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Congressional District # 03


EPA ID# ILN000510191
Last Updated: March, 2012

Site Description

The South Station former Manufactured Gas Plant (MGP) site ("South Station site") is located in Chicago, Illinois, near the intersection of Eleanor and Loomis Streets in Section 29, Township 39 North, Range 14 East (Cook County).  The site encompasses approximately 8.3 acres, with approximately half of the site owned by The Peoples Gas Light and Coke Company (two parcels comprising 4 acres) and half owned by the city of Chicago (two parcels comprising 4.3 acres).  The site is bounded to the northwest by the South Branch of the Chicago River, to the southeast by Eleanor Street, and to the northeast by Loomis Street.  Parcels A and B are owned by Peoples Gas and occupied by a storage warehouse constructed in the early 1970s.  Parcels C and D, owned by the city of Chicago, are currently vacant but will be developed into a city park.  Land use near the site is predominantly industrial and residential, with some residences located across Eleanor Street.

History and Former Operations

The Peoples Gas Light and Coke Company (Peoples Gas) built the plant and storage facility in 1874.  The site was used for gas manufacturing operations from 1874 to 1941, when plant operations shifted to the use of natural gas.  The plant produced gas by various manufacturing processes over the years:  coal gas (1874–1890); carbureted water gas (1890–1934); and oil gas (1934–1941).  The plant was used as a reformed natural gas facility from 1941 to 1961.  The primary MGP structures included various buildings, a 4.3 million cubic foot gas holder, a 104,000-cubic foot relief holder (which also served as a tar tank at one time), a 500,000-cubic foot relief holder, seven aboveground oil tanks, tar tanks, two large tar wells, four light oil tanks, four gas condensers, pumps and scrubbers, an underground oil tank, and three underground gas holders.  The plant was retired in 1961 and the MGP structures were dismantled during the mid to late 1960s.  A portion of the site was later utilized by a wood pallet manufacturing facility.

Site Responsibility

The site is being addressed through potentially responsible party (PRP)actions under federal and state oversight.

Threats and Contaminants

Groundwater has been detected at the site at depths ranging from 8 to 12 feet below ground surface (bgs).  The apparent direction of shallow groundwater flow is northwest, toward the South Branch of the Chicago River.  Groundwater samples collected in 1998 and 1999 contained cyanide, metals, volatile organic copounds (VOCs) including trichloroethylene (TCE), benzene, and naphthalene, and semi-volatile organic compounds (SVOCs) including polyaromatic hydrocarbons (PAHs).  Most of these chemicals were also detected in groundwater samples collected in 2004 after much of the recent remediation had been completed. 

Impacted soil was encountered to depths greater than 20 feet below ground surface beneath parts of the site.  Metals, cyanide, PAHs and other SVOCs, and VOCs were detected in soil samples taken in 1999.  Chemicals found at concentrations exceeding the Illinois Tier 1 screening levels include benzene, ethylbenzene, naphthalene, styrene, toluene, TCE, xylenes, and chromium.  Because soils were not excavated beneath the majority of the building footprint and in other areas of the site, soils with notable coal tar impacts remain in place. 

The site is adjacent to the South Branch of the Chicago River.  In 2000, the Agency collected sediment samples from a location in the South Branch of the Chicago River.  These samples contained high levels of PAHs, polychlorinated biphenyls (PCBs), oil and grease, and metals; the concentrations of these substances generally increased with depth.  Many of the reported concentrations of total and individual PAHs, PCBs, and metals suggest toxity to organisms (benthic invertebrates) that live in the sediment. 

Cleanup Progress

In 2005 EPA was approached by Wisconsin Public Service Corp. (WPSC)with a request to investigate and clean up seven former MGP sites in the state of Wisconsin under the Agency's Superfund Alternative Sites (SAS) program. (The SAS Program addresses potential cleanup sites that might otherwise be eligible for listing on the National Priorities List (NPL), but which will instead be investigated and cleaned up by a cooperative potentially responsible party (PRP) without formally listing the site on the NPL.) When WPSC merged with Peoples Energy to form Integrys Energy Group in 2007, Peoples Energy approached EPA with the request to address thirteen former MGP sites in the state of Illinois under the same SAS program. Two former MGP sites are located in Waukegan and eleven are in Chicago. The South Station site is one of the thirteen Illinois MGP sites.

In 2007 EPA and Integrys entered into an Administrative Order on Consent (AOC) to conduct a Remedial Investigation and Feasibility Study at the two Waukegan MGP sites and an AOC for Engineering Evaluations and Cost Analyses (EE/CAs) at the eleven Chicago MGP sites. Since all twenty MGP sites have similar conditions and contaminants, and Integrys the PRP for each, the AOCs allow a streamlined approach to site investigation and remedy development. Some benefits of the agreement include the use of multi-site documents, a mechanism to review the adequacy of past work, and scheduling flexibility to allow progress on the worst problems first. By the end of 2008, all of the multi-site documents had been approved, and site-specific work had begun on several of the sites. On October 31, 2008, EPA and Integrys entered into an AOC which converted the EE/CA AOC for the eleven Chicago former MGP sites to an RI/FS AOC.

To more effectively manage all 11 original Chicago sites, the RI/FS AOC organizes them into 4 sites: the North Shore Avenue Site, the North Branch Site, the South Branch Site. and the Crawford Site. Both the North Branch Site and the South Branch Site have several operable units. The North Branch Site is comprised of the Division Street Station Operable Unit (OU), the North Station OU, and the Willow Street/Hawthorned Avenue Station OU. One site is the the North Shore Avenue Station Site. The South Branch Site is comprised of the 22nd Street Station Upland OU, the Hough Place Station Upland OU, the Pitney Court Station Upland OU, the South Station Upland OU, the Throop Station Upland OU, and the South Branch River OU.

Investigations and Remediation Previously Performed

Conditions at the site were investigated for Peoples Gas from 1999 through 2004, and remedial actions were performed from 2001 through 2006 under the Illinois EPA Site Remediation Program.  Remediation activities involved removal of contents from underground tanks, demolition and removal of buried structures, excavation of soil to a maximum depth of approximately 30 feet on land, and dredging of impacted sediments from the river.  Dredging was necessary to address tar-impacted sediments located near a tar seep and a monitoring well that contained free product.  A post-remediation investigation of sediments in the river adjacent to the site found evidence of residual tar impacts.

Additional investigation of the remaining contamination will take place under the RI/FS.  A schedule for completion of the RI/FS will be established once more information is available to prioritize all 11 Chicago former MGP sites.


Remedial Project Manager, U.S. EPA
Ross Del Rosario (delrosario.rosauro@epa.gov)
(312) 886-6195



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