How can a water supply be protected from nitrate contamination?
When selecting a new well location, be sure to consider possible sources of contamination. Generally, the farther water travels through soil, the safer it becomes as contaminants are diluted or filtered out. Nitrate is an exception. It is not filtered out of water by the soil, so a new well must be totally isolated from nitrate leaching to prevent contamination. Because different soils have different filtering abilities, standards for well depths and for distances between wells and contaminants cannot guarantee a safe well. The minimum standards governing on-site sewage systems specified by the Missouri Department of Health or Missouri Department of Natural Resources are intended to provide the minimum distances and standards to protect private groundwater and surface water supplies. New and existing wells also need to be protected from surface drainage. Barnyard surface runoff, for example, can drain directly into an unprotected well and cause serious contamination. Also, if a well is
