What is Groundwater?
Introduction
Some individuals think groundwater is stored in a vast underground lake; others believe Nebraska's groundwater comes from the Rocky Mountains -flowing in underground rivers.
But in most areas of the world, and specifically in Nebraska, water does not flow in and is not stored in large underground lakes or rivers. Instead, groundwater is stored in the voids, spaces and cracks between particles of soil, sand, gravel, rock or other materials. These materials form what is sometimes called the aquifer or groundwater reservoir.
State of Nebraska addresses issues
Groundwater provides approximately 85 percent of the water used for human consumption in Nebraska.
Much effort is being placed on managing Nebraska's groundwater supplies and reducing the potentially negative effects of human activities.
State-designated Groundwater Control Areas, Special Protection Areas and Groundwater Management Plans produced by the state's 23 Natural Resources Districts contribute to prevention of further contamination in areas highly vulnerable to pollution.
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.
