Extramural Research - People, Prosperity and the Planet
Looking to the sky for a water supply
P3 Research Project Search
By JENNIFER KABBANY
(North County Times - April 15, 2006) - RIVERSIDE - Humans have harvested rainwater for thousands of years.
The Mayans constructed elaborate systems of terraces and underground tanks to capture water during their rainy seasons to use year-round. Today, some landscapers install underground tanks for homeowners to collect rain with which to later water lawns.
But a universal product that can be used to collect rain for thousands of homeowners and corporations alike and save it for a sunny day is far from becoming mainstream. A project generated by UC Riverside is working to change that.
What started two years ago as a class assignment and a joke about Dixie cups on rooftops to gather rain has turned into a multiyear project in which a UC Riverside graduate and his instructor are now seeking to reintroduce the old water conservation method and turn it into the latest trend.
Their so-called rooftop rainwater harvesting project earned two $10,000 grants late last year and is now in the running to earn another $75,000 this May from the U.S. Environmental Protection Agency to further develop the idea.
Right now, the concept is mostly on paper, but the idea is to somehow funnel rain that hits rooftops into a filtration system that then empties into containers built into homes or businesses. Those containers would be connected to systems that supply water to things such as toilets, dishwashers and sprinklers.
Solution to water shortages?
The project will compete in the EPA's second annual competition called "P3: People, Prosperity, Planet" in Washington, D.C. The event is designed to encourage college students to come up with creative and innovative ways to conserve natural resources and provide alternative fuels.
Underscoring the project's practical uses, its other main intention is to draw attention to rooftop rainwater harvesting as a possible solution to water shortages in the country and throughout the world, said Roland Cusick, a recent UC Riverside graduate leading the project's progression.
"There are 1.6 billion people in the world who do not have access to drinking water," Cusick said, citing a commonly accepted statistic in the scientific community. "Think about Mexico. Its water is almost brown. You can't drink it."
Cusick said his aim is to create a product that can not only be used in America by installing above-ground tanks in homes and large corporate buildings as they are constructed, but also for homes and businesses in Third World nations.
"It can be applied anywhere," he said.
The rooftop rainwater harvesting concept was developed two years ago by Cusick and four other students ---- Greg Guillen, Steven Gebelin, Andrew Chin and Temitope Ogunyoku --- as they worked on their senior class project.
Ontario the test
In October 2004, the students got a jump-start on their project before the class began in January so they could enter it into two grant competitions, one from the Metropolitan Water District of Southern California and the other from the U.S. Environmental Protection Agency.
Focusing on the city of Ontario because of its steady rainfall, rapid growth and preponderance of warehouses and rooftops, the students culled data from various sources and plugged it into a computer model that considered variables, such as tank sizes and lawn and roof areas.
They ultimately determined that rainwater harvesting in Ontario could collect more than 2,200 acre-feet of water per year, enough to meet the domestic needs of some 15,000 people each year.
Armed with that data, in early 2005 the students entered their project ---- which at this point was only on paper ---- in the two grant competitions.
Eight months later, in September, they learned that they had been awarded $10,000 from the Metropolitan Water District of Southern California. In December, they learned they had been awarded another $10,000 from the Environmental Protection Agency.
But the news came after all of the students except Cusick has graduated from UC Riverside.
Cusick, who graduated last December, used the $20,000 to continue the project with help from chemical and environmental engineering lecturer Kawai Tam, who originally issued the students the class assignment, as well as several undergrads.
They created a minisystem at the Riverside campus to gather more data in preparation for the P3 competition. University officials would not allow a large tank to hold the collected rain water on the campus as part of the data gathering, but they did give permission to funnel rainfall from a portion of a large building on the campus into a measuring system.
"Originally, the (grant) proposal was to purchase a tank that would hold all the rainwater that would come," Tam said. "We couldn't actually implement that. What the students then did was design an open-channelled weir system that would be able to measure the flow rate and also measure the quality of the water that comes off one of the roofs of our engineering building."
There was enough rain last winter and the beginning of this spring that fell on just 5,300-square-feet of rooftop space at the campus to collect 18,500 gallons of water, Cusick said.
"You can see how if this was applied to an industrial area with all that flat space, how much rainfall could be saved," Cusick said.
To make large storage tanks feasible, Cusick is working on a design that calls for the tanks to be built inside and flanking the walls of homes and businesses. The tanks could supply water to toilets, sprinkler systems, dishwashers, showers and other outlets.
Tam said the tank design is ideally applicable to homes and businesses prior to construction, that it would be difficult to retrofit such a system into an established home or business. However, she said it can be done.
The notion of installing the rainwater harvesting equipment into homes as they are built has potential, said Borre Winckel, executive director of the Riverside County chapter of the Building Industry Association of Southern California.
He said a trend toward a so-called "green build" philosophy has developers using different concepts to create environmentally friendly homes in master-planned communities. And some custom-built homes already employ similar concepts, he said.
Nevertheless, he said, for large-scale housing developments, the bottom line for most developers remains cost and affordability.
"Builders, although you might think they are a highly speculative group, they do have an outlay of every house," Winckel said. "These homes have to sell, and they are very risk adverse to putting in doodads that might have the house sitting there for a while."
Cusick and Tam said that, despite the potential high cost of implementing such a system, they hope it catches on. Tam added that there are tax incentives that could help offset any costs.
"Everybody knows that people like spending money on helping the environment," Cusick said.
Winning $75,000 next month would help take the design to the next step, they said.
Saving money, water
As for the quality of the water, Cusick said it's not an issue.
"There is no danger of the water being contaminated if it is filtered prior to entering the tank," Cusick said. "The tank is a closed system, so it would be impossible for mosquitoes to gain access."
Melodie Johnson, spokeswoman for the Western Municipal Water District, a regional water wholesaler that buys water from the Metropolitan Water District and distributes water to western Riverside County cities and districts in a 510-square-mile area, said the agencies hand out grants to conservation ideas with potential.
"We will have to see at the end of the day if the project is viable," she said of the UC Riverside project.
However, homeowners are learning that water conservation measures can, in the long run, save money on water bills, she said. And another possible benefit of rooftop rainwater harvesting could come from its application on an overall region, she said. If a region can save enough water through rooftop rainwater harvesting, its homeowners and businesses don't have to build, for example, an $80 million water pipeline, she said.
"If you are going to have a whole development or community saying 'This is what we want to put in our community,' then you get the benefits of avoiding major capital investments (in pipelines and other water-delivery systems)," she said. "It's a win-win situation for consumers and water agencies."
Contact staff writer Jennifer Kabbany at (951) 676-4315, Ext. 2625, or email@example.com.