Approximately one-half the population of the United States uses groundwater as a drinking water supply. Most groundwater is naturally clean and free of pollutants, but contamination of groundwater can cause serious health effects from harmful bacteria and nitrates. Elevated nitrate levels can pose a risk to infants. Babies under six months of age are particularly susceptible to health problems from high nitrate-nitrogen levels, resulting in the condition known as methemoglobinemia(blue baby syndrome). Wildlife can also be harmed by contaminated groundwater. Excessive levels of nutrients such as nitrogen and phosphorus can harm the health of freshwater and marine ecosystems. See the The Massachusetts Estuaries Project and Reports for information on Massachusetts coastal waters polluted by excess nitrogen in groundwater.
The U.S. Environmental Protection Agency maintains a collection of historical reports on Groveland Wells, which can be accessed here.