Region 5 Superfund (SF)

U.S. EPA REGION 5
WINNEBAGO COUNTY
ROCKFORD

Congressional District # 16

SOUTHEAST ROCKFORD GROUND WATER CONTAMINATION

EPA ID# ILD981000417
Last Updated: September, 2009

Site Description

The S.E. Rockford Groundwater site is a three mile long and two and one half mile wide area located in the southeastern portion of the City of Rockford, Illinois. Land use within the site is mainly residential with industrial/commercial developments. The population within one mile of the site is approximately 52,000 people. The site was added to the National Priorities List on June 24, 1998, after early ground water investigations by the State of Illinois indicated that residential and municipal wells were impacted by chlorinated solvent contamination.

The Site consists of three operable units (OUs): OU1 is the drinking water operable unit; OU2 is the ground water operable unit; and OU3 is the contaminant source control operable unit. OU3 is divided into four major source areas of ground water contamination. These are Source Areas 4, 7, 9/10, and 11.

Site Responsibility

This site is being addressed through Potentially Responsible Party, federal and state actions. The Illinois EPA is the primary technical lead for all of the OUs. US EPA is enforcement lead responsible for negotiating Consent Decrees (CDs), for Remedial Design/Remedial Action (RD/RA), and for issuing Unilateral Administrative Orders. Due to a Consent Decree with Hamilton Sundstrand, the potentially responsible party (PRP) for a portion of Source Area 9/10, US EPA is the primary lead agency for that portion of Source Area 9/10.

Threats and Contaminants

The primary site contaminants are chlorinated solvents in soil and groundwater. Trichloroethene (428 ppb), tetrachloroethene (545 ppb), 1,1,1-trichloroethane (991 ppb), cis-1,2-dichloroethene (1,233 ppb) and vinyl chloride (114 ppb) have been found in residential groundwater wells. High levels of similar compounds have also been identified at four source areas.

Cleanup Progress

U.S. EPA performed the first action at the site in 1991 on OU1 as a time-critical removal action. It included providing service connections for 283 residents to the municipal water supply and the installation of granular activated carbon treatment on Rockford Municipal Well #35.  In 1992 an action to connect an additional 264 homes to municipal water service performed by Illinois Environmental Protection Agency (Illinois EPA) and U.S. EPA . 

In September 1995, the EPA established long-term cleanup goals for the contaminated aquifer and selected natural attenuation as the cleanup approach. This decision was made with the assumption that major sources of contamination at the site would be addressed under a subsequent action. This decision also called for connection to the municipal water system of homes and businesses whose water wells either recently exceeded health standards or were predicted to exceed them within the next 70 years.

The city of Rockford began implementation of the final groundwater remedy in early 1998 under an enforcement action with Illinois EPA and U.S. EPA. Installation of over 9,200 feet of ductile iron water mains and hookup of an additional 262 homes/businesses to water service connections was accomplished by June 1999 (OU1). Nine additional groundwater monitoring wells were installed to supplement the existing monitoring network. A groundwater monitoring program was also established (OU2). Since 1999, groundwater sampling results have been compiled by the city of Rockford and have been reported to U.S. EPA and Illinois EPA. Such monitoring is to continue until cleanup goals are attained.

A separate enforcement action also recovered U.S. EPA's and Illinois EPA's past costs, with contributions from potentially responsible parties. This recovered money was placed in a special account to address the largest of four contaminated soil areas, Source Area 7. All four areas continue to pose a potential threat of further contaminant release. 

Illinois EPA has taken the lead on the remedial investigation to evaluate the nature and extent of site contamination, and a study to evaluate site cleanup options, for the four major sources of groundwater contamination. In June 2002, a Record of Decision (ROD) was signed to address these source areas of OU3. Source control techniques include soil vapor extraction, low temperature thermal desorption, and soil excavation. Pending unique source characteristics, some surface/near surface soil work may be supplemented with source-specific groundwater management zones and the use of techniques such as air sparging (using air under pressure below the water table to help remove contaminants from the groundwater) or limited pump and treat steps. 

IEPA has completed RD and the RA work plan for Source Area 4 and began RA for Source Area 4 during August 2009. IEPA has also begun the remedial design process at source areas 7 and 11. IEPA plans to modify RA work in Source Area 7 to include an excavation component due to the results of contamination source area investigations. This change will be recorded in an Explanation of Significant Differences (ESD), to be generated by IEPA.

U.S. EPA finalized negotiations in early 2003 with Hamilton Sundstrand a PRP for Source Area 9/10, and as a result RD work was completed. A Consent Decree for RA at Source Area 9/10 was signed by a federal judge on September 2, 2008. After US EPA and IEPA approval of the RA work plan, Remedial Actions in Source Area 9/10 began on November 24, 2008.

 

 

Success Story

RA work is complete for OUs 1 and 2. RD and RA work have begun for all of the Source Areas of OU3 either by IEPA or by PRPs. That work will continue into 2009 and beyond.

Community Involvement

At appropriate points in the process, IEPA and EPA will conduct joint public availability sessions.

Property Reuse

At the conclusion of RD/RA, properties will continue in their existing use as residential or industrial/commercial properties. 

Contacts

Remedial Project Manager, U.S. EPA
timothy drexler (drexler.timothy@epa.gov)
(312) 353-4367

Community Involvement Coordinator, U.S. EPA
mike joyce
(312) 353-5546

Aliases

SOUTHEAST ROCKFORD GD WTR CONTAMINATION
SOUTHEAST ROCKFORD DRY WELL
SE ROCKFORD GROUNDWATER CONT

 

Site Profile Information

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