Oil and water may be mixing at Lombard Lagoon thanks to some small, black rocks.
That's the concern of a Glen Ellyn man who said he frequently walks the path around the lagoon and watched as Lombard Park District crews recently added dark, marble-sized rocks to the shoreline.
"The stuff stinks of something that smells like an oily petrochemical of some sort," Dom De Bellis said. "It just seemed a little odd for it to be in nature like that in such a natural setting like the lagoon."
The park district, which owns the lagoon, hired Prairie Analytical Systems, an environmental laboratory that specializes in analyzing water, soil, sludge and oil, to test the rocks, Deputy Director Rick Poole said Friday.
"We did have somebody come out to run some tests on it," Poole said. "We want to make sure there's nothing unsafe."
Representatives from Prairie Analytical Systems took samples of the rocks Thursday, Poole said.
The rocks came from a construction company, which donated them for recent park district projects to prevent erosion at Lombard Lagoon, as well as ponds at Four Seasons Park and Old Grove Park, Poole said.
The company removes the rocks from the roofs of industrial buildings and donates only the top layer which was not in contact with the roofing material to the park district.
"We've talked to the people that supply us the rocks," Poole said. "They've produced for us a memo that says this is dirt and silt, not other products on (the rocks)."
The rocks De Bellis says may be coated in oil were only used at Lombard Lagoon, Poole said. Light-colored, golf ball-sized rocks received from the same contracting company were placed at the other two ponds as well as Lombard Lagoon.
De Bellis said the oily film appeared worse in early November, when park employees were spreading the two types of rocks along the shore.
"During the construction, there was some dirt and film on the water, but we have no evidence of any petroleum products or fuel," Poole said. "There seems to be no impact on the environment or the ecosystem at that site."
De Bellis said he brought the issue to the attention of the park district and Lombard village staff because he was concerned that if the rocks were tainted with chemicals, they could harm fish, ducks and geese that swim in the lagoon and children who play nearby.
"I come here every day with my dog ... I don't let my dog get on it," said Ed Malarich, who also uses the park. "It's possible to get sick from this stuff, too."
Dana Moreau, Lombard trustee and chairwoman of the village board's environmental concerns committee, said she heard about the possibly contaminated rocks and believes any threat they may pose would be accidental.
"I'm hoping it's nothing, but you never know, so you've got to investigate everything," Moreau said.
The park district expects results back before Thanksgiving to determine whether the rocks are coated in oil or any other substance that may be harmful to the environment.