Twice Removed; Reclaimed Water

Purple pipe supply line at Austin Bergstrom International Airport • Photo by Paul Robbins

In This Story…

• Reclaimed water is wastewater treated to a high standard and reused for both potable and non-potable purposes.  Some states and cities have made tremendous efforts to use this resource. 

• Nevada, Arizona, and Florida reclaim at least 50% of their wastewater.  San Antonio reclaims 17% of its wastewater.  The El Paso water utility is building the first direct wastewater-to-tap water treatment plant in the country.

• Austin, which considers itself a leader in water conservation, reclaimed less than 7% of its water in 2023.  If all of Austin’s remaining wastewater in 2023 were reclaimed to drinking water standards, it would provide for 764,000 more people.

A recently published story on water supply in Central Texas explained that acute water shortages could afflict our region in as little as 15 years.  New approaches to protecting water supplies are no longer a luxury. They are a prerequisite.

In addition to demand-side conservation and replacing old water pipes, another valuable strategy is reclaimed water.

In several states in the U.S., it is quite common to treat large percentages of wastewater as a resource.  In the arid state of Nevada, 85% of its wastewater is reclaimed.  In Florida, it is 55%.  Significant percentages of wastewater are also reclaimed in: Arizona, 52%; California, 22%; and New Mexico, 18%.  

Often the water is used directly in a dedicated reclaimed water utility constructed with purple pipe, so that it is not mistaken for potable water (drinking-water) pipes.  Reclaimed water is used for landscape irrigation, cooling towers for air conditioning in large buildings and electric power plants, industrial manufacturing, and toilet flushing.  

Other times, water is upgraded to an even higher standard, and used to replenish reservoirs and aquifers.  It is also used for crop irrigation.  And a trend is beginning to use advanced water treatment technology to upgrade wastewater directly into potable water, with some of the first plants of this kind in the U.S. being built in water-scarce regions of Texas.

The Texas Leaders
Though Texas only recycles about 4% of its wastewater, the state is planning to obtain 14% of its new water supplies from reclaimed water by 2070.

Some Texas cities have emerged as national leaders in reclaimed water use.  

• Big Spring – The spring for which this West Texas city was christened was never big by modern standards.  Even when it was a watering hole for Comanche and Apache Indians, its average daily flow would have only satisfied about 500 Austin-sized homes in 2023.  Due to growth from settlers and railroads, the spring went dry in the mid-1920s.  

This parched city’s water utility built a plant converting its treated and chlorinated sewage to drinking water via microfiltration, reverse osmosis, and ultraviolet-light/hydrogen peroxide disinfection.  When commissioned in 2013, the plant was the first of its kind in the U.S., and provided 40% of the city’s water supply.

The utility typically mixes this water with a different raw water source to reduce the stigma associated with direct use of sewage.  However, it provided undiluted water directly to consumers during a drought in 2014-2015. 

• El Paso – El Paso has three different kinds of reclaimed water production.  

1. Beginning in 1963, its purple pipe utility provided non-potable water for landscapes, cooling towers, street sweeping, fire protection, building construction, and industrial processes.  The system reused about 8% of its 2023 wastewater production.

2. Since 1985, wastewater upgraded to drinking water standards has been used to help recharge the Hueco Wells Aquifer, which provides 38% of the city’s total water supply.  

3. In 2025, the city began construction of the 10 million gallon per day Pure Water Center that will purify wastewater to drinking water, which will go online in 2028.  Its four-step process includes reverse osmosis, followed by an ultraviolet light/hydrogen peroxide disinfection process, followed by carbon-filtration, and finally completed with chlorination.

Unlike the Big Spring plant, it is intended for direct use without dilution from other water sources (another first in the U.S.), and it will process six times as much water.

• Wichita Falls – Since 2017, this city on the Oklahoma border has directed highly treated wastewater to Lake Arrowhead 17 miles away.  The mixture of raw and reclaimed water is then retreated to potable standards.

• San Antonio – San Antonio’s water utility began its reclaimed water system in 1999.  It provides non-potable water to commercial buildings, industries, and CPS Energy power plants for cooling.  In 2024, about 5% of its wastewater was used by individual customers, and 12% was used for power production.

The Austin Experience
To date, Austin Water has not invested as much attention and money in reclaimed water as other utilities with higher-achieving systems.

Austin began using reclaimed water in 1974, when it began to irrigate a golf course with it.  It was also sold as cooling water to Austin Energy’s Sandhill Power Plant in Southeast Austin.  

Austin’s reclaimed water line mileage has doubled between 2011 and 2023, when the system reached about 70 miles in length.  (This compares to the drinking water system over 3,900 miles long.)  If not reclaimed, this treated wastewater would otherwise flow back to the Colorado River.  

In 2023, about 3.3% of Austin’s wastewater was reclaimed for uses including cooling towers for Austin’s district chilling system, landscaping, and non-potable uses at the Mueller Airport redevelopment and Austin’s Bergstrom Airport.  Another 3.3% was used in the wastewater treatment process.

If all of the remaining wastewater in Austin could be treated to a high-quality standard and reused, it would supply the needs of an additional 764,000 people at Austin’s 2023 per capita level of consumption.  This would be equivalent to 67% of the population in Austin Water’s service territory in that year.

If you believe Austin should expand reclaimed water use as a central water supply strategy, write in and let local water policymakers know this matters today. Use the form letter link below to contact the Water and Wastewater Commission and the Water Forward Task Force to encourage smarter, more responsible water management. 

Speak Up Today

Paul Robbins is an environmental activist and consumer advocate living in Austin.  He has been Editor of the Austin Environmental Directory, a sourcebook of green issues, products, services, and organizations, since 1995.

NEXT WEEK: Part 2 – The Economics of Reclaimed Water in Austin