HaloSource manufactures a sort of turbocharged version of the cartridge that goes in your Brita pitcher at home. But whereas the Brita cartridge merely filters water, thus improving appearance and taste and removing some contaminants, the HaloPure biocidal cartridge -- packed with tiny polystyrene beads that have bromine ions chemically bonded to their surface -- disinfects it, eliminating viruses and bacteria.
Eureka Forbes is using HaloPure cartridges in gravity-fed countertop water purifiers that let a family treat and store up to 6.5 gallons of water at a time. Unlike ultraviolet purifiers, countertop water purifiers don't require electricity to work, and their lower cost -- $40 to $60, versus $200 to $300 -- puts them within reach of India's burgeoning middle class.
HaloSource also manufactures products used for recreational water treatment and storm-water management, as well as antimicrobial coatings for textiles. But the company, which has annual revenue of more than $10 million, sees its biggest opportunities in water purification. HaloSource has partnered with the Brazilian consumer-device maker Everest, which will use HaloPure cartridges in countertop water purifiers, and the Chinese manufacturer Chanitex, which uses them as a component in reverse-osmosis purifiers for homes and businesses. HaloSource now has manufacturing facilities in Bangalore and Shanghai, as well as in Washington State.
In 2007, the company secured $15 million in funding from the Abu Dhabi-based Masdar Clean Tech Fund. "In China and India combined, you've got close to three billion people who will be looking for consumer-product solutions to problems they've dealt with for generations," says Andrew Clews, HaloSource's vice president of marketing and business development. "Access to clean, safe drinking water is certainly one of those issues."
Storing It
It's nice to imagine that water flows magically from a pristine reservoir or spring to your home faucet, but that's simply not the case. As we have seen, it is disinfected and pumped along through a sprawling network of water mains and pipes. The U.S. water network, much of it built in the 1950s and '60s, will require some $277 billion worth of construction, upgrades, and replacement in the next 20 years, according to EPA estimates. With scarcity driving water agencies to fix leaks -- by some estimates, about six billion gallons per day in the U.S. are lost through literal cracks in the system -- companies making high-tech metering and leak-detection technologies are doing well for themselves.
San Rafael, California-based PAX Water Technologies, founded in 2006, is focusing elsewhere, on a relatively overlooked niche in the distribution chain: water storage tanks. Though the numbers are hard to tally, there may be as many as 400,000 storage tanks in use in the U.S. today, according to PAX Water's vice president of marketing, Jason Oppenheimer, who came to the company after nearly a decade of working on water infrastructure projects as a civil engineer.
After being treated, drinking water can spend as long as 100 days in the distribution system before reaching an end user. That's not necessarily a bad thing, but when water sits in a tank too long, it begins to stagnate and settle into layers of different temperatures, as in a lake. In warmer layers at the top, the disinfectants used in treatment are burned off, which increases the potential for contamination. Even when the water is being used, poor tank design can create an uneven distribution of disinfectant and encourage uneven aging, allowing water at the bottom of a tank to be replenished more quickly than water at the top.
The traditional solution is to dump more disinfecting chemicals into the holding system, which has environmental and economic costs and can lead to the formation of chemical byproducts. Water agencies also use energy-intensive "operational cycling" -- basically pumping moving water around from tank to tank -- or even dump some water at the end of the line to allow fresher water to flow into a stagnating system.
The energy-efficient, inexpensive, and elegant solution proposed by PAX Water is called the Lily impeller. Featured in a 2008 design exhibit at New York City's Museum of Modern Art, the Lily -- a spiral propeller whose shape calls to mind a calla lily -- is not just pretty but powerful. When installed on the bottom of a storage tank, the impeller, which weighs less than 70 pounds, can mix up to seven million gallons of water while drawing the same amount of energy as three 100-watt bulbs. Mimicking natural convection currents, the mixer evenly circulates water in the tank, thus reducing or eliminating the need to add disinfectant. Several states require new and retrofitted storage tanks to include some of kind of mixing system -- a potential boon for PAX Water.
The water mixer came to market in 2007 and won the People's Choice Award in the New Product Technology Showcase at the American Water Works Association convention. The same year, PAX Water launched a beta program in California. That helped open up the market, and by mid-2008, the company had about 25 of the $30,000 units installed in municipal storage tanks. Dan Heimel, a water quality specialist in Redwood City, California, which participated in the pilot study and subsequently purchased a mixer for a troublesome water tank, says the system solved the city's thermal stratification problem.
