If you’re purchasing a home that relies on well water, it’s a good idea to test the water, or verify test results, to determine if the water is safe to drink. If the homeowner who is selling the property cannot show proof that the water has been tested for the presence of coliform bacteria or nitrates, the potential buyers should request tests be performed or perform them themselves.
Since wells rely on ground water that’s replenished by rain that falls to the ground for several miles surrounding the well, contamination can come from sources outside the property the well sits on. Possible sources of well contamination include septic systems, agricultural and residential fertilizers and pesticides, animal waste, and industrial spills.
The presence of coliform bacteria can indicate the presence of other disease-producing organisms in the water supply, including viruses and other microorganisms. While coliform bacteria is usually naturally filtered out of rain water and other sources as it percolates through the soil, a poorly constructed, sealed or maintained well can become polluted by the bacteria.
If high levels of bacteria are found, it will likely be necessary to address and repair deficiencies with the well’s integrity or design. A disinfection of the well and the home’s plumbing system would also likely be required.
Nitrates are a byproduct from agricultural fertilizers, municipal wastewater and decaying plant debris. Although it’s commonly found in many forms of food, nitrates in water can cause health complications in children under 6 months old.
Well water should be tested about once a year, or whenever the water’s appearance, taste or odor changes dramatically. Water that doesn’t contain bacteria or nitrates may still pose potential problems.
Hard water, for example, has a high mineral content that can corrode faucets, damage washing machines and cause other problems with plumbing and appliances that worsen over time.
Local or state health departments maintain local drinking water standards, including determining local well water pollution hazards and acceptable levels of contaminants in the water supply. These offices often provide free or low cost well water testing.If you’re concerned about your home or potential home’s well water, check with your local health department for more details about testing.
In addition to testing for bacteria and other harmful contaminants before purchasing a home with a well, if the home has been vacant for a long period of time, the well should be tested for proper operation. Left unused for a long period of time, a well can develop high levels of sediment that may prevent the pump from operating properly.