Nevada’s first wastewater-to-drinking-water plant breaks ground in Reno

By the early 2030s, water that once went down a drain in North Valleys could be flowing back out of a kitchen tap.

The City of Reno and Truckee Meadows Water Authority (TMWA) broke ground last week on an Advanced Purified Water Facility, a plant that will treat roughly 2 million gallons of wastewater a day to make it compliant with drinking-water standards and send it into a groundwater aquifer near Stead Airport, a first for Nevada.

The groundbreaking capped more than 15 years of research, testing and planning, and once complete, officials say the facility will reduce the region’s reliance on the Truckee River and provide a locally controlled water source for residents. Construction is expected to continue through the fall of 2029, and an on-site education center is planned to open alongside the plant.

“Water is one of our community’s most important resources, and we have a responsibility to make sure we’re prepared for the future,” Reno Mayor Hillary Schieve said in a statement.

Water authority General Manager John Zimmerman called the project “an outstanding example of what regional cooperation can accomplish.”

The project has also drawn state support. Jennifer Carr, administrator of the Nevada Division of Environmental Protection (NDEP), said the agency helped establish Nevada’s regulatory framework for advanced purified water and provided roughly $128 million in State Revolving Fund financing toward construction. That approval process now gives every other Nevada utility a regulatory path to follow if they want to try something similar.

How it works

The process will start at the city’s Reno-Stead Water Reclamation Facility, which currently treats wastewater to Class A standard, the kind used to irrigate golf courses and school fields. From there, the water will cross the street to the water authority’s new plant for additional treatment designed to make the water drinking standard compliant.

Most advanced purified water facilities around the country rely on reverse osmosis, which forces water through an extremely fine membrane to strip out contaminants. But reverse osmosis produces a concentrated brine by-product that coastal facilities can discharge into the ocean. Inland communities such as Reno don’t have that option, so the water authority opted for a different process.

Instead, the plant will use an ozone biological activated carbon process. Rather than filtering contaminants out and concentrating them into waste, this method uses ozone gas and naturally occurring microbes to break contaminants down instead of just isolating them.

Lydia Teel, the authority’s Emerging Water Resources program administrator, said the process is also less expensive to build and operate than reverse osmosis.

From there, the water passes through granular activated carbon, which Teel compares to a large-scale version of a household water filter. Vessels packed with carbon work to trap pharmaceuticals and PFAs, or “forever chemicals.” The final step is ultraviolet disinfection, which uses high-intensity ultraviolet light to kill or inactivate viruses and parasites, such as giardia.

Even after all that treatment, Nevada regulations still require the water to pass through what’s called an “environmental buffer” before it can reach a tap. That means the water will get injected into a groundwater aquifer near Stead Airport, where it will sit for years while it filters further before the water authority pumps it back out and into the city’s tap water.

A flexible new water source

Teel said the facility’s real value is flexibility, a way to lean less on the Truckee River during years when the region can least afford to.

That’s not an abstract concern. The snow water equivalent in the Truckee River basin, a measure of how much water the snowpack actually holds, hit its second-lowest level since 1986 this year, and the Truckee Meadows and Lake Tahoe area has been classified as being in a moderate drought by the U.S. Drought Monitor.

The water authority has so far avoided dipping into drought reserves thanks to a network of upstream reservoirs it manages under the Truckee River Operating Agreement, but officials have acknowledged conditions are trending in the wrong direction as winters grow warmer and snowmelt arrives earlier.

The advanced purified water facility is designed to give the region another option when the river can’t be relied on, whether because of drought, a wildfire fouling water quality or maintenance work elsewhere in the system.

Teel described it as providing “a multibenefit” option, one that lets the utility rest other wells in the North Valleys rather than draw down groundwater reserves or pull more water from the river.

Danny Rotter, the water authority’s assistant general manager, put a number on that flexibility. The plant will add about 2,000 acre-feet of water annually to the water authority’s supply, roughly enough to cover 2,000 football fields in a foot of water, or supply about 4,000 average households for a year.

It’s a modest addition next to the utility’s 20-year growth projections, which call for roughly 20,000 acre-feet total, or about 1,000 acre-feet of new demand a year. The new facility alone will account for roughly 10 percent of the growth the water authority expects to serve over the next two decades.

Rotter said the new supply isn’t earmarked for anything specific, including data centers or other industries. The utility’s growth projections are based on land-use decisions made by cities and the county, he said.

A regulatory first for the state

Nevada adopted its indirect potable reuse regulations in 2016, giving the water authority the regulatory framework to pursue the project, which received the state’s first-ever Category A+ permit.

NDEP hasn’t yet issued the permit allowing the treated water to actually be injected underground, which requires a separate approval under the federal Safe Drinking Water Act’s Underground Injection Control program. So far, no other Nevada utility has applied for a similar project, though NDEP said it has begun fielding exploratory questions from communities outside the Las Vegas area about potable reuse.

“This permitted project is the current template for permitting future indirect potable reuse facilities” in Nevada, said Krystle Borgman, a spokesperson for the Department of Conservation and Natural Resources.

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This story was originally published by The Nevada Independent and distributed through a partnership with The Associated Press.