BY: Warren Tenney

Water Quality: How We Ensure You Have Safe and Reliable Water

Published Aug 12, 2019

Many people wonder about the quality of the water that comes out of their faucet, but did you know that your tap water goes through more testing and meets a higher standard than required for bottled water? In other words, your tap water is safe, clean and protected. In fact, water utilities are among the most regulated industries in the country which is precisely why they perform more than 100 tests on your tap water each and every day. However, ensuring water quality always remains high, is not a simple process.

Our municipalities consistently meet or exceed all of the safe drinking water standards set by the Environmental Protection Agency (EPA) , the Arizona Department of Environmental Quality (ADEQ) and the Maricopa County Environmental Services Department . These requirements fall under the Safe Water Drinking Act bringing accountability and safeguarding high water quality standards. 

Over the course of a year, Valley water utilities collectively perform millions of tests and measurements to ensure water treatment and distribution systems are safe.  Each of the AMWUA cities has an aggressive water quality program with dedicated staff.  These professionals head out daily to the various water service areas to test for hundreds of substances using state of the art equipment and laboratories to make sure your water consistently meets the safe drinking water standards, but again meeting those standards is not a simple process.

When you consider the multiple sources of water utilized by the AMWUA cities including the Colorado River, Salt River Project (SRP), groundwater and surface water we must realize that each of those require different levels of treatment due to varying particles that accompany the water from the diverse sources. Not all water can be treated equally which is why the water quality process is done at a stringent level. Addressing those treatment challenges is why the cities invested in their vast infrastructure and advanced treatment facilities so that there is always enough safe and regulated water for all of us to use whenever we need it, while striving to keep it affordable for households throughout the Valley.

The water which enters water treatment plants contains lots of particles, lots of which are natural, organic particles that are suspended in the water. This is what makes the water appear cloudy and is often referred to as turbidity, which is a measurement of how clear the water is. The goal of the water treatment process is to decrease turbidity, making the water clear and removing any particles that may be harmful. Here are the steps involved in that process:

  • Pre-Sedimentation - slows the water down so heavy particles can settle out.
  • Coagulation/Flocculation - Chemicals are added to the water and gently mixed to bring the suspended particles together. The small particles collide with each other and stick together forming larger particles.
  • Sedimentation - The water continues through the plant to a basin where the large particles settle to the bottom of the basin and are removed from the water.
  • Filtration - Water flows out of the top of the basin into a filter to remove the remaining particles. This makes the water clear.
  • Disinfection – This is the final stage where a chemical such as chlorine is added, to remove and prevent potentially harmful microorganisms from growing. A small amount of disinfectant is required to be in the drinking water system and maintained until the water is delivered to homes and businesses, schools and healthcare facilities throughout the Valley.

In addition to the treatment process and continual monitoring and testing of water samples, each municipality must provide regular reports on their water quality detailing each sample. And on an annual basis all of that data is compiled into a report and is then submitted to ADEQ for final approval. This process ensures water quality is at a high level and accountability is always being met, eliminating the danger of a major water contaminant crisis.

Each city provides an annual water quality report to its customers, which demonstrates the reliability of our safe drinking water.  Also please note that if water quality is ever an issue in your city, you will be notified.

To read the latest water quality report for your municipality please visit the appropriate links found below.


For 50 years, Arizona Municipal Water Users Association has worked to protect our member cities’ ability to provide assured, safe and sustainable water supplies to their communities. For more water information visit .

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