EAST MULTNOMAH COUNTY GROUND WATER CONTAMINATION
GRESHAM, MULTNOMAH COUNTY, OREGON
The proposed East Multnomah County Groundwater Contamination National Priorities List(NPL) Site is east of Portland, Oregon. The site covers three square miles in Multnomah Countyand includes portions of the cities of Troutdale, Fairview, and Gresham. Numerousenvironmental investigations indicate that the groundwater within the proposed NPL site has beencontaminated with various chlorinated organic solvents. The solvents originate from severallocations (e.g., Boeing Company and Cascade Corporation) and are mixing. According toOregon Department of Environmental Quality records, 19 wells used or formerly used fordomestic or municipal drinking water sources, irrigation, or industrial purposes (Boeing Companyof Portland and Cascade Corporation) are contaminated with chlorinated organic solvents(primarily trichloroethylene [TCE]). One well with TCE concentrations above the regulatorystandard of five micrograms of TCE per liter of water (µg/L), the Maximum Contaminant Level(MCL) of the Safe Drinking Water Act, is still in use for domestic water supply. It is located eastof 201st Avenue and provides water for two households. The remaining wells have either beenabandoned or are not in use (inactive), and alternate water supplies (e.g., municipal drinkingwater) are being provided to the well owners.
Because of the complex hydrogeology within the proposed NPL site, it is not possible todetermine precisely when each well became contaminated. Based upon the total extent ofgroundwater contamination, the average linear velocity of groundwater within the two uppergroundwater aquifers (i.e., Troutdale Gravel Aquifer and Troutdale Sandstone Aquifer), and thefact that industrial operations have been conducted at the Boeing Company and CascadeCorporation facilities since 1963 and 1953 respectively, it is possible to conclude that the drinkingwater wells near the Boeing Company and Cascade Corporation facilities might have beencontaminated for more than ten years. No matter when TCE and tetrachloroethylene entered thedrinking water wells, it is likely that the initial concentrations would have been well below healthcomparison values (i.e., 3 µg/L for TCE and 0.7 µg/L for tetrachloroethylene). The TCE andtetrachloroethylene drinking water well concentrations would have slowly increased over timeuntil the concentrations in some of the wells in the affected area reached the levels detectedrecently (a maximum of 105 µg/L for TCE and 3 µg/L for tetrachloroethylene).
Most of the people with contaminated wells have been given alternative drinking water sources. However, two homeowners have refused to accept alternative drinking water and might still bedrinking water from the contaminated well they share. This shared well is the water supply fortwo homes. Until the regional groundwater contamination is remediated, the range ofcontamination in that well is likely to increase over time because higher contamination is locatedupgradient of the well. Thus, people continuing to ingest the contaminated water from the wellmight have a low increased risk of developing cancer.
The other people who relied upon contaminated drinking water wells accepted alternativedrinking water supplies. Studies of workers and laboratory animals indicate that the levels ofTCE and tetrachloroethylene in wells formerly used for drinking water were not high enough tohave resulted in adverse health effects.
Based on the available information, the Agency for Toxic Substances and Disease Registry(ATSDR) concludes that the proposed East Multnomah County Groundwater ContaminationNPL Site is a public health hazard (past, current, and future). ATSDR representatives made thisdetermination because one contaminated drinking water well has been and is being used by twohouseholds. The site is not a public health hazard for the people who formerly obtained drinkingwater from contaminated wells. ATSDR recommends that the two homeowners who are stillusing their contaminated well be encouraged to obtain an alternative drinking water supply, thatthe drinking water wells downgradient of the sources of groundwater contamination be monitoredfor site-related contaminants annually, that any wells found to be contaminated and could result inhuman exposures at or above levels of health concern should not be used as a drinking watersupply, and that the cancer health statistics for the area of this NPL site be evaluated if the dataare available.
A. Site Description and History
The proposed East Multnomah County Groundwater Contamination National Priorities List(NPL) Site is east of Portland, Oregon. The site covers three square miles in Multnomah Countyand includes portions of the cities of Troutdale, Fairview, and Gresham (1). Appendix 1, Figure 1 depicts the approximate area of Multnomah County which is the proposed NPL site.
Numerous environmental investigations indicate that the groundwater within a portion of theproposed NPL site has been contaminated with various chlorinated organic solvents, primarilytrichloroethylene (TCE). Appendix 2 contains the Oregon Department of Environmental Quality(ODEQ) Community Relations Plan (March 1995) for this site. The plan discusses whatinvestigations and regulatory actions have been and will be conducted at this proposed NPL site. Regulatory activities that have occurred since 1993 are also summarized in the Public Health Actions section at the end of this public health assessment.
The groundwater contamination came to the attention of the U.S. Environmental ProtectionAgency (EPA) and the ODEQ in late 1985. The discovery resulted from groundwater samplingassociated with the closure of the surface impoundment located west of the main plant buildingfor the Boeing Company. [Note: The contamination originating at the Boeing Company plant isbeing remediated and regulated under the Resource Conservation and Recovery Act Subtitle Cprogram and the State of Oregon Hazardous Waste Remedial Action Act. Therefore, the Boeingplant and associated contamination at the facility is not a part of the proposed NPL site. Becausepeople might have been exposed to contaminants from the Boeing Company plant, the Boeing contamination is discussed in this Public Health Assessment.] Additional investigations byBoeing and Cascade Corporation found that the groundwater contamination had migrated intoseveral residential drinking water wells near the Boeing and Cascade facilities and that some ofthe groundwater contamination was originating from another location, Cascade Corporation. During 1987-1991, EPA and ODEQ conducted investigations at the other industrial facilities nearthe Boeing Plant. The results of these investigations documented localized groundwatercontamination at the Swift Adhesives facility. In addition, the investigations indicated thatpotential sources of contamination might exist at Norwest Paper, Firestone, Opticraft, NorthwestRetreader, and an area near Parker & Grantz Automotive (1).
According to the ODEQ records, 19 wells used for domestic or municipal drinking water sources,irrigation, or industrial purposes (Boeing Company and Cascade Corporation) have been found tobe contaminated to some degree with chlorinated organic solvents (primarily TCE) (2). One well(east of 201st Avenue) with TCE concentrations above the regulatory standard of fivemicrograms of TCE per liter of water (µg/L), the Maximum Contaminant Level (MCL) of theSafe Drinking Water Act, is still in use for domestic water supply. The remaining wells haveeither been abandoned or are not in use (inactive), and alternate water supplies (e.g., municipaldrinking water) have been provided to the well owners.
Portland's backup water supply wells are located along the south shore of the Columbia River andadjacent to Blue Lake (see Appendix 1, Figure 2). The backup wells are designed for use duringpeak-demand summer months and could be used during high turbidity events in the Bull RunWater System (the primary source of drinking water for Portland). Eight of the wells are locateddirectly north of the site-related groundwater contamination. Three of these wells (7, 8, and 14)could withdraw water from the aquifers which are partially contaminated by the proposed NPLsite. The approximate extent of groundwater contamination is delineated in Appendix 1, Figure 2 and Figure 3. The City of Portland last used the well field in August 1994 to a limited extent (excluding the wells that withdraw water from the aquifers impacted by the proposed NPL site). The city has used the well field at full capacity only once, that being in the fall of 1987. At thistime no site-related contaminants have been detected in the city wells.
B. Site Visit
A site visit was conducted by Agency for Toxic Substances and Disease Registry (ATSDR) staff(Sven E. Rodenbeck and Dr. John Crellin from ATSDR Headquarters, and Richard Robinsonfrom the ATSDR Region X Office) on November 29-December 2, 1993. They collectedinformation needed for the public health assessment for the proposed East Multnomah CountyGroundwater NPL Site (Update 14). Public availability sessions were held on December 1, 1993. In addition, meetings were held with representatives of EPA, ODEQ, and the City of Portland,Bureau of Water Works. During the public availability sessions, ATSDR staff members spokewith several representatives of Interlachen Citizens Group and Citizens Interested in Bull Run,Inc.
The ATSDR staff members also toured the total area of the proposed NPL site. They saw eachof the facilities that have contributed to the groundwater contamination.
Extensive remedial investigations have been conducted at the Boeing Company and CascadeCorporation facilities. The monitoring wells associated with the investigations were observed atand downgradient of the facilities. In addition, remediation and source reduction activities (e.g.,soil removal and groundwater extraction and treatment) have occurred at the Boeing Companyand the Cascade Corporation facilities.
C. Demographics, Land Use, And Natural Resource Use
During the 1980s Multnomah County had an approximate population of 570,000 people. Thepopulation is predominantly white (89 percent) and is roughly evenly split between male (48percent) and female (52 percent).
According to 1990 U.S. Census information, approximately 12,500 people live within an one mileradius of the Boeing Company or the Cascade Corporation facility. Approximately 1,212 of thoseindividuals are children five years or younger. The estimated population of adults 60 years orolder within the one mile radius of the facilities is 1,743. According to the 1990 U.S. Censusinformation, the approximate number of women of childbearing years (15 - 44) is 2,989. The onemile radius population is predominantly white (91.7 percent). The minority groups within the onemile radius are hispanic (2.7 percent), asian (2.2 percent), black (1.3 percent), and native american(1 percent). A little more than one percent of the population did not indicate a race or reportedtheir race as other during the 1990 U.S. Census.
The EPA has estimated that 750,000 people (including 267,500 in Portland and vicinity) use the groundwater aquifers that have been partially contaminated by the proposed NPL site as a standbyor primary drinking water source (1,3). The City of Portland wells are used only to supplementthe city's primary source of water, Bull Run Watershed, and have not been used at full capacitysince 1987. Portland provides drinking water to three local water districts: Rockwood,Hazelwood, and Gilbert.
The land within the proposed NPL site is used for residential areas, including trailer parks; lightindustry; and agriculture. The light industry has developed over the last 30 years.
The Rockwood Water People's Utility District formerly obtained 10% its drinking water fromtwo wells on 185 Avenue northwest of the Boeing facility (3). ODEQ ordered both abandoned in1990 because pumping could cause the groundwater contamination to enter the wells. TheRockwood People's Utility District has a third supply well on Halsey Street southwest of Cascade. This well is not used because sand enters the well and damages the pump. The Rockwood WaterPeople's Utility District obtains all its drinking water from Portland.
The West Interlachen Corporation, Interlachen Corporation, and the Blue Lake Co-op providedrinking water for their members from wells operated by the corporations or the Co-op (one wellapiece). The wells are located between Blue Lake and Fairview Lake. Approximately 148families are served by the wells. Current monitoring data from these wells indicate that no site-related chemicals are in the drinking water.
The cities of Wood Village, Fairview, and Troutdale obtain drinking water from wells (3). Thesewells appear to be unaffected by the groundwater contamination at the proposed NPL site.
Blue Lake and Fairview Lake are used for recreational purposes (e.g., boating and fishing). Thelakes are the major surface water collection basins for this part of Multnomah County. OsbournSpring Creek and Fairview Creek drain into Fairview Lake. Fairview Lake drains into theColumbia Slough. The Multnomah County Drainage District No. 1 controls water levels in theslough for summer irrigation and for winter flood control and field drainage. The district controlsthe water levels by operating pump stations that discharge to the Columbia River.
Shepard and Taggart springs, just north of the Cascade facility, had only been used as a drinkingwater source for livestock. Osbourn Spring, south of Interstate 84 and east of the Cascadefacility (more than 1,200 feet away), flows into Osbourn Spring Creek, which is not used as adrinking water source.
All surface water eventually drains into the Columbia River. Several of the groundwater aquifersalso discharge into the Columbia River. The Columbia is used for recreational purposes (e.g.,boating and fishing) and is also commercially fished.
The various investigations at this proposed NPL site have identified four primary groundwateraquifers (see Appendix 1, Figure 4). All of these aquifers are used as drinking water sources bythe various cities and private entities. The shallow aquifer is called the Troutdale Gravel Aquifer(TGA). The TGA underlies approximately two-thirds of the proposed NPL site. However, thisaquifer unit disappears roughly midway between I-84 and Sandy Boulevard and east of 192ndAvenue. Within the vicinity of the Cascade facility, the TGA flows towards the west and thenchanges directions towards the north near the Boeing Company facility.
A clayey siltstone confining layer separates the TGA from the intermediate Troutdale SandstoneAquifer (TSA). There is a hydraulic mound in the TSA north of the Cascade facility. This moundcauses the groundwater to flow primarily towards the east and west. However the predominantflow direction in the vicinity of the Boeing Company facility is north and northeast, dependingupon location.
The deeper aquifer is called the Sand and Gravel Aquifer (SGA). Another silt and clay confininglayer separates the TSA and the SGA. The SGA generally flows towards the northeast.
The Blue Lake Aquifer is located between Blue Lake and the Columbia River and underlies theeastern portion of the proposed NPL site. This aquifer abuts the TSA and SGA. Investigationsindicate that the Blue Lake Aquifer has not been affected by the contamination associated with theproposed NPL site.
D. Health Outcome Data
ATSDR selects health outcomes for further evaluation from health outcome databases that haveinformation on the area near the site. Oregon does not have a cancer incident registry or a birthdefect registry. However, the state does have mortality records which could possibly be used. The National Center for Health Statistics, Centers for Disease Control and Prevention (CDC),maintains vital statistics (birth and mortality records) information for the various counties in theU.S.
As some of the site-related chemicals are considered potential human carcinogens, cancer is apossible health outcome from exposure to these contaminants. Please refer to the ToxicologicEvaluation subsection for more detailed information. Cancer mortality statistics are available forMultnomah County for the years 1979 through 1991.
COMMUNITY HEALTH CONCERNS
During the November/December site visit, Agency for Toxic Substances and Disease Registry(ATSDR) staff determined the community health concerns through conversations with localgovernment officials, U.S. Environmental Protection Agency officials, Oregon Department ofEnvironmental Quality (ODEQ) officials, representatives of the Interlachen Citizens Group andthe Citizens Interested in Bull Run, Inc., and individual citizens (during the public availabilitysessions). The residents and officials raised the following health-related concerns:
- Occurrence of Cancer The primary health concern discussed by the residents was the occurrence of cancer in the area (i.e., is cancer incidence elevated?).
- Symptoms A mother indicated that she and her daughter suffered from flu-like symptoms, fatigue, and headaches during the late 1970s. She reported that the symptoms went away after they stopped drinking the well water. Analytical results of samples taken from the well found TCE. The mother also indicated that one of her children was born with "blood tumors."
- Birth Defects in Horses A resident reported that horses that drank water from a contaminatedspring downgradient from Cascade Corporation either absorbed their fetuses or had still birthswith major birth defects.
ATSDR addresses these concerns in the Community Health Concerns Evaluation section of thispublic health assessment.