Current through September 17, 2024
These requirements apply to all water wells constructed under
Title 178 NAC 12, except as modified in 178 NAC 12-004 through 12-014.
12-003.01
Protection and
Location:
12-003.01A A well must
not be located in a well pit.
12-003.01B
Protection: All water wells must be protected from
surface drainage, flooding and seepage from sources of contamination and
pollution by:
1. Locating the well site to
promote drainage away from the well, and
2. Terminating the top of the well and vent
above the 100 year flood plain, or
3. Locating on a berm and/or within a dike to
protect the well from a 100 year flood, or
4. Plugging the vent and seal at the top of
the well if yield is less than 50 GPM.
12-003.01C
Separation
distances must at a minimum comply with the distances listed in
Chart 1 (or Chart 2 if the requirements in 178 NAC 12-003.01C item 2 are met).
Be aware that other state, NRD, and local statutes and regulations may have
more restrictive requirements. If locations are found to not comply with more
stringent standards of other state or local regulations that apply, the
Department may notify the appropriate authority.
1. All water wells except those covered in
178 NAC 12-007 must meet the minimum separation distances in accordance with
Chart 1 below.
Chart 1
|
Minimum Distance in
Feet |
From |
|
1,000 |
Any Title 179 community water supply wells under
different ownership |
|
1,000 |
Any industrial wells under different
ownership |
|
600 |
Any irrigation wells under different
ownership |
|
100 |
Any waste water lagoon |
|
100 |
Any privy, cesspool, subsurface disposal
system |
|
100 |
Any septic lateral field (soil absorption
system) |
|
100 |
Any animal waste containment structure |
|
100 |
Any holding pens of animals |
|
100 |
Any other known sources of contamination or
pollution |
|
50 |
Any sewer line |
|
50 |
Any septic tank |
|
10 |
Any depression that could retain stagnant
water |
|
10 |
Any storm water way |
|
10 |
Any frost proof hydrant |
|
10 |
Any well pit |
2. A
well driller may locate a well as indicated in Chart 2 below only if:
a. Compliance with the separation distances
established in Chart 1 cannot be met; and
b. The well driller notifies the Department
in writing of his/her intent and receives Department written approval prior to
construction; and
c. The water well
is grouted the full length of the annular space from immediately above the
gravel pack above the screened openings to the surface with chip bentonite; and
d. The subsurface geology includes
sufficient silts and/or clays that will provide a protective seal to the
groundwater when combined with chip bentonite.
Chart 2
|
These Separation Distances Require Prior
Written Approval from the Department
|
|
Distance in Feet |
From |
|
50-100 |
Any waste water lagoon |
|
50-100 |
Any privy, cesspool and subsurface disposal
system |
|
50-100 |
Any septic lateral field (soil absorption
system) |
|
50-100 |
Any animal waste containment structure |
|
50-100 |
Any holding pens of animals |
|
50-100 |
Any other known sources of contamination or
pollution |
|
25-50 |
Any sewer line |
|
25-50 |
Any septic tank |
|
5-10 |
Any depression that could retain stagnant
water |
|
5-10 |
Any storm water way |
|
5-10 |
Any frost proof hydrant |
3. If a person wants to locate a well closer
than the listed separation distances in Chart 2, a declaratory order request
may be submitted to the Department so the Department can determine if the
proposal is substantially equivalent to the regulations.
12-003.02
Sanitation: All water wells must be constructed to
prevent the introduction of biological, chemical or radiological substances
which may degrade the ground water.
12-003.02A
Drilling Equipment: The water well contractor must use
precautions to ensure that all down hole equipment used in the construction of
water wells is free of contaminated or polluted materials.
12-003.02B
Secure
Cover: All water wells must be protected with a secure cover or
cap. All inactive water wells must be capped with a watertight secure cover.
When the pump is in place, it must be made secure and watertight in accordance
with 12-011.03D.
12-003.03
Well
Screens
12-003.03A
Materials: Well screens must be constructed of durable
non-toxic materials of sufficient strength to withstand the pressure to which
they may be subjected. They must also be resistant to any corrosion which may
result from the characteristics of the water and aquifer materials in which
they are placed.
12-003.03B
Screen Apertures: Screen apertures must be formed by
the continuous slot method, louver, punched casing, molded or mill slotted.
Torch slotted casing must not be used. The method of construction must allow
for control of aperture width. In general, the aperture width should retain a
minimum of 85% of the gravel pack, if used, or a minimum of 50% of the aquifer
material if gravel pack is not used.
12-003.04
Well
Casing: All wells other than test holes and closed loop heat pump
wells must be cased. Well casing must be composed of nontoxic durable material
compatible with the water quality encountered.
12-003.04A
Casing Wall
Thickness: The wall thickness of water well casing must be
sufficient to withstand the pressures exerted by the surrounding materials,
forces imposed on it during installation, and corrosion by soil and water
environments.
12-003.04B
Casing Placement: The casing must be centered in the
borehole in areas of grout so there is a minimum 2-inch uniform annular
space.
12-003.04C
Watertight Casing must be constructed of steel, PVC,
fiberglass, or teflon and must be manufactured expressly for water well
casing.
12-003.05
Gravel Pack
12-003.05A
Gravel
Pack must consist of clean sand or gravel of selected grain size
and gradation.
12-003.05B
Gravel Pack, Screen Size, and Gradation must be
determined based upon the grain size and gradation of the portion or portions
of the aquifer to be screened. Gravel pack must be designed to stabilize the
aquifer material and to permit the fine fraction to move into the water well
during development. Gravel pack, when used, must extend to a length equal to at
least 2.5 times the casing diameter above the screen
apertures.
12-003.06
Grout: Cement based grouts must not contain fly ash.
The Department has approved the following grout materials:
1.
Neat Cement Grout
Slurry which must consist of a mixture of portland cement and no
more than 5.2 gallons of clean water per bag (1 cubic foot or 94 pounds) of
cement. Non-toxic additives may be used to minimize shrinkage and
cracking.
2.
Sand
Cement Grout Slurry which must consist of a mixture of portland
cement, sand and water in the proportion of no more than 2 parts by weight of
sand to 1 part of cement with no more than 6 gallons of clean water per bag of
cement (1 cubic foot or 94 pounds).
3.
Non-slurry Bentonite
Grout which must consist of chip, chunk or pelletized bentonite
varieties that are hydrated to manufacturer's specifications.
4.
Cement/Bentonite Grout
Slurry which must consist of a mixture of portland cement and
bentonite in the following proportion: no more than 6.5 gallons of water and 3
to 5 pounds of bentonite per 94-pound sack of portland cement.
5.
High Solids Bentonite Grout
Slurry which must consist of an inorganic mixture of:
a. Soda ash for pre-treatment of makeup
water, and
b. Minimum of 20% by
weight active solids bentonite-to-water ratio, and
c. Fine to medium grade sand added at a
minimum ratio of 4:1 sand to bentonite by weight, and if needed
d. Additives designed for yield/rate control
for bentonite products that form a low permeability seal not greater than
1x10-7 cm/sec which resists flow of fluid through
the seal, is pumpable, and is mixed to the manufacturer's
specifications.
6.
Bentonite Grout Slurry which must consist of an
inorganic mixture of:
a. Soda ash for
pretreatment of makeup water, and
b.
Minimum of 20% solids by weight bentonite that forms a low permeability seal
not greater than 1x10-7 cm/sec which resists flow of
fluid through the seal, is pumpable, and is mixed to the manufacturer's
specifications, and if needed
c.
Additives designed for yield/rate control for bentonite products that form a
low permeability seal not greater than 1x10-7 cm/sec
which resists flow of fluid through the seal, is pumpable, and is mixed to the
manufacturer's specifications.
12-003.07
Placement of
Grout
12-003.07A
Slurry Grout: All grout slurries must be placed by
tremie or by pumping. Cement based grout must not be allowed to free-fall more
than 10 feet. Cement based grout must be separated from bentonite grouts by a
2-4 foot interval of fine sand.
12-003.07B
Non-slurry
Grout: Pellet, chip, chunk bentonite or any combination of those
materials must be placed, measured frequently, and hydrated, before installing
another interval to confirm the grout is placed without bridging and provides a
tight homogeneous seal.
12-003.08
Aquifer
Protection: All water wells must be filled and sealed in a manner
that protects the water bearing formations from contamination from surface
runoff and from subsurface contaminants.
12-003.08A
Primary Aquifer
Seal: All water wells, except (a) bored wells (178 NAC 12-004.04
and 12-005.03), (b) temporary dewatering wells (178 NAC 12-006.02), and (c)
wells that require surface casing and additional gravel pack throughout the
life of the well (178 NAC 12-005.05) must have a 5 foot primary aquifer seal of
nonslurry bentonite or high solids bentonite slurry as defined in 178 NAC
12-003.06 items 3 and 5, respectively. The primary aquifer seal must be placed
in the borehole at one or more of the following locations to provide optimal
aquifer protection.
1. On top of the gravel
pack just above the screened openings (See Figure 1A), and/or
2. Beginning at the base of the first layer
of silt/clay above the production zone (See Figure 1B), and/or
3. At/or immediately below the static water
level. (See Figure 1C)
12-003.08B
Filling the Annular
Space: The annular space of all wells except closed loop heat pump
wells that are part of a closed loop heat pump system in 178 NAC 12-010.03C
must be filled from the top of the primary aquifer seal to the bottom of the
surface seal (12-003.08C) with:
1. Non-slurry
bentonite grout, or
2. Non-slurry
bentonite grout mixed with gravel pack in a 1:1 ratio by weight, or
3. Sand and granular bentonite mixed in a 2:1
sand-to-bentonite ratio by weight, or
4. High solids bentonite slurry as defined in
12-003.06 item 6, or
5. A mixture
of bentonite/clay, drilling fluid, and gravel pack, or
6. Cement based grouts.
12-003.08C
Surface
Seal: The annular space of all wells, except bored wells and
temporary dewatering wells, must have at least 5 feet of non-slurry bentonite,
high solids bentonite slurry, or sand cement grout placed between 5 and 15 feet
below grade or at the static water level, whichever is less (See Figure 2A). If
a pitless unit is used to terminate the top of the well, the surface seal must
extend 5 feet down the borehole below the bottom of the pitless adapter (See
Figure 2B).
12-003.08D
Above Ground Protection: Cased water wells that
terminate in a pump house must be protected with a concrete floor measuring a
minimum of 4 inches thick by 12 inches beyond the borehole wall and sloping
away from the water well. Watertight casing must extend 12 inches above the
floor of the pump house.
12-003.08E
Surface Completion: The earth surrounding the casing
must slope away from the water well and must be firmly tamped to prevent water
from seeping down around the casing.
12-003.09
Well
Development: All cased water wells must be developed to repair the
alterations to the formation during the construction of the well and to enhance
the porosity and permeability of materials surrounding the intake portion of
the well. The development process is the application of mechanical devices
and/or the use of chemicals to remove drilling fluids and debris left in the
filter pack and formation as a result of the drilling process.
12-003.10
Test Pumping a
Well: Test pumping must be utilized to determine the most
efficient production rate for the well. The pumping water level must be
recorded during the period of test pumping.
12-003.11
Repairing a
Well: Only the portion(s) of a well being repaired must meet the
same minimum standards as it would if it were within a new well with regard to
design, construction, and material. Bored and dug wells must be repaired so
that they meet the standards of a bored well. (See Figure 3.)
12-003.12
Well Logs
: Any owner of a water well or any licensed water well contractor who engages
in the act of or business of constructing a water well must keep and maintain
an accurate well log of the construction of each water well and test hole. A
licensed water well contractor must forward a copy of the well log to the
owner.
12-003.12A
Required
Information: The well log must include the following information:
1. Legal description and the GPS coordinates
of the location of the water well or test hole;
2. Description and depth of geologic
materials encountered;
3. Depth and
diameter or dimension of constructed water well and test hole;
4. Diameter and depth or dimension of
excavated hole if applicable;
5.
Depth and volume of formation stabilizer or gravel pack and size of particles,
if used;
6. Depth and thickness
(intervals and volume) of grout or other sealing material if
applicable;
7. Casing and/or loop
pipe information, including length, inside and outside diameter (ID and OD),
wall thickness, and type of material if applicable;
8. Screen information, including length,
trade name, inside and outside diameter, slot size and type of material if
applicable;
9. Static water
level;
10. Water level when pumped
at the designed rate giving the rate of pumping and amount of time pumped, if
applicable;
11. Yield of water well
in gallons per minute or gallons per hour if applicable;
12. Signature of water well
contractor;
13. Dates drilling
commenced and construction completed;
14. Intended use of the water well;
15. Name and address of the
landowner;
16. Identification
number of any permit for the water well issued pursuant to Neb.
Rev. Stat. §
46-601 et seq. or Neb.
Rev. Stat.
§
66-1101 et seq., and
17. Name, address, and license number of any
license issued pursuant to the Water Well Standards and Contractors' Practice
Act of any individual, other than the owner of the water well, who constructed
the water well.
12-003.12B
Availability for
Inspection: The well log must be available to the Department for
inspection and copying during reasonable hours or the regular business hours of
the contractor.
12-003.13
Registration: A licensed water well contractor must
register all wells with the Nebraska Department of Natural Resources on forms
provided by that Department, except as otherwise provided by Neb.
Rev. Stat. §
46-602.
