S.C. Code Regs. § 61-71.G
Current through Register Vol. 48, No. 07, July 26, 2024
Section 61-71.G - BORED INDIVIDUAL RESIDENTIAL AND IRRIGATION WELLSThe construction of bored wells shall meet the following minimum requirements:
1. Drilling. a. The drilling process or use of drilling fluid additives shall not contaminate any aquifer.b. Water used in the drilling process shall be obtained from a source that will not result in chemical or biological contamination of any aquifer. Water taken directly from ponds, lakes, streams or other surface water sources shall not be used.2. Grouting. a. The diameter of the borehole shall be large enough to allow for a minimum of 1.5 inches of annular space on all sides of the casing for forced injection of grout through a tremie pipe.b. Grout is to be composed of neat cement, a bentonite cement mixture, or high solids sodium bentonite grout. (1) Neat cement grout shall be composed of Class A, Type I Portland Cement mixed with not more than seven (7) gallons of clean water per bag (one cubic foot or 94 pounds) of cement with a density of 15 to 16 pounds per gallon, or to manufacturers specifications(2) Bentonite-cement grout shall be composed of powdered bentonite (less than 5% by weight) mixed at not more than 8 gallons of water to the bag, with a density of 14 to 15 pounds per gallon, or to manufacturers specifications.(3) High solids sodium bentonite grout shall have a minimum of 20% solids and be mixed per manufacturers specifications with water and/or other required additives.c. When high solids sodium bentonite grouts are used, a vapor barrier at the land surface made of suitable natural materials as approved by the Department, such as native soils, gravel, or sand, is required.d. Grout shall fill the entire annular space from a minimum depth of fifteen feet from the land surface at the time of well completion to ensure that water does not enter the well from the joints in the well casing. Bored wells shall be greater than 15 feet in depth.e. Grouting shall be done by forced injection of grout. When emplacing the grouting material, the tremie pipe shall be lowered to the bottom of the zone to be grouted. The tremie pipe shall be kept full continuously from start to finish of the grouting procedure, with the discharge end of the tremie pipe being continuously submerged in the grout until the zone to be grouted is completely filled.f. Grouting shall take place within five (5) days after borehole completion.3. Development. Development shall be complete when the well produces water typical of the aquifer being utilized.
4. Well Tested for Yield. If a yield test is conducted, it shall be by a standard method and accurately measure flow. Results are to be included in the well record to be sent to the Department.
5. Backflow Prevention. Approved backflow prevention devices are required on all wells that utilize a chemical feed system for any purpose other than water treatment. The backflow prevention device shall be installed so as to preclude any direct pathway for any contaminant to enter an underground source of drinking water.
6. Disinfection. All individual residential wells shall be disinfected upon the initial installation of the pump and sanitary cover. The well shall also be disinfected upon any subsequent well maintenance, repair, pump repair, pump installation, or testing. Disinfectants shall be placed in the well in order to provide a chlorine residual from 50 ppm (milligrams per liter) to 250 ppm for a minimum of four hours before being flushed from the well. The method of chlorination shall be one that insures that the chlorine is uniformly distributed in the well. The well shall be flushed sufficiently after disinfection to remove the disinfectant and to condition the well for use.
7. Well Identification. All wells shall be properly labeled with an identification plate immediately upon well completion. The identification plate shall be constructed of a durable, weatherproof, rustproof, material. The identification plate shall be permanently secured to the well casing or enclosure floor around the casing where it is readily visible. The identification plate shall be permanently marked to show:
a. Company name and driller's certification number who installed the well;b. Date well was completed;8. Casing. a. Casing may be driven, lowered, or installed in any manner that will effect a continuous water tight and plumb installation.b. Any piping connecting through the well casing shall be watertight.9. Filter Pack. When a filter pack is used, the following criteria shall apply:
a. The filter pack shall be composed of uniformly sized, quartz sand or gravel being free from clay, silt, or other deleterious material.b. The filter pack shall be installed using a method approved by the Department into the annular space.c. The filter shall be disinfected prior to or during installation.10. Sanitary Cover. A sanitary cover shall be provided on the top of the well casing.
11. Reporting. a. The Water Well Record Form 1903, or other approved form, shall be completed and submitted to the Department by the contractor within thirty days after well completion. In addition to the water well record, the driller shall submit additional information as available such as chemical or bacterial results, if taken, and pumping information.b. A Form 1903 shall also be submitted for bored wells that are abandoned.12. Operations and Maintenance. Bored wells shall be operated and maintained at all times in such a manner so as to protect underground sources of drinking water from contamination and to protect public health. The well owner may be required to provide additional security against vandalism as appropriate. The well driller is responsible for ensuring wells are constructed in accordance with this regulation. Once the well driller has provided a properly constructed well to the well owner, the well driller is not responsible for normal wear of the well. The well owner is responsible for maintenance and operation of the well.
13. Abandonment. a. When a bored well is removed from service or prior to putting in service, the well shall be covered with a cap or seal. The well shall be maintained such that it is not a source or channel of contamination while not in service. Until a well is abandoned, all provisions for protection of the water against contamination and for maintaining sanitary conditions around the well shall be carried out to the same extent as though the well were in routine use. This goal shall be met when conducting repair or maintenance on the well, surrounding structures, or pumps.b. Any well removed from service for longer than thirty-six months shall be permanently abandoned unless a variance from the Department is requested.c. Any well that acts as a source of contamination shall be repaired or permanently abandoned immediately after receipt of notice from the Department.d. Abandonment shall be by forced injection of grout or pouring through a tremie pipe starting at the bottom of the well or fill material and proceeding to the surface in one continuous operation, unless compacted clay is used.e. The bored well shall be abandoned immediately upon being permanently taken out of service. The well may be filled with either bentonite-cement, neat cement, 20% high solids sodium bentonite grout, sand, or gravel to no closer than twenty feet below the ground surface. The remaining twenty feet to the ground surface shall be filled with neat cement, bentonite-cement, or 20% high solids sodium bentonite grout, or compacted clay.