Much of the water we use comes from the ground. Learn more about ground water, the threats to its safety, and how to protect its sources during Ground Water Awareness Week.
Clean water is one of the world’s most precious resources. People use water every day for many activities, such as drinking, bathing, recreation, agriculture, cooling, manufacturing, and medical uses. Although water plays an essential role in everyone’s life, many people don’t realize that much of their water comes from the ground.
National Ground Water Awareness Week, an annual observance sponsored by the National Ground Water Association (NGWA), is March 5–11, 2017. This observance highlights how important ground water is to people’s health and the environment.
Ground water is water that is located below the surface of the earth in spaces between rock and soil. Thirty percent of all freshwater is ground water.2 Ground water supplies water to wells and springs and is an important source of water for public water systems and private wells in the United States.3
Protecting the safety of ground water is an important priority for countries throughout the world, including the United States. Most of the time, ground water in the United States is safe to use. However, ground water sources can become contaminated with germs, such as bacteria, viruses, and parasites, as well as chemicals, like those used in fertilizers and pesticides, which can cause sickness and disease.
Naturally occurring germs and harmful chemicals from the environment, such as arsenic and radon, sometimes can be found in ground water. However, contamination is more often the result of human activities.4 These activities can include incorrect use of fertilizers and pesticides; poorly sited, constructed, or maintained septic systems; improper removal or storage of wastes; mining and construction; and chemical spills at work sites.4
Research has shown that most reported disease outbreaks from drinking water were caused by contamination of ground water systems, either because the ground water was untreated or because of problems with water treatment.5 The most common germs identified in ground water outbreaks include:
Other germs that cause outbreaks from ground water include parasites (Cryptosporidium), bacteria (Escherichia coli O157:H7), and viruses. Between 2009 and 2012, 28 outbreaks caused by contaminated drinking water from ground water systems were reported to CDC.6,7
The presence of germs and harmful chemicals in our drinking water can lead to health problems, including diarrhea, reproductive problems, and neurological disorders.6,8 Infants, young children, pregnant women, the elderly, and people whose immune systems are compromised because of HIV/AIDS, chemotherapy, or transplant medications may be more likely to get sick from certain germs and chemicals.
Concerns for ground water contaminants led the U.S. Environmental Protection Agency (EPA) and individual states to develop regulations such as the Ground Water Rule, which was published in 2006 to protect public water systems.
105 million Americans get their tap water from a public water system that uses ground water
One-third of Americans get their drinking water from public water systems that use ground water. That’s more than 105 million people.9 The EPA regulates drinking water quality in public water systems. You can find out more about your local drinking water quality and possible contaminants by viewing your consumer confidence report (CCR), which most utility companies are required to provide to customers.10
An estimated 34 million Americans get their water from private ground water wells, which are not subject to EPA regulations.11 Private ground water wells can provide safe, clean water. However, contamination that can cause sickness also can occur in well water. If you have a well, you should take steps to protect it and have the water tested annually to make sure your water is safe from harmful germs and chemicals.12 State and local health departments provide information to help well users protect their drinking water.