Common Groundwater Pollutants

Overuse of groundwater has caused water tables in some areas to become diminished.

Nearly 25 percent of all water used in the U.S. comes from the ground, and approximately half the population in the country relies on groundwater to meet a portion of their water needs. According to the Environmental Protection Agency, of the 70,000 organic chemicals that can be found in groundwater, 654 are hazardous to humans.

Organic

Organic Chemicals that have been detected in groundwater include degreasers, petroleum components, pesticides, solvents, industrial by-products, viral pathogens and bacterial pathogens. Carbon and hydrogen are common toxic components of these chemicals. They can also contain chlorine, sulfur, phosphorus and nitrogen. Trace amounts of these pollutants can be found in groundwater. The concentration is measured in parts per billion and parts per trillion. One part per billion is the equivalent to a teaspoon of creamer in 1.3 million gallons of coffee.

Organic Pollutants' Health Effects

The effects on humans is difficult to determine, though toxic substances are known to cause birth defects, cancer, and other chronic ailments. Most health problems resulting from groundwater organic pollutants are not fatal. Health problems related to "nonlethal acute toxicity" are easier to detect because they are generally short and reversible. Patients suffering from the nonlethal effects often fully recover after exposure to the contaminated water stops.

Inorganic Health Effects

Inorganic pollutants include fertilizers, decayed organics, chlorides and nitrates. Heavy metals such as lead and copper are also toxic. Some amount of nitrate can be consumed by adults without harmful effects, but if a baby younger than six months drinks or eats food containing nitrate, it turns into nitrite, which is toxic and can kill. The fatal condition is called methemoglobinemia, or blue baby syndrome. As the name implies, bluish skin around the eyes and mouth of an infant are symptoms of methemoglobinemia.

Fertilizers and Pesticides

Fertilizers and pesticides fall under the category of inorganic pollutants. These are usually produced by farmers and urban residents maintaining their lawn. When the chemicals are absorbed through the ground, they can reach aquifers, which supply municipalities with drinking water. Farmers have to be particularly careful not to contaminate their wells.

Common Sources

Contaminants that could be either organic or inorganic come from seepage around industrial waste disposal sites and leaky storage tanks, as well as runoff from municipalities and landfills. Pollutants seeping into water from larger sites can seriously effect the toxicity of groundwater for an entire community.

References

• Water Encyclopedia: Pollution of Groundwater
• North Carolina State University: Pollutants in Groundwater, Health Effects