The EPA designated the area as a Superfund site â¿¿ marking it as of the nation's most toxic uncontrolled hazardous waste sites â¿¿ in 2011, and officials cautioned residents to stay out of their basements to prevent potential chromium exposure. EPA officials removed chromium from the building and demolished it last year, and found that some tanks had holes in them, potentially releasing even more chromium into the groundwater.

Officials say the contamination has not affected the city's drinking water, which is drawn from an outside source. Instead, they worry that people could inhale chromium dust that has been found in basements where groundwater has leached in.

The chromium plume is about three-quarters of a mile wide and slightly more than an eighth-mile long, EPA officials said. The substance has traveled from the site underneath the Passaic River and into the city of Passaic. The agency has installed about 40 monitoring wells to monitor how far the metal has spread.

"We're trying to find out the extent of the plume," said Rich Puvogel, a project manager with the EPA.

High quantities of the metal have been found in 14 homes that have since been cleaned up. Trace amounts were found in 30 to 40 homes. Testing continues, and a nearby school did not show elevated chromium levels.

Cathy Garrone, who bought a house in the neighborhood in 1985, walked her small dog recently across the street from the site where the plant once stood, a lot now fenced off and peppered with mounds of rocks and dirt.

She said she wouldn't have bought there if she had known about the chromium spill, and thinks much more testing needs to be conducted, both of the environment and people.

"I'd like them to do more testing to assure my safety," she said.

The research study is being done in conjunction with the city of Garfield. Officials are hoping the testing can bring some answers to residents.

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