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This Health Consultation addresses environmental contamination of the groundwater in andaround the Oregon State Penitentiary (OSP) in Salem, Oregon. The primary contaminants ofconcern at this site are tetrachloroethylene (PCE) and trichloroethylene (TCE). The consult explores pathways of human exposure to these contaminants and considers the possibility of health effects. This Health Consultation was requested by ATSDR (Agency for Toxic Substances and Disease Registry) Region X Office, Richard Kauffman, Senior Representative.


The Oregon State Penitentiary (OSP) is a 306 acre site located in Salem, Marion County, Oregon. The penitentiary buildings are predominantly located on the west side of the site, while the eastside of the site is an open field. Adjacent to the site to the north is the Oregon State Hospitalfacility. Single-family and multi-family residential use property is located west of the site. [SeeAttachment 1 map.]

The State of Oregon has owned and operated the property as a penitentiary since approximately1865. An industrial laundry facility is located in the northwest quadrant of the property andcurrently includes approximately 28,880 square feet of building space. According to personnel atOSP, dry cleaning and laundering operations have occurred at the site since the late 1950s. In1983, the facility was remodeled to automate and upgrade laundry and dry cleaning operationswith new equipment. Drinking water supplies for OSP were derived from on-site drinking waterwells between approximately 1866 and 1989, when OSP was put on water supplied by the city ofSalem. [1]

In October 1989, the Oregon Department of Corrections sampled four water supply wells locatedat the Oregon State Penitentiary, in anticipation of testing required by law with the passage of theSafe Drinking Water Act. Various chlorinated volatile organic compounds (VOCs) weredetected in two wells. Subsequent investigations confirmed that the groundwater had beenimpacted with VOCs, primarily consisting of tetrachloroethylene (PCE) and trichloroethylene(TCE), which were likely the result of past dry cleaning operations at the site. PCE levels in onewell were as high as 1690 ppb and TCE levels were as high as 61 ppb. [1]

Since 1991 various investigations and studies were performed under the supervision of theOregon Department of Environmental Quality (DEQ) as part of the voluntary cleanup program.[2, 4] A plume of contaminated groundwater extends from the OSP facility toward nearbyresidential areas to the west-northwest. Some of the key facts about the investigations aresummarized below:

  • The lateral and vertical extent of the groundwater plume has been verified. PCE ispresent beneath the site from a depth of approximately 10 to 120 feet below groundsurface. Based on the data from ongoing groundwater sampling, the highest PCEconcentrations detected in groundwater beneath the OSP site is 17,000 parts per billion(ppb). The highest TCE concentrations detected in groundwater beneath the OSP site is600 ppb. These maximum detected levels of PCE and TCE beneath the OSP site weretaken from Monitor Well #5 in 1994. Levels under the site have been consistently lowerover the past five years. The highest concentration of PCE detected in groundwater underthe residential neighborhood is 220 ppb. The highest concentration of TCE detected ingroundwater under the residential neighborhood is 12 ppb. Other chlorinated organiccompounds such as cis-1,2-dichloroethene (DCE) and 1,1,1-trichloroethane (TCA) werefound in much lower levels. [2]

  • No chemicals were detected in shallow soil samples (less that 8 feet below groundsurface) collected from the residential neighborhood. No significant source was detectedin shallow soil samples collected around the site of the former dry cleaning operation atOSP. There is no evidence that pockets of pure PCE (otherwise known as DenseNon-Aqueous Phase Liquids or DNAPLs) exist at the site. [2]

  • The Baseline Human Health Risk Assessment [4] concludes that as long as thegroundwater is not used for drinking or other household purposes, there is no increasedhealth risk for inmates, OSP staff, or residents. Specifically, neither EnvironmentalProtection Agency (EPA) limits nor DEQ levels of concern would be exceeded.



There are still a number of uncertainties and questions about the degree of exposure at this site. Consideration should be given to three distinct populations-penitentiary staff, inmates, andcommunity members. A completed pathway in the past has exposed both OSP staff and inmates. This exposure has been stopped, but it is unclear what degree of exposure occurred and whatpotential human health effects, if any, might be anticipated. Community members are nowdealing with a contaminated plume of groundwater moving beneath their residential area. Pastexposure of this population at significant levels is doubtful, but potential future exposure ispossible if water from this plume reaches any private wells which are still in use. If thecontaminated groundwater plume reaches wells which are still in use for household purposes andplume contaminants do not attenuate significantly, exposures would potentially be aboveacceptable drinking water guidelines for PCE and TCE.

The Oregon Department of Corrections has contracted with SECOR International Incorporated tobetter characterize the plume of contaminated groundwater. Halogenated volatile organiccompounds detected during the previous and current sampling events include tetrachloroethylene(PCE), trichloroethylene (TCE), cis-1,2-dichloroethene (DCE), and 1,1,1-trichloroethane (TCA). Calculated relative groundwater elevations were used to infer the groundwater flow direction andgradient at the site. Based on static water level (SWL) data collected from the shallowgroundwater monitoring wells the inferred groundwater flow direction in the shallow aquiferzone across the OSP facility and the residential area was oriented in a northwesterly directionunder an average gradient of 0.007 foot per foot (ft/ft). Based on SWL measurements theinferred groundwater flow direction in the intermediate aquifer zone was oriented to thewest-northwest under an average gradient of 0.004 ft/ft. SWL measurements from the deepaquifer zone indicates groundwater gradient and flow direction in the deep zone are similar to theintermediate zone. Transport time of the contaminants in the plume over the past 30-40 yearswas estimated at 57 to 71 ft/yr. Over the next 50 years a rate between 123 and 174 ft/yr isestimated. [2]

The significance of the plume to off-site exposures may need further characterization. The basicissue is whether any private wells might be pumping from a contaminated aquifer, and whetherany of this water is being used for drinking or other household purposes. Field work has beendone attempting to answer these questions, but ongoing surveillance is needed.

The Oregon State Penitentiary has recently installed an interim cleanup system. This systemconsists of a groundwater extraction well (RW-1 on attached map) and a treatment system thatwill treat groundwater that is pumped from the well. This system will provide data that isrequired to better understand how the groundwater moves beneath the site and is designed toprevent further migration of the groundwater plume into the residential neighborhood. It willalso have a carbon recovery filter system to minimize release of volatilized contaminants intoambient air. If this carbon filter system is in place, exposure of individuals by off-gassing fromthe system should not occur. SECOR International Incorporated (SECOR) has been contractedby the Oregon Department of Corrections (DOC) to conduct remedial investigation (RI) activitiesat the Oregon State Penitentiary (OSP). [2]

Past exposure of Oregon State Penitentiary staff and inmates by contaminated soil is a potentialpathway. Details of how the chlorinated organic compounds left the laundry facilities andentered the groundwater are not known. It is presumed that the contaminants leaked or werepoured onto soil which would then prove an additional pathway through soil ingestion anddermal absorption. Significant soil contamination is not currently detected at the site. [2]

Concern by residents regarding possible exposure through flooding of basements has beenexpressed in the past. Contaminants in the groundwater are too deep to enter these basementspaces. Volatilization through the soil at significant levels is unlikely. The likely source ofbasement flooding is surface water, which has not been shown to be contaminated.

Completed Pathways of Exposure

Media Route of Exposure Exposure Point Exposed Population Time
Groundwater Ingestion
Inhalation of aerosol
Dermal absorption
Staff/Inmates Past

Potential Pathways of Exposure

Media Route of Exposure Exposure Point Exposed Population Time
Soil Ingestion
Dermal absorption
OSP grounds Staff/Inmates
Groundwater Ingestion
Inhalation of aerosol
Dermal absorption
Contaminated private wells used for domestic water Residents Future
Air Inhalation Air stripping system Residents Future


The chlorinated solvents at this site consist of tetrachloroethylene (PCE), trichloroethylene(TCE), and various breakdown products of these chemicals. A brief description of PCE and TCEis included as Attachment II and includes their use, environmental fate, and possible healtheffects [5, 6].

Although no significant exposures are occurring at present, it is clear that past exposure ofworkers and inmates to PCE and TCE at this site did occur. Water that was being used fordrinking, bathing, and other purposes was documented in 1989 to be contaminated. Thechlorinated solvents in this water may have been present for as long as 30 years (since the late1950s). Additionally, potential future exposure pathways to nearby community members should be considered as the contaminated groundwater plume moves off-site.


  1. A plume of groundwater contaminated with chlorinated volatile organic compounds exists both on-site and off-site at the Oregon State Penitentiary.

  2. Completed exposure pathways to inmates and workers identified in the past were stopped in 1989 after the contamination was discovered.

  3. No completed exposure pathways are identified at present.

  4. Water from the contaminated plume might present a threat to human health if used for drinking or other household purposes and therefore represents a potential future off-site pathway.

  5. Inhalation exposure is unlikely from use of the water treatment system if the carbon recovery filter is utilized.


  1. Document that no significant current exposure to chlorinated solvents is taking place related to this site. Expanded surveys for private wells in the path of the migrating plume should be conducted.

  2. Perform an exposure dose reconstruction (ATSDR staff) to better characterize past exposures of Oregon State Penitentiary staff and inmates, and to predict migration of the contaminated plume.

  3. Consider a health study regarding the significance of past exposures to inmates and staff. The feasibility of performing a health study on former inmates and staff should be considered after determining exposure information from the exposure dose reconstruction.

Prepared by:

Robert H. Johnson, MD

Concurrence by:

Susan Moore


  1. Remedial Investigation Report, Oregon State Penitentiary, Salem, OR, SECOR PN: F0051-002-07, August 21, 1996.

  2. Final Remedial Investigation Report, Oregon State Penitentiary, Salem, OR, SECOR PN: F0051-002-07, June 5, 1998.

  3. Revised Risk Evaluation, Emissions from the Groundwater Air Stripping System, Oregon State Penitentiary, SECOR PN: F0051-002-08, October 19, 1998.

  4. Baseline Human Health Risk Assessment, Oregon State Penitentiary, SECOR PN: F0051-002-08, October 23, 1998.

  5. Toxicological Profile for Trichloroethylene, Agency for Toxic Substances and Disease Registry, Division of Toxicology, August, 1995.

  6. Toxicological Profile for Tetrachloroethylene, Agency for Toxic Substances and Disease Registry, Division of Toxicology, August, 1995.

  7. Agency for Toxic Substances and Disease Registry. National exposure registry trichloroethylene (TCE) subregistry, baseline technical report. Atlanta: ATSDR, 1993.


Site Plan with Monitoring Well Locations
Figure 1. Site Plan with Monitoring Well Locations



1. Tetrachloroethylene

Tetrachloroethylene is a synthetic chemical that is widely used for dry cleaning fabrics and formetal-degreasing operations. It is also used as a starting material (building block) for makingother chemicals and is used in some consumer products. Other names for tetrachloroethyleneinclude perchloroethylene, PCE, perc, tetrachloroethene, perclene, and perchlor. It is anonflammable liquid at room temperature. It evaporates easily into the air and has a sharp,sweet odor.

Tetrachloroethylene enters the environment mostly by evaporating into the air during use. It canalso get into water supplies and the soil during disposal of sewage sludge and factory waste. Tetrachloroethylene may also get into the air, soil, or water by leaking or evaporating fromstorage and waste sites. It can stay in the air for several months before it is broken down intoother chemicals or is brought back down to the soil and water by rain. Some of the chemicalsthat are formed from tetrachloroethylene may be harmful if encountered in high, toxicconcentrations.

Much of the tetrachloroethylene that gets into water and soil will evaporate to the air. However,because tetrachloroethylene can travel through many soils quite easily, it can get intounderground drinking water supplies. Tetrachloroethylene that gets into underground water maystay there for many months without being broken down. If conditions are right, bacteria willbreak down some of it and some of the chemicals formed may also be harmful. Under someconditions, tetrachloroethylene may stick to the soil and stay there.

In general, tetrachloroethylene levels in air are higher in cities or industrial areas where it is inuse than in more rural or remote areas. You can smell it at levels of 1 ppm in air. However, thebackground level of tetrachloroethylene in air in rural areas is less than 1 part in 1 billion parts ofair (ppb). The air close to dry cleaning shops and chemical waste sites has levels of tetrachloroethylene higher than background levels. These levels are still less than 1 ppm, thelevel at which you can smell it. Water, both above and below ground, may containtetrachloroethylene. Levels in water are also usually less than 1 ppb. Levels in contaminatedwater near disposal sites are higher than levels in water far away from those sites. Water pollutedwith tetrachloroethylene may have levels greater than 1 ppm. In soil, background levels areprobably 100-1,000 times lower than 1 ppm.

Tetrachloroethylene can enter your body when you breathe air containing it. How much entersyour body by this route depends on how much of the chemical is in the air, how fast and deeplyyou are breathing, and how long you are exposed to it. Tetrachloroethylene may also enter yourbody when you drink water or eat food containing the chemical. How much enters your bodydepends on how much of the chemical you drink or eat. These two routes are the most likelyways people will take in tetrachloroethylene. These are also the most likely ways that peopleliving near areas polluted with the chemical, such as hazardous waste sites, might take intetrachloroethylene. If tetrachloroethylene is placed directly on your skin, a portion of it can passthrough your skin into your body. Very little tetrachloroethylene in the air can pass through yourskin into your body.

Most tetrachloroethylene leaves your body from your lungs when you breathe out. This is truewhether you take up the chemical by breathing, drinking, eating, or touching it. A small amountof the tetrachloroethylene is changed by your body into other chemicals that are removed fromyour body in urine. One of these chemicals, trichloroacetic acid (TCA), is also thought to beharmful. Most of the changed tetrachloroethylene leaves your body in a few days. Some of thetetrachloroethylene that you take in is found in the blood and other tissues, especially body fat.Part of the tetrachloroethylene that is stored in fat may stay in your body for several days orweeks before it is eliminated.

Results of animal studies, conducted with amounts much higher than those that most people areexposed to, show that tetrachloroethylene can cause liver and kidney damage and liver andkidney cancers. Although it has not been shown to cause cancer in people, the U. S. Departmentof Health and Human Services has determined that tetrachloroethylene may reasonably beanticipated to be a carcinogen. The International Agency for Research on Cancer has determinedthat tetrachloroethylene is possibly carcinogenic to humans. Tetrachloroethylene can be toxic tothe unborn pups of pregnant rats and mice. Changes in behavior were observed in the offspringof rats that breathed high levels of the chemical while they were pregnant. Rats that were givenoral doses of tetrachloroethylene when they were very young, when their brains were stilldeveloping, were hyperactive when they became adults. How tetrachloroethylene may affect thedeveloping brain in human babies is not known.

The federal government develops regulations and recommendations to protect public health. EPA has recommended limits on how much tetrachloroethylene can be present in drinking water. EPA recommends that there should not be more than 5 parts per billion (ppb) in the drinkingwater.

2. Trichloroethylene

Trichloroethylene is also known as Triclene and Vitran and by other trade names in industry. Itis a nonflammable, colorless liquid at room temperature with a somewhat sweet odor and asweet, burning taste. This manmade chemical does not occur naturally in the environment.Trichloroethylene is now mainly used as a solvent to remove grease from metal parts. It is alsoused as a solvent in other ways and is used to make other chemicals. Trichloroethylene can alsobe found in some household products, including typewriter correction fluid, paint removers,adhesives, and spot removers.

By far, the biggest source of trichloroethylene in the environment is evaporation from factoriesthat use it to remove grease from metals. It can also enter the air and water when it is disposed of at chemical waste sites. It evaporates easily but can stay in the soil and in groundwater. Onceit is in the air, about half will be broken down within a week. When trichloroethylene is broken down in the air, phosgene, a lung irritant, can be formed. Under certain conditions found in theworkplace, trichloroethylene can break down into chemicals such as dichloroacetylene andphosgene. In the body, trichloroethylene may break down into dichloroacetic acid (DCA),trichloroacetic acid (TCA), chloral hydrate, and 2-chloroacetaldehyde. These chemical productshave been shown to be toxic to animals and are probably toxic to humans.

Once trichloroethylene is in water, much will evaporate into the air again and about half willbreak down within a week. It will take days to weeks to break down in surface water; ingroundwater the breakdown is much slower because of the much slower evaporation rate. Verylittle trichloroethylene breaks down in the soil, and it can pass through the soil into undergroundwater. It is found in some foods; the trichloroethylene found in foods is believed to come fromcontamination of the water used in food processing, or from the food processing equipmentcleaned with trichloroethylene.

Trichloroethylene is found in the outdoor air at levels far less than 1 ppm. When measuredseveral years ago, some of the water supplies in the United States were found to havetrichloroethylene. The most recent monitoring study found mean levels in surface water rangingfrom 0.0001 to 0.001 parts of trichloroethylene per million parts (ppm) of water and a mean levelof 0.007 ppm in groundwater. About 400,000 workers are exposed to trichloroethylene in theUnited States on a full-time (i.e., a 40-hour workweek) basis. The chemical can also get into theair or water in many ways-for example, at waste treatment facilities; by evaporation from paints,glues, and other products; or by release from factories where it is made. Another way you maybe exposed is by breathing the air around factories that use the chemical. People living nearhazardous waste sites may be exposed to it in the air or in their drinking water, or in the waterused for bathing or cooking. Products that may contain trichloroethylene are some types oftypewriter correction fluids, paints and paint removers, glues, spot removers, rug cleaning fluids,and metal cleaners.

Trichloroethylene enters your body when you breathe air or drink water containing it. It can alsoenter your body if you get it on your skin. You could be exposed to contaminated water or air if you live near or work in a factory that uses trichloroethylene or if you live near a waste disposalsite that contains trichloroethylene. If you breathe the chemical, about half the amount you breathe in will get into your bloodstream and organs; you will exhale the rest. If you drinktrichloroethylene, most of it will be absorbed into your blood. If trichloroethylene comes incontact with your skin, some of it can enter your body, although not as easily as when youbreathe or swallow it.

Once in your blood, your liver changes much of the trichloroethylene into other chemicals. Themajority of these breakdown products leave your body in the urine within a day. You will alsoquickly breathe out much of the trichloroethylene that is in your bloodstream. Some of thetrichloroethylene or its breakdown products can be stored in body fat for a brief period, and thusmay build up in your body if exposure continues.

It is uncertain whether people who breathe air or drink water containing trichloroethylene are athigher risk of cancer or if their children have more birth defects. At a site in Woburn,Massachusetts, people who used water for several years from two wells that had high levels oftrichloroethylene may have had a higher incidence of childhood leukemia than other people. Increased numbers of children were reported to be born with cardiac abnormalities, a findingwhich is supported by data from some animal studies showing developmental effects oftrichloroethylene on the heart. However, other chemicals were also in the water from this well. We do not have any clear evidence that trichloroethylene alone can cause leukemia or any othertype of cancer in humans.

As part of the National Exposure Registry, the Agency for Toxic Substances and DiseaseRegistry (ATSDR) compiled data on 4,280 residents of three states (Michigan, Illinois, andIndiana) who had environmental exposure to trichloroethylene. It found no definitive evidencefor an excess of cancers from trichloroethylene exposure. In studies using high doses oftrichloroethylene in rats and mice, tumors in the lungs, liver, and testes were found, providingsome evidence that high doses of trichloroethylene can cause cancer in experimental animals. We do not know if trichloroethylene affects human reproduction.

Some tests can show if you have been recently exposed to trichloroethylene since this chemicalcan be measured in your breath. Also, a doctor can have a number of breakdown products of trichloroethylene measured in your urine or blood. None of these tests, however, are routinelyavailable at your doctor's office. If the measurements are done soon after the exposure, thebreath levels can indicate whether you have been exposed to a large amount of trichloroethyleneor only a small amount. Urine and blood tests can also show if you have been exposed to largeamounts of this chemical. Because one of the breakdown products leaves your body very slowly,it can be measured in the urine for up to one week after trichloroethylene exposure. However,exposure to other similar chemicals can produce the same breakdown products in your urine andblood. Therefore, these methods cannot determine for sure whether you have been exposed totrichloroethylene.

ATSDR maintains a registry of individuals in various locations around the country who havebeen exposed to TCE. [7] Approximately 4,300 people are participating in the ATSDR TCEexposure subregistry. The participants were exposed to 2 ppb to 19,380 ppb of TCE in drinkingwater for up to 18 years. Information from the TCE exposure subregistry indicates thatparticipants in the subregistry reported that they had more health problems than what is normallyexpected, however, only the rate for strokes was reported to increase with increasingconcentration of TCE in drinking water. This suggests that there may be a relationship betweenexposure to TCE and an increased chance of having a stroke. However, these results do not provea cause and effect relationship. In addition, the current scientific literature does not document any known association of stroke and TCE exposure. [5,6]

The federal government develops regulations and recommendations to protect public health. EPA has set a drinking water standard of 5 parts of trichloroethylene per one billion parts ofwater (ppb). This standard became effective on January 9, 1989, and applies to community andother water systems that serve the same 25 or more persons for at least 6 months.

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