By David H. Martin
The shocking news from Flint, MI has sunk public confidence in home drinking water like a lead balloon. High levels of health-threatening lead in Flint’s water has drawn national attention to the disastrous consequences of failing to properly maintain a public water system to prevent corrosion (Figure 1) and dangerous lead contamination.What has Flint taught us? More than ever, final-barrier treatment is needed.
Final-barrier treatment (called POU) is technology installed at the point where water is consumed. It can be an adjunct to central treatment as well as primary treatment in homes using untreated well water.
Types of final barrier equipment include:
• Pour-through pitchers
• Countertop units
• Faucet-attached devices
• Under-the-sink filters
• Refrigerator filters
• RO technology units
Final-barrier technologies include:
• Ion exchange, distillation and RO for inorganics
• RO, distillation, UV and carbon block
for microbiological organisms
• RO, distillation and UV for particulates
• Activated carbon for volatile organics
• Proven reduction of DBPs
• Corrosion byproducts (including lead) from plumbing and the distribution system
• Contaminant intrusions into the system
• Disease-causing microbiological organisms
• Trace elements of endocrine disruptors, personal care products and pharmaceuticals
Who coined the term?
But where did this uniquely powerful term for POU originate? Regu P. Regunathan, PhD, President of ReguNathan Associates Inc., technical consultant to WQA and well-known as a long-time advocate of the final-barrier approach, claims he first voiced it in 1987 at a US EPA meeting in Cincinnati, OH. “It didn’t catch on right away, but eventually the Water Quality Association built their POU promotional efforts around final barrier. Former WQA Executive Director Peter Censky and former WWA President Richard Mest led the efforts,” says Regunathan.
“While I’ve been disappointed that interest in the Final Barrier campaign has seemed to soften in the last two years, it certainly makes sense that now (in national response to), the Flint water contamination incident will spur new support,” he says. “And the publicity is not just coming from Flint. How about the incidents in Sebring, OH and Jackson, MS? While these are lead problems, when you think about all the other potentially harmful contaminants in drinking water, the Final Barrier technology program can provide a valuable insurance policy against most, if not all of them.”
And in a February 5th phone interview with WC&P, he noted that more testing of industry products for lead reduction must be conducted before certification can be completed. According to Regunathan, a May Water Sciences Committee meeting on this subject is planned. (The Association offers a full-color brochure and a 14-page electronic presentation [Figure 2] that dealers can use to explain the concept on laptop and notebook computers. For more information, visit to www.wqa.com.)
Sierra Club mounts action against “contaminants of emerging concern”
In an ongoing campaign warning of the presence of endocrine-disrupting chemicals (EDCs) in drinking water, Sierra Club’s National Toxics Team is distributing a four-page fact sheet and color literature (shown in Figure 3) urging home POU filtration: “Use the best possible point-of-use water filters because many CECs are not removed by (central) drinking water treatment, and some treated water contains disinfection byproducts. The Silent Spring Institute recommends solid carbon block filters.”
These websites provide helpful information:
WQA reminds us that only one percent of all municipal water is consumed by humans. Therefore, it seems that the future of water treatment will be to treat it once at the central plant to protect the immediate health of the general population. Final-barrier water treatment, applied at the point of use, is in the hands of dealers and their customers, working together to determine the appropriate solution in each case. Well water customers will benefit from the same protective partnerships with professional dealers.
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