Ground water in Georgia is generally of very high quality and, for the most part, is free of manmade contamination. Where wells have been tested and found to be contaminated, the source of contamination is usually at or very near the well site. For this reason, it is vital to do all you can to protect your well and the surrounding area from all potential sources of pollution.

A good supply of fresh water is essential to human existence. We use fresh water not only for drinking, but for bathing, growing food, cleaning, watering animals and watering lawns. In Georgia, about 95 percent of rural residents get their household water supply from private wells. If they are not properly protected, these wells are at risk of being contaminated from several sources.

Potential sources of ground water contamination which may be present near your home include:

• Septic tanks.
• Animal waste.
• Pesticides.
• Fertilizers.
• Fuel storage tanks.
• Household chemicals, used motor oil, etc.

SIX PRINCIPLES OF WELLHEAD PROTECTION

There are six principles of wellhead protection that you as a homeowner should do to insure that you don't contaminate your own well and, in the process, possibly contaminate other wells in your area: (1) proper well siting; (2) proper well construction; (3) keeping contaminates away from well; (4) backflow prevention; (5) sealing abandoned wells; and (6) testing well water.

1. Proper Well Siting

Proper well location can go a long way toward preventing contamination of a well. Unfortunately, many landowners place a higher priority on convenience and cost when deciding where to drill a well.

Locate the well a safe distance away from all present or future sources of potential pollutants (See Rule 3). Where known sources of contaminants exist, locate the well in a direction opposite the ground water flow (if known) and as far removed as the general layout of the premises and surroundings permits.

If possible, avoid locating a well in areas which are subject to flooding. If this is not possible, the well casing should extend at least two feet above the level of the highest known flood of record. Avoid low-lying areas and depressions where standing water is likely to accumulate around the well. Install the well where surface water can be diverted away from the wellhead.

2. Proper Well Construction

When contamination occurs at a well site, it is usually the result of a pollutant entering the well either down the inside of the casing or around the outside of the casing. A well which is improperly constructed creates a direct conduit between the ground surface and the underground water supply.

In 1985, the Georgia legislature passed the "Water Well Standards Act of 1985." Among other things, this law provides standards for the construction, operation, maintenance and abandonment of wells and bore holes. It also requires that all well drillers have a state license.

The following is a list of some of the well construction requirements for a private well which should interest anyone who is having a well drilled:

"Water-bearing formations that are likely to be polluted shall be sealed off;"

"All drilled cuttings and other materials shall be removed from the entire depth of the well and the well shall be disinfected;"

"The upper terminal of the well shall be protected by a sanitary seal or cover to prevent entrance of pollutants to the well;"

"The drilling contractor shall maintain in his office and shall furnish the owner a copy of the well construction data within 30 days of the well completion."

"A well having an open annular space between the casing and the bore hole shall be grouted and shall be filled with neat or sand cement grout or other impervious materials to prevent the entrance of pollutants or contaminants to the well." The minimum depth of seal for individual wells is 10 feet. It is preferred, however, that the well grout extend all the way from the ground surface to the water-bearing formation.

"All individual and nonpublic wells shall be curbed at the surface by the owner with a watertight curbing of concrete at least four inches thick and extending at least two feet in all directions from the well casing and sloping away from the casing;"

The requirements most often violated which pose a threat to ground water include lack of adequate grouting, lack of a proper seal at the top of the casing, lack of a concrete slab around the well casing and failure to disinfect the well after construction or well service.

The most common method for disinfecting a well involves placing a strong chlorine solution in the well to kill any microorganisms which might be present.

3. Keeping Contaminants Away from Well

To reduce the chances of an accidental spill near a well, or contamination of soil around a well, maintain certain minimum horizontal distances between the well and sources of contamination. Here are some recommended minimum distances to maintain between a well and potential pollution sources which might exist near a rural home:

Septic tank: 50 feet.
Septic tank absorption field: 100 feet.
Waste lagoon: 150 feet.
Dead animal burial pits: 150 feet.
Animal or fowl enclosure: 100 feet.
Pesticide storage, mixing and loading facilities: 100 feet.
Fertilizer storage: 100 feet.
Petroleum storage: 100 feet.

Do not mix pesticides or discard empty pesticide containers near a well. Keep all such activities at least 100 feet from the well. Never store pesticides or fertilizers in the pump house next to a well.

Use all household chemicals (cleaners, solvents, etc.) completely for their intended purpose and properly dispose of the empty containers. Do not store or discard such items near your well site. Also, never dispose of excess household chemicals by flushing them down the toilet. The chemicals will enter the septic tank and could contaminate ground water in the area.

If you change the oil in your vehicles yourself, be sure to collect the oil in a container and carry it to a collection center for recycling. Some auto repair shops and service stations will accept used motor oil. Never dispose of the oil by dumping it on the ground.

4. Backflow Prevention

Back-siphoning, or backflow, of concentrated pollutants is one of the more hazardous situations that can happen with a private well. The several ways backflow can occur can all be prevented.

Backflow usually occurs when a well shuts off unexpectedly (power failure, lightning damage, etc.). When this happens, most private wells have a single check valve which prevents the water in the column pipe from falling back into the well. However, if the check valve leaks (and they often do), the water will flow back into the well, creating a suction throughout the water delivery system. If you were filling a pesticide tank with water when this happened, and the end of the hose were submerged in the tank, a siphoning effect could be created and an entire tank of chemical could end up in your well.

This situation could be prevented by never submerging the end of a water hose into any material which could contaminate a well. Better yet, install a simple atmospheric vacuum breaker on each outside faucet to prevent backflow. Many municipal water systems require that homeowners use these devices.

Many homeowners often use a hose-end device to apply fertilizers or pesticides to their lawn. These devices typically consist of a quart jar to hold the chemical and a proportioning device which attaches to the end of a water hose. Never leave these connected to the end of a water hose.

Backflow can also occur in lawn sprinkler systems. If one sprinkler happens to be in a low area with a puddle of water above it, this contaminated surface water could be siphoned into the well. Several devices can prevent this from happening, but one of the simplest and most common is a double check valve backflow preventer installed between the well and the irrigation system. You can buy these from any irrigation dealer and most plumbing suppliers. Injecting chemicals or fertilizers into your irrigation system creates a higher degree of hazard. This situation could call for a more expensive device called a reduced pressure zone (RPZ) backflow preventer.

5. Sealing Abandoned Wells

Many parcels of land in Georgia have old abandoned wells. These wells pose a potential threat to operating wells in the area because they can serve as a conduit for contaminants at the surface to enter the aquifer. Never use an abandoned well to dispose of garbage or any other material which could contaminate ground water.

The "Water Well Standards Act of 1985" requires that all abandoned wells in the state must be "filled, sealed and plugged." In order to legally seal an abandoned well, the work must be performed by a licensed water well contractor or by a county or municipal government. Some counties in Georgia will fill abandoned wells if the landowner reports it to them.

6. Testing Well Water

All private wells in Georgia (farm, residential or otherwise) should be tested routinely to insure that no contamination has occurred. All wells should at least be tested for bacteria and nitrates. Test shallow wells drawing from water table aquifers at least once a year. Check deeper wells tapping confined aquifers at least every three years. A complete mineral analysis should be done on all wells every three years. This test should include copper, lead and other heavy metals and may include iron, manganese, hardness and other minerals which can cause tastes or staining problems.

A test for pesticides, petroleum products or other volatile organic chemicals is usually not needed on a routine basis. If you suspect contamination from any of these sources, however, these tests are available. It helps if you can specify which particular chemicals you suspect. Otherwise, the cost can be very high.

Municipal water supplies are regulated and routinely monitored by state and federal agencies. There are no monitoring regulations, however, for private wells and, therefore, it is the responsibility of the well owner to insure the safety of the water.

To have your water tested, contact your county Extension agent to test for mineral analysis, nitrates, pesticides or volatile organic chemicals. The health department in most counties will perform a coliform bacteria test. Several private labs in the state also offer these services.

REFERENCES

Individual Water Supply in Georgia - Construction of Wells. Georgia Department of Human Resources Publication. July, 1971.

McManus, Maxine. Water Quality and Private Water Supplies. University of Tennessee Extension Bulletin PB 1357. 1990.

Pesticides in Drinking-Water Wells. EPA Publication H-7506C. September, 1989.

Private Water Systems Handbook. Midwest Plan Service MWPS-14. 1979.

Protecting Our Groundwater - A Grower's Guide, produced by American Farm Bureau Federation, National Agricultural Aviation Association, National Agricultural Chemicals Association, USDA Extension Service.

Tyson, A. W. Proper Well Construction to Prevent Groundwater Contamination. UGA Miscellaneous Leaflet. 1990.

Water Well Standards Act of 1985. Georgia House Bill No. 32. 1985.

Wellhead Protection - Keeping your Well Water Safe. Publication of Alliance for a Clean Rural Environment. 1991.

The University of Georgia and Ft. Valley State College, the U.S. Department of Agriculture and counties of the state cooperating. The Cooperative Extension Service offers educational programs, assistance and materials to all people without regard to race, color, national origin, age, sex or disability.

An Equal Opportunity Employer/Affirmative Action Organization Committed to a Diverse Work Force

Issued in furtherance of Cooperative Extenison work, Acts of May 8 and June 30, 1914, The University of Georgia College of Agricultural and Environmental Sciences and the U.S. Department of Agriculture cooperating.

Gale A. Buchanan, Dean and Director