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
|Sewage Lagoons; Leaching Pits||200 feet|
|Animal Pens; Feed Lots||100 feet|
|Sludge; Septage Disposal Sites||100 feet|
|Pit Privies||75 feet|
|Sewer Lines||50 feet|
|Septic Tanks; Drain Fields||50 feet|
|House To Septic Tank Connections (Tightline)||10 feet|
- 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
- The well should
be at least five (5) feet away from any overhanging rooftops or power
- 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
- 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
- The well should
be sealed at the top of the casing with a suitable cap or sanitary
- 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
- 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 wells 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.
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, 6th FL
Nashville, TN 37243-1549
Statewide Environmental Field Offices
537 Brick Church Pike
Nashville, TN 37243
540 McCallie Avenue
Chattanooga, TN 37402
2305 Silverdale RD
Johnson City, TN 37601
3711 Middlebrook Pike
Knoxville, TN 37921
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).
|Tennessee Department of Environment and Conservation Authorization No. 327756, 5,000 copies. This public document was promulgated at a cost of $0.04 per copy, June 1999.|