Shallow, older wells in Connecticut are more likely to pose a health risk, because shallow groundwater may become more easily contaminated and metal casings in older wells may have deteriorated over time. In surveys of private wells, it has been found that CT wells less than 50 feet deep or more than 40 years old are more likely to be contaminated with nitrate or bacteria.
However, a deep well is no guarantee against contamination from surface sources if the well is not properly constructed or maintained. If a deep well is properly constructed and still contains nitrate, the source of contamination may be a considerable distance away and difficult or impossible to locate.
Bacteria and nitrates are pollutants found in human and animal wastes. Septic tanks can cause bacterial and nitrate pollution. So can large numbers of farm animals. Both septic systems and animal manures must be carefully managed to prevent pollution. Sanitary landfills and garbage dumps are also sources.
Children and some adults are at extra risk when exposed to water-born bacteria. These include the elderly and people whose immune systems are compromised due to AIDS or treatments for cancer. Fertilizers can add to nitrate problems. Nitrates cause a health threat in very young infants called “blue baby” syndrome. This condition disrupts oxygen flow in the blood.
Typically well water tests include testing for bacteria, lead and nitrate and nitrites, as well as contaminants of local concern, such as arsenic or radon. More sophisticated tests can include Volatile Organic Compounds (VOCs).
In older homes, the wellhead is often located in the basement or under the back steps. New wells or replacements may not be drilled within the foundation and must meet CT state requirements for separation distances from the house, sewers, septic system, and other water bodies.
