PUBLIC HEALTH ASSESSMENT
KENNECOTT (SOUTH ZONE)
COPPERTON, SALT LAKE COUNTY, UTAH
The Kennecott, South Zone, site comprises approximately 150 square miles in southwest Salt Lake County, west of Salt Lake City, Utah. Agency for Toxic Substances and Disease Registry (ATSDR) staff members toured the site and met with staff members from Utah Department of Environmental Quality (UDEQ), the U.S. Environmental Protection Agency (EPA) and Kennecott Utah Copper (KUC) Corporation. ATSDR staff members also held open public availability sessions in October 1994 to meet individual citizens and gather community concerns. ATSDR staff members evaluated environmental health information provided by KUC, UDEQ, EPA, and information from other organizations.
ATSDR has identified seven exposure situations for the KUC South National Priorities List (NPL) site (Table 2 on page 5). Though undergoing removal and remediation, one exposure situation, Butterfield Creek, is considered a past and current public health hazard until removal is complete because people may still be exposed to high levels of lead from surface soils.
Present and future conditions of soils in the Bingham Creek area are considered no apparent public health concern because Kennecott, EPA, and ARCO successfully removed highly contaminated soils. Before removal actions, two areas of Bingham Creek contained contaminated soils that may have posed a public health hazard. The surface soils in the Copperton area are classified as no apparent health hazard because the contaminant concentrations, frequency and duration of exposure, and opportunity for human exposure are not sufficient to generate adverse health effects in the residential population.
Though mitigated, one exposure situation (Southwest Jordan Groundwater), is considered a past public health hazard because a few people used a private drinking water well with concentrations above the 1500 ppm EPA Region VIII recommended risk level. In addition to providing alternative water supplies, Kennecott's comprehensive well inventory, groundwater monitoring, and private well testing programs have greatly reduced the potential for human exposure to concentrations of sulfate above 1500 parts per million
Investigators did not have sufficient information to determine the public health hazard status one of the exposure situations (Pine Canyon groundwater). This area is identified as indeterminate public health hazard.
In response to a resident's concern about his family's exposure to the lead-contaminated soils, ATSDR evaluated the soil-lead levels and the family's blood lead measurements. The soil lead levels may have been high enough to result in health effects if there were frequent exposure to the contaminated soil. However, the results of the blood lead testing indicate that significant exposures were not occurring at that time. It is not possible to determine whether significant exposures could have occurred at another time.
In this public health assessment, the Agency for Toxic Substances and Disease Registry (ATSDR) evaluates the public health significance of the proposed Kennecott South Zone National Priorities List (NPL) site in southwestern Salt Lake County and eastern Tooele County. More specifically, ATSDR has reviewed available environmental and health outcome data and community health concerns to determine whether adverse health effects are possible. In addition, this public health assessment recommends actions to reduce, prevent, or further identify the possibility for site-related adverse health effects.
Comments on the Public Comment Draft of the Public Health Assessment
A draft of the Public Health Assessment for the Kennecott South Zone NPL Site was released for public review and comment in June 1996 with the comment period extended through August 1996. ATSDR did not receive any comments from citizens living in the communities in the vicinity of the proposed NPL site. ATSDR did receive comments from the Utah Department of Health, the Utah Department of Environmental Quality (UDEQ), the Kennecott Utah Copper (KUC) Corporation, the Atlantic Richfield Company (ARCO), and the University of Cincinnati. Comments from KUC and ARCO are reproduced in Appendix F. Comments from University of Cincinnati were not reproduced because of concern because of massive among of information associated with the comments.. Some changes in the public health assessment were made in response to the comments received. In particular, the public health hazard category for the Southwest Salt Lake County Groundwater plume was changed in response to information provided by Kennecott Corporation and later, EPA Region VIII.
In January 1994, the EPA proposed that the Kennecott South Zone site be added to the NPL. The Kennecott (South Zone) site covers portions of Salt Lake County (southwest of Salt Lake City) and eastern Tooele County, Utah. Comprising approximately 150 square miles, the site area encompasses the communities of Copperton, Herriman, South Jordan, Riverton, and West Jordan. The site area includes a majority of the historic mining area in the Oquirrh Mountains that lie along the boundary between Salt Lake and Tooele counties. It also includes certain properties of KUC and ARCO. EPA has tentatively divided the NPL site into 14 operable units, which are listed in Table 1 (the majority are depicted in Figure 1 in Appendix A).
Table 1 EPA designated Operable Units for Kennecott South NPL site.
| Name | Number | Description |
| Bingham Creek | OU1 | Includes the channel and floodplain of Bingham Creek east of the Large Bingham Reservoir to Brookside Trailer Court. |
| Southwest Salt Lake County (SWSLC) Groundwater Plume | OU2 | This includes the contaminated groundwater pollutants and contaminants originating at or near Bingham Creek, Lark, and the Evaporation Ponds and extending downgrade (generally eastward to Jordan River). Source areas are in separate operable units. |
| Butterfield Mine | OU3 | Includes Butterfield Mine and Butterfield Creek watershed. |
| Large Bingham Reservoir | OU4 | Includes Large Bingham Reservoir and other reservoirs in immediate vicinity. |
| ARCO Tails | OU5 | Includes the ARCO Tailings and drainage ditches downstream. |
| Lark Waste Rock and Tailings | OU6 | Includes all mining waste areas in and near former Lark community. |
| South Jordan Evaporation Ponds | OU7 | Includes the evaporation ponds and associated canals and ditches. |
| Copperton Soils | OU10 | Contaminated soils in town of Copperton. |
| Bingham Canyon and Mine | OU11 | Watershed of Bingham Canyon upstream of the Large Bingham Reservoir. |
| Eastside Collection System | OU12 | Eastside Leachate Collection System and Stormwater Collection System associated with waste dumps south of Bingham Creek. |
| Bingham Canyon Underflow | OU16 | Groundwater plume originating in Bingham Canyon upstream of the Large Bingham Reservoir. |
| Bastian Area and Canals | OU17 | Bastian Sink area and nearby properties; may be merged with OU5. |
| Acid Mine Drainage | OU18 | Includes all the drainages from underground mine portals and tunnels; may be handled with other operable units in the vicinity as appropriate. |
| Pine Canyon in Tooele County | OU20 | Includes the International Smelter operations and waste piles in Pine Canyon in eastern Tooele Valley; soils and groundwater contamination issues downstream and downwind from Pine Canyon may be associated with this operable unit. |
Historic mining and ore milling practices in the area included dumping waste rock and tailings into drainages and streams. From the later part of the nineteenth century into the twentieth century, waterborne mine tailings migrated from the Oquirrh Mountains into area streams. This migration resulted in contamination of Bingham Creek channel and an associated floodplain located between 3200 West Street and 2700 West Street. Residential and commercial buildings have been constructed adjacent to contaminated channel segments; in the floodplain area, residences were constructed on top of contaminated materials. Removal of substantively contaminated materials by EPA, KUC, and ARCO has been underway in Bingham Creek since about 1990 and will soon be completed.
Mining and milling operations also leaked acidic waste waters into the drinking water aquifer in southwest Salt Lake County. Plumes with high sulfate concentrations have spread eastward from the mining area and associated evaporation ponds. In response to private well contamination problems, KUC has an ongoing program for providing alternative drinking water supplies for residences with contaminated water supply wells.
Public Health Evaluation Methodology and Scope--Overview
ATSDR staff members evaluated public health implications through a sequential process that considers contaminant concentrations, plausible human exposure pathways, health concerns expressed by community members, and plausibility of related carcinogenic and noncarcinogenic health effects.
Evaluations included a visit to the operable units(1) and site vicinity to help ATSDR staff members develop an understanding of the geographic, physical, and demographic settings and the relationships between sources of contaminants and the people living and working nearby. Exposure evaluations considered multiple contaminant origins, including the following:
Those evaluations and observations helped investigators to identify community members that might experience exposure. They used that information, together with environmental sampling data, in further evaluations to decide whether exposures are likely to have any associated public health implications. Further description of major components of the evaluation process is in Appendix C.
The key exposure situations and the public health classification for each are listed in Table 2.
| TABLE 2 - KEY EXPOSURE SITUATIONS AND THEIR PUBLIC HEALTH HAZARD CATEGORIES | |
| Exposure Situation | Public Health Classification |
| Upper Bingham Creek Soils 4800 west to 3200 West (OU1) |
No apparent public health hazard |
| Bingham Creek Floodplain Soils 3200 West to 2700 West (OU1) |
For present and future site conditions, no apparent public health hazard (Some areas may have posed a public health hazard prior to removal and cleanup.) | Lower Bingham Creek Soils 2700 West through Brookside Trailer Court* (OU1) |
For present and future site conditions, no apparent public health hazard (Some areas may have posed a public health hazard prior to removal and cleanup.) |
| Copperton Soils (OU10) |
No apparent public health hazard |
| Butterfield Creek Soils (the floodplain portion of OU3) |
Past and future public health hazard, no future public health hazard anticipated after removal is complete. (Kennecott sponsored health study underway may determine extent of exposure) |
| SWSLC Groundwater (OU2) |
Past public health hazard (The drinking water problems have been mitigated by provision of alternative water) |
| Pine Canyon Groundwater (groundwater from OU20) |
Insufficient data to classify hazard (indeterminate public health hazard) |
| * EPA has not included the segment from the trailer court to the Jordan river in this operable unit at this time. EPA staff members advise that the segment will be examined later. | |
Exposure situations were identified for operable units 1, 2, 10, 20, and the Butterfield Creek portion of OU3. Operable units 4, 6, 7, 11, 12, 16, 17, 18, and the Butterfield Mine portion of OU3 were excluded from further evaluation because the community has no or very limited access, and any exposures that might occur to workers at those operable units (e.g., employees and contractors) or visitors would be within the jurisdiction of state and federal occupational health agencies.
This public health assessment focuses on six of the seven exposure situations summarized in Table 2. We do not have sufficient information at this time to make a public health determination for one of the exposure situations listed ( Pine Canyon Groundwater). Preliminary reports for Pine Canyon groundwater are unavailable for review. ATSDR will make a public health determination after reviewing additional information anticipated from EPA and UDEQ.
In addition to those situations listed in Table 2, ATSDR has evaluated sampling and removal information and potential health consequences for properties at the intersection of 3200 West and 9000 South, where materials excavated from the creek may have been deposited. These properties are not described further because we concluded that there are not likely to have been significant human exposures. Bingham Creek from its source to 4800 West is also excluded because, within that reach, it traverses industrial- and municipal-owned properties where community members have no or very limited access. Likewise, Bingham Creek from the Brookside Trailer Court to the Jordan River is not part of the operable unit and has not been addressed; EPA staff members advised ATSDR that the agency plans to consider that segment later.
EVALUATION OF CONTAMINANTS IN SOIL
In this portion of the Kennecott Utah Copper (KUC) South public health assessment, we evaluate the possible health impacts of five exposure situations (three along Bingham Creek, Copperton soils, and Butterfield Creek soils) involving soil contaminants. Table 3 summarizes the results of these evaluations.
We divide the segments of Bingham Creek that go through residential areas into three exposure situations: upper channel soils, floodplain soils, and lower channel soils. For the Bingham Creek situations, the term "soils" applies to any combination of soil, sediment, or tailings. The upper channel soil exposure situation extends from 4800 West Street to 3200 West; there, the stream bed is mostly channelized (i.e., the stream bed typically is well below ground level). The floodplain soil exposure situation is located between 3200 West and 2700 West. There, the stream bed (now mostly contained in a culvert) has been at about the same level as the surrounding terrain (i.e., the creek is in a floodplain). The lower channel soil exposure situation extends from 2700 West through the Brookside Trailer Court; there, the steam bed is largely channelized.
As previously mentioned, Bingham Creek from the Brookside Trailer Court to the Jordan River is not part of the operable unit and has not been addressed. The majority of the properties in this stretch of Bingham Creek appear to be agricultural with very limited opportunity for current human exposure. The Agency for Toxic Substances and Disease Registry (ATSDR) will address this segment if additional investigations by the Environmental Protection Agency (EPA) or the Utah Department of Environmental Quality (UDEQ) indicate significant potential for adverse human health problems.
The Copperton soil exposure situation is the community of Copperton. For this situation, the term "soils" has been used for any combination of soil and tailings. The Butterfield Creek exposure situation is in the Herriman community area.
ATSDR does not consider the Bingham Creek or Copperton soils exposure situations to
be
ongoing public health hazards. The Bingham Creek situations may have been public health
hazards in past. Highly contaminated soils are currently being removed at the Butterfield Creek
exposure situation. Until removal is complete and follow up studies, such as the health study
sponsored by Kennecott Corporation, the Butterfield Creek exposure situation is considered a
current public health hazard, as well as, a past public health hazard.
| TABLE 3 - EXPOSURE TO SOIL CONTAMINANTS | |||||
| Situation | Contaminants | Exposed Population |
Route of Exposure |
Frequency of Exposure |
Public Health Classification |
| Upper Bingham Creek Channel |
Arsenic Cadmium Lead |
1,100 residents within 500 meters of creek (1990) | ingestion | Never to Daily | For present and future, no Apparent Public Health Hazard |
| Bingham Creek Floodplain Area |
Arsenic Cadmium Lead |
332 residents within 500 meters of creek (1990) | Ingestion | Seldom to Daily | For present and future, no apparent public health hazard |
| Lower Bingham Creek Channel |
Arsenic Cadmium Lead |
980 residents within 500 meters of creek (1990) | Ingestion | Seldom to Daily | For present and future, no apparent public health hazard |
| Copperton | Arsenic Cadmium Lead |
550 residents | Ingestion | Seldom to Daily | No apparent public health hazard |
| Butterfield Creek | Arsenic, Lead | 120 residents (1997 estimate) |
Ingestion | Seldom to Daily | Past and current public health hazard |
Route of exposure refers to how people might come in contact with contaminated soils. For the exposure situations listed in Table 3, individuals, primarily children, were probably exposed to the surface soils via incidental consumption and skin contact with the soil on hands and food items, mouthing of objects, or the ingestion of nonfood items (pica). All children mouth or ingest nonfood items to some extent. The degree of pica behavior varies widely in the population and is influenced by nutritional status and the quality of care and supervision. Groups that are at increased risk for pica behavior are children aged 1 to 3 years old, children from families of low socioeconomic status, and children with neurologic disorders (e.g. brain damage, epilepsy, and mental retardation).
Bingham Creek Soil Exposure Situations
Bingham Creek originates in the Bingham Canyon (in the Oquirrh Mountains) (Figure 1) and is the primary natural drainage from the mine district. The creek flowed freely to the Jordan River until about 1853, when it was dammed or diverted to accommodate many different mining and processing enterprises. Before the 1930s, the entire runoff from the canyon watershed discharged into the natural Bingham Creek drainage. Historic mining and processing operations discharged considerable quantities of tailings into the waterway. Some of those tailings deposited within the channel, some flowed (via flooding) onto properties beyond the channel, and some discharged into the Jordan River. More recently, Kennecott Corporation (Kennecott) has been controlling mine and processing wastes, and the Bingham Reservoir and other control structures on the company's property now capture canyon flow and recycle it to help fulfill operational water needs. Presently, the creek channel downstream from the reservoir receives random inflow of snow melt, storm runoff, and irrigation water and is typically dry for most of its length (1).
Copperton Soil Exposure Situation
Copperton is on the north side of Bingham Creek, on the lower flank of Bingham Canyon, approximately 2 miles west of State Route 111 (Figure 2A). ATSDR staff members noted a conveyor transfer station at the west edge of town, and a segment of covered conveyor closely parallels the west boundary of the community. Historic documents provide information that suggests tailings have been deposited in and around Copperton. An author described construction in 1928 of homes that required installation of pillars to provide adequate foundation support. EPA has confirmed tailings on the east side of town through interviews with several current and former residents. In 1980, 16 homes removed from Lark were relocated to that area (2). A continuous chain-link fence along the east, south, and west edges of town separates the community from Kennecott property, nearby process facilities, and Bingham Creek.
Butterfield Creek Soil Exposure Situation
Butterfield Creek carried sediments from the mining areas within Butterfield Creek Canyon, located in the southern Oquirrh Mountains, eastward through the community of Herriman, Utah. Sediments containing elevated levels of lead and arsenic were deposited along the stream channel, banks, and associated irrigation canals in the community area. EPA and Kennecott Corporation are currently sampling and removing highly contaminated soils within the Herriman community. The extent of contamination is still being characterized.
B. Environmental Contamination
Soil contaminants were selected for evaluation in this public health assessment primarily by comparison of contaminant levels with values for noncarcinogenic and carcinogenic endpoints. Appendix C contains a full description of the process for selecting contaminants for evaluation.
Upper Bingham Creek Channel Soil Exposure Situation
Arsenic, cadmium, and lead were identified as key contaminants.
Table 4 summarizes pre- and post-removal concentrations.
| TABLE 4 - KEY CONTAMINANTS FOR UPPER CHANNEL SOIL EXPOSURE SITUATION1 | ||
| Contaminant | Range of pre-removal levels in milligrams per kilograms | Maximum post-removal levels in milligrams per kilogram |
| Arsenic | 19 - 880 | 75 -100 |
| Cadmium | ND - 5.4 | no data |
| Lead | 200 - 54,000 | 500 - 1,000 |
| 1 There is a more detailed list of concentrations of
contaminants in
tables D1 & D2 in Appendix D. Appendix C contains a description of
the process for selecting contaminants. Non-Detect is abbreviated as ND. | ||
Contaminant Levels Prior to Removal of Contaminated Soil
From 4800 West to where Bingham Creek intersects 9000 South, contamination was essentially confined to the area within the creek banks. Within the banks, concentrations of lead and arsenic were as much as 54,000 and 630 parts per million (ppm) respectively in materials visually identified as tailings and were elevated for many other samples (Table D1, Appendix D, references 3-11). On adjacent properties (e.g., a ball field, a park, a bike path, and a residential yard), lead and arsenic concentrations were somewhat elevated for some samples; for most samples, however, the metals were in the range of expected background levels.
From where Bingham Creek intersects 9000 South to where it intersects 3200 West, contaminants are found in the channel, and formerly occurring high waters also distributed contaminants beyond the banks at some locations. Maximum concentrations in the channel and in the off-channel "plumes" ranged from 20,000 to 20,700 ppm for lead and 570 to 880 ppm for arsenic (Table D2, Appendix D, references 3, 5-8). A few samples taken on residential properties showed somewhat elevated lead and arsenic; for most samples, however, concentrations were in the range of expected background levels.
Contaminant Levels after Removal of Contaminated Soil
Review of removal protocols and sampling information indicates that post-removal lead and arsenic levels are less than 1,000 and 100 ppm respectively. Kennecott staff members report that for most samples lead levels were below 500 and arsenic levels were below 75 ppm.
Bingham Creek Floodplain Soil Exposure Situation
Arsenic, cadmium, and lead were identified as key contaminants.
Table 5 summarizes pre- and post-removal concentration data.
Contaminant Levels Before Removal of Contaminated Soil
Between 3200 West and 2700 West, floods distributed tailings across a broad area. The
Jordan
View Estates and Fahnian Ranchettes subdivisions and the IRECO/Rigby property (undeveloped
land) immediately north of Jordan View Estates were substantively affected. On subdivision
properties, lead and arsenic concentrations were as much as 17,000 and 410 ppm, respectively
(Table D3, Appendix D, references 6,9,12,13), and many samples showed elevated
concentrations. On the IRECO/Rigby property, lead and arsenic levels ranged up to 11,000 and
251 ppm respectively. Farther north, a small segment of the Meadow Greens Subdivision,
including a playground, was moderately affected. At the Bluegrass Subdivision still farther north,
a few lots had concentrations slightly above expected background levels and might also have been
affected.
| TABLE 5 - KEY CONTAMINANTS FOR FLOODPLAIN SOIL EXPOSURE SITUATION1 | ||
| Contaminant | Range of pre-removal levels in milligrams per kilograms | Maximum post-removal levels in milligrams per kilograms |
| Arsenic | ND - 410 | Residential: 100 (100 is removal target level; removal is ongoing) IRECO property: 75 |
| Cadmium | ND - 20.6 | no data |
| Lead | ND - 17,300 | Residential: 1,100 (1,100 is removal target level; removal is ongoing) IRECO property: 2,000 |
| 1 There is a more detailed list of concentrations of
contaminants in Table D3 in
Appendix D. Appendix C contains a description of the process for selecting
contaminants. Non-Detect is abbreviated as ND. | ||
Contaminant Levels After Removal of Contaminated Soil
Early removals within the subdivisions targeted areas where sampling showed lead levels were greater than 2,500 ppm. The final removal phase, which is expected to be completed by mid-1996, reevaluates all residential properties for new removal actions. This phase is expected to achieve average soil concentrations in the surficial zone of 1,100 ppm or less for lead and 100 ppm or less for arsenic. The current program includes residential properties where removals had been conducted earlier, residential properties that had not been sampled previously, and residential properties for which access could not be obtained during earlier phases.
Sampling conducted after removal at the undeveloped IRECO/Rigby property showed lead levels in surface materials to about 2,000 ppm and arsenic levels to about 75 ppm.
Bingham Creek Lower Channel Soil Exposure Situation
Arsenic and lead were identified as key contaminants.
Table 6 summarizes pre- and post-removal concentration data.
| TABLE 6 - KEY CONTAMINANTS FOR LOWER CHANNEL SOIL EXPOSURE SITUATION1 | ||
| Contaminant | Range of Pre-removal levels in milligrams per kilogram | Maximum post-removal levels in milligrams per kilogram |
| Arsenic | ND - 80 | most less than 90; 2 ranged up to 145 |
| Lead | ND - 7,129 | 2,000 |
| 1 There is a more detailed list of concentrations of
contaminants in Table D4
in Appendix D. Appendix C contains a description of the process for
selecting contaminants. Non-Detect is abbreviated as ND | ||
Contaminant Levels Before Removal of Contaminated Soil
Downstream from 2700 West for 1,700 feet to a long culvert (which then encloses the creek), off-channel sampling on adjacent residential properties has shown lead present in surficial materials to as much as 1,365 ppm and arsenic to 50 ppm (Table D4, Appendix D [6]); most samples exceeded the expected range of background levels. No samples are reported within the creek channel within that reach.
From the downstream end of the culvert to Sugar Factory Road, a few samples taken within the channel near that road showed the surficial materials contained lead to about 3,400 ppm; those samples were not analyzed for arsenic. On nearby residential properties, lead was found to about 800 ppm and arsenic to 50 ppm; about half of the samples exceeded the expected range of background levels.
Within the channel from Sugar Factory Road to Redwood Road, lead was found in samples at levels up to about 7,100 ppm; all samples exceeded the expected background levels (Table D4 [6]). Arsenic data are not available for the channel samples. On adjacent and nearby residential and undeveloped property, lead in surficial materials was up to about 1,800 ppm and arsenic to 80 ppm. More than half of the samples exceeded the expected range of background levels.
In Brookside Trailer Court, sampling of channel materials showed lead present at levels up to about 4,400 ppm; all samples exceeded the expected range of background levels (Table D4 [6]). No arsenic analyses were performed on those samples. On the adjacent residential properties, lead was present in surface materials at concentrations as high as 2,000 ppm and arsenic to 60 ppm. Lead exceeded the expected range of background levels for about half of the samples. At the playground, lead occurred in surface materials at levels up to 200 ppm and arsenic to 20 ppm; these are well within background levels.
Contaminant Levels After Removal of Contaminated Soil
Lead levels shown in surface materials after removal within this segment were less than 2,000 ppm; arsenic levels were essentially less than 90 (2 samples ranged up to 145).
Copperton Soil Exposure Situation
Arsenic, cadmium, copper, and lead are key contaminants.
Essentially all samples of surface soils taken on several residential properties located in
various
parts of the community show lead (maximum 253 ppm) to be close to or within the range of
expected background levels (Table D5, Appendix D, references 14-16). For arsenic (maximum
54 ppm), the concentrations for essentially all samples taken in residential areas exceed expected
background (based on arsenic being about 3% of lead values). Copper in one sample (maximum
2,020 ppm) seems quite elevated and is clearly much more than is typically found in western soils.
Values for metals at the playground and middle school seem to be within the range of expected
background concentrations.
| TABLE 7 - KEY CONTAMINANTS FOR COPPERTON SOIL EXPOSURE SITUATION1 | |
| Contaminant | Range of levels in milligrams per kilogram |
| Arsenic | ND -53.8 |
| Cadmium | ND - 8.8 |
| Copper | ND - 2,020 |
| Lead | ND - 253.4 |
| 1 There is a more detailed list concentrations of contaminants
in Table
D5 in Appendix D. Appendix C contains a description of the process
for selecting contaminants. Non-Detect is abbreviated as ND | |
Butterfield Creek Soil Exposure Situation
Arsenic and lead are key contaminants.
Contaminant Levels Before Removal of Contaminated Soil
As of May, 1997, 5,000 soil samples had been analyzed, of which 1,000 were surface soils in the
Herriman community. Bureau of Reclamation (BOR) data summary indicates that 84 properties
have surface soil lead concentrations greater than 1200 ppm with some averaging as high as 4,000
ppm of lead (32). Arsenic concentration is residential surface soils was reported as high as 236
ppm with 6 residential properties having arsenic levels in the surface soils greater than 150 ppm.
| TABLE 8 - KEY CONTAMINANTS FOR BUTTERFIELD CREEK SOIL EXPOSURE SITUATION1 | |
| Contaminant | Range of Pre-removal levels in parts per million in surface soils |
| Arsenic | 23 - 339 |
| Lead | 35 - 27,988 |
| 1 Appendix C contains a description of the process for
selecting contaminants. Source: July 1997 EPA Region VIII Endangerment Assessment for Herriman, Utah | |
Bingham Creek Upper Channel Soil Exposure Situation
Ingestion of key contaminants in the Upper Channel Soil Exposure Situation occurred in the past whenever residents went into the channel area of the creek. However, this likely happened only occasionally because no homes are actually in the channel area and contamination was limited to the channel. Current exposures are to much lower levels of contaminants.
Based on an estimate of residential properties (count of homes), indications are that about 1,100 people live within 500 meters of Bingham Creek in the area from 4800 West to 3200 West. The 1990 census indicates the population is about 94% white; a small percentage are Hispanic.
Below 4800 West, for about 6,800 feet, the channel bottom is 25 to 40 feet lower than the surrounding topography. Lot boundaries do not extend into the channel (17). For the next 3,100 feet, to about 9000 South, the channel bottom is 10 to 15 feet below surrounding topography and some lot boundaries extend into the channel. There are many homes near the creek within these two reaches. Between 9000 West and 3200 West, the channel is shallower and portions have flatter bank slopes. There are few residences between 9000 South and 3200 West, and none are close to the creek. The channel is accessible at many points throughout the residential areas. Evidence such as bicycle tracks, caves in the channel banks, and slide marks on the banks shows children use the channel as a recreational area. Children also have been observed in the channel (3).
However, daily exposure of children under 6 years old is unlikely because few residential yards actually extend into the channel. It is assumed that children under 6 would not routinely be allowed to leave their yards and go into the channel.
Before removal activities, lead concentrations ranged from 200 to 54,000 ppm. The arsenic level ranged from 19 to 880 ppm. After removal of contaminated soil, lead levels are below 1,000 ppm and arsenic levels below 100 ppm.
Bingham Creek Floodplain Soil Exposure Situation
Residents may have ingested lead, arsenic, and/or cadmium in the past in the many residential yards with contaminated soil in the area described as Floodplain Soil Exposure Situation. Current levels of contaminants are much lower on properties where removals have been conducted in recent years. After the ongoing final removal is completed in 1996, exposures on all residential properties are expected to be to substantively lower levels of contaminants. Pre-removal exposures on the undeveloped IRECO/Rigby property may have involved high concentrations but probably occurred infrequently. Current exposures, following removal, are at much lower levels of contaminants and are likely to continue to occur infrequently, unless the property is developed for residences.
Based on an estimate of residential properties (count of homes), indications are that about 332 people live within 500 meters of Bingham Creek in the area from 3200 West to 2700 West. The 1990 census indicates the population is about 94% white; a small percentage are Hispanic.
The creek now flows in a culvert through residential areas. Before culvert installation, the creek bed was quite shallow, and flood conditions that occurred before the Bingham Reservoir system was in place resulted in extensive contaminant deposition in areas beyond the creek. Unlike the upper channel exposure situation, much of the population in the floodplain situation area has had the opportunity for daily contact with soils containing elevated levels of arsenic and lead at their residences.
Before removal activities, lead concentrations ranged from not detected to 17,300 ppm, and arsenic ranged up to 410 ppm. The ongoing final removal is targeted to reduce lead to below 1,100 and arsenic to below 100 ppm in surface soils on all residential properties. Post-removal levels in surface soils on the undeveloped IRECO property range up to 2,000 ppm for lead and 75 for arsenic.
Bingham Creek Lower Channel Soil Exposure Situation
Ingestion of key contaminants in the Lower Channel Soil Exposure Situation may have occurred in the past in those yards contaminated with lead and arsenic. Current exposures are to much lower levels of contaminants in the areas where removal has occurred.
Based on an estimate of residential properties (count of homes), indications are that about 980 people live within 500 meters of Bingham Creek in the area from 2700 West to the Jordan River. The 1990 census indicates the population is about 94% white; a small percentage are Hispanic.
The opportunity to have daily contact with soil contaminated with arsenic and lead in the lower channel area appears to be greatest on residential properties within the first 1,700 feet below 2700 West and in Brookside Trailer Court. ATSDR staff members saw that, from 2700 West to Sugar Factory Road (Figure 2B), the first 1,700 feet of creek has residences on one side of the channel and a golf course the other. The creek then is carried within a pipe for about 1,600 feet (18). The channel then reappears and crosses about 1,700 feet of undeveloped land that is bounded on the southwest by residential properties. ATSDR investigators observed that a high fence is present between the channel and those residences. From Sugar Factory Road to Brookside Trailer Court (1,500 feet), which is on the eastern side of Redwood Road, the channel crosses properties that are predominantly undeveloped. Within the trailer court, ATSDR staff members saw that the channel segment (about 1,500 feet) is narrow, shallow, and very close to many homes.
Prior to removal activities, lead concentrations in the channel ranged from not detected to 7,129 ppm. There was no analysis for arsenic in channel samples. The highest levels where daily exposure is probable were for samples obtained within the Brookside Trailer Court. Lead occurred there as high as 2,003 ppm on a residential property. Lead levels within the channel there were as much as 4,365 ppm. Arsenic levels there were up to 60 ppm.
Copperton Soil Exposure Situation
Ingestion of the key contaminants in the Copperton Soil Exposure Situation may have occurred in the past in those yards contaminated with lead, copper, cadmium, and arsenic.
ATSDR staff members' review of census block data for the Copperton vicinity indicates that the town has a total population of about 550 and about 40 children age 5 or less (19). The population is about 97% white. Sampling showed arsenic up to 54 ppm, cadmium to 9 ppm, copper to 2,020 ppm, and lead to 254 ppm. Although there were only a few samples taken, all soils in Copperton are expected to contain those contaminants to at least background levels.
Butterfield Creek Exposure Situation
Ingestion of key contaminants in the Butterfield Creek Exposure Situation may have occurred in the past and may still occur on residential properties with high concentrations of arsenic and lead until current removal and remedial actions by Kennecott and EPA are complete.
Based on the information provided in the EPA Endangerment Assessment (32), 30 residential properties in the Herriman community are contaminated with high levels arsenic and lead in the surface soils. Assuming an average of 4 persons per household, 120 people are estimated to be potentially exposed to arsenic and lead.
Before the current removal actions began, the concentrations of lead in residential surface soils ranged from 35 to 27,988 ppm for lead and 23 - 339 ppm for arsenic.
Typically, the toxicological evaluation in a public health assessment is a comparison of the exposure dose (i.e., the amount of a substance individuals in an exposure pathway are exposed to daily) with appropriate health guidelines for carcinogenic and non-carcinogenic effects. There were health guidelines for non-carcinogenic and carcinogenic effects for arsenic and non-carcinogenic effects for cadmium but no guidelines for copper or lead. Appendix E contains a description of the methodology for calculating exposure doses and cancer risk, along with the results of those calculations (tables E1 - E5).
Blood Lead and Urine Arsenic Studies of Area Residents
Health surveys of Bingham Creek area residents were conducted in 1990 and 1993. In 1990, the Utah Department of Health tested the blood of 157 children and 12 adults from the Bingham Creek area for lead (20). None of the participants had a lead level above the Centers for Disease Control and Prevention's (CDC) concern level of 10 micrograms of lead per deciliter of blood (µg/dL). As indicated in the Utah Department of Health's report, the survey was limited in that, "The population of this area (i.e., Bingham Creek) was not systematically sampled, and some persons with higher blood lead levels may not have volunteered for testing."
In 1993, the University of Cincinnati conducted a study of Bingham Creek area children under 6 years old (less than 72 months old) (21-23). Overall, this investigation evaluated lead and arsenic concentrations for residential soil and interior dust from 728 homes and blood lead and urine arsenic levels for 971 children under age 6 (22). As part of their study, University of Cincinnati investigators identified the total number of children under 6 in the study area as 1,706, so about 57 % of area children participated in the study (24).
The study found that 2 of 284 children, whom the investigators identified as being from contaminated areas, had blood lead levels above 10 µg/dL and 1 of 174 had urine arsenic levels above 20 µg/L. All the children under 6 in the Bingham Creek area (the specific area of concern was identified by EPA) were identified and offered testing. However, because the main purpose of the study was to determine the mean blood lead level for children under 6 in the community, only a participation rate of 50% of the children under 6 was considered necessary. Therefore, it is possible that some areas or populations within the community could be over or under represented. An EPA comparison of results for residences included in this study with environmental sampling results indicates that there were about 75 properties with lead levels above 500 ppm from which no study participants were recruited (22).
ATSDR received a data set from the University of Cincinnati for the 284 children who lived in what were identified by EPA as contaminated areas (21). Our analysis identified mean and maximum blood lead levels for children from the Bingham Creek upper channel exposure situation of 2.5 µg/dL and 7.1 µg/dL, respectively; for the Bingham Creek Floodplain situation, the mean and maximum were 2.6 and 7.6 µg/dL; and for the Bingham Creek lower channel, the mean was 2.7 µg/dL and the maximum was 13.1 µg/dL. This study was conducted before the removal action in the upper channel area, but after the removals in the floodplain and lower channel areas.
Bingham Creek Upper Channel Soil Exposure Situation
It is very unlikely that ongoing exposures to arsenic, cadmium, and lead in upper channel area soil will result in health effects in area residents.
Exposure to arsenic and lead before removal of contaminated soil from the upper channel probably did not result in health effects in area residents because exposure was not frequent enough. Few, if any, small children, had regular access to the channel. This conclusion is further supported by ATSDR's analysis of the University of Cincinnati which identified mean and maximum blood lead levels (2.5 and 7.1 µg/dL) which were below the Center for Disease Control and Prevention (CDC) action level of 10 µg/dL.
Post-Removal Exposures
Post-remediation sampling data indicate that it is very unlikely that ongoing exposures to arsenic, cadmium, and lead in upper channel area soil will result in health effects in area residents.
Pre-Removal Exposure
Arsenic
While the adult, child, and pica child exposure doses for the maximum pre-removal arsenic concentration in soil exceeded the health guideline for arsenic, further evaluation indicates that it is unlikely that these exposures will result in adverse health effects. The maximum exposure doses for adults, children, and pica children vary from about equal to about 29 times greater than the lowest observed adverse health effect level (LOAEL) of 0.014 milligrams per kilogram per day (mg/kg/day) for humans (21). However, the LOAEL is based on long-term exposure to arsenic in water, not soil. Arsenic appears to be less available in soil than in water. In addition, these exposure doses are for daily exposures to the maximum arsenic soil level. Few, if any, individuals were exposed daily because people would have to travel to encounter contaminated soil; few residential yards extend into the channel. We assumed that small children would not be allowed to go into the channel very often or for very long. Given those two factors, it is unlikely that health effects would occur. This conclusion is further supported by ATSDR's analysis of the University of Cincinnati which identified mean and maximum urine arsenic levels (7.8 and 8.7 µg/L) well below the maximum background level of 20 µg/L (21).
Arsenic is considered a known carcinogen, based on human epidemiological studies (25). The maximum arsenic concentrations found in the upper channel soil would present an increased lifetime risk of cancer if exposures were daily for 70 years. However, daily exposure to the maximum arsenic levels is unlikely because the most-contaminated soil has been removed, and most of the homes in the upper channel area were probably built in the last 20 years. A more reasonable "worst case" estimate is 100 milligrams a week for a 10 years duration. We conclude be no apparent increased risk of cancer if the average ingestion of soil were 100 milligrams a week and for 10 years.
Cadmium
The pica child exposure dose for cadmium exceeded the health guideline, but further evaluation indicates that these exposures will not result in health effects. The exposure dose for pica children is about 2½ times less than the LOAEL of 0.0075 mg/kg/day (22). Also, as discussed in the Arsenic Section, it is unlikely that exposure was daily. Given those factors, it is unlikely that health effects would occur.
Animal data indicate that cadmium is a probable human carcinogen (26). However, there is no cancer slope factor (see Appendix E for explanation of term) for cadmium, so it was not possible to evaluate carcinogenic risk. In addition, the data indicate that cadmium probably causes cancer in animals only through inhalation and not through ingestion, which appears to be the principal route of exposure in the Bingham Creek area.
Lead
It is unlikely that health effects would have resulted from the infrequency of exposure of children under age 6. As discussed earlier, few, if any, small children, had regular access to the channel. This conclusion is further supported by ATSDR's analysis of the University of Cincinnati which identified mean and maximum blood lead levels (2.5 and 7.1 µg/dL) which were below the Center for Disease Control and Prevention (CDC) action level of 10 µg/dL (21).
Animal data indicate that lead is a probable human carcinogen (27). However, there is no cancer slope factor for lead, so it was not possible to evaluate carcinogenic risk. In addition, the conclusion that lead causes cancer in animals is based on experiments with a form of lead not found at Bingham Creek.
Bingham Creek Floodplain Soil Exposure Situation
It is unlikely that ongoing exposures to arsenic, cadmium, and lead in the floodplain area soil will result in health effects in area residents. Arsenic, cadmium, and lead soil concentrations are too low to result in noncarcinogenic effects or a significant increase in risk for cancer.
Exposure to arsenic before removal of contaminated soil from the floodplain area may have resulted in a moderate increase in an individual's lifetime risk of cancer. Also, lead levels at least some locations may have been high enough to result in health effects if children under 6 years were exposed daily. Health effects due to exposure to cadmium are very unlikely because 5 grams of contaminated soil would have to ingested for over 50 years before health effects would occur.
Post-removal Exposures
It is unlikely that ongoing exposures to arsenic, cadmium, and lead in the areas of the floodplain where contaminated soil has been removed will result in health effects, because levels of arsenic, cadmium and lead are too low. This conclusion is further supported by ATSDR's analysis of the University of Cincinnati which identified a mean urine arsenic level (4.6 µg/L) well below the maximum background level of 20 µg/L and a mean blood lead level (2.5 µg/dL) below CDC's action level of 10 µg/dL(21).
Pre-Removal Exposure
Arsenic
While the adult, child, and pica child exposure doses for the maximum pre-removal arsenic concentration in soil exceeded the health guideline for arsenic, further evaluation indicates that it is unlikely that these exposures will result in noncarcinogenic health effects. The maximum exposure doses for adults, children, and pica children vary from about 24 times lower to 14 times greater than the LOAEL of 0.014 mg/kg/day for humans (25). However, the LOAEL is based on long-term exposure to arsenic in water, not soil. Arsenic appears to be less available in soil than in water. Given this factor, it is unlikely that health effects would occur.
Human epidemiological studies indicate that arsenic is a carcinogen (25). The maximum arsenic concentrations found in the floodplain soil would present a low increased lifetime risk of cancer assuming that maximum exposure was 30 years. It appears that residential development of this area began in the 1960s.
Cadmium
The pica child exposure dose for the maximum soil cadmium concentration exceeded the health guideline. The exposure dose for pica children is about 1.3 times greater than the LOAEL of 0.0075 mg/kg/day. The LOAEL is from a study of a population in Japan exposed for many years to cadmium in drinking water (26). However, health effects appear very unlikely based on a review of how cadmium causes damage to the kidney. The study from Japan and other studies of human exposures to cadmium indicate that damage occurs only after prolonged exposure. It is estimated that 2,000 mg of cadmium have to be ingested before the kidney is harmed. At the maximum concentration of cadmium in the floodplain exposure situation (20.6 ppm), it would take over 50 years for someone to ingest enough soil to result in a total cadmium exposure of 2,000 mg. This is assuming that 5 grams of contaminated soil would be ingested daily. Thus, cadmium-related health effects are very unlikely.
Animal data indicate that cadmium is a probable human carcinogen (26). However, there is no cancer slope factor for cadmium, so it was not possible to evaluate carcinogenic risk. In addition, the data indicate that cadmium probably causes cancer in animals only through inhalation and not through ingestion, which appears to be the principal route of exposure in the Bingham Creek area.
Lead
The levels of lead in floodplain soil could have resulted in health effects in children under age 6. Soil lead levels of 1,000 mg/kg could increase concentrations in blood from 0.7 to 68 µg/dL, with an average increase of 4-5 µg/dL (27). This wide range resulted from the presence of different sources of lead, exposure conditions, and exposed populations. A recent EPA evaluation of the 1993 University of Cincinnati Exposure Study described on page 16 indicates that contaminated Bingham Creek soil and house dust can elevate blood lead levels (22). The health effects associated with such an increase would depend partly on the existing body burden of lead. Exposure to lead causes a wide range of effects. The level of lead in blood is a good measure of recent exposure and also correlates well with health effects. Children are especially sensitive to lead, and many of its effects are observed at lower concentrations in children than in adults. Levels of 10 µg/dL and perhaps lower in children's blood have been associated with small decreases in IQ and slightly impaired hearing and growth (27).
Animal data indicate that lead is a probable human carcinogen (27). However, there is no cancer slope factor for lead, so it was not possible to evaluate carcinogenic risk. In addition, the conclusion that lead causes cancer in animals is based on experiments with a form of lead not found at Bingham Creek.
Bingham Creek Lower Channel Soil Exposure Situation
It is possible that the highest lead levels found within the channel from the first 1700 feet of the lower channel area and the Brookside Trailer Court could result in health effects in children under age 6 if they were exposed daily. It is unlikely that ongoing exposures to arsenic and lead in lower channel area soil will result in health effects in area residents. Arsenic and lead soil concentrations are too low to result in noncarcinogenic effects or a significant increase in risk for cancer.
Post-Removal Exposure
It is unlikely that ongoing exposures to arsenic and lead in the areas of the lower channel, where contaminated soil has been removed, will result in health effects, because levels of arsenic, cadmium and lead are too low. This conclusion is further supported by ATSDR's analysis of the University of Cincinnati which identified a mean urine arsenic level (4.6 µg/L) well below the maximum background level of 20 µg/L and a mean blood lead level (2.7 µg/dL) below CDC's action level of 10 µg/dL(21).
Pre-Removal Exposure
Arsenic
While the child and pica child exposure doses for the maximum arsenic concentration in soil exceeded the health guideline for arsenic, further evaluation indicates that it is unlikely that these exposures will result in noncarcinogenic health effects. The maximum exposure doses for children and pica children vary from about 7 times lower to 3 times greater than the LOAEL of 0.014 mg/kg/day for humans (25). However, the LOAEL is based on long-term exposure to arsenic in water, not soil. Arsenic appears to be less available in soil than in water. Given this factor, it is unlikely that health effects would occur.
Human epidemiological studies indicate that arsenic is a known carcinogen (25). The arsenic concentrations found in the lower channel area do not represent a significant increased lifetime risk of cancer.
Lead
The highest levels of lead found within the creek channel from the first 1,700 feet of this area (3,393 ppm) and the Brookside Trailer Court (4,365 ppm) may have resulted in health effects in children under age 6, if regular exposure occurred.
Soil lead levels of 1,000 mg/kg could increase lead concentrations in blood from 0.7 to 68 µg/dL with an average increase of 4-5 µg/dL (27). This wide range resulted from the presence of different sources of lead, exposure conditions, and exposed populations. The health effects associated with such an increase would depend partly on the existing body burden of lead. Exposure to lead causes a wide range of effects. The level of lead in blood is a good measure of recent exposure and also correlates well with health effects. Children are especially sensitive to lead, and many of its effects are observed at lower concentrations in children than in adults. Levels of 10 µg/dL and perhaps lower in children's blood have been associated with small decreases in IQ and slightly impaired hearing and growth (27).
Animal data indicate that lead is a probable human carcinogen (27). However, there is no cancer slope factor for lead, so it was not possible to evaluate carcinogenic risk. In addition, the conclusion that lead causes cancer in animals is based on experiments with a form of lead not found at Bingham Creek.
Copperton Soil Exposure Situation
It is unlikely that exposures to arsenic, cadmium, copper, and lead in the soil tested in Copperton will result in health effects in area residents. Arsenic, cadmium, copper, and lead soil concentrations are too low to result in noncarcinogenic effects or a significant increase in the risk of cancer.
Arsenic
While the child and pica child exposure doses for the maximum arsenic concentration in soil exceeded the health guideline for arsenic, further evaluation indicates that it is unlikely that these exposures will result in noncarcinogenic health effects. The maximum exposure doses for children and pica children vary from about 14 times lower to 2 times greater than the LOAEL of 0.014 mg/kg/day for humans (25). However, the LOAEL is based on long-term exposure to arsenic in water, not soil. Arsenic appears to be less available in soil than in water. Given this factor, it is unlikely that health effects would occur.
Human epidemiological studies indicate that arsenic is a known carcinogen (25). The arsenic concentrations found in the Copperton yards tested do not present an increased lifetime risk of cancer.
Cadmium
The pica child exposure dose for cadmium exceeded the health guideline, but further evaluation indicates that these exposures will not result in health effects. The exposure dose for pica children is about 2 times less than the LOAEL of 0.0075 mg/kg/day (26).
Animal data indicate that cadmium is a probable human carcinogen (26). However, there is no cancer slope factor for cadmium, so it was not possible to evaluate carcinogenic risk. In addition, the data indicate that cadmium probably causes cancer in animals only through inhalation and not through ingestion, which appears to be the principal route of exposure in the Bingham Creek area.
Copper
There was no health guideline for copper, but a comparison of the exposure doses to a LOAEL and a consideration of the metabolism of copper in humans indicates that health effects are unlikely (28). The adult and child exposure doses for the highest copper concentrations from soil samples are about 19 and 1.4 times lower, respectively, than a LOAEL of 0.06 mg/kg/day, which is based on exposures of humans to copper in water. The exposure dose for pica children is about 18 times greater than the LOAEL. However, all the other soil samples had copper concentrations less than 500 ppm. Another factor in determining whether adverse health effects might occur is that a large portion of the copper in soil is not available to be absorbed from the gastrointestinal tract into the bloodstream. In addition, the body has an effective mechanism to limit the amount of copper absorbed.
Copper is not considered a carcinogen (28).
Lead
While there is no health guideline for lead, a review of the literature indicates that the maximum soil level of 253 ppm found in testing of some Copperton locations is too low to result in adverse health effects (27).
Animal data indicate that lead is a probable human carcinogen (27). However, there is no cancer slope factor for lead, so it was not possible to evaluate carcinogenic risk. In addition, the conclusion that lead causes cancer in animals is based on experiments with a form of lead not found at Bingham Creek.
Butterfield Creek Exposure Situation
It is possible that the highest lead levels found in residential surface soils could result in
health
effects in children under age 6 if they were exposed daily.
Pre-Removal Exposure
Arsenic
While the child and pica child exposure doses for the maximum arsenic concentration in soil exceeded the health guideline for arsenic, further evaluation indicates that it is unlikely that these exposures will result in noncarcinogenic health effects. The maximum exposure doses for children and pica children vary from about 29 times lower to 12 times greater than the LOAEL of 0.014 mg/kg/day for humans (25). However, the LOAEL is based on long-term exposure to arsenic in water, not soil. Arsenic appears to be less available in soil than in water. Given this factor, it is unlikely that health effects would occur.
Human epidemiological studies indicate that arsenic is a known carcinogen (25). The maximum arsenic concentrations found in the Butterfield Creek area do not represent a low increased lifetime risk of cancer.
Lead
The highest levels of lead found in residential surface soils may have resulted in health effects in children under age 6, if regular exposure occurred. The current health study in the Herriman community may indicate if elevated blood lead levels are evident in children in the area.
Soil lead levels of 1,000 mg/kg could increase lead concentrations in blood from 0.7 to 68 µg/dL with an average increase of 4-5 µg/dL (27). This wide range resulted from the presence of different sources of lead, exposure conditions, and exposed populations. The health effects associated with such an increase would depend partly on the existing body burden of lead. Exposure to lead causes a wide range of effects. The level of lead in blood is a good measure of recent exposure and also correlates well with health effects. Children are especially sensitive to lead, and many of its effects are observed at lower concentrations in children than in adults. Levels of 10 µg/dL and perhaps lower in children's blood have been associated with small decreases in IQ and slightly impaired hearing and growth (27).
Animal data indicate that lead is a probable human carcinogen (27). However, there is no cancer slope factor for lead, so it was not possible to evaluate carcinogenic risk. In addition, the conclusion that lead causes cancer in animals is based on experiments with a form of lead not found at Butterfield Creek.
E. Conclusions, Recommendations, and Public Health Actions
ATSDR does not consider the Bingham Creek upper channel, floodplain, and lower channel and Copperton soil exposure situations to be current public health hazards. Until removal and remediation of residential properties are complete, the Butterfield Creek soil exposure situation is considered a current public health hazard.
Exposure to arsenic and lead before removal of contaminated soil from the Bingham Creek upper channel probably did not result in health effects in area residents because exposure was not frequent enough. Few, if any, small children, had regular access to the channel. This conclusion is further supported by ATSDR's analysis of the University of Cincinnati which identified mean and maximum blood lead levels (2.5 and 7.1 µg/dL) which were below the Center for Disease Control and Prevention (CDC) action level of 10 µg/dL.
Exposure to arsenic before removal of contaminated residential soils from the Bingham Creek floodplain may have resulted in a moderate increase in an individual's lifetime risk of cancer. Also, lead levels at some locations may have been high enough to result in health effects if children under 6 years old were exposed daily. Health effects due to exposure to cadmium are very unlikely because 5 grams of contaminated soil would have to ingested for over 50 years before health effects would occur.
Lead levels in two segments of the lower channel soil exposure situation--the first 1,700 feet of the lower channel area and within the Brookside Trailer Court--may have been high enough to result in health effects if children under 6 years old were exposed daily.
Exposure to arsenic in Butterfield Creek Residential soils may have resulted in a low increase in an individual's lifetime risk of cancer. Lead levels in the residential surface soils in the Butterfield Creek exposure situation may have been high enough to result in health effects if children under 6 years old were exposed daily. The health study sponsored by Kennecott and performed by University of Utah is designed to provide the information on presence of elevated blood lead levels in the area.
No public health actions or recommendations were identified at this time.
Next Section
Table of Contents
