September 18, 2019

There’s so much to know about our H2O! Where does it come from and how does it get into our homes? How is it cleaned before we drink it? Which laws protect it? What other benefits does it offer besides public health and fire protection? We’ll get to these important topics in a minute. But first, we have a test for you!

We know that water plays a critical role in our daily lives and the quality of life we enjoy. But are you water-wise? Just how much do you know about H20? Take the challenge and find out!

  1. What is water made of?
  2. How much does one gallon of water weigh?
  3. What uses the most water in a household?
  4. What is the scientific term for rain, sleet or snow?
  5. How much of the human body is made of water?
  6. What does not biodegrade in water?
  7. What is an underground formation of saturated soil or rock that is capable of storing and transmitting water?
  8. What are the three forms of water found naturally on Earth?
  9. What is the name of water-saving methods to reduce the amount of water needed?
  10. What is a geographical area called where all the water drains naturally to one place?

Score yourself and see if you’re a water genius!

Now, to answer some of the questions we posed at the beginning.

Where do we get our water and how does it get into our homes?

There are two primary water sources in the Southwest – groundwater and surface water. Groundwater is found in aquifers, which are underground layers of porous stone, earth, or gravel where the water has accumulated over millions of years. Wells are drilled into the ground in order to pump the water out of the ground.

Surface water comes from rivers or streams, such as the Colorado, Salt, and Verde Rivers. The rivers and streams are fed by snowmelt or natural springs in the mountains. In Arizona, we also store surface water in reservoirs (man-made lakes made by constructing dams) for future use. The area of land that directs the rainfall and snowmelt into streams, rivers, and reservoirs is called a watershed.

But how does that water get to your home? Before it arrives at your home, it must travel many miles until it reaches your community’s water treatment plant, either from a groundwater aquifer or a surface water source. Once the water is treated, it is transported through a series of pipes to homes and businesses so that it is available when you turn on the tap, take a bath, or water your landscape.

Roosevelt Lake in south-central Arizona is the state’s third-largest man-made lake. Only Lakes Powell and Mead are larger.


How is it cleaned before we drink it?

The water that arrives at the treatment plant is called raw water, meaning that it has not been treated and is not ready to drink. As the water enters the treatment plant and flows into the treatment basins, it is disinfected with chlorine dioxide to kill bacteria or viruses. Next, aluminum sulfate (or alum) is added to the water, which causes small impurities to stick together, forming a bi-product called “floc.” The floc settles to the bottom of the basin and is removed. For further disinfection, chlorine is added again at this stage in the process. The water is then filtered through layers of sand and coal to remove any fine particles that were not removed earlier. Supplemental fluoride and additional chlorine are added before the water leaves the treatment plant and enters your home. Some new water treatment plants are using state-of-the-art ozone disinfection for the treatment process to improve taste and reduce chemical treatment byproducts.

The raw water that comes into the treatment plant goes through many steps to ensure it is clean and safe when it reaches your home. Illustration: City of Mesa. Reprinted with permission.


Which laws protect it?

There are both state and federal laws that protect our water and water supplies. Here are a few of the most notable ones. The Safe Drinking Water Act of 1974 is the federal law that protects our public drinking water sources. The Environmental Protection Agency (EPA) sets water quality standards that water providers must meet. The Clean Water Act (CWA), also known as the Federal Water Pollution Control Act Amendments, was enacted in 1972 to restore and maintain clean and healthy waters. This was in response to a growing public concern for the environment and the condition of the nation’s waters. In Arizona, we have the 1980 Groundwater Management Code that requires an assured 100-year water supply for new residential development, limits drilling new wells, and imposes mandatory conservation requirements.

What other benefits does it offer besides public health and fire protection?

Besides the obvious health benefits of hydrating our bodies, aiding in digestion, and eliminating toxins, we need water for everyday activities such as cooking, bathing, laundry, and caring for our landscapes. We also use water for recreation. Swimming pools are popular in the Southwest where the temperatures can rise well above 100 degrees in the hottest months. And the reservoirs that we talked about earlier provide many opportunities for recreation—fishing, boating, swimming, picnicking, camping, bird watching, and more.

Wakeboarding on Bartlett Lake. Photo by Rick L. from our 2014 Spring Celebrate AZ Water Photo Contest.


We can’t live without water, so conservation and learning how to make our homes more water-efficient are also important parts of knowing about water. Remember that water is precious and there is never enough to waste. That’s why Water – Use It Wisely has more than 100+ ways to help you conserve indoors and out.

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