1. How many people lack access to safe drinking water?

According to the United Nations, between 1990 and 2015, 2.6 billion people gained access to improved drinking water sources while 663 million people—about 10% of the global population—still do not have access to safe drinking water. And at least 1.8 billion people worldwide rely on a source of drinking water that is contaminated with animal and/or human waste.For more information, please see “Meeting the Goal of Safe Drinking Water and Sanitation for All.

2. Where does drinking water come from?

Although many people might say drinking water comes from a faucet (or perhaps bottled water), it may surprise you to learn that drinking water ultimately comes from many sources—most commonly surface waters such as rivers, streams, and lakes, and ground water sources such as aquifers and springs. Additionally, less common sources include captured rainwater, snow-melt, and desalinated seawater.

For more information, please see “Science, Technology, and the Future of America’s Drinking Water.

3. How do you make drinking water safe?

Treating drinking water for safe use is one of the greatest public health achievements of the twentieth century and takes place around the world each and every day. Providing clean, safe drinking water requires a “multi-barrier approach” that includes protecting source waters from contamination, appropriately filtering and treating “raw water,” and ensuring safe distribution of treated water to consumers’ taps.

For more information, please see “Water Treatment Fundamentals.

4. What is drinking water disinfection?

Water is treated to make it safe for consumption. Most drinking water treatment involves filtration of solids and disinfection that kills or inactivates germs like bacteria, viruses, and even microscopic parasites. By far, the most common method of drinking water disinfection in the U.S. and abroad is through chlorination, which may also be added to help protect water from microbial contamination during storage or distribution to homes and  businesses throughout the community.

For more information, see “Drinking Water Chlorination: A Review of U.S. Disinfection Practices and Issues.

5. How is tap water regulated?

Regulations to ensure safe drinking water vary widely from country to country. Enacted in 1974, the Safe Drinking Water Act and its amendments protect the quality of U.S. drinking water, including over 400 billion gallons of water provided by over 150,000 public drinking water systems each day.

For more information, see “The Safe Drinking Water Act: A Blueprint for Protecting the Nation’s Drinking Water.