Officials from the City of Tallahassee today issued a statement responding to a report released earlier this week that identifies Florida’s capital, along with Miami, as one of 31 U.S. cities with municipal water supplies that contain hexavalent chromium, a cancer-causing carcinogen.
The study, produced by the nonprofit Environmental Working Group, tested water samples submitted by volunteers from 35 cities from around the country in an effort to encourage the EPA to establish legal limits for the toxic chemical in drinking water currently tested for alongside the harmless chromium-3 — akin to “grouping arsenic and vitamin C.”
From the city’s statement:
Chromium occurs in many different forms in the environment and is a naturally occurring component in tap water. It’s also an essential micro-nutrient for human health The City tests drinking water for total chromium which includes, if present, chromium-6, one of several forms of the compound. The presence of chromium-6 in the environment is typically associated with heavy industrial activities generally not found in Tallahassee. The recent report from the Environmental Working Group (EWG) cited the Erin Brockovich case, in which a man-made industrial by-product was improperly disposed. This is not the same issue as naturally occurring chromium in the Tallahassee area.
However, the City does conduct rigorous testing of its water supply for compounds like chromium. The U.S. Environmental Protection Agency (EPA) and the Florida Department of Environmental Protection have set a drinking water standard for total chromium (all forms including chromium-6) at 100 parts per billion (ppb). The annual water quality report for the City of Tallahassee contains vital information on the City’s drinking water and is available online at Talgov.com/YOU. The annual report shows the 2009 total chromium range between non-detectable and 2.5 ppb, with these values far below the EPA’s requirement of 100 ppb.
While the Working Group report concludes that none of the cities tested contained “total chromium” levels exceeding the 100 parts per billion allowed by the EPA and Florida Department of Environmental Protection, 25 of those cities found to have chromium-6 had concentrations beyond the 0.06 ppb “public health goal” threshold proposed by California officials in 2009:
Despite mounting evidence of the contaminant’s toxic effects, including a U.S. Environmental Protection Agency (EPA) draft toxicological review that classifies it as “likely to be carcinogenic to humans” when consumed in drinking water, the agency has not set a legal limit for chromium-6 in tap water and does not require water utilities to test for it. Hexavalent chromium is commonly discharged from steel and pulp mills as well as metal-plating and leather-tanning facilities. It can also pollute water through erosion of soil and rock.
The National Toxicology Program has found that hexavalent chromium in drinking water shows clear evidence of carcinogenic activity in laboratory animals, increasing the risk of otherwise rare gastrointestinal tumors (NTP 2007, 2008). In response to this study and others, California officials last year proposed setting a public health goal for chromium-6 in drinking water of 0.06 parts per billion (ppb). This is the first step toward establishing a statewide enforceable limit (OEHHA 2009).
Levels of the carcinogen in 25 cities tested by EWG were higher than California’s proposed public health goal. Tap water from Norman, Okla. (population 90,000) contained more than 200 times California’s proposed safe limit.
Tallahassee’s general manager of Underground Utilities, Mike Tadros, stressed the “vigilant scrutiny” of their Water Quality Division, adding that Tallahassee’s tap water is “within all applicable federal and state guidelines” and that the city has been recognized by the American Water Works Association for having the “Best Tasting Water” in Florida.
The press release also questioned the methods employed by Working Group, noting that the group has not shared its lab data and that the findings clash with samples collected by the city itself.
According to the Tallahassee Democrat, testing by the city detected levels of chromium-6 in levels only as high as 1.0 ppb — still exceeding California’s proposed safe level. The annual water quality report referred to in the press release shows only the levels of “total chromium” detected.
The EPA has announced an assessment slated for completion next year, which will include a review of the Working Group study and will determine if a new standard is required.