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Drinking WaterDrinking Water

The Basics

A cool glass of tap water is the perfect drink on a hot summer day. The water is clean and refreshing. It has no color or strong smell. But where does it come from? In the United States, it comes from streams, ponds, rivers, and other natural sources. Before it gets to your glass, it has been cleaned, treated, and tested for safety.

Do you ever wonder what chemicals and pollutants might be in your glass of tap water? In the United States, you shouldn’t have to worry. Our water supply is protected by law, so it is usually safe to drink. The U.S. Environmental Protection Agency (EPA) sets acceptable limits for pollutants in our water that might harm our health. To date, EPA has set such limits for more than 90 pollutants. Yet people do things that pollute water. And drinking polluted water can cause diseases and other health problems.


Did you know ?

Small amounts of medicines can find their way to our drinking water supply when people flush unused medicines down the toilet.

Learn More

Explore the links below to learn more about drinking water in the United States, including how you can prevent pollution and protect your health.

Read About It Read About It

Methane Threat to Drinking Water (Baylor College of Medicine) - Describes the concern of methane contamination in drinking water.

Water (PDF, 216.82 KB)(U.S. Navy and Marine Corp Public Health Center) - PDF with information about the water cycle, drinking water, underground water, and the detrimental impact humans have on water.

A Guide to Drinking Water Treatment and Sanitation for Backcountry & Travel Use (Centers for Disease Control and Prevention) - Description of four contaminants found in untreated and poorly treated drinking water; contaminant removal methods.

What's Swimming in Your Glass? (Johns Hopkins University Ecohealth) - Describes how drinking water can be polluted and how to protect oneself from unsafe water.

Why is Safe Water Essential? (National Academy of Sciences) - Information about safe drinking water, global implications, and treatment options.

Agricultural Runoff in Tox Town (Tox Town - National Library of Medicine) - Description of what agricultural runoff is and its hazardous effects on the environment.

Commercially Bottled Water (Centers for Disease Control and Prevention) - Provides information about different types of bottled waters, safety regulations, and water contamination outbreaks.

Drinking Water Facts: Perfluorinated Chemicals in Drinking Water (PDF, 658.27 KB)(State of New Jersey) - PDF of facts on perfluorinated chemicals in drinking water; what they are, how they occur, and effects they can have on health.

Pharmaceutical and Personal Care Products in Drinking Water Supplies (The Ground Water Foundation) - Describes the detrimental effects of pharmaceutical and personal care products in drinking water supplies.

Pharmaceuticals in Drinking Water (PDF, 3.92 MB)(Utah State University) - Information on pharmaceutical and personal care products, proper disposal, and additional resource links.

Water Quality Homepage (U.S. Geological Survey) - Information and links to water quality properties, surface water quality, ground water quality, and activities.

For Teachers For Teachers

Arizona Water Quality Education Activities for Grades 1 - 12 (University of Arizona, College of Agriculture and Life Sciences) - Hands-on activities to teach students about water quality and effects on human health.

Give Water a Hand (University of Wisconsin) - Project to clean up the watersheds in your community.