Whether you use a private well or are connected to a public drinking water system, the water that flows from your tap is likely ground water, as it provides 95% of Idaho's drinking water. If your water is from a public system, you rely on your water provider to ensure your water is safe to drink. However, if you use a private well, you are responsible for the safety of your water. Since wells (public and private) are drilled into ground water, the same contaminants present in ground water, such as nitrate and arsenic, can be present in well water.
In Idaho, DEQ and the Idaho Department of Water Resources (IDWR) share responsibility for managing Idaho's ground water resources. DEQ is charged with protecting the quality of ground water in Idaho; IDWR concentrates on ground water quantity. One of IDWR's specific responsibilities is to regulate the drilling of all wells in Idaho, including private drinking water wells.
Well Owner's Responsibility
Public water suppliers are required to test their drinking water regularly and make these tests results available to the public. If you use a private well, it is your responsibility to maintain the well and ensure your water is safe to drink. To do this, you must periodically test the well water for contaminants and protect the wellhead.
Testing Well Water
It is recommended that private drinking water wells be tested for contaminants at least once per year (test for nitrate more frequently if a pregnant woman or an infant will be using the water). Contact your DEQ regional office or public health district to learn about constituents of concern in your area. Nitrate, total coliform, and arsenic are three of the most common contaminants in Idaho,
To test your water, you can take water samples yourself and have them tested by a laboratory. Click here for a list of Idaho-certified laboratories. The laboratory, your DEQ regional office, or public health district can tell you how to get the necessary sample containers, how to take the sample, and how quickly you must get the sample to the laboratory. If you do not want to take the samples yourself, an environmental consultant can sample for you.
A sudden change in the taste, odor, or appearance of your drinking water may indicate contamination or a problem with your system that may warrant testing. Contact your local public health district for advice.
Protecting Your Wellhead
Proper well design, construction, and maintenance can reduce the chance that surface contaminants will get into your well water in the first place. Identify and remove sources of contaminants near the well. Fertilizers, animal wastes, pesticides, and other sources of contamination should be located and managed so that they do not contaminate the well. If a contaminant source is found to be impacting a well, you may need to hire a licensed well contractor to permanently seal and relocate the well.
It is also a good idea to have the well inspected by a licensed well contractor if the well is old, or if you do not know whether it is structurally sound. Problems with land use related contaminants, such as nitrate and pesticides, are sometimes caused by structural flaws, which allow contaminated surface water to enter the well. Repairing the well or constructing a new, deeper well may reduce the level of land use related contaminants in your water. To find licensed well drillers in your area, contact the Idaho Department of Water Resources.
Inspect your well and surrounding area frequently and follow the guidelines below when working on or near a well.
Properly install and maintain the well.
- Research ground water and area conditions and potential contaminant sources, including neighboring and historical land uses, prior to drilling a new well.
- Hire a licensed well driller for well construction, modification, and abandonment and closure. Idaho law requires all well drillers to be licensed and to obtain a permit before drilling a well. Some older wells drilled prior to this ruling may not be constructed to current standards and may need to be updated.
- Keep accurate records of well maintenance.
- Obtain a copy of your well log (if available). If you are having a new well drilled, get a copy of the log from the well driller. Well logs for wells drilled since 1987 are on file with the Idaho Department of Water Resources.
Inspect the well and area surrounding it regularly.
- Exposed parts of the well: Are the well casing, well cap, and surface seals intact and in good shape? Is the top of the well at least 18 inches above the ground?
- Area around the well: Is it sloped to drain surface water away from the well?
- Lawn watering system: Are the valves set properly to prevent backflow?
Take precautions when working on or near a well.
- Avoid mixing or using fertilizers, herbicides, fuels, motor oil, and other pollutants near the well.
- Do not pile snow, leaves, or other materials around the well.
- Take care when working or mowing around the well to avoid damaging the casing.
Take precautions with your septic system.
- Properly locate your septic system to reduce the potential of contaminant migration from the septic system to the well.
- Properly maintain your septic system and never dispose of hazardous materials in it.
- Avoid planting trees or driving on your drainfield.
- Pump and service your septic system every two to three years.
What to Do if You Have Problems With Water Quality
It is important first to distinguish between water quality problems that may be harmful to your health and water quality problems that are only aesthetic problems. Hard water is a common aesthetic problem; a contaminant such as total coliform is a potential health problem.
If your well water tests positive for a contaminant that may harm your health, discuss your test results with an environmental health specialist at your local public health district. These professionals can help you determine if your health is at risk.
If you determine your water is contaminated to a point that it may harm your health, fix the problem as soon as possible. You may need to find an alternative drinking water source (for temporary or permanent use), disinfect your well, repair your system, or install a water treatment device.
Many different treatment devices are available. However, no one treatment unit can solve all water quality problems; you may need to purchase several units (combine them in to one system) to treat all of your problems. Research all possible treatment devices carefully to find the best solution for your problem. Before you purchase a system, contact the National Sanitation Foundation (1-800-673-6275) to ensure the treatment system is certified to perform as stated or has the National Sanitation Foundation seal of approval.
If you have elevated levels of nitrate in your water, do NOT boil it in an attempt to remove the nitrate; boiling concentrates the nitrate instead. Treat nitrate with a water treatment system designed to remove nitrate.