for any contaminant to enter an underground source of drinking water.
6. Disinfection.
All individual residential wells shall be disinfected upon the
initial installation of the pump and sanitary cover. The well shall also be
disinfected upon any subsequent well maintenance, repair, pump repair, pump
installation, or testing. Disinfectants shall be placed in the well in order to
provide a chlorine residual from 50 ppm (milligrams per liter) to 250 ppm for a
minimum of four hours before being flushed from the well. The method of chlorination
shall be one that insures that the chlorine is uniformly distributed in the well.
The well shall be flushed sufficiently after disinfection to remove the disinfectant
and to condition the well for use.
7. Well Identification.
All wells shall be properly labeled with an identification plate
immediately upon well completion. The identification plate shall be constructed of a
durable, weatherproof, rustproof, material. The identification plate shall be
permanently secured to the well casing or enclosure floor around the casing where it
is readily visible. The identification plate shall be permanently marked to
show:
a. Company name and driller's
certification number who installed the well;
b. Date well was completed;
c. Total depth (feet);
d. Casing depth (feet).
8. Casing.
a.
Casing may be driven, lowered, or installed in any manner that will effect a
continuous water tight and plumb installation.
b. Any piping connecting through the well casing
shall be watertight.
9.
Filter Pack.
When a filter pack is used, the following criteria shall
apply:
a. The filter pack shall be composed
of uniformly sized, quartz sand or gravel being free from clay, silt, or other
deleterious material.
b. The filter pack
shall be installed using a method approved by the Department into the annular
space.
c. The filter shall be
disinfected prior to or during installation.
10. Sanitary Cover.
A sanitary cover shall be provided on the top of the well
casing.
11. Reporting.
a. The Water Well Record Form 1903, or other
approved form, shall be completed and submitted to the Department by the contractor
within thirty days after well completion. In addition to the water well record, the
driller shall submit additional information as available such as chemical or
bacterial results, if taken, and pumping information.
b. A Form 1903 shall also be submitted for bored
wells that are abandoned.
12.
Operations and Maintenance.
Bored wells shall be operated and maintained at all times in such a
manner so as to protect underground sources of drinking water from contamination and
to protect public health. The well owner may be required to provide additional
security against vandalism as appropriate. The well driller is responsible for
ensuring wells are constructed in accordance with this regulation. Once the well
driller has provided a properly constructed well to the well owner, the well driller
is not responsible for normal wear of the well. The well owner is responsible for
maintenance and operation of the well.
13. Abandonment.
a. When a bored well is removed from service or
prior to putting in service, the well shall be covered with a cap or seal. The well
shall be maintained such that it is not a source or channel of contamination while
not in service. Until a well is abandoned, all provisions for protection of the
water against contamination and for maintaining sanitary conditions around the well
shall be carried out to the same extent as though the well were in routine use. This
goal shall be met when conducting repair or maintenance on the well, surrounding
structures, or pumps.
b. Any well
removed from service for longer than thirty-six months shall be permanently
abandoned unless a variance from the Department is requested.
c. Any well that acts as a source of contamination
shall be repaired or permanently abandoned immediately after receipt of notice from
the Department.
d. Abandonment shall be
by forced injection of grout or pouring through a tremie pipe starting at the bottom
of the well or fill material and proceeding to the surface in one continuous
operation, unless compacted clay is used.
e. The bored well shall be abandoned immediately
upon being permanently taken out of service. The well may be filled with either
bentonite-cement, neat cement, 20% high solids sodium bentonite grout, sand, or
gravel to no closer than twenty feet below the ground surface. The remaining twenty
feet to the ground surface shall be filled with neat cement, bentonite-cement, or
20% high solids sodium bentonite grout, or compacted clay.
