Our water has has a lot of chlorine, but I am confused about which type of water-filtration system is best for the environment, me, and my wallet. I have looked into whole-house reverse osmosis systems, which either have replaceable filters or have a permanent filter at a much higher cost. Brita is what I currently use, but I hate throwing those filters away. —Mele Brobeck
You can heave a sigh of relief: An expensive reverse osmosis (RO) system would actually be less effective than your Brita, according to Richard Andrew, general manager of the Drinking Water Treatment Unit of National Sanitation Foundation (NSF), an international nonprofit organization that certifies water-filtration systems and other products. If chlorine is your main concern, RO would be overkill.
That's because Brita, Pur, and Zero Water carafes and faucet-mounted filters use activated carbon. "For chlorine, activated carbon is really the treatment of choice," Andrew says. "Reverse osmosis by itself probably isn't going to be as effective on chlorine."
In general, a faucet-mounted carbon filter, because of its greater capacity (up to 200 gallons), will need replacing less often than a carafe cartridge (typically 40 gallons), says Andrew. Personally, he has opted for a carbon filter mounted in his refrigerator faucet, from which his children draw most of their drinking water. It’s installed by a plumber, and easy to maintain. “I just move the ketchup bottle out of the way and change the filter,” Andrew says.
Happily, recycling carbon filters is a growing trend, Andrew says, and NSF has added “sustainability evaluations” to its criteria. “We continue to raise the bar over time,” he says.
You can send Brita filters them to be recycled through the company’s partnership with Preserve, Filter for Good. You can mail or drop off your Brita cartridges (along with yogurt containers and other #5 plastics) at participating Whole Foods Markets and other locations. Preserve makes the plastic into post-consumer food tools and tableware, and the carbon is “regenerated for alternative use or converted into energy,” according to Brita’s website. Participants also get discount coupons for Preserve’s bright, durable, ultra green products.
Zero Water also has a recycling program for their pitcher and faucet carbon cartridges. You mail them at your own expense, and the company gives you a $10 coupon towards your next cartridge purchase.
More About Reverse Osmosis Filters
RO systems are best at removing heavy metals, such as calcium, arsenic, and especially lead—which is not reliably blocked by carbon filters, Andrew says. He says the only carbon filter certified for lead removal by NSF is Zero Water’s.
Because RO membranes collect dirt and bacteria and can develop holes, RO systems need to be inspected annually, and the membranes either cleaned or replaced, according to the green homeowners’ bible, Prescriptions for a Healthy House.
What’s in Your Water?
Before deciding on a filtration system, check your utility’s water quality report to find out what, if any, are contaminants of concern. The Natural Resources Defense Council provides helpful guidance. Then check NSF’s certification listings, which are updated every day, for products that are effective at removing those contaminants.
For more information, check out NSF’s consumer home drinking water treatment guide.