The U.S. Environmental Protection Agency said Tuesday it found no hazardous conditions or injuries in the hundreds of homes and businesses inspected in St. Louis Park as part of an effort to mitigate vapors rising out of contaminated soil.

The agency, which was called into the area last December, said it has spent $1 million to collect and test soil samples from 268 locations and install free ventilation systems in 40 of the properties.

The EPA said the ventilation systems were placed in locations where the levels of volatile organic compounds were high enough that continued monitoring was recommended by state health guidelines.

But Sonia Vega, the EPA's on-site coordinator, said Tuesday that none of the levels detected was considered dangerous.

As a result, Vega said, the EPA at the end of this month is closing an emergency office it opened at 6528 W. Lake St.

"The emergency is taken care of," she said. "Now the focus is on where [the contamination] is coming from."

The agency will conduct two meetings next month to talk with residents and business owners about its findings. They will be held on July 10 at the St. Louis Park Senior High School cafeteria, 6425 W. 33rd St.

The first session is scheduled from 2 to 4 p.m. and the second from 6 to 8 p.m.

Getting involved

The EPA became involved in the St. Louis Park project after vapors from volatile organic compounds (VOCs) were found in local groundwater.

Although the compounds had no effect on drinking water supplies, investigators feared that the fumes could rise from the soil into basements through slab and foundation cracks.

Vega said the EPA checked 219 residential properties and 49 commercial sites near the intersection of Hwy. 7 and Wooddale Avenue.

A total of 41 residential and 12 commercial or industrial properties had VOC levels that exceeded the state Department of Health screening levels. Vega said the screening levels do not indicate imminent danger, but simply show more investigation is needed.

She said the agency will conduct follow-up sampling of the homes with the new ventilation systems, which are similar to systems used to remove radon, after 30 and 90 days.

Vega said the agency and its lawyers are continuing to investigate the possible source of the contamination.

The main chemicals of concern -- trichloroethylene and perchloroethylene -- have been used for decades as industrial degreasers, metal cleaners and dry-cleaning fluids.

Long-term exposure to them at certain levels has been linked to cancer, liver disease and other problems, according to state health officials.

Investigators theorize that a business in the area dumped the chemicals onto the ground or into the groundwater. From there the chemicals migrated as far away as Edina.

Although the agency has narrowed its list of suspects, it still does not know when and where the chemicals were dumped.

"There is no way to know when it was dumped," said Vega, who noted that there is a possibility the agency may never be sure of the source.

Heron Marquez Estrada • 612-673-4280