Select Page

Your Own Private Water

By Silvia Harris

Rain and snowmelt are swelling the rivers and reservoirs that many Vermonters depend on for water. But about 30 percent of the state’s residents use private wells. Whether the old-fashioned shallow dug well or converted spring, or the modern deep drilled well, such facilities can provide safe drinking water, if properly designed and maintained. If not taken care of, however, they can lead to groundwater contaminated with bacteria or chemicals, and these contaminants can cause a variety of health problems. As we humans are about 70% water, it’s important to have a constant supply of safe water to drink.

Federal and state standards for drinking-water quality help ensure that public drinking-water supplies are as safe as possible. In Vermont however, there are no set standards for one’s private well. The Vermont Department of Health (DOH), though, has published guidelines for acceptable levels of common chemical contaminants and bacteria in drinking water as well as recommendations for private well water testing. The DOH can mail you a test kit and has information on other certified water testing labs in Vermont.The DOH recommends testing private wells for bacteria once every year. The DOH bacteria test looks for the most common bacterial contaminants; coliforms and E. coli. Coliform bacteria occur naturally in the soil. This family of bacteria may not make you sick, but if they are present in your water, it is an indication that other more harmful bacteria may be present. As E. coli live only in animal intestines, the presence of these bacteria indicates fecal contamination. The DOH recommends testing your well water for the inorganic chemicals arsenic, chlorides, copper, iron, lead, manganese, nitrate, sodium, and uranium every five years. There are also some organic chemicals (pesticides and herbicides) that can make their may into your well water and should be analyzed.

Natural processes, which vary with location, season, climate, and soil type, can affect water quality. Rainwater and snowmelt stir up soil, creating muddy water that percolates through leaves, dissolves minerals in rocks and soil and reacts with microscopic soil organisms. We sometimes see the result of a heavy storm in our shallow dug wells and springs as the well water becomes temporarily silty, cloudy or odorous. Some bedrock and soil formations are more likely than others to release chemical contaminants.

Wells nearer to potential man-made pollution sources can become contaminated, particularly if they are shallow or in poor condition. For example, dug wells and wells with cracked casings close to septic systems, roads, development or livestock are susceptible to contamination with bacteria, nitrates, oil or pesticides.

How can we keep our well water clean and safe? Prevention of well water contamination is the crucial first step. Depending on the pollutant, once your well is contaminated, it can be very difficult to clean up. A contaminated well can also affect the groundwater supplying any other wells in the area.

The Vermont Water Supply Rule contains standards for well construction that minimize risk of contamination. The Department of Health has information on disinfecting wells contaminated by bacteria. Your local well driller can also offer advice on well protection, disinfection and maintenance. Or go on-line. Some good web sites on private wells are: and

Sylvia Harris is an Agricultural Resource Specialist for the Vermont Association of Conservation Districts (VACD) in southern Vermont. Her responsibilities include helping farmers protect groundwater resources, assisting in the state’s watershed planning efforts, and advising the agricultural community on accepted agricultural practices (AAP’s).