Although a vast majority of Americans get their water from a municipal water source, over 20 million Americans have privately owned wells. This section is designed to provide private well owners with general information on water quality and the special needs of well water users.
Even though many municipalities obtain their drinking water from wells, there are two main differences between municipal well water and private well water:
Because water supplied by a public utility is regulated be the EPA and individuals states, consumers of water supplied from a municipality can be quite confident that their water quality meets specific health guidelines. However, very few regulations exist to govern the quality of private well water supplies. Typically, well water is required to be evaluated for microbiological contamination only at the time the well is installed. Some health departments have begun requiring microbiological testing when the property changes ownership as well. During routine operation, however, it is up to the well owner to monitor and ensure the quality of their well water supply.
There are several basic tests that private well owners may wish to consider having performed on their well water supplies to determine its quality. Many county health departments offer water testing, or you may want to consider using an accredited private testing laboratory.
In addition, private well water can be influenced by many local and regional factors. Some of these factors are natural, and others are the result of human activity. Although there are a wide variety of possible factors, some of the more common factors can be evaluated through the following tests:
Well water users can sometimes experience odor or staining problems on appliances and laundry. Several of the more common complaints are described below.
Once your water has been analyzed, you can compare your test results against EPA or state drinking water regulations to see if any contaminants are exceeding recommended levels. Once you have identified if any problems exist, you can begin your search for a specific treatment for your well water.
The treatment of well water will depend on the result of your water quality analysis. Some water quality problems are better handled through point-of-entry applications, such as color and odor problems, or conditions such as hardness. Other contaminants can be best handled through point-of-use devices.
Keep in mind that some treatment technologies may require that the homeowner pretreat the water in order for the product to be effective. For example, reverse osmosis systems designed for arsenic or nitrate reduction will last longer if hard water is softened prior to entering the unit. In addition, arsenic can be present in water in two forms - if your water contains trivalent arsenic (Arsenic 3 or Arsenite), prechlorination will be required prior to using a reverse osmosis system.
If you decide to install a home water treatment device, it is important to ensure the system is installed and operated according to the manufacturer's instructions. In addition, it is important to conduct follow-up testing of the treated water to ensure the system is working well. The system may have to be adjusted depending upon its performance. Follow-up testing should be conducted several times throughout the first year of operation of the treatment system and after any adjustment made to the system.
You should continue to monitor the quality of your well water at least annually, even if you choose not to use a home water treatment system. This continuing analysis will help you to determine if the quality of your well water has changed during the previous year. If you installed a home water treatment product, the annual analysis will also help you to determine how well your system is functioning and whether maintenance or replacement of components such as filter cartridges may be necessary.
When selecting a water treatment system, it is important that you verify that the technology is safe and effective. One good way to ensure that water treatment products are both safe and effective is to use only certified water treatment devices. Certification by NSF to NSF/ANSI standards means that the manufacturer's performance claims have been validated and that the materials used in the construction of the product have been determined by toxicologists to be safe for use with potable water. In addition, NSF ensures that the product literature is correct and not misleading. Through ongoing certification audits of manufacturing facilities and periodic retesting of the system, we also ensure that the water treatment products we certify continue to meet rigorous public health standards year after year.
Please visit our online drinking water treatment unit product database if you wish to obtain further information on the water treatment products analyzed by NSF International. If you would like further information on the various contaminants commonly found in drinking water supplies, please checked out the Common Contaminants section of our consumer web pages.
For further questions regarding NSF or any of its product certification programs, please contact our Consumer Affairs Office.
To assist consumers in obtaining further information on the subject of well water quality and treatment, NSF has assembled the following list of resources: