Story and Photos by Camas Frank
It may seem a little anti-intuitive to — in the middle of a drought — fill six pools with water just to watch them evaporate, but there’s method in the act.
Cal Poly Civil Engineering Professor, Misgana Muleta, and grad student, Ernesto Jimenez, are spending 60 days practicing the scientific method, hands-on, at the newly reopened Cal Poly National Pool Industry Research Center.
Representatives from all aspects of the industry are hoping the data generated from the study will help save billions of gallons over the long term, as the scientists monitor the effect of evaporation on six small pools protected by different types of cover and a seventh, unprotected control.
Alan Smith, chairman of the National Plasterers Council’s Research Committee, was there driving a dump truck full of materials to build the center more than a decade ago, when the research center was envisioned as a place to test the interaction of concrete and chemicals.
In 2008, the economic crisis and end to the housing boom dried up funding for research and the industry refocused on maintenance and survival.
Now that there’s money back in building, said center co-founder and the NPC’s national technical advisor, Greg Garrett, the California Pool and Spa Association, The Association of Pool and & Spa Professionals, World of Recreational Water, and the Independent Pool and Spa Service Association have come back to Cal Poly looking for ways to allow people to keep their pools during a drought.
Research on “liquid evaporation suppressants” done in 2001 in Arizona showed promise, with the possibility of 30% to 50% reduction in water losses but the treatments weren’t compared to other, cover methods on the market and no studies have been done since.
“We’re very happy to have the center working again,” said Debra Larson, dean of the College of Engineering. “It fits with our mission as a university. We love these kinds of projects that can be put to immediate use.”
Associate Dean, Rakesh Goel, whose area of responsibility includes research and graduate programs, added that part of the value of having an academic instruction involved is that students will approach the problems of the industry from an engineering mindset.
First tackling evaporation in a time when every drop counts, but also coming up with future options, for instance, one day preventing the need to drain and refill pools for maintenance.
“Sometimes, to solve complicated problems low-tech options will provide a solution. Simple day-to-day science is required,” said Goel. “This is the first study to undertake measurements in a controlled setting. There is no other research center like this in the country for a comparative study.”
For Jimenez, a master’s student working on the study this summer, it’s the perfect opportunity to dive in on a subject that’s fascinated him.
“It was actually my second assignment with Prof. Muleta to calculate evaporation in a project and you could identify huge losses,” Jimenez explained. “I had to go back and run the numbers with him to make sure it was correct. For an engineer, evaporation is a fantastic problem.”
The study will look at three different types of solid covers — a foam cover and two liquid applications that change the chemical composition of water at the surface. Brand names are not important to the study, as the industry backers are more interested in having data to compare broad categories of products’ effectiveness.
All of the items used are duplicates of something already on the market and the idea is to simulate day-to-day use in real life, although they don’t want anyone actually taking a dip and messing up their study.
According to the numbers collected by the NPC, “achieving a 30-percent reduction in evaporation from California pools would save more than 10,833 acre-feet of water per year, enough to supply a city of about a hundred thousand people.”
Getting people to actually use the information collected to help save the most water will be an interesting challenge from a marketing perspective, but Garrett was also interested in being able to take a reputable study to the State Legislature in the event that regulation of swimming pools becomes a drought issue.
“I live in Phoenix. We’ve already got this [gravel yards],” he said, while scuffing his foot in the white rocks surrounding the pools. “The State of California is going to have a hard slap when it comes to water.”
Just in case some water actually does happen to fall from the sky during the study period though, the Cal Poly weather station is nearby and it’s data will be included in the final report, due sometime in September.
