178 Neb. Admin. Code, ch. 12, § 004

Current through June 17, 2024

Section 178-12-004 - POTABLE WELL CONSTRUCTION

A water well contractor must verify the purpose of a new well with the owner or the system's engineer. If the well is to serve water to the public, see 178 NAC 12-008.

12-004.01Construction of Potable Well:

1. A potable water well to be used for human consumption must not be constructed as a driven sandpoint well.

2. It must meet the requirements specified in 178 NAC 12-003.

12-004.02Casing a Potable Well: A potable water well must be cased with unused watertight casing in the following manner:

12-004.02A The top of the well must extend at least 12 inches above the grade of the land surface. The earth surrounding the well must slope away from the well and must be firmly tamped to prevent water from seeping down the casing.

12-004.02B Non-steel cased wells must be fitted with a watertight connection to .237 inch wall minimum steel casing through the frost zone, unless terminating in a pump house.

12-004.02C Non-steel watertight casing must be manufactured expressly for well casing, and must meet the following specific requirements:

1. Casing strength must be not less than 160 pounds per square inch or Standard Dimension Ratio (SDR) 26.

2. Plastic or other non-steel casing must bear the National Sanitation Foundation (NSF) 61 stamp of approval.

12-004.02D Special Engineered (SE) plastic piping systems must meet the requirements of 178 NAC 12-004.02C item 2.

12-004.02E Packaging of thread compounds, sealants and lubricants must bear the NSF Standard 61 stamp of approval.

12-004.03Potable Well Shock Decontamination

12-004.03A When a well which will produce water for human consumption is constructed or altered, it must be decontaminated.

12-004.03B The water well contractor/pump installation contractor must supply the landowner with an informational brochure that tells the owner why s/he should test his/her water and what the results mean.

12-004.03C Shock decontamination must be accomplished by:

1. Using a solution equivalent to 200 parts per million chlorine (See Table 1);

2. Pouring the solution directly into the well; splashing the well pump, piping, casing, and other well equipment as much as possible; agitating the water in the well by surging the pump or by other means to mix the solution with the water or recirculating the water into the well, always washing down the casing or drop pipe;

3. Letting the mixture stand in the well for a minimum of 4 hours;

4. Opening all water taps and pumping the well until evidence of the solution is detected at all taps. The system must be allowed to stand idle for a minimum of 2 additional hours and then the entire system must be flushed to waste.

12-004.04Bored (Seep or Cistern) Wells must be constructed to the same minimum standards for potable wells with the following exceptions: (See Figure 3)

12-004.04A Casing materials may be concrete, tile, or other material approved in 178 NAC 12-003.04C.

12-004.04B The annular space below the surface seal must be filled with gravel.

12-004.04C Watertight casing and grout must be placed from 10 feet below the surface or the static water level, whichever is less, to the surface or the bottom of the pitless unit. (See Figure 3)

12-004.05Open Hole Wells must be constructed to the same minimum standards for potable wells and in the following manner. (See Figure 4)

12-004.05AThe casing must extend at least 2 feet into the open borehole. A seal must be created between the casing and the lower borehole to ensure that the annular fill material remains in the upper borehole. This can be accomplished by using a collar attached to the casing, a drive shoe, or other sealing device.

12-004.05B A minimum 5 foot primary aquifer seal must be placed in the annular space directly above the collar, drive shoe, or other sealing device.

12-004.05COpen Hole Wells in Multiple Aquifers must be constructed to the same minimum standards for potable wells and must comply with 178 NAC 12-004.05A and 12-004.05B. The screened section must be gravel packed. The gravel pack must extend both above and below the screen for a length equal to 2.5 times the diameter of the well. A 5 foot minimum primary aquifer seal must be placed directly above the gravel pack. (See Figure 5)

178 Neb. Admin. Code, ch. 12, § 004