The Milwaukee Water Works, responding to inquiries and reporting this weekend about a toxic metal showing up in a sample of drinking water in Milwaukee and other communities (Madison, according to the national report, seems to have a worse situation), has sent me this statement and will post it on its website.
Consumer Information about Chromium-VI -- Dec. 20, 2010
There is a news story today about a study by an environmental advocacy group that says America’s drinking water is contaminated with Chromium-VI or Hexavalent Chromium, a chemical that came to national attention in the 2000 feature film Erin Brockovich. The Environmental Working Group (EWG) released a report on its recent study of Chromium-VI, as found in water samples the EWG gathered from many cities that have previously detected Total Chromium. The EWG wants the U.S. Environmental Protection Agency (EPA) to set a legal limit for Chromium-VI and require water utilities to test for the chemical.
Consumers can be assured Milwaukee drinking water meets all EPA regulatory requirements for safe and healthful drinking water. The Milwaukee Water Works (MWW) is committed to protecting public health.
The EPA, in its Safe Drinking Water Act (SDWA), regulates Total Chromium in the finished water leaving the treatment plants. The allowable limit per EPA is 100 micrograms/L or parts per billion. The EPA does not currently regulate Chromium-VI.
The Milwaukee Water Works tests annually for Total Chromium as required by the SDWA. The most recent test in 2010 found no Total Chromium. The detection limit for MWW analyses for Total Chromium is 2 micrograms/L, so MWW reports <2 micrograms/L (less than 2 micrograms/L). In previous years, Total Chromium was measured between none detectable and 9 micrograms/L. MWW has not previously tested specifically for Chromium-VI, but has arranged to test for it in the finished water and distribution system.
EPA is evaluating new health effects data on Chromium-VI. The evaluation is expected to be completed in late 2011. MWW is prepared to respond in a way that protects public health and meets federal and state standards.
The Milwaukee Water Works tests source and treated drinking water for over 500 contaminants even though the EPA requires tests for only 90. This is done as a precaution to ensure safe water, to collect baseline data for study and to meet future regulations. To ensure the public is fully aware of all water quality monitoring data, MWW publicizes it in the annual consumer confidence report and on its website.
The Milwaukee Water Works treats Lake Michigan water in a multiple-step process to remove illness-causing microorganisms and contaminants. The water is disinfected with ozone, a highly reactive gas that destroys microorganisms, removes taste and odor, and reduces byproducts from chlorine disinfection. Coagulation, settling, and biologically active filtration remove additional particles. Fluoride is added for dental health. Final chloramine disinfection ensures safe drinking water throughout the distribution system and at consumer faucets.