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  • Currently, the PCE contamination at the Osborn CCI site poses no apparent public health hazard; residents have been supplied filters for their household water supply, and prison officials have discontinued use of the PCE-contaminated supply well. Also, a municipal water line has been extended to affected residents.
  • Residents and Osborn CCI inmates and staff consumed PCE-contaminated water in the past. Available information indicates that this exposure was not enough to cause adverse health effects, nor should it adversely affect the health of residents in the future.
  • Based on a review of available data and use of computational models, the Exposure Investigation (EI) activities resulted in the following conclusions (APPENDIX H):

     1. Contaminated groundwater moves rapidly through the glacial till overlying the bedrock aquifer. Simulation results indicate that groundwater contaminated with PCE migrates down to the bedrock aquifer within one year at concentrations exceeding the MCL (5 ppb).

     2. ATSDR's EI study indicates that residents in the Rye Hill Circle area may have been exposed to PCE-contaminated groundwater for at least 16 years. Simulation results indicate that the bedrock aquifer was probably contaminated at the time the domestic wells were installed (assuming a well installation date of 1978).

     3. Modeling results indicate:

     (a) contaminated groundwater in the bedrock aquifer is a consequence of the PCE contaminant source located in the sand filter bed area; and

     (b) the highest measured and simulated concentrations of PCE-contaminated groundwater in the Osborn CCI and Rye Hill Circle Area wells occurred during the third quarter of 1993 (for example, well MW-5D had a measured value of 770 ppb and a simulated value of 846 ppb; well RHC-082 had a measured value of 545 ppb and a simulated value of 521 ppb).

     4. Evaluation of modeling results suggest the high levels of PCE found in the domestic wells are probably a consequence of:

          (a) hydrogeologic conditions allowing the migration of PCE-contaminated groundwater from the Osborn CCI area to the Rye Hill Circle area;

          (b) infiltration of PCE-contaminated groundwater from the overlying glacial material to the bedrock aquifer;

          (c) additional undocumented sources of PCE; or

               (d) some combination of all of the above factors.

     5. It is unlikely that past consumption of the most highly-contaminated well water in the Rye Hill Circle area would have resulted in any acute toxic effects in the affected residents of the area (ATSDR, 1994). Furthermore, no long-term adverse human health effects, including cancer, are likely to occur in the future as a result of past exposure to and consumption of PCE-contaminated water by residents in the Rye Hill Circle area.

  • Other possible pathways of exposure, including contact with PCE-contaminated surface water, sediments, and/or on-site soil, do not pose a public health hazard.
  • The presence of PCE-contaminated soil gas on-site does not pose a public health hazard for nearby residential areas. There is no indication that soil gas has migrated off-site, or escaped through bedrock from the groundwater.


A. Recommendations and HARP Statement

  • The municipal water supply system is currently available to all residents in the area, according to the Bureau of Water Management of the Connecticut Department of Environmental Protection. Residents are encouraged to connect to the municipal water supply.
  • Osborn CCI should continue obtaining their water from the well on the Enfield prison property, and from Osborn CCI supply wells numbers one and four. Use of well number 2 should be discontinued.
  • ATSDR Regional Representative, Region 1 should maintain open lines of communication with Rye Hill Circle residents and discuss findings as needed in informal meetings and/or public availability sessions.

Health Activities Recommendation Panel (HARP) Statement

On March 15, 1995, data and information developed in this public health assessment were evaluated by the ATSDR Health Activities Recommendation Panel (HARP). HARP determined the following health activities are indicated for the Osborn CCI Site:

    The data and information developed in the Osborn CCI Public Health Assessment have been evaluated for appropriate public health actions. Because past exposures to PCE-contaminated groundwater have occurred, HARP has determined that two follow-up actions are indicated. First, health education to the community and health professionals should be continued to assist the community in understanding the implications of their past exposure. HARP will reevaluate the public health issues at this site as new data and information become available, including that generated in the groundwater Exposure-Dose Investigation and general information about PCE.

B. Public Health Actions

The Public Health Action Plan (PHAP) for the Osborn CCI site contains a description of actions to be taken by ATSDR at and in the vicinity of the site subsequent to the completion of this public health assessment. For those actions already taken at the site, please see the BACKGROUND section of this Public Health Assessment. The purpose of the PHAP is to ensure that this public health assessment not only identifies public health hazards, but provides a plan of action designed to mitigate and prevent adverse human health effects resulting from exposure to hazardous substances in the environment.

Included is a commitment on the part of ATSDR to follow up on this plan to ensure that it is implemented. The public health actions to be implemented by ATSDR are as follows:

ATSDR has conducted public availability sessions to provide information regarding the implications of past exposure to PCE-contaminated groundwater within the community. A public availability session was held in July 1996 to discuss the health implications determined by the exposure investigation (APPENDIX H).

ATSDR completed an exposure investigation of the Rye Hill Circle area. The investigation used computational models for groundwater transport of contaminants. Given sufficient data on aquifer, water use, and continued disposal history characterization, these models were used to estimate duration of exposure and the level of exposure for the prisoners/workers at the Osborn CCI and citizens of the Hill Circle area. Information obtained from this exposure investigation can be found in (APPENDIX H).

ATSDR has provided community and health professionals education as requested by the community. ATSDR will continue to provide health information as needed.


Lynelle Phillips, RN MPH
Environmental Health Scientist
Petition Response Branch
Division of Health Assessment and Consultation, ATSDR

Maureen Kolasa, RN MPH
Environmental Health Scientist
Petition Response Branch
Division of Health Assessment and Consultation, ATSDR

Frank Schnell, PhD
Senior Toxicologist
Petition Response Branch
Division of Health Assessment and Consultation, ATSDR

James R. Gates, RS. MS
Environmental Health Scientist
Petition Reponse Branch
Division of Health Assessment and Consultation, ATSDR

ATSDR Regional Representative:
Susanne Simon
ATSDR Regional Representative
EPA Region I


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ATSDR's Exposure Investigation Activities Related to PCE Contamination of Groundwater Supplies in the Osborn Connecticut Correctional Institution (OCCI) Area, Somers, Connecticut. July 1996

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Ellenhorn, M.J, and Barceloux, D.G. (1988). Hydrocarbon products. In: Medical Toxicology: Diagnosis and treatment of human poisoning. Elsevier, New York, pg. 986.

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Fuss & O'Neill Inc., Additional Environmental Investigations, Osborn CCI. January 1996.

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Fuss & O'Neill Inc. PCE Source Investigation: Phase II. Somers Correctional Facility, Somers, CT. October 1993.

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Jacobs, Steven, Registered Sanitarian, Town of Somers. May 1994.

Klassen, Curtis D., and Eaton, David L. (1991). Principles of Toxicology. In: Amdur MO, Doull J, Klaasen CD, editors. Casarett and Doull's Toxicology: The basic science of poisons, 4th Edition. New York: Pergamon Press, 1991. pg 13.

Koppel, C., Arndt, I., Arendt, U., and Koeppe, P. (1985). Acyte tetrachloroethylene poisoning: Blood elimination kinetics during hyperventilation therapy. Journal Toxicol. Clin. Toxicol. 23: 103-115.

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Patty (1981). pp. 3561-3566 In: Patty's Industrial Hygiene and Toxicology, 3rd revised Ed., Vol. 2A, Toxicology (G.D. Clayton and F.E. Clayton, Eds.), John Wiley & Sons, New York, N.Y., 1981.

Petition letter. To the Assistant Administrator of ATSDR. April 7, 1993.

Petition letter. To the Assistant Administrator of ATSDR. April 13, 1993.

US District Court for the District of Connecticut. Burnett vs. the State of Connecticut. March 18, 1994.

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