While recents tests on Madison’s public drinking water found that a cancer-causing contaminant is present in a majority of the city’s water wells, city officials are urging residents not to be alarmed.

Joseph Grande, water quality manager for Madison’s Water Utility, said the city tested all of the wells currently in operation and found only three did not contain trace levels of chromium-6.

Grande said there is no federal requirement for cities to test for the contaminant in drinking water but said the city decided to further evaluate the water’s level after an independent organization found traces during a study earlier this year.

“There is no requirement to test for chromium-6, but in recent months there has been a concern that there may be some cancer-causing effects due to the ingestion of chromium-6 in drinking water,” Grande said. “The Environmental Protection Agency and other federal agencies are currently evaluating the effects.”

Grande said Madisonians should not be alarmed by the recent findings because the chromium-6 levels will most likely fall below new federal health safety limits, which will be implemented in the coming months.

Only two of the wells tested were found to have above one part per billion of chromium-6, Grande said. None of the wells tested as high as the 1.79 ppb trace level found in the January study.

Madison Water Utility is currently partnering with Public Health to address any concerns about possible health-related effects.

“I really do not think there is a significant issue based on what the test results were, but the information we have has been provided to Public Health,” Grande said. “We partner with Public Health whenever there is a concern about the safety or health- related effects due to our drinking water.”

Environmental Working Group, the independent organization that originally found the contaminant in drinking water throughout the country, praised Madison for its continued efforts to test the chromium-6 levels despite lack of federal or state requirement.

EWG spokesperson Leeann Brown said the organization was proud of Madison for responding so quickly to the group’s test results and to the EPA’s response to the study.

“Following our test results, EPA recommended water utilities conduct their own testing, which Madison did,” Brown said. “Madison tested in response to its citizens’ concerns, which is spot on.”

Brown said collecting data is the most important thing Madison can do right now because without an appropriate data set it would be difficult to figure out where the contaminant was coming from or how to further treat or combat the contaminant.

She said Madison residents should be aware of the issue, and EWG is not expecting to see health concerns arise from this particular contaminant over the course of the next several years, but there is not agreement about what the effects could be in the long term.

“People should still drink the water but should remain proactive in looking at ways to limit the chromium-6 in drinking water,” Brown said.

Studies have found chromium-6 is carcinogenic when inhaled. It is used in the production process for materials such as dyes, stainless steel and leather.