PUBLIC HEALTH ASSESSMENT
CHROME CRANKSHAFT
AND
J&S CHROME PLATING
BELL GARDENS, LOS ANGELES COUNTY, CALIFORNIA
The Environmental Health Investigations Branch (EHIB) within the California Department of Health Services (CDHS) has prepared this public health assessment under a cooperative agreement with the federal Agency for Toxic Substance and Disease Registry (ATSDR). The public health assessment is a mechanism to provide communities with information on the public health implications of specific hazardous waste sites and to identify those populations for which further health actions are indicated. The Chrome Crankshaft and J&S Plating sites operated as electroplating facilities between the 1950s through the 1990s. Site characterization and remediation activities are under way at both sites. This public health assessment addresses municipal water quality for the City of Bell Gardens, in the areas which are near the Chrome Crankshaft and J&S Plating hazardous waste sites.
Health concerns have been raised by the community surrounding Chrome Crankshaft and J&S Plating sites, and parents and faculty of the neighboring Suva Elementary and Intermediate Schools. Most of the concerns are related to past and current exposures related to the following: exposure from past aerial emissions; concern about cancer among children, parents, and staff of Suva Schools; safety of drinking water at Suva Elementary School; exposure to chromium-contaminated drinking water; and general concerns about taste and discolored water. This public health assessment will focus on concerns relating to the drinking water. The remaining health concerns will be addressed by future public health assessment activities conducted by CDHS/EHIB and ATSDR.
The Southern California Water Company (SCWC) manages the water system and distributes drinking water for two service areas within the City of Bell Gardens. SCWC uses two sources for the municipal water supply: local groundwater supply wells, and water purchased from Metropolitan Water District of Southern California (MWDSC). MWDSC water is supplied by non-local water sources. Suva Elementary and Intermediate Schools are located in the area of Bell Gardens that receives drinking water from MWDSC, not local groundwater wells.
CDHS/EHIB reviewed water quality data from 1988 to 1998 for groundwater supply wells used for the municipal water supply near the Chrome Crankshaft facility. Chromium contamination was first detected in a municipal water supply well in Bell Gardens in 1991; however, the well had already been taken off-line in 1987 because of contamination from another chemical, and has not been used since that time for the municipal water supply. At the time of this writing, no other groundwater wells used for municipal drinking water have been impacted by the chromium contamination originating from the Chrome Crankshaft and J&S Plating facilities.
For residents living in the City of Bell Gardens and who receive water from SCWC, no current exposure pathway exists. First, the only contaminated well has been off-line since 1987. Second, chromium contamination has not reached the other water supply wells and, thus, no one is drinking contaminated water. CDHS/EHIB has determined that there may be a future exposure pathway if the chromium-contaminated groundwater plume migrates into other water supply wells. CDHS/EHIB concludes that water distributed by the Southern California Water Company presents no public health hazard to consumers in Bell Gardens and Suva Elementary and Intermediate Schools.
The purpose of this public health assessment is to review groundwater data from municipal water supply wells used for Bell Gardens domestic water supply, and to determine if the levels of contaminants present represent a health threat. This public health assessment will evaluate only the potential health impact caused by ingestion of chromium-contaminated drinking water.
BACKGROUND AND STATEMENT OF ISSUES
The Environmental Health Investigations Branch (EHIB) within the California Department of Health Services (CDHS), under cooperative agreement with the federal Agency for Toxic Substance and Disease Registry (ATSDR) is conducting public health assessment activities in Bell Gardens, California. The public health assessment activities will include: evaluating the potential health impact from airborne chromium; providing health education and training to doctors and clinic staff about health effects caused by environmental chemical exposures; and evaluating the potential for exposure to chromium contamination in the municipal drinking water. This public health assessment will focus on water quality, specifically chromium contamination in the City of Bell Gardens' drinking water and evaluate the potential public health impacts. Other public health assessments will address the impact of airborne chromium contamination on the Bell Gardens community, near the Chrome Crankshaft and J&S Chrome Plating facilities. Concerns about the facilities have been raised by community members, teachers, and parents of the adjacent Suva Elementary and Intermediate Schools.
The Chrome Crankshaft facility is located at 6845 E. Florence Place, and was in operation from 1963 to 1999 (Attachment: Figure 1). J&S Chrome Plating is located at 6863 E. Florence Place, and was in operation from 1953 to 1991 [1] (Attachment: Figure 1). Chromium was first detected in soil and groundwater beneath the Chrome Crankshaft facility in 1989, as part of an investigation required by Los Angeles County Department of Public Works to register underground process tanks [2]. As a result, the site was referred to the Los Angeles Regional Water Quality Control Board (LARWQCB) for further investigation [2]. Contamination to the soil at J&S Plating was first documented by the County of Los Angeles in 1981, during an inspection by the Project Planning and Pollution Control Division [3]. In 1987 a site assessment was conducted at J&S Plating, and contamination to the groundwater and soil was confirmed [4]. Chrome Crankshaft and J&S Plating are currently under investigation by the Department of Toxic Substance Control (DTSC), and the LARWQCB, due to contamination of the soil and groundwater, resulting from operations at the facilities. Both sites have been directed by DTSC, with the support of LARWQCB, to initiate remedial and clean up activities.
J&S Plating began remedial work in 1992. The DTSC took over remedial activities at the J&S Plating site in 2000, and coordination of field work activities are in progress (P. Saucedo, DTSC, personal communication, Oct. 2, 2000). In August 2000, Chrome Crankshaft submitted a Remedial Investigation Work Plan to DTSC for comment and approval (P. Saucedo, DTSC, personal communication, Oct. 2, 2000). At the time of this writing, the extent of the chromium-contaminated groundwater plume has not yet been defined.
The Chrome Crankshaft and J&S Plating sites are bordered to the north by vacant lots, and to the east by industrial facilities [2]. Residential areas are located south of the facilities and Suva Elementary and Intermediate Schools are located west of the facilities (Attachment: Figure 1). The Suva Elementary and Intermediate Schools are located at 6740 and 6660 East Suva Street, adjacent to the Chrome Crankshaft facility (Attachment: Figure 1). The western boundary of the Chrome Crankshaft facility and the eastern boundary of the Suva Elementary School are separated by a chain link fence [2]. Other industrial facilities are located northwest of Suva Street.
Based on 1990 census, approximately 42,355 people live in the City of Bell Gardens. The ethnic makeup is 59% Latino; 38% Caucasian; <2% Native American; <1% African American; <1% Asian Pacific Islander. In 1990, 18% of the total population was under the age of 18, and 36% was over the age of 65.
The Suva Elementary and Intermediate Schools, located adjacent to the Chrome Crankshaft site, have a combined student population of approximately 2,855. Suva Elementary School includes kindergarten through 4th graders, with a total of 1,070 students. Suva Intermediate School includes 5th through 8th graders, with a total of 1,785 students.
Before water is distributed to the public, the water must meet the standards mandated in the California Health and Safety Code, Title 22. The United States Environmental Protection Agency (USEPA) and the CDHS-Division of Drinking Water have issued drinking water standards or Maximum Contaminant Levels (MCLs) for more than 80 contaminants in drinking water [5]. The MCL is the maximum permissible concentration of a contaminant allowable in drinking water. MCLs are set as close to the level that no adverse health effects are expected to occur, which also account for sensitive subgroups such as, children, pregnant women, the elderly; and the ability of various technologies to remove the contaminant, their effectiveness, and cost of treatment.
CDHS used MCLs and health comparison values as a general screening in our evaluation. Health comparison values are devised by the ATSDR and other agencies to allow an investigator to quickly sort contaminants into groups that are either unlikely to cause adverse health effects, or contaminants that should be evaluated further. If a contaminant concentration exceeds the health comparison value, it may then be considered as a "contaminant of concern," and further evaluated. If a contaminant does not exceed health comparison values, then exposure to the contaminant is not expected to cause adverse health effects, and no further evaluation is needed.
Municipal Drinking Water Systems for the City of Bell Gardens
The drinking water for Bell Gardens is managed and distributed by the Southern California Water Company (SCWC), which is comprised of two distinct water systems: The City of Bell Gardens Water System and the SCWC-Bell/Bell Gardens Water System [6,7]. The City of Bell Gardens Water System serves areas located north of Florence Place, east of Darwell Avenue, south of East Gage Avenue, and west of Scout Avenue, and receives water from the Metropolitan Water District of Southern California (MWDSC) (Attachment: Figure 2) [6,7]. The system consists of 1,500 connections, and approximately 7,000 customers (J. Wen, SCWC, personal communication, May 12, 1999). These areas receive 100% of their water from MWDSC-supplied water. The only potential local source connected to this system is a deep well located at 6840 Gage Avenue, which is used as a standby well for an emergency supply (i.e., this well does not contribute to the municipal drinking water). The source of the water received from MWDSC is typically a blend of 75% Colorado River water, and 25% from the California State Water Project [7]. The State Water Project is a water storage and delivery system that treats and distributes surface water originating from Northern California. Because water is brought in from other locations, water customers in these areas have not been impacted by the chromium-contaminated groundwater plume originating from the Chrome Crankshaft and J&S Plating facilities. The Suva Elementary and Intermediate Schools are located within this area, thus they receive water from other locations; not from local groundwater sources. Additionally, the water is monitored (tested) regularly to ensure drinking water quality standards are met.
The SCWC Bell/Bell Gardens Water System serves the remaining areas in Bell Gardens, south of Florence Place, west of Darwell and north of Gage Avenue. This area receives approximately 30% imported water from MWDSC and 70% from local groundwater sources (Attachment: Figure 2). In addition, the system has a connection with the City of Bell for supplementary needs. The SCWC Bell/Bell Gardens Water System supplies water to 7,004 connections, approximately 48,500 people, for residential and commercial use (J. Wen, SCWC, personal communication, May 12, 1999). The water supply system used for SCWC Bell Gardens Water System consists of seven groundwater wells (five active and one inactive), Clara Well No. 1, Darwell No. 1, Florence Well No. 1, Gage Well No. 1, Gage Well No. 2, and Priory Well No.2, and the City of Bell Gardens Well No. 1 (Attachment: Figure 3) [7]. The City of Bell Gardens Well No. 1, located at 6607 Florence Place, went on-line in April 2000. The wells are drilled to depths ranging from 290 feet to 1050 feet, and are pumped at varying depths ranging between 87 feet to 610 feet (Table 1) [7]. The wells are screened (perforations in the pipe) at varied depths to allow infiltration of groundwater from different aquifers into the well. Water drawn from the Gage Well No.1 is blended with water from Gage Well No.2 in order to meet water quality standards for tetrachloroethylene (PCE) and trichloroethylene (TCE) [7].
Table 1. Bell Gardens Water System: Well and Pumping Depths
| Well Name | Status | Well Depth (feet) | Pumping Depth (feet) |
| Darwell No.1 | Abandoned (destroyed) | 290 | 114 |
| Florence No. 1 | Inactive | 316 | 98 |
| Clara No. 1 | Active | 357 | 87 |
| Gage No. 1 | Active | 530 | 99 |
| Gage No. 2 | Active | 595 | 109 |
| Priory No. 2 | Active | 650 | 203 |
| City of Bell Gardens Well No.1 | Active | 1050 | 410 and 610 |
Darwell No. 1 has been off-line (inactive) since June 1987, when TCE contamination was detected (J. O'Keefe, CDHS, Drinking Water Field Operations Branch, personal communication Jan. 21, 1999). Florence Well No. 1 was taken off-line in 1998 for routine well maintenance. During the scheduled maintenance, the well casing was found collapsed and the well has since been abandoned [6].
Chromium Measurements
Title 22 of the California Code of Regulations (CCR) requires monitoring for inorganic chemicals, such as total chromium, every 3 years. Currently, the California MCL (maximum contaminant level) for total chromium in drinking water is 50 micrograms per liter (g/L) [5]. Total chromium is composed of trivalent chromium and hexavalent chromium. These two forms of chromium are not usually analyzed separately unless there are high levels of total chromium (above the MCL) detected, and a source of contamination is suspected.
CDHS/EHIB reviewed SCWC Bell Gardens water quality data of inorganic chemicals (focusing on chromium) for a 10-year period (1988 through 1998). The total chromium results are presented at the end of this document (Attachment: Table 2) [8]. The well samples were processed with a reporting limit of 10 g/L, with the exception of the samples collected on November 17, 1998, which had a reporting limit of 1 g/L (Attachment: Table 2). For the past 10 years, chromium levels in all the groundwater wells used for the SCWC Bell Gardens drinking water were reported at less than 10 g/L, which is five times less than the allowable level, or MCL of 50 g/L (Attachment: Table 2) [8].
The November 17, 1998, sampling also included analysis of hexavalent chromium in the Florence Well No. 1, because of its close proximity to the Chrome Crankshaft facility. Results of hexavalent chromium were reported at less than the reporting limit of 0.5 g/L [8].
Since the City of Bell Gardens Well No.1 became operational in April 2000, only data from a limited time period (December 1999 through July 2000) was available for review. From December 1999 through July 2000, total chromium levels in the City of Bell Gardens Well No. 1 were reported at less than 10 g/L, which is five times less than the allowable level, or MCL of 50 g/L [9]. Additionally, sampling for the new City of Bell Gardens Well No.1 included analysis of hexavalent chromium. All sampling results of hexavalent chromium were reported at less than the reporting limit of 0.5 g/L [9].
The only well that has clearly been impacted by chromium is Darwell No.1. Chromium was first detected in Darwell No.1 in 1991, at a level of 62 g/L (Attachment: Table 2). Chromium levels prior to 1991 were reported at less than 10 g/L. Chromium levels in this well have fluctuated between 1991 and 1997, with the highest level reported at 127 g/L, in October 1997 (Attachment: Table 2) [8] . Since the Darwell No. 1 has been off-line since 1987 because of TCE contamination, residents did not receive chromium-contaminated water from this well [7]. The Darwell remained off-line until it was formally destroyed in August 2000 (J. Wen, Southern California Water Company, personal communication, September 19, 2000). Thus, this data shows that residents receiving water from the SCWC Bell Gardens Water System were not impacted by chromium contamination in the municipal well water.
It is difficult to determine the future impact of chromium on the other wells in the SCWC Bell Gardens system [1]. The regional groundwater flow is generally in a west-southwest direction, moving across (or under) the J&S Plating and Chrome Crankshaft sites in the general direction of the city wells [1]. There is not adequate information on the extent the chromium-contaminated groundwater plume has migrated vertically or horizontally. In addition, the fact that the wells are screened and sampled at varying depths contributes to the difficulty in knowing what will occur in the future. The Chrome Crankshaft and J&S Plating facilities have been directed by the LARWQCB to initiate groundwater remediation (cleanup) activities, in order to prevent further degradation of the groundwater [10].
Water Sampling at Suva Schools
As discussed at the beginning of this section, Suva Elementary and Intermediate Schools receive water that is purchased from MWDSC, and not local groundwater supply wells. On September 10, 1998, in response to community concern about the safety of the drinking water at Suva Elementary and Intermediate Schools, the LARWQCB collected water samples from three drinking fountains at the schools [10]. The samples were analyzed by CDHS Sanitation and Radiation Laboratory in Berkeley for total chromium, hexavalent chromium, and 17 different metals. Hexavalent chromium and total chromium levels were reported as less than the laboratory reporting limit (1.0 g/L and 0.5 g/L, respectively) at the three locations [10]. The samples were also analyzed for mercury and general minerals by the CDHS Sanitation and Radiation Laboratory in Los Angeles [10]. Mercury levels were reported at less than the laboratory reporting limit of 1 g/L, and results of the general mineral analysis were below drinking water standards [10]. Thus, analysis of the drinking water at Suva Elementary and Intermediate Schools found no problems with chromium, mercury, or any of the other metals analyzed [10].
Taste and Color Issues
On October 19, 1999, at a Suva Advisory Group meeting held by CDHS/EHIB, and at other public meetings as well, parents have expressed concerns relating to discolored and bad tasting water. In response to their concerns CDHS staff discussed these issues with a representative of SCWC (J. Wen, SCWC, personal communication, Nov. 8, 1999). Based on our discussion, the color and taste issues in the SCWC Bell Gardens Water System appear to be related to old piping and natural minerals in the water.
Chemical Contamination in the Groundwater other than Chromium
Regional groundwater contamination of volatile organic compounds (VOCs) have resulted in elevated levels of TCE and PCE in a number of Bell Gardens' municipal water supply wells [6]. These wells are monitored and various measures, such as groundwater remediation (air stripping, which removes contaminants from the water), and blending (a process of dilution where water with contaminants is mixed with water that does not have contaminants) are in place to ensure that water distributed to customers does not exceed the MCL of 5 parts per billion (ppb) for TCE and PCE [5].
In the late 1980s, community concerns were raised when air sampling revealed elevated levels of hexavalent chromium. As a result, the South Coast Air Quality Management District (SCAQMD) directed the Chrome Crankshaft facility to reduce emissions.
In July 1998, Los Angeles County, DTSC, and ATSDR Regional Representatives requested assistance from ATSDR/CDHS because of ongoing health concerns by community members, parents of students and faculty at Suva Schools, and the belief that emissions from the Chrome Crankshaft facility were the cause of their health concerns.
Since July 1998, CDHS staff met with community members on a number of occasions to discuss their concerns. Additionally, CDHS formed a community advisory group to act as a partnership in considering health issues related to the Chrome Crankshaft and J&S Chrome Plating sites. Most of the concerns expressed by the community were related to past and current exposures which include the following:
Community Concerns Evaluation
The concerns raised about the safety of the drinking water at Suva Schools, and within the Bell Gardens community are addressed in this public health assessment. CDHS staff reviewed the soil data presented in the Suva Schools Environmental Investigation, prepared by DTSC, and concluded that the soils at Suva Schools do not pose a public health hazard. Health concerns relating to inhalation exposures will be addressed in another public health assessment focusing on past aerial emissions from the Chrome Crankshaft and J&S Chrome Plating sites. CDHS will also be reviewing cancer information for the community surrounding the sites and Suva Schools.
Exposure pathways are means by which people in areas surrounding the sites could have been or could be exposed to contaminants from the sites. The following discussion will focus on exposure pathways relating to chromium-contamination in the groundwater.
For target populations to be exposed to environmental contamination, there must be a mechanism by which the contamination comes into direct contact with a human population [11]. This is called an exposure pathway. Exposure pathways are classified as either completed, potential, or eliminated.
In order for an exposure pathway to be considered "completed," the following five elements must be present: a source of contamination, an environmental medium and transport mechanism, a point of exposure, a route of exposure, and a receptor population. For a population to be exposed to an environmental contaminant, a completed exposure pathway (all five elements) must be present. The following is an example of a completed exposure pathway: a contaminant from a hazardous waste site (source) leaches into groundwater (medium, transport mechanism), the groundwater is then pumped and piped into houses and businesses (point of exposure) where the occupants drink the water (route of exposure and receptor population) (Attachment: Table 3).
Potential exposure pathways are either: 1) not currently complete but could become complete in the future, or 2) are indeterminate due to a lack of information. Pathways are eliminated from further assessment if one or more elements are missing and are never likely to exist.
Eliminated Exposure Pathways
Currently or for the past 10 years, no completed exposure pathway exist to chromium in the SCWC Bell Gardens Water System, because the levels of chromium present in drinking water served to customers were/are below health comparison values and drinking water standards (MCLs). Health comparison values are devised by the ATSDR and other agencies to be used as a general screening of contaminants in order to determine if a further health evaluation is warranted. For example, if a contaminant concentration exceeds the health comparison value, then the contaminant will be considered a contaminant of concern, and evaluated further. On the other hand, if a contaminant concentration does not exceed the health comparison value, it is not likely to cause health effects, and no further evaluation is performed.
Since chromium levels in the SCWC Bell Gardens Water System are below health comparison values, there is no need to conduct any further health evaluation relating to exposure to chromium in drinking water distributed by SCWC.
Potential Exposure Pathway
CDHS has determined that a potential exposure pathway to chromium may exist in the future for customers who drink water from the SCWC Bell Gardens Water System. The potential for a future pathway exists for the following reason: since chromium is typically analyzed at 3-year intervals, and the vertical and horizontal extent of the chromium-contaminated groundwater plume has not yet been defined, it is conceivable that the chromium could migrate to other wells and remain undetected for up to a 3-year period of time.
CDHS recognizes that infants and children may be more sensitive to chemical exposures,depending on the substance and the exposure situation, than adults in communities with contamination of their water, soil, air, and/or food. This sensitivity is a result of many factors including: 1) Children may have higher exposures to environmental toxins than adults because pound-for-pound of body weight, children drink more water, eat more food, and breathe more air than adults; and 2) Children's bodies are rapidly growing and developing; thus, they can sustain permanent damage if toxic exposures occur during critical growth stages.
CDHS did not evaluate exposures for a child living within the SCWC Bell Gardens system because chromium levels in the drinking are below drinking water standards (MCLs) and health comparison values, which account for sensitive populations such as children, pregnant women, and the elderly. Thus, there have been no exposures to chromium at levels that would be likely to cause health effects to children.
Existing health databases such as the cancer and birth defects registries are generally useful when substantial exposures are documented or suspected for the neighborhoods in the vicinity of a site. Based on this review of the drinking water quality in the SCWC Bell Gardens Water System, CDHS did not review health outcome data because a review of disease statistics would not be useful for determining potential health impact from exposure to chromium in the Bell Gardens system due to the following: 1) chromium distributed in the drinking water was/is below levels of health concern; and 2) toxicological information does not indicate an association with cancer from ingestion of chromium.
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