Why Should I Be Concerned With the Condition of My Well?
About 95% of Georgia’s rural residents rely on their own wells for all of their household water needs—including drinking water. Wells that are properly constructed and maintained generally provide good quality water. However, wells that are improperly constructed or maintained may allow bacteria, nitrates, pesticides, or petroleum products to contaminate the groundwater. These contaminants can put family and livestock health at risk.
Farm activities near drinking water wells have caused many documented cases of well contamination. The condition of your well and its proximity to contamination sources determine the risk of contamination in your drinking water. A well with a cracked casing may allow various contaminants to enter the well. Depending on proximity to the well, feedlots, fertilizer application, animal yards, septic systems, and waste storage areas could release nitrates and bacteria that contaminate the well. Fertilizers or pesticides that are mixed and loaded near the well could spill and contaminate your family’s drinking water supply.
Proper maintenance of your well is crucial. If wells are improperly maintained, they pose a substantial risk of contamination to groundwater resources. A contaminated well also can affect your neighbors’ wells, which threatens their health in addition to your family’s. Once the groundwater supplying your well is contaminated, it is difficult and costly to clean. The only options may be treating the water, drilling a new well, or obtaining water from another source.
How Does This Assessment Help Protect Drinking Water and the Environment?
This assessment allows you to evaluate the environmental soundness of your home, farm, and operational practices related to the condition of your drinking water well. You should read and work through this entire document as it contains information that’s useful when completing the assessment.
The assessment asks a series of questions about your well’s condition and location.
The assessment evaluation uses your answers (rankings) to identify practices or structures that are at risk and should be modified to prevent well water contamination.
The well condition facts section provides an overview of sound environmental practices that may be used to prevent contamination caused directly by well condition or location.
You are encouraged to develop an action plan based on your needs as identified by the assessment.
The assessment should be conducted by you for your use.
No information from this assessment needs to leave your home.
Assessing Risk to Well Condition
For each category listed on the left, read across to the right and circle the statement that best describes the conditions on your home and/or property. If an assessment category does not apply (e.g., it asks about the separation distance of animal enclosures but you do not have any pets) then skip that question. Once you have decided on the most appropriate answer, look above that description to find your rank number (4, 3, 2, or 1) and enter that number in the “Rank” column. The entire assessment should take less than 30 min. The glossary of terms used in this assessment appears on page 15; terms that appear in italics are defined in the glossary.
What Do I Do With These Rankings?
Step 1: Identify areas determined to be at risk.
Low-risk practices (4s) are ideal and should be your goal. Low- to moderate-risk practices (3s) provide reasonable protection. Moderate- to high-risk practices (2s) provide inadequate protection in many circumstances. Highrisk practices (1s) are inadequate and pose a high risk for causing environmental, health, economic, or regulatory problems.
High-risk practices (1s) need immediate attention. Some practices may require little effort to correct, while others could be major time commitments or costly to modify. These bigger changes may require planning or prioritizing before you act. You should list all activities identified as “high risk” or “1” in your action plan. Examine rankings of “2” further to determine the exact level of risk and give the problems attention accordingly.
Step 2: Determine your well risk ranking.
The well risk ranking provides a general idea of how your well condition might be affecting your ground and surface water and contaminating your soil. Use your ranking total and the total number of areas ranked to determine your well risk ranking.
This ranking gives you an idea of how your well condition and location might be affecting your drinking water. It should serve only as a general guide and not as a precise diagnosis because it represents the average of many individual rankings.
Step 3: Read the Well Condition Facts section.
While reading, think about how you could modify your practices to address some of your moderate- and high-risk areas. If you have any questions that are not addressed in the well condition facts portion of this assessment, consult the references in the back of the publication or contact your county Extension agent for more information.
Step 4: Transfer information to a larger assessment if needed
If you are completing this assessment as part of a larger homestead assessment, you should transfer your Well Risk Ranking and your identified high-risk practices to the overall assessment.
Well Condition Facts
Improving the Condition of a Drinking Water Well
A well’s location is a crucial factor in avoiding drinking water contamination, whether it taps water from just below the ground surface or from several hundred feet down. Locating a well in a safe place takes careful planning and consideration of factors like the flow of surface water and ground water. A well located downhill from animal enclosures, a leaking fuel tank, or a failing septic system is at greater risk of contamination than a well located uphill from these contamination sources.
Surface slope does not always indicate the direction a pollutant might flow once it gets into the ground. In shallow aquifers, groundwater flow often is in the same direction as surface water flow. If the aquifer supplying water to your well is deep below the surface, the surface slope may not be an accurate indicator of groundwater flow direction. Determining groundwater movement on your own may require special monitoring equipment (see Contacts and References section).
Ensuring minimum separation distances from potential contamination sources is an integral part of wellhead protection because soil acts as a natural barrier to and filter against contaminants. The type of soil is an important determinant in the effectiveness of such protection. In sandy soils with low organic content, recommended separation distances may not offer adequate protection. State well codes may not address all activities and structures that are near the wellhead. For example, in Georgia, the Water Well Standards Act of 1985 does not specifically acknowledge some potential pollution sources such as pesticide mixing, pesticide and fertilizer application, vehicle maintenance, and waste-disposal areas.
In areas where wells are located close to livestock operations, the only specified requirement is that the well shall be not less than 100 ft from an animal or fowl enclosure. Other required setbacks are listed in Table 1 and/or illustrated in Figure 1.
Both soil and slope can make siting a well a tricky business. Greater setback distances may be required based on hydrogeology and soil type. When no distances are specified, provide as much separation as possible between your well and any potential contamination source. This is especially important if your farm is on highly permeable soils or thin soil overlying limestone bedrock, or if the contamination source or activity presents a high risk of contamination. Be sure to consider contamination sources on adjacent properties.
Minimum separation distances are regulated for new well installation. Existing wells are required by law only to meet separation requirements that were in effect at the time of well construction. Keep in mind that separation distances required by the state are minimums. You may want to choose greater separation distances depending on factors at your site. Paying attention to separation distances and proper well construction will provide reasonable assurance that your well will not be contaminated by farm activities in the near future.
Changing the location of your well in relation to contamination sources may protect your water supply, but not the groundwater itself. Any condition likely to cause groundwater contamination should be addressed, even if your well is far away from the potential source. Groundwater contamination is a violation of Georgia law, even if drinking water is not immediately affected.
Simply separating your well from a contamination source may reduce the chance of well water contamination, but it does not guarantee that the well will be safe. Storm water can carry bacteria, nitrates, oil products, pesticides, and other contaminants from one place to another. Wells located in the path of contaminated surface water may be tainted by surface water washing into an improperly sealed well.
Poor well design can allow groundwater contamination from surface water that reaches the water table without filtering through soil. Wells located in pits or wells constructed without grout or a cap can allow surface water to carry bacteria, nitrates, pesticides, fertilizer, or oil products into the drinking-water supply. Proper well design and construction reduces the risk of pollution by reducing the entry of contaminants from the surface (Figure 2).
The way in which a well is constructed, even when the design is sound, affects its ability to keep out contaminants. You should check the casing, cap, grout depth, casing depth, and aboveground height of the casing. You should also determine the well’s age, type, and depth.
The following overview of well construction and inspection can help you understand the contamination risk of your drinking water.
Casing and Well Cap. A licensed water-well contractor will install a steel or plastic pipe called casing during construction to prevent collapse of the borehole. Left unsealed, the space between the casing and the sides of the borehole, called the annular space, provides a direct channel for surface water (and contaminants) to reach the well water. To seal off the annular space, a licensed water-well contractor fills the space with grout, which can be made of cement, concrete, a special type of clay called bentonite, or a mixture of Portland cement and water, depending on the geologic materials encountered while drilling the well. Both grout and casing prevent water and contaminants from seeping into the well.
According to the requirements of Georgia law, “A well having an open annular space between the casing and borehole shall be grouted and shall be filled with neat or sand-cement or other impervious materials to prevent the entrance of pollutants or contaminants to the well.” The minimum depth of grout seal for individual wells is 10 ft. However, it is preferred for the well grout to extend all the way from the ground surface to the end of the casing depth.
You can use a light to visually inspect your well casing for holes or cracks at the surface or down the inside of the casing. If you can move the casing around by pushing against it, you may have a problem with your well’s ability to keep contaminants out. You can check the well casing by listening for water running down into the well when the pump is not running. If you hear running water, there could be a crack or hole in the casing, or the well may not be cased down to the water level. Either situation increases risk and is sufficient reason to avoid drinking the water until the situation is corrected.
To prevent contaminants from flowing into the top of the well casing, a licensed water-well contractor will install a tight-fitting, tamper-resistant, vermin-proof well cap. This prevents the entry of insects, small animals, or surface water. The cap should be firmly installed and include a screened vent so that air can enter the well. Vents should (a) face the ground, (b) be tightly connected to the well cap or seal, and (c) be properly screened to keep insects out.
Aboveground Casing Height and Concrete Curbing.
To prevent surface water or runoff from entering the well (especially during heavy rainfall), the upper terminal or section of the well casing should extend at least 12 in. above ground level. All Georgia wells built in areas subject to flooding should have a well casing that extends at least 2 ft above the level of the highest known flood of record.
The Georgia Water Well Standards Act of 1985 also states, “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.”
One of the simplest ways to curb a well is to dig a trench 4 in. deep, extend it at least 2 ft in all directions around the casing, and fill it with concrete.
Instructions for Installing a Well Curbing.
Step 1. Carefully remove soil from around the well’s casing to expose the top of the grout seal. Dig a shallow, 4-in.-deep trench around the outside of the grouting. If the grout seal is missing, you will need to use a post-hole digger to dig a hole that is 3–4 ft deep and as wide as the post-hole digger (4 to 6 in.) around the casing.
Step 2. Continue to dig a shallow, 4-in.-deep trench that extends 2 ft from the casing in all directions. Optional: Install flexible landscape edging into the ground to provide a form to pour the concrete into. It may be necessary to pile the soil excavated from the trench around the outside of the form to help ensure that the form will hold the weight of the concrete.
Step 3. Pour premixed concrete to fill the trench. The concrete should be at least 4 in. thick at its thinnest point. Before it sets, lightly trowel or brush the concrete toward the well casing so that when it dries the curbing will have enough slope to carry water away from the casing.
Step 4. After the concrete slab hardens, remove the landscape edging (if used).
Materials for Installing a Well Curbing.
For wells with an existing grout seal, a bored well with a casing that is 2 ft in diameter will require about 20 linear feet of landscape edging and 12–15 cu ft of concrete. For a drilled well with a casing that is 6 in. in diameter, a curbing will require approximately 15 ft of landscape edging and 7–10 cu ft of concrete. These numbers are for a circular concrete slab. If you desire any other shape for the slab, the numbers provided will need to be adjusted.
Curbing a well that lacks a grout seal requires considerably more labor and expense. However, it is imperative that these wells be curbed. Otherwise, they will not be protected from potential surface-water contamination.
Well age is an important factor in predicting the likelihood of contamination. A well that was constructed more than 70 years ago likely was situated at the center of the farm or in a readily accessible location when it was installed. It may be shallower than recommended and may be surrounded by many potential contamination 10UGA Cooperative Extension Bulletin 1152-03 | Improving the Condition of Your Drinking Water Well sources. Older well pumps are more likely to leak lubricating oils, which can get into the well. Older wells also are more likely to have thinner casings with gaps caused by corrosion or improper grouting. Even wells with modern casings that are 30 to 40 years old are subject to corrosion and perforations. If you have an older well, you should have it inspected by a water-well specialist or a licensed water-well contractor.
Status and Revision History
Published on Mar 18, 2004
Published on Feb 20, 2009
In Review on Jan 05, 2010
In Review for Minor Revisions on Jan 05, 2010
Published with Minor Revisions on Apr 27, 2011
Published with Minor Revisions on Mar 16, 2023