The U.S. Environmental Protection Agency’s (EPA) Water Infrastructure Resiliency and Finance Center, in collaboration with the...
Selecting the right combination of tests for water wells
Approximately 30 million Americans get their drinking water from private household wells. Protection of private wells does not fall under the U.S. Environmental Protection Agency’s (EPA) Safe Drinking Water Act, so well owners must take it upon themselves to ensure their water quality. To keep water clean and pure and the well operating at peak performance, regular water testing is an important maintenance tool.
At a minimum, well water should be tested every year for bacteria, the most common water quality problem. Other tests may be required, depending on the region and potential contaminants located near the water supply.
If the well is in an area of intensive agricultural use, testing for nitrates and possibly ammonia and the pesticides commonly used in that region is necessary. If household tests for radon in the air are high, it is critical to test for radon in the water. If there are problems with water taste, odor, staining or color, then test iron, manganese, chlorine and sulfate levels.
Testing more than once a year may be warranted in special situations, such as when:
Contact the local health department, cooperative extension service, state health or environmental agency or a well professional for guidance in selecting tests.
If you are using a third-party agency for water testing, approach it as a smart shopper. Get an up-to-date list of all state-approved laboratories and the specific tests they are certified to perform from the state health or environmental agency. Check with individual laboratories to get prices. Ask how soon to expect results and about the information that will be provided with the test results. A good lab should help interpret the results and make sense of the scientific data.
The laboratory chosen should provide specific sampling instructions and clean bottles in which to collect the water samples. Carefully follow instructions for taking samples. This is the most important part of testing — a carelessly collected sample can give inaccurate results.
The report of analysis, or test results, can take a variety of forms. It may be a computer printout of results for the specific tests requested, or a preprinted form with the results typed or written into blocks or spaces. It may include some general information about the laboratory that performs the test and the types of tests that
were done, or it may provide only the results.
The amount of a specific contaminant in the water sample will be expressed as a concentration of a specific weight of the substance in a specific volume of water.
The test results also may include other symbols and abbreviations. Laboratory methods have detection limits, or levels below which contaminants cannot be reliably detected. That does not necessarily mean that the chemical is not present, but there could be so little present that it cannot be reliably detected with the laboratory equipment or testing procedures being used.
The important question is whether the contaminant poses a health threat at that particular concentration. Compare the water test results with the federal standards and to other guidance numbers, such as health advisories, to assess the potential for health problems. If in doubt, contact your state health department or environmental agency, the local extension service or a water well professional.
Wells are viable, sustainable and cost-effective. Yearly testing is an important step in the maintenance of these safe drinking water systems.