June 2002: Volume 44, Number 6
POU/POE for Small System Arsenic Compliance & Pool Water, THMs and Pregnancy
by Carlos David Mogollón, WC&P Executive Editor
Big news came on the home front for POU/POE and acceptability as a solution for Safe Drinking Water Act compliance.
The document, “Centrally Managed Point-of-Use Compliance Strategy: Analysis of Implementation Issues,” runs only 12 pages long and is part of a 345-page Appendices to the draft document being prepared for Congress on implementing the controversial new rule, which drops the MCL for arsenic from 50 ppb to 10 ppb.
It’s expected to result in a “Guidance for Implementing a Point-of-Use or Point-of-Entry Treatment Strategy for Compliance with the Safe Drinking Water Act,” a companion document to the overall final rule being planned by the agency that was to be available in May. In July, all community water systems are to begin providing health information and arsenic concentrations in their annual consumer confidence reports for water that exceeds half the new MCL.
Before getting overly optimistic, though, Bruce Macler, of the USEPA Region IX Office in San Francisco, points out whatever the agency releases as a guidance must be implemented by the states. And they’re still wary of POU/POE’s applicability because of monitoring, control and liability issues -- particularly for small systems, he added.
“It’s the state folks that will make the final determination,” Macler said. “If they don’t think it will work, they won’t embrace it. They’re the ones that are going to have to accept it in the end.”
The issue is extremely important, as the WQA correctly reports, because this should spur additional public attention on the issue and indirectly help promote POU/POE solutions to arsenic reduction, RO and, to a lesser degree, ion exchange (which has yet to be fully embraced by the USEPA as an arsenic solution).
By the way, if you’re looking for the latest information from the USEPA, the fastest way to find it is at the Office of Water’s “Recent Additions in Water” webpage and the Office of Ground Water and Drinking Water’s “What’s New” webpage.
Secondly, a report this spring in the British Medical Association journal Occupational & Environmental Medicine published a survey regarding trihalomethanes in pool water treated with chlorine. Coverage on the report and potential risks to pregnant women appeared in media outlets from Reuters to Singapore’s Strait Times to CBS News, and a slew of environmental, academic and other websites around the globe.
The report concentrates on 44 samples taken from eight indoor pools, indicating much higher mean levels of disinfection by-products than found in tap water -- total THMs = 132.4 µg/L; chloroform = 113.3 µg/L -- and drawing a correlation with high total organic carbon (TOC = 5.8 mg/L). No direct link with the suspected impact on the health of pregnant women or their fetuses was made in the survey but was a major focus of the articles, which tied it to other studies associating THMs with miscarriage, low birth weight and some birth defects (see "TTHMs, TCE & PCE: Drinking Water Contaminants & Adverse Pregnancy Outcomes," Frank Bove, WC&P, May 2002).
CBS’s headline blares: “Chlorinated Pools Harmful to Pregnant Women?” Whereas, a British health foundation, BUPA, stresses “No need for pool panic,” but supports recommendations to cut chemical concentrations. These include proper filtration and taking a shower before swimming to reduce DBPs. Regardless, it supports alternative means of disinfection such as UV and ozone for pool water treatment to allow less chemical additives.
“I had not heard that frankly, the risk to pregnant women (from pool water) in particular. But, we have absolutely heard about THMs as a precursor to cancer. As far as I know, THMs are not a carcinogen so much as a precursor. THMs have been an issue in pool water for some time,” said Ted Rich, executive vice president of ClearWater Tech, an ozone equipment company that also specializes in pool water treatment.