By Denise Meeks

Rather than using Arizona’s valuable groundwater for irrigation, the Desert Museum keeps its flora thriving by recycling its wastewater, about 3,000,000 gallons annually.

The water, used by our visitors and in our deer and bighorn sheep enclosures, begins its recycling adventure by flowing through sewer pipes into clarification tanks, and ends its journey on the museum’s desert trees, flowers and cactus.

Maintenance technician Josh Bland is responsible for keeping the museum’s wastewater reclamation system working and in compliance with Arizona Department of Environmental Quality (ADEQ) regulations. He checks the clarification tanks weekly. When the solid material in the tanks reaches a depth of two feet, he notifies a pumping contractor who removes the solid particles a few times each year.   

The reclaimed, solid-free water runs downhill into a 15-foot-deep, 448,000 gallon concrete-lined aerated pond containing hyacinth plants. The plants’ feather-like roots remove any remaining solid particles and help the absorb nitrates and nitrites, which could cause a variety of health-related issues if not removed.

The water then flows into two 112,000 and 187,000-gallon black rubber-lined gravel-and-reed-filled basins, where remaining bacteria, nitrates and nitrites are absorbed. Next, the water flows into a 500-gallon underground tank. A pump moves half the water uphill to a sand-filled basin that filters the water again. This cleaner water then cycles back through the system, into the hyacinth and reed-filled basins to help keep the water moving.

The other half of the water in the 500-gallon underground tank is exposed to ultraviolet light to kill any remaining bacteria. Each week, Bland cleans and tests these lights and monitors bacteria levels. He checks nitrate and nitrite levels monthly per ADEQ requirements.

Next, the reclaimed water is pumped into a 35,000 gallon in-ground storage tank, where it is tested monthly for coliform and nitrogen, to ensure that our stored water won’t contaminate local groundwater.

The water remains in this tank until our irrigation system’s solar-powered pump moves it into a non-drinkable pool in our filter building, where it is mixed with wastewater from the beaver and otter ponds.  

Finally, the water is ready to be pumped around the museum grounds through our purple pipes, where 20,000 to 30,000 gallons of reclaimed water is used every day in the museum’s irrigation system. The majority of the Museum’s irrigation water comes from this source! You may glimpse the purple pipes and irrigation systems among the museum’s spectacular desert landscaping.