Congressional District # 16
SOUTHEAST ROCKFORD GROUND WATER CONTAMINATIONEPA ID# ILD981000417
Last Updated: March, 2012
The Southeast Rockford Groundwater (SE Rockford) 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 area is mainly residential with industrial/commercial developments. The population within one mile of the site is about 52,000.
EPA added the SE Rockford site to the National Priorities List on June 24, 1998, after groundwater investigations conducted by the state of Illinois indicated that residential and municipal wells were impacted by chlorinated solvent contamination. The site consists of three operable units (OU): 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 further subdivided into four major groundwater contaminant source areas that are called Source Areas 4, 7, 9/10, and 11.
The SE Rockford site is being addressed through a combination of state, federal, and potentially responsible party (PRP) actions.
The Illinois EPA is the primary technical lead for all of the OUs. The U.S. EPA is the enforcement lead agency and it is responsible for negotiating consent decrees (CD) for Remedial Design/Remedial Action (RD/RA) with PRPs and for issuing Unilateral Administrative Orders (if necessary). U.S. EPA signed a consent decree with Hamilton Sundstrand, the PRP for a portion of Source Area 9/10, and therefore is the primary technical lead for that portion of the site.
Threats and Contaminants
Soil and groundwater at the SE Rockford site are primarily contaminated with chlorinated solvents. Trichloroethene (TCE) (428 ppb), tetrachloroethene (PCE) (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 the four Source Area locations.
Ingestion of contaminated groundwater could lead to adverse human health effects.
Cleanup ProgressU.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 was performed by Illinois Environmental Protection Agency (IEPA) and U.S. EPA (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 included soil vapor extraction, low temperature thermal desorption, and soil excavation. Due to unique source characteristics, some surface/near surface soil work has and will be supplemented with source-specific groundwater management zones (GMZs) and the use of air sparging/soil vapor extraction (AS/SVE) or limited pump and treat steps.
IEPA has completed a groundwater treatment system for Source Area 4. A pre-final inspection of that system was conducted in October 2010. Some soil excavation was also performed in Area 4, but additional contaminated soil remains. IEPA is currently developing a strategy for remedial actions to address the remaining contaminated soil at Source Area 4. An Explanation of Significant Differences for soil clean-up is planned for June 2012.
IEPA completed sampling at Source Areas 7 and 11 and excavation of contaminated soil from Area 7 was completed in 2011. Monitoring wells have been installed in Area 11 as a part of the Remedial Design for that remedy. The completion of Remedial Design for Area 7 is planned for Spring 2012 and the start of water treatment equipment installation for Area 7 is planned for Summer 2012.
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. An ESD for soil excavation in the former Outside Storage Area (OSA) was signed in February 2009. Currently, the second phase in the installation of an AS/SVE system is complete and operating. EPA and IEPA conducted a pre-final inspection in March 2011. Soil excavation of the OSA was conducted, however, due to the presence of residual soil contamination at the edges of the excavated area, the PRP will develop a plan for additional work for EPA to review and approve.
Success StoryRA 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 2012 and beyond.
At appropriate points in the process, IEPA and U.S. EPA have conducted public meetings. The most recent public meeting was held by IEPA in September 2009 regarding the Source Area 7 soil excavation ESD.
Property ReuseAt the conclusion of RD/RA, properties will continue in their existing use as residential or industrial/commercial properties.
ContactsRemedial Project Manager, U.S. EPA
timothy drexler (firstname.lastname@example.org)
Community Involvement Coordinator, U.S. EPA
AliasesSOUTHEAST ROCKFORD GD WTR CONTAMINATION
SOUTHEAST ROCKFORD DRY WELL
SE ROCKFORD GROUNDWATER CONT