Environmentalists in the stands need not fret about how much drinking water is being used to keep Kenan Stadium’s field green and healthy. The answer is none. Kenan field is the first place on the UNC campus to be irrigated with reclaimed water.
Reclaimed water is wastewater that has received advanced treatment, including filtration and disinfection with ultraviolet light and chlorine. While not suitable for drinking, the water is safe for such uses as irrigation, toilet flushing and evaporative cooling at the chilled water plants on campus. (Chilled water plants provide energy-efficient cooling for campus buildings; in the process, large quantities of water are evaporated.)
In fact, the chilled water plants are by far the largest use of reclaimed water on campus, said Sally Hoyt, who manages UNC’s nonpotable water utility. In the past 12 months, 210 million gallons of reclaimed water have been used in the cooling towers, a whopping 24 percent of total water use by the University and UNC Health Care.
By comparison, irrigating Kenan field will use only 4 million gallons of reclaimed water in a year.
“By using reclaimed water, we’re not only conserving drinking water in a drought and in the peak use time in the summer, we’re also delaying the need to build new water plants to meet that peak demand,” Hoyt said.
The reclaimed water system became operational in March 2009, making UNC the first university with a nonpotable water utility that combines reclaimed water and rainwater, Hoyt said. The University began collecting stormwater in 2002, primarily to prevent pollutants and excess volume from reaching creeks and streams that feed into downstream drinking water sources.
But capturing the stormwater in underground cisterns – such as the ones at Hooker fields, Ramshead Plaza, Hanes Hall and Boshamer Stadium – also allowed the University to irrigate athletic fields and landscape areas without using drinking water.
That will be the case for Kenan field, too, when construction on the neighboring Genomic Sciences Building is complete and access to the stormwater cistern there is available. Reclaimed water irrigation will remain as a backup.