UT's purchase and consumption of potable water was creeping ever upward, reaching 1 billion gallons per year by the start of the project. At the same time, city water and wastewater rates were steadily rising to fund both debt service and new capital projects to meet increasing population and peak day demands. With much new campus construction and proposed future construction, we realized these trends would continue, representing an ever increasing cost to state taxpayers.
Readily recoverable sources of water from "once-through" water-cooled equipment such as lasers, furnances, magnets, diffusion pumps, etc., were repiped to collect in tanks with pumps. When the tanks are full, a pump discharges the "recovered water" through a network of dedicated piping to the University's cooling towers where it displaces the need to buy additional potable water to make up evaporative losses for cooling campus buildings and electrical power generating turbines. As the system grew in scope, other sources of acceptable, non-potable water were added, including swimming pool blowdown, groundwater picked up by building french drains, and air conditioning condensate. This "direct reuse" program reduces the demand on the city's potable water supply and reduces the pumping energy required to distribute the potable water.
Details of Reductions
Additional Information :
The University of Texas at Austin Department of Utilities and Energy Management operates a combined cycle--Combined Heating and Power (CHP) co-gen natural gas-fired power plant and generates 100% of the electrical, steam, and chilled water needed by all but a few campus facilities. Located in a "cooling demand" climate, much water is evaporated to provide the cooling needed for buildings and power generating equipment. Knowing the cost of water and wastewater service, the impact of increasing use and rates can easily be accessed. The department also knows the cost of capital investment to recover and reuse the water, and monitors the savings by metering the volumes of water collected over the years. Reduced consumption of water saves money for students by slowing the rate of tuition increase, for faculty and employees by providing more discretionary funds, for city taxpayers by forestalling the need for capital investment in new infrastructure, and for state taxpayers who ultimately pay for utility costs at state universities.