The Science and Safety Behind Your Tap Water Quality

Providing high-quality drinking water is a top priority for AMWUA cities. Every day, water professionals test, analyze, and monitor water quality. Because of their hard work, residents and businesses can count on a safe, reliable, and clean water supply.

The ten AMWUA cities consistently meet or exceed all drinking water safety standards established by the Environmental Protection Agency (EPA), the Arizona Department of Environmental Quality (ADEQ), and the Maricopa County Environmental Services Department. These safeguards, mandated by the Safe Drinking Water Act, ensure accountability and maintain the highest water quality standards for your community.

Your tap water is both safe and clean, surpassing bottled water standards, thanks to strict regulations and over 100 daily tests conducted by water utilities. These tests assess contaminants, chemicals, and minerals to ensure compliance with EPA safety thresholds. Regular monitoring, infrastructure upgrades, and new treatment technologies help maintain high water quality year-round. Valley water utilities collectively perform millions of tests annually, with each AMWUA city leading a comprehensive water quality program supervised by expert chemists, technicians, and specialists who use advanced lab equipment to test for hundreds of substances, ensuring your drinking water consistently meets the strictest safety standards. 

All AMWUA cities rely on several water sources—including the Colorado River, the Salt River Project (SRP), reclaimed water, and groundwater—each requiring specialized treatment due to its unique composition. Recognizing these differences, cities have invested in advanced infrastructure and treatment facilities to deliver a consistent, safe, and regulated water supply despite the variability of these sources.

Water entering treatment plants often contains natural particles that can make it appear cloudy. This is called turbidity. The treatment process removes these particles and reduces turbidity. After several treatment steps, a disinfectant such as chlorine is added to kill and prevent the growth of harmful germs. A small, controlled amount of disinfectant stays in the water until it reaches homes, businesses, schools, and healthcare facilities across the Valley, providing ongoing protection.

After treatment, water quality is regularly monitored and sampled. This helps catch and fix any changes quickly. Each city shares regular water quality reports with the public, and a full report is sent to ADEQ every year for review. This open process keeps standards high, encourages accountability, and lowers the risk of problems. If any issues come up, residents will be notified right away by their city.

For additional peace of mind, you can always access up-to-date information about your community’s water quality from your local provider. To view your municipality’s most recent water quality report, please visit the links below.

For 57 years, the Arizona Municipal Water Users Association has worked to protect our member cities' ability to provide assured, safe, and sustainable water supplies to their communities — Avondale, Chandler, Gilbert, Glendale, Goodyear, Mesa, Peoria, Phoenix, Scottsdale, and Tempe. For more information, visit amwua.org.