178 Neb. Admin. Code, ch. 12, § 003

Current through September 17, 2024

Section 178-12-003 - GENERAL REQUIREMENTS

These requirements apply to all water wells constructed under Title 178 NAC 12, except as modified in 178 NAC 12-004 through 12-014.

12-003.01Protection and Location:

12-003.01A A well must not be located in a well pit.

12-003.01BProtection: 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.

12-003.01CSeparation 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.

12-003.02Sanitation: All water wells must be constructed to prevent the introduction of biological, chemical or radiological substances which may degrade the ground water.

12-003.02ADrilling 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.

12-003.02BSecure 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.

12-003.03Well Screens

12-003.03AMaterials: 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.

12-003.03BScreen 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.

12-003.04Well 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.

12-003.04ACasing 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.

12-003.04BCasing Placement: The casing must be centered in the borehole in areas of grout so there is a minimum 2-inch uniform annular space.

12-003.04CWatertight Casing must be constructed of steel, PVC, fiberglass, or teflon and must be manufactured expressly for water well casing.

12-003.05Gravel Pack

12-003.05AGravel Pack must consist of clean sand or gravel of selected grain size and gradation.

12-003.05BGravel 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.

12-003.06Grout: 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.

12-003.07Placement of Grout

12-003.07ASlurry 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.

12-003.07BNon-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.

12-003.08Aquifer 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.

12-003.08APrimary 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)

12-003.08BFilling 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.

12-003.08CSurface 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).

12-003.08DAbove 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.

12-003.08ESurface 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.

12-003.09Well 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.

12-003.10Test 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.

12-003.11Repairing 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.)

12-003.12Well 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.

12-003.12ARequired 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.

12-003.12BAvailability 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.

12-003.13Registration: 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.

178 Neb. Admin. Code, ch. 12, § 003