People are exposed to lead from a variety of sources. In Virginia there are negligible amounts of lead in surface water and groundwater, but the water in household plumbing systems can contain high levels of lead. Because lead is a serious health hazard, it is very important to reduce lead contamination of drinking water.

Iron and manganese are metallic elements that are found in the earth's crust. These elements usually do not present a health hazard when they are present in the household water supply; however, they can cause nuisance problems, such as staining and objectionable taste.