Drilling And Owning A Water Well In Tennessee

The Tennessee Water Well Act of 1963 requires all persons drilling a water well to be licensed.

A water well is any well for the production of water for beneficial use such as: domestic use, irrigation, livestock watering, etc.

A person installing a pump or water treatment device on a water well must also be licensed.

Selecting A Well Drilling Contractor

Tennessee requires that all water well drillers, pump and water treatment device installers be licensed by the State.

A list of licensed drillers and installers is available from the Division of Water Supply by calling 1-800-523-4873. The following questions should be asked of a water well driller and/or a pump or water treatment device installer:

• Will you provide a written contract?
  
  
• Does your insurance cover damages that might occur to property or other liabilities?
  
  
• Can you provide your license certificate and a list of references?
  
  
• Will you itemize what the well system will cost; include the registration fee paid to State of Tennessee?
  
  
• How will the well be constructed?
  -size of the borehole
  -type of cap
  -well casing (steel, plastic)
  -how is the well disinfected
  -type of screen, if required
  -how is the well developed
  -how is the well backfilled and sealed
  -well report furnished

Locating The Well

Quantity and availability of ground water varies considerably across the State. A licensed driller and/or a representative of the Division of Water Supply can help determine the prospects for ground water in your area.

• Locate the well a safe distance from potential sources of contamination. The following distances of separation are required by regulation:

Potential Sources of Contamination Minimum Distances

• The well site should not be subject to flooding. If site conditions make it necessary to construct a well in an area subject to flooding, the watertight casing should extend at least two (2) feet above the 100-year flood elevation.
  
  
• The well should be at least five (5) feet away from any overhanging rooftops or power lines.
  
  
• The well should not be constructed in pits, basements or in areas where future construction may take place. The ground should slope away from the top of the well. For a well on a hillside, the uphill side of the well should be designed to prevent runoff from entering the well.
  
  
• The well should not be located closer than ten (10) feet from a property line.

Constructing The Well

Although the type and depth of well construction varies with location, there are several important things to be aware of concerning the construction of a well:

• The outside diameter of most private, domestic water wells is 6 5/8 inches in Middle and East TN, and 4 inches in West TN.
  
  
• New black or galvanized steel casing is required when drilling and completing a well in bedrock. Most wells in Middle and East Tennessee require steel casing.
  
  
• Wells developed in sand or other loose material may be cased with plastic pipe approved by the National Sanitation Foundation (NSF) with a minimum stress design rating Standard Dimension Ratio (SDR) 26.
  
  
• Watertight casing should extend at least six (6) inches above ground level; a minimum of two (2) feet for areas subject to flooding.
  
  
• Wells constructed in bedrock should have watertight casing down to nineteen (19) feet or five (5) feet into the top of bedrock, whichever is greater.
  
  
• Wells constructed in unconsolidated material such as sand or gravel should have watertight casing down to nineteen (19) feet or to the top of the aquifer, whichever is greater.
  
  
• The well should be sealed at the top of the casing with a suitable cap or sanitary seal.
  
  
• The outside of the well casing should be backfilled with an impervious material such as cement grout or bentonite clay, from a minimum of three (3) feet to ten (10) feet below land surface to prevent surface water from entering the well. The remaining backfill material may consist of bentonite, cement, drill cuttings or a mix of cuttings and bentonite. The backfill should be free of cracks or any evidence of collapse.
  
  
• The size of the pump and storage tank needed depends upon the yield of the well and the number of persons in the household. Generally, a well which yields 3-5 gallons per minute or more will adequately serve a household of four (4) to six (6) people.
  
  
• Underground pipes leading from the well should be fitted with a pitless adaptor, which provides a watertight, frost-free connection.
  
  
• The driller is required to "develop" the well after the drilling is completed to remove any debris, sediment or cuttings from the well.
  
  
• Following development of the well, the driller should disinfect the well to kill any bacteria which may have been introduced into the well during drilling and/or pump installation.
  
  
• The driller is required to send a Tennessee Water Well Drillers Report (CN-0825) to the Division of Water Supply. The report must give the name and address of the owner, the location of the well, the date of completion and a description of the well’s construction. The well owner should request a copy of this report from the driller. This report may be valuable to you or subsequent owners in the event of any problem with the well.
  
  
• The well casing should never be cut off by the owner after the well is completed. Not only is the well I.D. tag lost, but the well becomes more susceptible to surface water and bacterial contamination.
  
  
• The use and/or storage of chemicals, including pesticides, gasoline, paint thinner, solvents, etc., should not take place within a twenty (20) ft. radius of the well.

Disinfecting The Well

Bacteria can enter a well from the handling of the pump and pipe as well as from the drilling equipment. A strong chlorine solution will kill most bacteria in a well if allowed to remain for at least twelve (12) hours. The Water Well Construction standards require both the driller and pump installer to disinfect the well.

• To disinfect the well, pour into the well one (1) gallon of chlorine bleach or one (1) ounce HTH super chlorinated solution for every fifty (50) feet of well depth.
  
  
• Once the chlorine is in the well, the faucets in the home should run until a chlorine odor is noticed. The water is then turned off and allowed to remain in the well and pipes for at least twelve (12) hours.
  
  
• After twelve (12) hours, the water should be pumped out of the well until the chlorine odor is gone. Do not run heavily chlorinated wastewater through a septic tank system or discharge into a surface water body.
  
  
• The disinfection procedure should be repeated each time the well, pump or pipes are serviced.

Installing a Pump

Pumps must be installed by a licensed installer. Selection of the correct pump is based in part upon the diameter of the well casing, well depth, static water level, well yield, friction loss, vertical lift, drawdown, and number of water fixtures or residents in the home. The installer will use these figures to determine the appropriate size and type pump for your water well. Installation must follow National Electric Code (NEC) Standards. All pumps must be grounded from the pump motor frame to the service entrance per NEC Section 250-43 (k). Also, any pump placed in metal casing must be grounded to the casing above land surface, either by welding the ground wire or using a crimp or set screw.

In addition, proper electrical cables should be selected. Type "TW" wire, Submersible Pump Cable, should never be buried directly in the ground unless it is placed in conduit and buried eighteen (18) inches deep. Type "UF" and Type "USE" cable may be directly buried twenty-four (24) inches deep. Consult the NEC for more information.

Testing The Water Quality

It is strongly recommended that private water supplies be tested annually for bacteria. You can contact your county health department and request that your water be tested for coliform bacteria. Coliform bacteria are indicator organisms used to assess the potential for disease causing-bacteria in well water. If your well tests positive for bacteria, disinfect the well and have it retested. If bacteria persists in the well, it may be necessary to install some type of permanent disinfection equipment, such as a chlorinator or ultraviolet light. If you have reason to suspect that your well is contaminated by a chemical pollutant, contact an Environmental Assistance Center at 1-888-891-8332 to obtain a list of private labs certified for drinking water analysis.

Well Abandonment

Existing wells no longer in service or those that may pose a threat to ground water should be properly backfilled and abandoned. The Division recommends that these wells be abandoned by a licensed water well driller.

Licensed well drillers are required to backfill and abandon in accordance with state standards any newly drilled well in which casing has not been installed or from which casing has been removed.

Where Can I Get More Information?

To get more information on water wells or a list of licensed well drillers and pump or treatment installers, contact one of the offices listed below.

Division of Water Supply

Nashville Central Office
401 Church Street
L&C Tower, 6^th FL
Nashville, TN 37243-1549
1-800-523-4873

Statewide Environmental Field Offices

1-888-891-8332

The Tennessee Department of Environment and Conservation is committed to the principles of equal opportunity, equal access and affirmative action. Contact the TDEC EEO/AA Coordinator or the ADA Coordinator on the 21st Floor L&C Tower, 401 Church Street, Nashville, Tennessee 37243, 615-532-0103 for further information. Hearing impaired callers may use the Tennessee Relay Service (1-800-848-0298).