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04/21/2016 16:53:45

Even Before the Drought, Caltech Set Sights on Water Conservation

The California drought has become increasingly dire since its onset in 2012, recently prompting state officials to implement mandatory water use reductions of 25 percent. Various municipalities, including Pasadena, have urged even greater conservation.

At Caltech that call to action has been more of an affirmation of efforts already under way for more than a decade. Since 2006, Caltech has targeted energy- and water-wasting activities campus-wide, slashing water use by 38 percent.

John Onderdonk, Caltech's director of sustainability programs, says he scores the campus's conservation efforts thus far "in the A-minus range. We've certainly done more than a lot of our peer institutions in the state and city, but we have more to do."

Ironically, he notes, the Institute's proactive focus on maximizing water efficiency over the long-term has made it harder to meet the state's recent mandate to reduce water from 2014 levels. Even so, Caltech did manage to wring out an additional 15 percent in water savings from 2014 to 2015.

Water conversation began in 2006 with simple improvements, based on a building-by-building assessment by the conservation team. For example, the urinals in Ramo Auditorium had been programmed to flush every 15 minutes, which wasted water. "That was an immediate retrofit," says Onderdonk.   

At the same time, the team conducted an extensive survey of "where and for what our water was being used," he explains.

The answer surprised Onderdonk, who expected that tending to the landscaping across Caltech's 126-acre campus would easily rank number 1. Instead, the data showed that the central and satellite utility plants consume half the Institute's water in order to generate electricity and produce water needed in research, as well as in the heating and cooling of the campus. Most of the remaining supply was allocated to domestic uses (34 percent) followed by irrigation (16 percent).

Given the impracticality of slashing the allocation of research water at a premier research institute, Onderdonk and his team looked instead at reducing the water needed for energy generation, recommending the introduction of new technologies including fuel cells and solar photovoltaics to convert solar energy into direct-current electricity. The adoption of these new technologies produced water savings by obviating the need for the water-based cooling required by traditional generators.

Over the past few years, as drought conditions worsened, Caltech has taken new measures to cut back on the amount of water dedicated to landscape irrigation. Where practical, the Institute has replaced high-use turf, which annually requires 20 gallons of water per square foot, with low-use turf, which requires 15 gallons of water per square foot.

"It's a steady, consistent effort," says Onderdonk. Nearly 75 percent of the turf on campus is now low-water use.

Caltech also switched to a weather-based irrigation system, which automatically shuts down during days when nature provides sufficient moisture to plants, grass, and trees.

This past June, workers drained water from many of the fountains located across campus. For other water features, Caltech has introduced air-conditioning condensate capture as a water-saving measure; this is currently benefitting the Beckman Institute "Gene Pool," Watson lab fountain, and Linde + Robinson Perception fountain.

Typically, the water that condenses off an air conditioning unit would otherwise be dumped into a drain, where it disappears. But, last summer, the Institute reworked some capture systems to feed condensate into the three fountains, making up for losses from evaporation and reducing the need to use potable water in those areas.

"I am excited by the progress we've collectively made to date," notes Onderdonk, referring to the water conservation program as a whole, "and I think we are on the cusp of establishing Caltech as a leader in the responsible use of water by demonstrating that large-scale water reuse is a viable solution to future water volatility in Southern California." 

Written by Jon Nalick