Groundwater, Surface Water, Hydrology, Water 101
Brief History of Nebraska Irrigation | Nitrate and Bacteria are Primary Nebraska Concerns | Water Basics | What is Groundwater?
Nitrate, Bacteria Main Source of Concern in Nebraska
While municipal wells are regulated by state and federal standards, private wells are not. Owners of a private water supply are responsible for ensuring that their water supply is safe.
The most common contaminants found in private wells are bacteria and nitrate. The only way to know if your water contains harmful bacteria or high levels of nitrate is to have it tested.
Bacteria in drinking water can be hazardous to human and animal health. Sources of bacterial pollution include runoff from feedlots, pastures and other land areas where animal wastes are deposited, and the discharge from septic tanks and sewage treatment facilities. Human and domestic animal wastes are primary sources of bacteria found in water.
The bacterial safety of drinking water is checked by testing for coliform bacteria, which are commonly associated with human and livestock waste. By observing coliform bacteria, the increase and decrease of other disease-causing bacteria also can be estimated. The coliform bacteria may not necessarily produce disease, but can indicate the presence of other bacteria, which may cause infections, hepatitis, typhoid fever and other illnesses. Nitrate-nitrogen is a basic part of the environment and is essential for living things. It is the nutrient most used for crop production.
However, excessive concentrations of nitrate-nitrogen can be hazardous to human and animal health. Nitrate-nitrogen in groundwater may come from sewage disposal systems and livestock facilities, from fertilized cropland or from naturally occurring sources of nitrogen.
The Environmental Protection Agency has set 10 milligrams of nitrate-nitrogen per liter as the Maximum Contaminant Level for public water systems. The main health hazard from nitrate-nitrogen results when nitrate is reduced to nitrite in the digestive system. Nitrite reduces the ability of the blood to carry oxygen and can result in "blue baby syndrome" in newborns. Pregnant women and infants should drink water that contains less than 10 mg of nitrate-nitrogen.
Adults are less sensitive to nitrate and can tolerate a higher level of nitrate. However, little is known about the possible long-term effects of drinking high nitrate content water. A potential cancer risk from nitrate (and nitrite) in water and food has been reported. The magnitude of the risk of cancer from nitrate in drinking water is not known.
