Do you know where your water comes from?
According to the Centers for Disease Control and Prevention (CDC), an estimated 145 million Americans get their tap water from a groundwater source. National Groundwater Awareness Week will be observed March 6-12, 2022, as a reminder of how important groundwater is to our health and environment.
Groundwater is found below the earth's surface in spaces between rock and soil. It is an important source of water for both public water systems and private wells.
One-third of all Americans get their drinking water from public water systems that use groundwater and are regulated by the US Environmental Protection Agency (EPA). If you have a public water supply, a local government agency or private industry delivers water to your home. You can find out more about your local drinking water quality and possible contaminants by viewing your local Consumer Confidence Report (CCR), which most utility companies are required to provide to customers.
Another 43 million people in the U.S. get their water from private groundwater wells, which are not subject to EPA regulations. Private wells can provide safe, clean water. But if you have a well, you should take steps to protect it from contaminants and test your water annually.
Because drinking water comes from natural sources, it can be exposed to pollutants. Anything on the ground or in the air can end up in the water. Some pollutants—like iron or chloride—only cause bad odors or tastes. Others—like bacteria, lead, and nitrates—can cause health problems.
How Does Groundwater Get Polluted?
There are many ways that water sources can become polluted. While some groundwater contaminants are naturally occurring, the majority of groundwater contamination is the result of human activity.
Drinking contaminated groundwater can have serious health effects, including diseases like hepatitis and dysentery to certain types of cancers, depending on the specific pollutant. Below are a few examples of ways that groundwater can become unsafe.
- Overuse: Groundwater depletion can make it harder for you to get water, especially if the groundwater is reduced to the point that your well no longer reaches it. If the overdrawing is severe enough, the water may be contaminated with salt water, making it unsuitable for many residential uses.
- Wildfire: After a wildfire, private wells can become contaminated due to the chemicals that are released after a fire burns through wood, grass, plastics, and other building materials.
- Flooding: Flood waters often carry hazardous and toxic materials like raw sewage, oil, or pesticides. If those substances enter a well, they can make the well water unsafe to drink for a long time after the flood waters have receded.
- Nitrates: Runoff from fertilizers is the most common source of nitrates. While harmless in small amounts, high levels of nitrates can be dangerous for pregnant women and infants.
- PFAS: Per- and polyfluoroalkyl substances (PFAS) are a large group of human-made, environmentally persistent organic compounds with properties that make many of them toxic and persistent in the environment. These common chemicals can migrate into large groundwater aquifers.
Learn more about potential sources of groundwater contamination from the Groundwater Foundation. The EPA's Safe Drinking Water Standards also detail the maximum amount considered safe for up to 90 different chemicals in drinking water.
Protect Your Home's Water
If you have a well, you should test it at least once a year for contaminants. Routine inspection of a water well system can help ensure it is operating properly and protect your health.
Contact your local health department to find a certified laboratory near you and to find out what substances may be common in your area's groundwater.
In addition to testing, be sure you aren't making common water quality mistakes. Keep hazardous chemicals far away from your well. Always maintain proper separation between your well and buildings, waste systems, or chemical storage areas. Don't over-fertilize your lawn to prevent nutrient runoff.
Learn More About Your Groundwater
Celebrate National Groundwater Awareness Week by learning about the many ways we rely on groundwater every day—and the importance of keeping it safe and clean for our health.
- WellOwner.org: This website from the National Ground Water Association and the Rural Community Assistance Partnership offers private well owners tip sheets on water well maintenance and assistance with finding certified local water well contractors in their area.
- The Water We Drink: This Penn State resource written for grades 6-12 introduces public and private water systems and includes an activity on how to read a water quality test report.
- NEEF Water Quality Backyard Activity Guide: Use this activity guide at school or at home to learn more and explore the topic of water quality with interactive activities.