25 April 2011

What's in Tallahassee's tap water? FSU professors talk about chromium and a recent study

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Chromium-6, the same hazardous chemical that made Erin Brockovich famous, is in Tallahassee's drinking water — but is there enough of it there to be a concern? Most would say no, a few would say maybe, and one or two might even say yes. Fortunately, you have a chance to learn more about this controversial chemical and its presence in your drinking water at the upcoming May 3 Science Café.

That's when Magnet Lab scientist Vincent Salters will share the results of a study he recently did with the help of oceanographer Bill Landing and several Florida State University students. Together, the professors and their students analyzed 41 water samples taken from residents' tap water, city wells and Wakulla Springs.

"The level of chromium that you would expect in the water here should be extremely low: less than one-tenth parts per billion (0.1 ppb)," said Salters, an FSU professor of geochemistry. "The levels that we found are between 0.8 and 1.4 ppb."

All of the chromium levels in Tallahassee's water are far below the federal standard, which is 100 ppb. California, however, has adopted a significantly lower public-health goal for the toxic form of chromium in its drinking water.

Science Café kicks off at 6:15 p.m. at Ray's Steel City Saloon, 515 John Knox Road. The event, which is presented by the National High Magnet Field Laboratory, will last until about 7:30 p.m. It's free.

Also speaking will be Robert Deyle, a Florida State University professor of environmental planning. Deyle will offer a brief overview of public-health concerns regarding the dangerous form of chromium, which is chromium-6 or hexavalent chromium.

Chromium is a metal naturally present in the earth's crust. But chromium-6 is a toxic form of chromium used in various industrial processes, such as to make stainless steel, tan hides, etc. Chromium-6 has been linked to stomach cancer and other health problems.

Most people first learned about the potential carcinogenic danger of chromium-6 in 2000, when the film "Erin Brockovich" was released. The movie retold the true story of the polluted drinking water of Hinkley, Calif., whose residents were awarded a $333-million settlement from Pacific Gas and Electric Co., the source of the town's groundwater contamination. Hinkley's drinking water reportedly had as much as 580 ppb of chromium-6 in its tap water, which is well over the EPA's standard of 100 ppb for total chromium.

The EPA's standard for total chromium is a figure that includes chromium-6. Most cities test only for total chromium. It takes more money, time and expertise to test for chromium-6. If a city's test result for total chromium is high, then it tests specifically for chromium-6. Salters found that, in his Tallahassee area samples, chromium-6 made up anywhere from 60 to 90 percent of the samples' total chromium concentration.

Salters got interested in the topic of chromium in drinking water after a national advocacy group, the Environmental Working Group, released the results of a drinking water study in December 2010. Its analysis of the tap water of 35 cities found that 31 had chromium-6 in their water. Of the 31 cities, Tallahassee had 1.25 ppb — the sixth highest level. All the cities' chromium-6 levels were well below the EPA's accepted total chromium level.

In the wake of the Hickley, Calif. settlement, the EWG's assertion that chromium-6 is more widespread in drinking water than generally assumed and for other reasons, the EPA may change its 20-year-old chromium standard this year. It may lower its acceptable level for chromium or create a new regulation for chromium-6.

California has set a much lower public-health drinking-water goal for chromium-6 of 0.06 ppb. But that goal is not enforceable — and California has not set an enforceable drinking-water standard based on that goal.

In an unfortunate twist of events, the town of Hinkley is once again facing chromium-6 contamination. In a Nov. 15 Los Angeles Times story, Hinkley resident Lillie Stone told the Times that her drinking water tested at 2.9 ppb for chromium-6. But, she added, "a PG&E representative sat right here at my table and said he wouldn't even consider buying us out until we reach 4 ppb." PG&E is supplying bottled water to some Hinkley residents, according to the article, and a hearing is scheduled for this month.

To hear more about chromium and Tallahassee's tap water — including Salters' ideas about where the chromium-6 in our drinking water may come from — pull up a chair at Science Café. Come early to get a good seat.