How’s this for drought response? Earlier this month the utilities division opened the valve on a project that will save 61 million gallons of potable water annually on the Davis campus.
And all it took was $20,000 in materials and two weeks of staff labor!
The saved water amounts to about 9 percent of the campus’s total potable water use for a year. With this project and other conservation measures, UC Davis has cut potable and nonpotable water use by 13 percent over 2013 and expects to achieve a 20 percent reduction by the end of this year.
In the cooling system project, the utilities division started using recycled water instead of well water to help cool the water that keeps the campus cool. The two supplies never touch each other as one of them, the recycled water, draws heat off the other through the process of heat exchange. The other supply, the one giving off heat, is the “chilled water return” — that is, the water (not so chill anymore) that comes back to the cooling plant after looping through air handling systems in buildings all around the campus.
The rechilled water goes back out to the campus, while the recycled water goes through cooling towers. After cooling down, the recycled water is used again (and again) to draw heat off the chilled water return.
See box for a more thorough explanation, and slideshow for construction photos and schematics.
“With the drought the way it is, we dusted off an idea that had been around for a while,” said David Phillips, director of utilities.
Dave Lawlor, vice chancellor-chief financial officer, in charge of Finance, Operations and Administration, said UC Davis thrives on finding new ways to solve problems.
“This is definitely a clever way to save big on water,” he said. “Credit goes to David and his staff for putting this plan into action, and for doing it so quickly.”
The right team
Phillips had everyone he needed on his team to get the job done: Mike Fan and his wastewater crew, Lew Pollock and his water and gas crew, and John Larsen and his staff from the Central Heating and Cooling Plant.
“Everyone bought into it right away,” said Terry Duncan, a supervisor on the water and gas team. “Water’s on the top of everyone’s mind.”
Phillips said projects like this are common throughout the state wherever high-quality recycled water is available. “The trick is having the water in the vicinity of where it’s needed, and getting it there,” he said. The Davis campus not only has a nearby source — our own sewage treatment plant, south of Interstate 80 — but we already had a pipeline in the ground to carry the treated water to the main campus.
This pipe was already delivering treated water to the arboretum waterway (to help with circulation), and now we are diverting some of the water to a set of four cooling towers off Putah Creek Lodge Drive, between the arboretum and La Rue Road.
All our crew had to do was lay down about 725 feet of 6-inch PVC pipe. A pump, valves and controls — all connected to the central plant — round out the project.
“I think it is a great example of UC Davis’ taking a leadership position on water management in response to the drought,” Phillips said. “If this works as well as we anticipate, we plan to keep this system in place long after the drought ends.”
How's the “chill” in your building? Too warm, too cold? Tell the utilities division via the “Thermal Feedback” tile on MyUCDavis.