look for
Putting WaterSense® to Work
University Makes the Most of
Onsite Alternative Water Sources
Sector: Universities; Focus: Orisite Alternative Water Sources
Project Summary
Once the largest water-using entity in the city of Austin, the University
of Texas at Austin (UT Austin) has been implementing programs to
reduce its water use for three decades. Although UT Austin continues
to expand its campus, its comprehensive water conservation program
has resulted in declining water use over the years.
The 400-acre campus, comprised of 17 million square feet of building
space, serves approximately 51,000 students and nearly 24,000
faculty and staff. The campus includes administrative offices,
academic lecture buildings, dormitories, research laboratories,
cafeterias, museums, libraries, athletic venues, and industrial facilities,
UT Austin has focused on recovering and reusing onsite alternative
water sources in these facilities to serve non-potable water needs
around the campus.
Single-Pass Cooling Water Recovery
Historically, UT Austin used single-pass cooling to supply chilled water
for dormitory drinking fountains. Water was used to cool the drinking
fountain chillers, then sent down the drain at a rate of 1 gallon per
minute (gpm), 24 hours per day, 365 days per year. In addition,
several pieces of laboratory equipment used single-pass cooling.
Recognizing this opportunity for water savings, UT Austin installed a
network of PVC pipes within existing underground tunneling to send
the single-pass cooling water as make-up water to the campus' cooling
tower. All onsite alternative water sources directed to the cooling tower
are now collected through this piping system.
At one point, UT Austin maintained nearly 250 pieces of equipment
connected to the recovery system. Overtime, UT Austin has replaced
some of the older single-pass cooling equipment with more efficient,
air-cooled equipment to eliminate some unnecessary water use,
including replacing the old drinking fountain chillers with air-cooled
heat exchangers.
Ground Water Sump Recovery
Some buildings on campus sit two or three stories below ground level and, as a result, ground water must be
removed from these foundations to prevent building flooding. Before the mid-1980s, all of the recovered
foundation ground water was pumped to the storm sewer. However, UT Austin saw this as an opportunity to use
water that otherwise would go down the drain, as long as the hard water is treated prior to use in the cooling
towers.
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Case Study
Highlights
•	Facility name: The University of
Texas at Austin
•	Location: Austin, Texas
•	Number of occupants: 51,000
students and nearly 24,000
faculty and staff
•	Size: 400-acre campus with 17
million square feet of building
space
•	Water savings: Reduced
potable water use by more than
33 percent and saved more than
1.6 billion gallons of water in total
since the program began in the
1980s.
•	Cost savings: $7.5 million since
the program's inception
PHONE (866) WTR-SENS (987-7367) WEBSITE www.epa.gov/watersense EMAlLwatersense@epa.gov
A rn* EPA-832-F 14-002-L
WtlVA July 2014

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Air Handler Condensate Recovery
In 1985, UT Austin began recovering air handler condensate
and using it as make-up water for the cooling tower. Air
handler condensate has relatively low conductivity and is
cold, so it provides a good source of make-up water for the
cooling tower. In addition, it is produced during the hot,
humid summer months, when the cooling towers are running
constantly and generate the highest demand for make-up
water.
With the use of air handler condensate as make-up water,
UT Austin was able to increase the average cycles of
concentration of the cooling tower from five to an average of
nine and a peak of 14 cycles in the hottest summer months.
Due to the success of air handler condensate recovery, UT
Austin now constructs all new buildings with air handler
condensate recovery systems.
Approximately 40 buildings recover condensate from 100 air
handler units. UT Austin has also been working to retrofit existing buildings to recover air handler condensate.
Because the generation of single-pass cooling water has diminished due to the installation of air-cooled
equipment, UT Austin now relies primarily on air handler condensate, rainwater harvesting, and some recovered
foundation ground water to provide cooling tower make-up.
Rainwater Harvesting
Rainwater harvesting has been a relatively new addition to the UT Austin's alternative water source repertoire
Over the last five or six years, all newly constructed buildings on the campus have been equipped with rainwater
harvesting capability, some with 5,000-gallon storage tanks, which collect rainwater for lawn irrigation. The
rainwater harvesting system at UT Austin recovers 40 to 50 million gallons of water per year, depending upon the
amount of rainfall.
Reclaimed Wastewater
After capturing all feasible sources of onsite alternative water that
would otherwise be wasted, UT Austin is now preparing to use city-
supplied reclaimed water as an additional source of make-up water to
help achieve its goal of using non-potable water wherever possible.
UT Austin is currently reengineering the campus' infrastructure to be
able to use reclaimed city water in its processes. This includes
installing water meters, replacing valves where needed, and installing
additional piping at the property boundary to connect the city-supplied
reclaimed water to the cooling towers.
In addition to water efficiency, UT Austin is focused on sustainability
as a whole. As of 2007, all new buildings on the UT Austin campus
have received at least LEED Silver certification, and several are LEED
Gold certified. To continue with its water efficiency initiatives, UT
Austin has begun focusing on measurement and verification and has
installed submeters on water, steam condensate, and chilled water
lines. Newly constructed buildings have all of these techniques
incorporated into the design phase, while existing buildings are being
retrofitted.
Two 2,500-gallon tanks storing air handier
condensate and harvested rainwater for irrigation
Construction of city-supplied reclaimed
water distribution lines

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Savings Summary
In the early 1980s, UT Austin's facilities were using 1 billion gallons of potable water per year. In 2010, UT Austin
reduced this potable water use to 668 million gallons. This decrease in total potable water use was achieved
despite a 70 percent increase in overall building square footage. Much of this reduction is attributed to the use of
onsite alternative water sources.
In 2009, UT Austin used approximately 395 million gallons of water for cooling, 11 percent of which was supplied
from onsite alternative water sources, including recovered single-pass cooling water, foundation groundwater, air
handler condensate, and rainwater. The University also recovers rainwater to provide supplemental irrigation. UT
Austin has recovered and reused more than 1.6 billion gallons of water since the water conservation program
began, saving $7.5 million in water and sewer costs.
Acknowledgements
The U.S. Environmental Protection Agency's (EPA's) WaterSense program acknowledges UT Austin retired
Utilities and Energy Management employee Rusty Osborne for providing information for this case study.
Learn More
To learn more about water efficiency in commercial and institutional buildings, visit the WaterSense website at
www.epa.gov/watersense/commercial to access WaterSense at Work best management practices, tools, case
studies, and more.

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