Mainstream use calls for consumer lessons
By Tammy Wright
San Diego — While industry has been reaping the benefits of filtration technology for decades, its expanding use in mainstream applications is uncovering a need to educate consumers about contamination control.
The City of San Diego got a first-hand lesson on the subject recently when it announced its plan to combat the area`s water shortage problems resulting from a burgeoning population. Officials are proposing to build a wastewater treatment plant that would utilize multiple-barrier filtration methods to turn sewage water into drinking water. According to The Wall Street Journal (September 8, 1998, page B-1), however, residents are repulsed by the idea, with many dubbing it “toilet to tap.”
While the technology to recycle and reuse sewage water is in place, public opinion is a factor that determines its acceptability, says H. Martin Jessen, senior vice president at U.S. Filter Corp. in Palm Desert, CA, a global provider of commercial, industrial, municipal and residential water and wastewater treatment systems.
“Consumers aren`t quite ready for it yet,” he says, “but, if a (wastewater treatment) system is designed, installed and operated properly, the water will be safe. It could be healthier than some ground water in the U.S.”
Dave Schlesinger, director of San Diego`s Metropolitan Water Department, says the city has spent about $400,000 on public outreach and education in its efforts to clean up the project`s dirty image. San Diego even commissioned an independent panel of scientists appointed by the National Water Research Institute to review its plan, which they have endorsed as a viable means of providing “a safe and appropriate supplemental drinking water supply” for the city.
San Diego`s outlined repurification process calls for contaminants to be first filtered out of wastewater as it passes through tiny membranes and then minerals and other pollutants would be filtered out through reverse osmosis. Softeners and ozone would be used to treat and disinfect the water, which would be placed in a surface reservoir where it would be blended with raw water from runoff and imported sources. As an additional safety measure, the water would sit there for a year and then be filtered one more time prior to human consumption.
“We`re finding that if we can spend as little as an hour with a group of people we can convince them it`s a good idea,” says Schlesinger. “Thin film composites have gotten very good over the last few years (in terms of) durability and quality, and it`s a cost-effective option for providing a locally controlled source of water to our city.”
Schlesinger believes the public`s negative reaction to the project stems more from the fact that the proposed wastewater treatment plant will be above the ground and visible. During the last 20 years, he says several states have implemented water repurification programs; however, most of them have been underground.
“People get agitated when you put it where they can see it,” Schlesinger notes.
Jessen of U.S. Filter agrees that consumers need to be schooled in contamination control as the technology moves into new arenas. He says there are also less offensive options available to cities to augment their water supplies.
For example, last year, U.S. Filter purchased 42,000 acres of farmland in California`s Imperial Valley, which currently exports water to the City of San Diego. The company has started a pilot irrigation runoff reclamation project to recycle agricultural wastewater. U.S. Filter executives say that if agriculture can reuse its drain water, much less fresh water will be required to farm. Research shows that more water is required for farming than for home or industrial use.
In the future, Jessen also believes that progressive water suppliers will offer major industries, like microelectronics, incentives to recycle water at the point of use. In these facilities, he says, large vats can use 1,000 to 1,500 gallons per minute.
“In some cities in the West, for every two gallons of water brought in, only one gallon is acceptable for use,” Jessen adds. “The net effect (of these methods) would be freeing up raw water.” CR