(1)
Approval. No person shall construct a well as a source of water
supply for a public water system without having first obtained approval from
the Division. This requirement may be waived by the Director during emergency
situations. Any well that is constructed and does not meet the rules of this
Chapter shall not later be used as a drinking water source for a public water
system.
(2)
Prohibited
Wells. Dug, bored, or jetted wells are prohibited for all new public
water systems.
(3)
Protection
from Contamination. Each well must be protected from contamination by
surface waters and other sources of contamination. The location of wells must
be in compliance with the latest edition of the Division's "Minimum Standards
for Public Water Systems."
(4)
Fill, Plug and Seal. Whenever a bore hole of any depth is
excavated for, but not used as a source of water supply it shall be the
supplier's responsibility to fill, plug and seal the hole within thirty (30)
days of the excavation in a manner approved by the Division to restore as
nearly as possible the natural earth condition existing before the hole was
excavated and to protect against contamination of the ground water. This
paragraph shall not apply where some other use is made of the ground water from
the well hole.
(5)
Well
Construction Standards. All wells must be constructed as hereinafter
provided, however, deviations from these rules may be permitted or required by
the Division due to the variable conditions of the subsurface and ground water
quality in a specific area.
(a) Drilling
fluids must be from an uncontaminated source or must be disinfected.
(b) All permanent casing, liners, screens and
other manufactured material used in the well installation must be new and
adequate to protect the well against entrance of contaminants during the
expected life of the well. All casing and liner pipe joints shall be water
tight the entire length in drilled wells.
1.
Steel pipe well casing shall conform to American Society for Testing and
Materials (ASTM) Specification A 53, American Petroleum Institute (API)
Specification 5L, or equal standard, and meet the following minimum wall
thickness unless otherwise approved by the Division.
|
Nominal Casing Diameter
(inches)
|
Minimum Wall Thickness
(inches)
|
|
4*
|
0.188
|
|
5*
|
0.188
|
|
6
|
0.280
|
|
8
|
0.322
|
|
10
|
0.365
|
|
12
|
0.375
|
|
14
|
0.375
|
|
16
|
0.375
|
|
18
|
0.375
|
|
20
|
0.375
|
|
24
|
0.500
|
|
26
|
0.500
|
* not recommended for use in corrosive or high alkalinity
water
2. The use of plastic
well casing and screens must be approved by the Division prior to well
installation. The well casing and couplings shall meet the requirements of the
ASTM Standard F 480 or equal standard and the National Sanitation Foundation
for use with potable water. When approved for use by the Division, plastic well
casing shall conform to the following minimum wall thickness. However, plastic
well casing diameters of 12 inches or greater or deep wells may require greater
wall thickness to meet the collapse strength requirements.
|
Nominal Casing Diameter
(inches)
|
Minimum Wall Thickness
(inches)
|
|
4
|
0.265
|
|
4.5
|
0.291
|
|
6
|
0.390
|
|
8
|
0.508
|
|
10
|
0.632
|
|
12
|
0.750
|
Plastic well casing and screen shall not extend to a depth of
greater than 300 feet below the ground surface.
(c) The outer, permanent, protective casing
shall extend at least five (5) feet into the first solid, unweathered or
impervious subsurface rock strata encountered, and shall have a minimum length
of twenty-five (25) feet from the ground surface into a well excavated into
water-bearing formations in crystalline rocks and fifty (50) feet in a well
excavated into sedimentary water-bearing formations. The outer, permanent,
protective casing shall be cement grouted its entire length with a cement
slurry consisting of not more than six (6) gallons of water to one cubic foot
cement, plus standard additives, when necessary, to facilitate placing or
setting and shall be placed under pressure from the bottom of the annular space
to be grouted upward until the grout is extruded at the earth's surface. The
wall thickness of the cement grout surrounding the outer, permanent, protective
casing shall be not less than one and one-half (1-1/2) inches at any point.
Subsurface well construction shall cease for at least twenty-four (24) hours
after grouting. Other grouting materials for sealing the annular space may be
used upon the approval of the Division prior to well construction.
(d) Any ground water of unacceptable quality
encountered during the well construction must be sealed off.
(e) The gravel for gravel-packed wells must
be washed, free of organic matter, and composed of well rounded
particles.
(6)
Stoppage During Construction. During the periods of stoppage of
the well construction and when the site is unattended, the drilling contractor
must have the well opening securely covered to prevent tampering and possible
contamination.
(7)
Sanitary
Conditions. During the well construction, the premises, construction
material, tools and equipment must be maintained in a sanitary manner to
prevent contamination of the well by the person excavating the well.
(8)
Proper Well Development.
Every well must be properly developed, disinfected, and pump tested by the
drilling contractor. The well must be test pumped at not less than the desired
yield for a period of at least twenty-four (24) hours and shall continue for at
least four (4) hours after the pumping level has stabilized. The static water
level, drawdown and pumping water level must be measured.
(9)
Disinfection of the Well.
(a) The well must be disinfected prior to the
pumping test by the introduction of a chlorine solution into the well under
sufficient pressure to overcome the natural flow pressures of all developed
water-bearing zones, and in sufficient quantity to produce a minimum chlorine
residual of fifty (50) parts per million in six (6) hours after such
application.
(b) After
disinfection, the well must be pumped until no trace of chlorine remains in the
water, and water samples taken for microbiological analysis. No water may be
furnished for human consumption until samples of water are collected by the
supplier, and submitted to the Division for microbiological examination, and
the quality of the water approved by the Division. If the water samples
submitted are found to be unsatisfactory, the disinfection procedure must be
repeated as required by the Division.
(c) The permanent pump and pumping equipment
shall be disinfected with a chlorine solution prior to being placed into
service.
(d) Well disinfection
shall be conducted in accordance with American Water Works Association (AWWA)
Standard C654.
(10)
Licensed Water Well Contractor. The person constructing the well
shall be a licensed water well contractor in the State of Georgia in accordance
with the provisions of the Water Well Standards Act of 1985 (O.C.G.A. §
12-5-120, et. seq.). The
contractor must maintain accurate driller logs, material setting and grouting
data, complete results of the pump test, including water level measurements,
and must furnish a signed copy of the results to the owner and to the Division
on forms provided by the Division.
(11)
Installation Standards. A
well used as a source of water supply must include the following:
(a) A concrete slab with a minimum thickness
of six (6) inches shall be constructed around the well casing and shall extend
at least two (2) feet in all directions, and slope away, from the
casing.
(b) The well casing shall
extend at least twelve (12) inches above the concrete slab of the
floor.
(c) For submersible pump
installations, the well casing shall be provided with a sealed cover plate and,
when required by the Division, vented by a screened riser pipe so that the
screened opening terminated downward at least twelve (12) inches above the top
of the casing or ground level.
(d)
For turbine pump installations, a concrete block to support the pump motor
shall be constructed around the outer well casing and shall extend at least
twelve (12) inches above the concrete slab, and:
1. the outer casing shall extend at least one
(1) inch above the pump motor block;
2. the well head and pump base shall be
sealed to prevent seepage and the casing shall be vented by a screened riser
pipe so that the screen opening terminates downward and above any point of back
flow of contaminants into the well; and
3. oil lubricated vertical turbine pumps
shall be lubricated with an acceptable turbine oil as prescribed by the pump
manufacturer.
(e) A raw
water sampling tap shall be installed prior to the well discharge pipe check
valve.
(f) An access port of not
less than five-eights (5/8) inch in diameter, with screw cap, for water level
measurements; a deep well air line and gage may also be used in conjunction
with the access port.
(12)
Deepening Existing Wells.
Existing wells that are deepened shall be regarded by the Division as a
development of a new ground water source and must meet the requirements for
approval.
(13)
Rehabilitating
Existing Wells. When an existing well is rehabilitated or reworked, the
well shall be disinfected according to procedures described in this
Rule.
(14)
Infrastructure
Security. The pumping and water treatment equipment shall be protected
from unauthorized entry and use by an enclosed shelter or enclosed by a fence.
In addition, the water treatment equipment shall be enclosed in a weather proof
shelter.