(WBBM NEWSRADIO) -- A landslide at a Dolton landfill over the weekend sent a giant swath of soil and grass onto a stretch of Cottage Grove Avenue, and crews were trying to clear the roadway on Monday.
Mary Margaret Cowhey, president of Land and Lakes, the family-run company that owns the landfill, said water must have infiltrated the cover system at the top of the landfill. A vegetative layer that sits on top of that “literally just slid off,” Cowhey told WBBM Newsradio as she stopped at the scene.
In the 50 years her family has owned landfills, she’s only seen a landslide like this once before, she said.
The 2-foot-tall section of dirt and grass that slid was estimated at 100 feet by 100 feet section. The plunging mass also tipped a ComEd utility pole to a 45-degree angle.
Cowey says her engineers and surveyors will map out a plan to repair the plastic geo-membrane that covers the foot of clay that seals the landfill. The company will run their plan past environmental officials, she said.
“There is no environmental issue. The landfill is still enclosed. The liner is intact. It’s the liner that you’re looking at that’s exposed today. It’s the dirt on top of the liner that just became, we think, saturated with the extremely heavy rainfall yesterday and slid down the slope,” Cowey said.
To seal a full landfill, she said: “You put down a compacted one-foot of clay cover, then a plastic geo-membrane that is impermeable and impenetrable goes onto the site and then, on top of that, there’s protective soil and then a vegetative cover.”
It’s that top layer of soil and greenery that slid off the landfill.
Cowhey hoped her crew could clear the mound of dirt and grass from the street by later Monday.
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