The public learned last week of contaminants at the Sam's Club construction site in Warwick following an I-Team report.
Warwick Mayor Scott Avedisian told NBC 10 he, too, only recently learned about them.
"Probably about a month ago we were notified the normal procedure of alerting DEM had not been followed to the letter of the law," Avedisian said.
Sam's Club was fined $37,500 by the Environmental Protection Agency after the company's contractor dug up an old industrial-sized motor, a large rusted out fuel tank and other junk buried at the site at 25 Pace Blvd. off of Bald Hill Road.
High levels of PCBs, which are known to cause cancer, were found in soil samples in August 2012. Some of the levels registered well above state and federal standards.
An EPA representative told the I-Team that the contractor should have stopped work, but continued stockpiling the contaminated soil off to the side.
"I think we were all surprised to hear that. I think the mitigating factor for us was that they admitted they needed to do the clean-up and bring it to where it needed to be. It just would have been nice to know at the very beginning," said Avedisian.
Walmart, which owns Sam's Club, told the I-Team that it didn't bury the waste. It said the company is working with the land owner, Kalikow Yaphank Development Corp. of New York, to clean it up.
Documents the I-Team found at the Rhode Island Department of Environmental Management lay out some of the clean-up plans and precautions.
"Rags and sorbent pads will be dampened with organic solvents (diesel fuel) ... and used to decontaminate heavy equipment buckets and tools. Equipment will be wipe tested for PCBs", according the documents.
"Obviously, it's in their best interests to have a store location that's going to prosper. So, I'm confident that they're going to follow that plan," Avedisian said.
A DEM representative said Sam's Club and Kalikow would be the performing parties and therefore responsible to notify the city and abutters.
A phone call to Sam's Club was not immediately returned. The store is expected to open in January, about three years after the original store closed.