Groundwater—water that comes from the ground via wells—is the water most of us drink every day. People also use water for numerous activities including bathing, cooking, recreating, cooling, manufacturing, food production, and medical use.

Approximately 95% of Idaho’s drinking water comes from ground water sources, with the remaining 5% supplied through surface water sources like lakes and rivers. This is one of the key reasons protecting groundwater is an important priority, and everyone’s responsibility. If you have a well, you should test it at least annually for contaminants and conduct routine inspections to ensure it is operating properly to protect your family. 

Most of the time you can assume groundwater is safe, but sometimes it can become contaminated with bacteria, viruses, parasites, and chemicals, such as fertilizers and pesticides. In addition, there are many natural germs and harmful chemicals that can get in groundwater from the environment, such as arsenic, nitrate, and radon.

Contamination is commonly caused from the incorrect use of fertilizers and pesticides; poorly situated, built, or maintained septic systems; improper removal of storage wastes; mining and construction; and chemical spills.

All of these contamination situations can result in illness among many people..

National Groundwater Awareness Week runs March 6 - 12 and is a great time to learn where your drinking water comes from and how to protect it.

Please visit the Idaho Department of Health and Welfare’s Environmental Health webpage or contact the department at 800-445-8647 for more information on how you can protect your groundwater, including testing and maintenance.

Brigitta Gruenberg is the Environmental Health Program manager in the Division of Public Health.  

The Idaho Department of Health and Welfare is dedicated to strengthening Idahoans' health, safety, and independence. Learn more at healthandwelfare.idaho.gov.