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Site Type: Long Term/National Priorities List (NPL)  |  |
KELLOGG-DEERING WELL FIELD | |
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Map this site in Cleanups in My Community |
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| Norwalk, Connecticut |
Fairfield County
| Street Address: | NORWALK WATER DEPARTMENT |
| Zip Code: | 06856 |
Congressional
District(s): |
04 |
| EPA ID #: | CTD980670814 |
| Site ID #: | 0100252 |
| Site Aliases: | Smith Well Field
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| Site Responsibility: | Federal, State, Potentially Responsible Parties |
| NPL LISTING HISTORY |
| Proposed Date | 09/08/1983 |
| Final Date | 09/21/1984 |
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Site Description
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www.epa.gov/superfund/kellogg
The Kellogg-Deering Well Field site consists of an approximately 10-acre municipal well field and adjacent areas that contribute to the well field contamination. Groundwater sampling data indicated that a significant source of contamination exists below the Elinco/Pitney Bowes/Matheis Court Complex located at the eastern edge of the site. The well field supplies approximately 20 percent of the drinking water to 80,000 residents in the City of Norwalk. The primary source of public water supply to the Norwalk First Taxing District (NFTD) Water Department is surface water from four reservoirs. Reservoir water is blended with well field water at varying ratios, depending on reservoir storage and distribution system location. The well field is adjacent to residential and light industrial areas.
Threats and Contaminants
The groundwater and soil are contaminated with volatile organic compounds (VOCs), primarily trichloroethylene (TCE) and perchloroethylene (PCE). People could be exposed to chemical contaminants by drinking contaminated water if no treatment were provided; however, the water department is treating and blending water from the wells and reservoir to provide a safe drinking water supply.
Cleanup Approach
The site is being addressed in three long-term remedial phases focusing on wellhead treatment, source control, and downgradient aquifer management.
Response Action Status
| OU-1, Wellhead Treatment | The Water Department installed an aerator in 1981 at one of the wells to reduce the concentration of volatile organics in the groundwater. In 1988, an additional air stripper was completed to increase the removal of VOCs at the wellfield. The air stripper is part of the water treatment plant and will remain in operation until the contaminants are reduced to EPA-approved levels. Contaminants are being removed from the water by air filtering the volatile contaminants into a gaseous state. The treated water is discharged into the existing conventional water treatment plant and distribution system.
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| OU-2, Source Control | The remedy selected by EPA for controlling the source of contamination
involves removal of contaminants from the soil with vacuum extraction, extraction and treatment of contaminated groundwater, and institutional controls to prevent exposure during the cleanup process. Construction of this treatment facility was completed in September 1996 and is currently operational. Air and groundwater monitoring are being performed as part of the operation and maintenance at the site.
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| OU-3, Downgradient Aquifer Management | Through groundwater monitoring, EPA has been tracking the extent and migration of contaminants in the area downgradient from the source of contamination and above the well field. EPA will evaluate the impact of the cleanup at the well head and source control areas on reducing the levels of contaminants downgradient from the source and above the well field over time.
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| 2002 Five-Year Review. | EPA conducted a five-year review during the summer 2002 as required by Superfund. This review was the third one for the wellfield, and the first for the source control and downgradient aquifer. The purpose of the review was to assess whether the implemented remedy remained protective for human health and the environment.
The assessment of this five-year review found that the OU1 remedy for the the site is currently protective of human health and the environment and exposure pathways that could result in unacceptable risks are being controlled by the wellhead treatment system. However, should contamination from OU2 not be fully contained and if it is moving toward the well field, protectiveness in the future could be threatened if wellhead treatment is no longer occurring. Recent outdoor soil gas sampling indicates that vapor intrusion to residences and businesses is a possibility over OU2 and OU3 areas. The vapor intrusion pathway will be further investigated to determine if any response measures need to be taken to address unacceptable risks.
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| Source Control | In April 2006 EPA concurred that the soil performance standards set in the 1989 Record of Decision had been attained. Subsequent to this, the soil vapor extraction system was dismantled.
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| 2007 Five-Year Review | EPA completed a five-year review in 2007. It concluded that the remedy was currently protective of human health and the environment For the long-term, the review stated the effectiveness of the groundwater remedy should be confirmed and that the investigation of the potential vapor intrusion pathway should be completed.
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| Vapor Intrusion | In 2009 EPA completed the investigation of the potential vapor intrusion pathway. Based on the sampling data, EPA concluded that the pathway did not create unacceptable risks in the downgradient area.
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| OU-2 Management of Migration | In 2010 EPA issued an optimization report for the groundwater extraction system. The report recommendations included pump tests of various configurations of the extraction wells and installation of downgradient wells to confirm capture of the contaminant plume.
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| 2012 Five-Year Review | EPA completed the fifth five-year review in 2012. It concluded that the remedy remained protective of human health and the environment. The optimization of the OU-2 remedy was underway and the vapor intrusion data was reviewed against the current risk values. The review affirmed that the pathway did not present an unacceptable risk.
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| Enforcement Highlights | In 1987, an EPA Administrative Order was issued to one of the potentially responsible parties to ensure the effectiveness of wellhead treatment. In 1990, EPA signed a Consent Decree with four potentially responsible parties that required them to design and implement source control cleanup activities. |
Environmental Progress
Wellhead treatment and controlling the sources of soil and groundwater contamination have reduced the potential of exposure to hazardous substances in the drinking water and will continue to protect the neighboring residents while final cleanup activities at the Kellogg-Deering site are completed.
Current Site Status
A 1989 Record of Decision (ROD) for the Source Area (OU2) included soil vapor extraction to reduce volatile organic carbon concentration in the soil, the extraction and treatment of the groundwater, and the use of Institutional Controls. The treatment facility became operational in 1996. EPA determined in 2006 that the soil cleanup standards had been attained. Subsequently, EPA's major focus has been the oversight of the groundwater treatment and monitoring program and investigation of the potential vapor intrusion pathway. These components have been periodically evaluated in five-year reviews (FYR).
The 2002 FYR concluded that the remedy for the wellfield remained protective, and that the remedy for the source control and downgradient aquifer remained protective in the short-term. The 2007 FYR recommended an evaluation of methods currently being used at the Source Area to increase the rate of contaminant removal and to consider implementation of viable technologies to optimize treatment at the site. It additionally recommended that further studies be conducted at the site to evaluate the vapor intrusion pathway and to take mitigative response actions as necessary to be protective of human health. The vapor intrusion study was completed in 2009 and concluded that there were no unacceptable risks associated with this pathway. The 2012 FYR, after re-evaluating the vapor intrusion pathway because of new toxicity values, concluded that the remedy remained protective.
The Settling Defendants (the parties that signed the 1992 Consent Decree with EPA) implemented the recommendations of EPA's optimization report for the groundwater extraction and treatment system. Follow-up monitoring confirms that the groundwater plume continues to be captured by the extraction wells.
The next five-year review is scheduled to be completed in 2017.
Site Photos
Links to Other Site Information
Newsletters & Press Releases:
Federal Register Notices:
Administrative Records:
Reports and Studies:
Five Year Review Report, December 29, 1992 (2043KB)  | | |
| Second Five Year Report, September 30, 1997 (2373KB) | | |
| Third Five Year Report, September 23, 2002 (1703KB) | | |
| Reuse Assessment, September 01, 2004 (6.26 MB) | | |
| Fourth Five Year Review Report, September 28, 2007 (1.26 MB) | | |
| Fifth Five Year Review Report, September 28, 2012 (4.49 MB) | | |
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Decision Documents:
Other Links:
Site Repositories
Norwalk Public Library, One Beldon Avenue, Norwalk CT 06770
OSRR Records and Information Center, 1st Floor, 5 Post Office Square, Suite 100 (HSC), Boston, MA 02109-3912 (617) 918-1440
Contacts
| EPA Remedial Project Manager: | Terry Connelly |
| Address: | US Environmental Protection Agency
5 Post Office Square, Suite 100
Mail Code OSRR07-1
Boston, MA 02109-3912 |
| Phone #: | 617-918-1373 |
| E-Mail Address: | connelly.terry@epa.gov |
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| EPA Community Involvement Coordinator: | Emily Bender |
| Address: | US Environmental Protection Agency
5 Post Office Square, Suite 100
Mail Code ORA01-1
Boston, MA 02109-3912 |
| Phone #: | 617-918-1037 |
| E-Mail Address: | bender.emily@epa.gov |
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