Congressional District # 03
PEOPLES GAS SOUTH STATION FORMER MGPEPA ID# ILN000510191
Last Updated: March, 2015
The 8.3-acre South Station former manufactured gas plant (MGP) site ("South Station site") is located near the intersection of Eleanor and Loomis Streets in Chicago, Cook County, Illinois. About half of the site is owned by the Peoples Gas Light and Coke Company (Peoples Gas) (Parcels "A" and "B" comprising 4 acres) and half is owned by the city of Chicago (Parcels "C" and "D" comprising 4.3 acres). The properties are 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 occupied by a storage warehouse constructed in the early 1970s. Parcels C and D are currently vacant, but the city plans to develop them 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
Peoples Gas built the manufactured gas 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 occupied by a wood pallet manufacturing facility.
The South Station site is be addressed under EPA's Superfund Alternative (SA) site program.
The South Station MGP site is being addressed through potentially responsible party (PRP) actions under federal and state oversight.
Threats and Contaminants
Groundwater at the South Station site has been detected at depths ranging from 8 to 12 feet below ground surface. 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 compounds (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 initial site cleanup work (see "Cleanup Progress" section, below) had been completed.
Contaminated soil was encountered to depths greater than 20 feet below ground surface beneath parts of the site. Metals, cyanide, PAHs, SVOCs, and VOCs were detected in soil samples taken in 1999. Chemicals found at concentrations exceeding state screening levels include chromium, benzene, ethylbenzene, naphthalene, styrene, toluene, TCE, and xylenes. Because contaminated soil was not excavated from beneath much of the building footprint and in other areas of the site, soil with notable coal tar impacts remains in place.
Human contact with contaminated soil or groundwater could cause both carcinogenic (cancer-causing) and non-carcinogenic effects over time.
In 2000, EPA collected sediment samples from the South Branch of the Chicago River next to the site. The samples contained high levels of PAHs, polychlorinated biphenyls (PCBs), oil and grease, and metals and the concentrations of these substances generally increased with depth. Many of the reported concentrations of total and individual PAHs, PCBs, and metals suggest toxicity to organisms (benthic invertebrates) that live in the sediment.
Previous Investigation and Cleanup Actions
Peoples Gas investigated conditions at the South Station MGP site from 1999 through 2004 and it conducted cleanup actions there from 2001 through 2006 under the Illinois EPA Site Remediation Program. Remedial activities involved the removal of contents from underground tanks, the demolition and removal of buried structures, the excavation of soil to a maximum depth of about 30 feet on land, and the dredging of impacted sediment from the river. Dredging was necessary to address tar-impacted sediment 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.
In 2005, EPA was approached by the Wisconsin Public Service Corporation (WPSC) with a request to investigate and clean up seven former MGP sites in Wisconsin under EPA's Superfund Alternative site (SA) program. The SA program addresses potential cleanup sites that might otherwise be eligible for listing on the Superfund National Priorities List (NPL), but which will instead be investigated and cleaned up by a cooperative PRP without formally listing the site on the NPL. When WPSC merged with Peoples Energy (Peoples Gas) to form Integrys Energy Group (Integrys) in 2007, Integrys approached EPA with the request to address thirteen former MGP sites in Illinois under the same SA 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 (RI/FS) 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 is the PRP for each, the AOCs allowed for 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, EPA had approved all of the multi-site documents and site-specific work had begun at 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 the eleven Chicago-area sites, the new RI/FS AOC organized them into four larger 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/Hawthorne Avenue Station OU. The North Shore Avenue Station site is a single 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.
The initial field investigation at South Station began in May 2009, with a draft RI report originally targeted for submital by September 2010. However, additional vapor intrusion (VI)/indoor air and soil gas sampling was necessary as a result of reviewing existing data from the on-site storage building. Two rounds of supplemental VI/soil gas sampling have been completed as of the end of 2014. An RI summary report is expected in summer 2015, with a draft RI report to be submitted before the end of the year.
The South Station site is located on the South Branch of the Chicago River in an area experiencing redevelopment due to its proximity to the river. In 2011, EPA modified the site boundaries by removing two parcels from the site description because the city had announced its plans to construct a boathouse facility at this location with the intent to provide greater recreational access to the river.
ContactsRemedial Project Manager, U.S. EPA
Rosauro Del Rosario (firstname.lastname@example.org)