The new study found the substance in the tap water of 31 of the 35 cities sampled, and 25 had levels exceeding California?s proposed goal.

Hexavalent chromium was a commonly used industrial chemical until the early 1990s, the Washington Post reported Sunday. It?s still used in some industries, such as chrome plating and the manufacture of plastics and dies. It also can leach into groundwater from natural ores.

The highest levels were found in Norman, Oklahoma, where the water contained more than 200 times the California goal.

The Avion Water sample tested at was 0.78 parts per billion, ranked 10th among the 31 water systems studied.

Brokovich told the Post, ?This chemical has been so widely used by so many industries across the U.S. that this doesn?t surprise me.? Her fight for the residents of Hinkley, Calif., against Pacific Gas & Electric led to a $333 million damage settlement and became the subject of a 2000 film.

?Our municipal water supplies are in danger all over the U.S.,? Brokovich said. ?This is a chemical that should be regulated.?

Hexavalent chromium has long been known to cause lung cancer when inhaled, but scientists only recently found evidence it causes cancer in lab animals when ingested. It has been linked in animals to liver and kidney damage, as well as leukemia, stomach cancer and other cancers.

Asked about the report, city of Bend spokesman Justin Finestone said, "Our water quality reports are available online, and we comply with each and every federal and state water quality regulation. If regulations change and we have to treat for this substance in the future, we will."

"Public health and safety has always been and will always be our top priority," Finestone added. "Bottom line is, our water is completely safe and up to federal and state standards."

The American Chemistry Council, which represents the chemical industry, calls the California goal unrealistic, saying some water supplies have naturally occurring hexavalent chromium higher than .06 parts per billion.

The group?s director says the EPA?s most sophisticated analysis methods cannot detect such ?extremely low levels.? The group supports a uniform, national standards ?based on sound science,? and says research is under way to provide data to EPA by mid-2011.

Ken Cook, president of the Environmental Working Group, says water utilities are resistant to the regulation because of the extraordinary expense it would take to remove the chemical, but added, ?The real focus has to be on public health.?