How Does Your Water System Work? (Text only)

When you turn on your faucet, water seems to magically appear. EPA, states, and water utilities work together to bring clean, safe water into homes and businesses every day.

In the US, approximately 90% of the population gets drinking water from a public water system (PWS) that treats, stores, and distributes the water.

1. Water Sources - The source of the water flowing from your tap may be hundreds—even thousands—of miles away. Most PWS use surface water as their source of water— for example, a lake, river, or reservoir—while some public water systems use ground water sources, such as aquifers.
2. Water Treatment - The PWS treats the source water to make sure it’s safe. The Safe Water Drinking Act requires EPA to establish and enforce the safety standards that all PWS must follow. Treatment methods include filtration and disinfection to remove debris and bacteria.
3. Water Storage and Distribution - After treatment, the PWS may store the water in holding tanks. Eventually, the water is pumped and distributed to communities through water mains—large, buried pipes—and water lines (smaller pipes that run from the main to a residence or business).

How do I know my water is safe?

Community Water Systems (CWS) - Provide water to the same population year-round. Most people—more than 300 million—in the US get their water from a CWS.

Non-transient Non-community Water Systems (NTNC) - Provide water to the same people at least six months a year, but not all year. For example, NTNCs may serve schools or businesses that have their own water systems.

Transient Non-community Water Systems (TNC) - Provide water to areas where people don’t stay for very long—for example, campgrounds.

Original webpage

For more information, visit: epa.gov/safewater.