Environmental Progress - Fall 1999

Work Easing Threat Of Chicago "Garbalanche"

Garbage mountain threatened to slide into heavily populated urban area

It rises 170 feet high, its steep slopes covering 58 acres on the southeast side of Chicago, and offers panoramic views from its summit.

But this mountain of garbage near Lake Calumet, the Paxton II landfill, where years of improper operation led to enforcement actions by Illinois EPA, the Attorney General and the city of Chicago, posed an ominous threat at the start of this year.

An assessment in January by Patrick Engineering of Springfield for IEPA's Bureau of Land warned there was a potential for part of the state's tallest landfill, closed in 1992, to break off and start sliding across busy adjacent Stony Island Avenue.

"An environmental disaster waiting to happen"

In January, new Agency Director Tom Skinner was briefed by Bureau of Land staff on the possibility of “an environmental disaster waiting to happen” at Paxton II. A slide could send as much as 300,000 cubic yards of garbage onto Stony Island Avenue and on to a business (ironically, one of the state's largest environmental cleanup contractors), set off massive fires and release toxic fumes and disease-spreading vermin across the area, he was told. A worst case scenario could include having to evacuate nearby homes and even close down Interstate 94 (Bishop Ford Expressway).

Skinner took the issue to Governor George H. Ryan's top staff. The governor soon responded by including funding for Paxton II "stabilization" in his February state budget proposal. In the meantime, Skinner ordered the shift of some existing Agency funds to this high priority, and work began in March to start pumping out millions of gallons of leachate (contaminated rainwater that had been seeping into the landfill for years) to relieve the pressure on the sides.

The start of the work and the potential "garbalanche" at Paxton II drew substantial coverage by the Chicago news media.

The work was initially slow going as leachate was tapped from individual manholes into trucks for treatment at nearby Clean Harbors Environmental Inc., the firm whose facility was most immediately threatened by a possible collapse. A manifold system to connect the manholes at Paxton was devised to make the process more efficient and less expensive.

While leachate pumping continued, Bureau of Land Remedial Project Management Section site manager Stan Komperda and other Agency staff and contractors and consultants tackled the major cause of the leachate buildup.

How not to build a landfill

Instead of a concave crown to divert water that is essential to good landfill design, Paxton II was left with a convex bowl that acted like a sieve as it allowed accumulated rainwater to infiltrate the landfill. Steep slopes that steadily eroded and became less stable were other textbook examples of how not to build a landfill.

Through the spring and summer, a parade of trucks began depositing what would eventually be more than 100,000 cubic yards of new fill to eliminate the bowl and create a dome-shaped crown on the most critical 19 acres on top of Paxton. The city of Chicago assisted in providing much of the fill material. Work began in the autumn on a nine-inch drainage layer of shredded tires on the top. It was then topped with 24 inches of compacted clay.

Leachate removal continues, with an estimated 1.5 million gallons withdrawn as of mid-October, the equivalent of about a one-mile long train of tank cars.

Complete remediation could take another two years

Work still to be done includes more soil cover, prairie vegetation, and a protective geolayer fabric on the landfill's sides and construction of the landfill (methane) gas management and long-term leachate and storm water collection systems.

The state has legal rights to any revenue from the sale of methane gas at the site and is hoping it can be used to produce electricity and recoup at least some of the costs of corrective action at the landfill. Governor Ryan and state lawmakers provided $2.6 million for last fiscal year and $8 million for the current fiscal year for the Paxton II work. As of late October, about $6 million had been spent on the project. The work may take another two years to complete. Total costs may reach $16.5 million, the most extensive remediation project directly undertaken by Illinois EPA.

The Lake Calumet Cluster Sites Work Group, which includes local community representatives, environmental organizations and U.S. EPA, has assisted Illinois EPA in keeping the local community informed throughout the Paxton II project and has been supportive of the work done so far, hailing it as a model for remediation in an area of the city that is plagued with a legacy of environmental problems.

Agency staff and consultants believe the potential for a catastrophic failure of the landfill continues to diminish as the work progresses. While the corrective action continued, though, Illinois EPA Community Relations staff worked closely with Chicago's fire, emergency response, police, and streets departments on contingency plans in case a slide did occur.

In late summer, on Stony Island Avenue next to Paxton II, the city erected what is certainly the only street sign of its kind in Illinois, and perhaps in the nation. It reads: "Caution: Landfill Slope Failure Zone Next 1/4 Mile."