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Reclaimed Water System

Reclaimed Water Facility Building

Responsible Party: Energy Services in Partnership with OWASA

Project Highlights

  • Nearly five miles of purple pipes
  • 200 million gallons of drinking water saved by the UNC chiller plants annually
  • Decreased UNC use of potable water by 30 percent

Project Summary

  • Partnered with OWASA to create infrastructure that increases drought resiliency, decreases campus demands for potable water, and reduces OWASA’s need for new freshwater acquisitions.
  • Installed pipes to bring reclaimed water to the university from the plant.
  • Created reclaimed water connections to chilled water plants, new building toilets and urinals.

Project Description and Approach

When waste goes down the drain in Chapel Hill and Carrboro, it flows through sewer pipes to the Mason Farm Treatment Plant, operated by the Orange Water and Sewer Authority (OWASA). All wastewater experiences three treatment steps: primary and secondary treatment—where suspended particles settle and microorganisms consume organic matter—as well as an expanded tertiary treatment—involving filtration, UV disinfection, and aeration. Reclaimed water receives an additional disinfection step with chlorination. Pumped back to campus in purple pipes, reclaimed water is used on campus for chilled water cooling towers, for flushing toilets, and for irrigating athletic fields and landscape areas. This saves hundreds of millions of gallons of potable water—water that is of high enough quality to drink—each year.

Limited local water sources and droughts in 2003 and 2008 highlighted the vulnerability of campus and the Chapel Hill-Carrboro community to water shortages. To ensure a sustainable water supply for the future, OWASA and UNC partnered to bring reclaimed water to campus. The system became operational in 2009, and has moved UNC exponentially closer to the Three Zeros Environmental Initiative’s goal of net zero water usage.