Tucson seeking companies to design & build ‘toilet to tap’ facility

Tucson city officials are moving to advance a plan to turn wastewater into drinking water by seeking a company to design and build an advanced water purification facility capable of filtering 2.5 million gallons per day.

Last month, Tucson Water moved forward with plans for the facility on land now owned by Pima County, just southwest of the current Tres Rios Water Reclamation Facility near Ina Road and Interstate 10.

The city published a request for qualifications on Oct. 15. The deadline for inquiries is Dec. 3 and an “anticipated” contract award will come in spring 2026.

Last year, the Arizona Department of Environmental Quality passed new
rules allowing municipal water officials to build so-called
“toilet-to-tap” systems, treating wastewater to what officials called
“very-high quality” water.

In January, city officials and the U.S. Bureau of Reclamation
officials signed an agreement to build the $86.7 million
water-purification facility, scheduled for completion by June 2031. 

This is part
of a wider effort to conserve and recycle water as part of the city’s
One Water 2100 plan, approved by Mayor Regina Romero and the City
Council in 2023. In January, city officials said the new facility could
help conserve 56,000 acre-feet of water in Lake Mead over the next 10
years, reducing the strain on the Colorado River.

Each
acre-foot — the amount of water it would take to cover one acre with a
foot of water — is equivalent to the annual water use for a few
households.

As part of the plan, the city aims to “protect the reliability and quality of Tucson’s water supply” through 2100 using surface water,
groundwater, recycled water, and storm-water supplies.

The plan also considers a
future when “the region’s water supply portfolio is increasingly
diversified, and water demands are well managed,” city officials said. This includes efforts to begin purifying recycled water to
drinking water standards.

Currently, the city’s allotment of Colorado River
water is about 144,000 acre-feet, however, the city uses around 100,000
acre-feet per year, John Kmiec, the director for Tucson Water told the Tucson Sentinel in January. In
the meantime, the city has been “banking” the excess water for the
future at recharge facilities in Avra Valley, he said.

Kmiec said the
future facility will support the city’s water system, particularly on the
Northwest Side where wells have been closed because of PFAS
contamination. Beginning in 2026, the city will seek less water from the
Colorado River, he told reporters in January.

As part of putting the project out to bid, city officials said they want to use some of the city’s local water resources, including effluent, to “diversify” Tucson’s water resources. 

By purifying and reusing water, the project “aims to improve water quality, water supply reliability, address distribution system capacity issues due to PFAS-related well shutdowns, and provide long-term conservation benefits for both the local community and the Colorado River system.”

Data from the University of Arizona shows the city of Tucson has reduced individual residential water use by over 37 percent from 1996 to 2022. In 1996, people in Tucson consumed 121 gallons per person each day, however by 2022 that decreased to 76 gallons per person each day. This has meant that overall water use in the region has declined slightly, even as the population has increased.