[Adopted 1-11-2012 by Ord. No. 2012-06]
All individual water supply wells shall be located in accordance with the requirements of Chapter 250, the Township Zoning Ordinance, and shall be constructed or closed in accordance with the requirements of this article.
If the State of Pennsylvania adopts regulations governing the
construction of individual water supply wells, the state regulations
shall supersede the requirements of this article in any instance where
the state regulations are more stringent.
Refer to Chapter 250, the Township Zoning Ordinance, for permit requirements.
A.
Casing.
(1)
All individual water supply wells shall be equipped with watertight
steel casing of a minimum nominal diameter of six inches (O.D. of
6.625 inches), having a minimum wall thickness of 0.188 inch and weight
of 13 pounds per foot. The minimum casing depth below grade shall
be 40 feet, with the casing set a minimum of five feet into competent
bedrock. The top of casing shall extend a minimum of 12 inches above
finished grade, resulting in a minimum casing length of 41 feet. A
minimum annular space of 1.5 inches in radial thickness must be maintained
so that grout may be placed. The criteria established in AWWA Standard
A 10090, as amended, must be followed.
(2)
Steel casings shall be new pipe meeting ASTM or API specifications
for water well construction. If the minimum thickness is not considered
sufficient to assure reasonable life expectancy of the well, additional
thickness shall be provided. Steel casing shall be equipped with a
drive shoe welded to the bottom of the casing. Casing joints shall
have full circumferential welds or be threaded and coupled pipe joints.
(3)
Casing material other than steel requires prior written approval
from the Board of Supervisors. Failure to receive such approval for
use of alternate casing types will result in enforcement action and
prohibition on use of the water supply.
(4)
Watertight well casing and grout must be placed at a sufficient depth
to prevent the entrance of pollution from surface runoff and polluted
aquifers. The casing shall be grouted along its entire length with
a portland cement or bentonite grout.
(5)
The casing shall extend above the finished grade a minimum of 12
inches or to such height as is necessary to prevent entrance of surface
water from runoff or flooding at the one-hundred-year flood level.
The casing top shall be fitted with a sanitary well cap that provides
a seal which prevents the entry of debris, foreign objects, insects,
and other unwanted material into the well.
B.
Grout materials and location.
(1)
All grout information (i.e., type of grout and number of bags of
material used for grouting) must be submitted in writing by the licensed
water well driller within 30 days of completion of the well drilling
process, with a certificate of individual water supply well construction
or closure.
(2)
In all well installations, an annular space shall be provided between
the well casing and the earth formation. The annular space shall be
completely filled with approved grout materials in one continuous
operation from the bottom to the natural land surface within 24 hours
after completion of the drilling. The annular space shall be completely
cleared of all obstructions prior to the placement of the grout material.
Exterior grouting methods must be used.
(3)
Grouting shall be accomplished by inserting a minimum one-inch-diameter
tremie pipe to the bottom of the casing annulus and pumping grout
through the tremie pipe using a positive displacement pump, until
grout of the same density as what is being pumped returns to the ground
surface. The casing shall be sealed effectively against entrance of
water from water-bearing zones which are subject to pollution. During
the installation of a pitless adaptor, grout material may be removed
from the exterior of the casing in order to provide a watertight seal
between the casing and the pitless adaptor.
(4)
When drilling is to be continued after grouting, a curing time of
72 hours must be provided during which drilling is not permitted.
If quick-setting cement is used, this period may be reduced to 24
hours.
(5)
The annular space of all well installations must be filled with one
of the grout materials described below.
(6)
Neat cement grout shall consist of a mixture of portland cement Type
I or Type II and water in the ratio of five gallons to six gallons
of water per ninety-four-pound sack of cement weighing approximately
118 pounds per cubic foot. A maximum of 5% by weight of bentonite
and 2% by weight of calcium chloride may be added.
(7)
Bentonite or sealing clay shall consist of a manufactured clay product
that expands in contact with moisture to form a seal that prevents
the movement of water. Bentonite must be activated with water prior
to resumption of drilling.
(8)
In all well installations, if rapid loss of grout material occurs
during placement, clean, coarse fill material (e.g., sand, gravel,
crushed stone, chip or pellet bentonite) may be used in the zone(s)
in which the rapid loss is occurring. The remainder of the annular
space shall be grouted as provided below. In no case shall pouring,
dumping, or shoveling of grout material into the annular space be
deemed an approved method of grout placement.
C.
Grout placement.
(1)
Positive displacement - exterior method.
(a)
The annular space shall be a minimum of 1.5 inches (the diameter
of the drilled hole shall be at least three inches larger than the
casing outer diameter). All grout shall be placed by pumping through
the tremie pipe. The entire interval to be grouted shall be open and
without obstructions. It is required that the tremie grout pipe extend
from the surface to the bottom of the interval to be grouted. The
discharge end of the grout pipe shall remain submerged in the placed
grout at all times until grouting is completed; it may remain extended
to the bottom during the grouting, or it may be raised slowly as the
grout is placed.
(2)
Unstable formations (i.e., fractured limestone, saturated soils etc.).
(a)
If caving conditions are experienced on wells, the borehole
shall be kept open with an outer casing and the annular space shall
be grouted from the bottom of the inner casing, which shall be at
least 10 feet below where caving occurred.
D.
Pitless adaptors.
(1)
For pitless installations where the casing terminates above the ground
surface and the well pump discharges through a buried adapter, the
pitless unit shall be of a watertight construction throughout which
provides an effective seal against the entrance of ground- or surface
water into the well. The pitless unit shall be threaded or welded
to the well casing or use certified compression fittings. All buried
suction lines shall be effectively encased or otherwise protected
to prevent external damage or contamination.
(2)
Pitless installations must be so designed as to be structurally sound
and to provide for ready removal of drop piping without excavation.
The access casing shall be effectively protected against corrosion
and shall extend at least 12 inches above the natural ground surface
and to a point below the frost line. The ground level at this point
shall be elevated above the adjacent ground level and graded to drain
away in all directions. The top of the access shall be effectively
sealed against the entrance of water, insects, and rodents. The pitless
adaptor shall not be submerged in water or used in areas used by automobiles
and other vehicles unless adequately protected.
E.
Pump installations.
(1)
All pump information must be completed on the certificate of individual
water supply well construction.
F.
Disinfection.
(1)
Following completion of construction of an individual water supply
well and installation of the pumping equipment, or alteration, repair
or maintenance work, the well shall be pumped continuously until the
water discharged is clear. The well, pump, piping system, and other
fixtures shall be filled with water containing a concentration of
not less than 50 parts per million (ppm) of free chlorine. (One-half
ounce of dry hypochlorite, which has 70% available chlorine, dissolved
in 52.5 gallons of water, makes a 50 ppm strength disinfectant solution.)
A portion of the chlorine solution shall be circulated directly to
the well in order to ensure proper agitation.
(2)
The water shall not be used for a period of 24 hours. Other combinations
of concentration and time intervals or other disinfectants such as
HTH tablets may be used if demonstrated to be equally effective. The
purged water shall not be discharged into any subsurface sewage disposal
system and shall be discharged at a location that will prevent any
adverse effects to aquatic life.
(3)
After well disinfection, water samples shall be collected and analyzed
for pH, total solids, iron, nitrate, nitrogen, and coliform bacteria.
One copy of the analysis results from a Pennsylvania Department of
Environmental Protection certified testing laboratory shall be provided
to the owner and the Township with the certificate of individual water
supply well construction.
G.
Cross-connections.
(1)
If pump and piping is not installed by the well driller, the owner
is responsible for proper installation of check valves and backflow
prevention valves.
(2)
Backflow prevention valves must be incorporated into the system and
shall be used as needed for each outside water hose connection. At
least two check valves must be incorporated into each water system
that derives water from a well.
(3)
Except where not practical, a cross-connection prevention assembly
shall be provided.
H.
Wells shall be decommissioned/closed according to the following standards:
(1)
If the use of an individual water supply well is permanently discontinued,
the well shall be filled and sealed in such a way that it will not
act as a channel for the interchange of waters of undesirable quality
with those whose quality is desirable and to prevent the contamination
of groundwater.
(2)
Only concrete, cement grout or bentonite clay, or a combination of
these materials, may be used to seal a well.
(3)
Before the well borehole is filled, all obstructions, such as the
pump, piping, wiring, and air lines, must be removed. An attempt shall
be made to remove the casing when it will not jeopardize the integrity
of the borehole. If the casing cannot be removed, it shall be perforated
to assure that sealing material fills all annular spaces and voids.
(4)
Sealing material shall be placed from the bottom of the well upward
by methods that will avoid dilution and/or separation thereof.
(5)
When a well is to be abandoned, the person abandoning it or the owner
of the property (if not the person abandoning the well) shall notify
the Township prior to initiating the procedures set forth above.
