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| BASELINE HEALTH RISK ASSESSMENT
THE MARQUARDT COMPANY FACILITY
Van Nuys, California
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The Marquardt Company facility in Van Nuys, California is a partially active industrial facility, with varying levels of soil contamination due to chlorinated solvents and heavy metals. Portions of the approximately 56-acre site have been used for aerospace-related research, development, and manufacturing since the early 1940's. The northern portion of the site was owned by the United States government and used for military personnel until the late 1940's or early 1950's. The northern portion of the site was purchased by Marquardt prior to 1963 and integrated into the functions of the rest of the facility.
Currently, there are 2 hazardous waste treatment areas, 4 hazardous waste storage areas, and 3 rocket test cell gas scrubbers, which are undergoing RCRA closure under the jurisdiction of the California EPA.
During closure activities, a total of 3 volatile organic compounds were identified in soil beneath RCRA units at the Marquardt facility:
A total of 5 inorganic substances were identified in soil beneath RCRA units at the Marquardt facility:
- Cadmium
- Chlorine
- Hexavalent Chromium
- Copper
- Nickel
In support of the RCRA closure, SCS Engineers prepared a baseline health risk assessment (HRA) for the site following implementation of the approved RCRA closure plan. The purpose of a baseline HRA was to evaluate the probability and magnitude of potential health effects posed to human and ecological receptors by substances at the site under existing site conditions.
As part of the HRA, analytical data from the closure investigation was summarized and evaluated for inclusion in the HRA. Following data validation, chemical of potential concern were identified for inclusion in risk calculations. These chemicals of potential concern were further evaluated as part of the exposure assessment, including identification of exposed populations, identification of exposure pathways, and estimation of exposure point concentrations. The exposure assessment was followed by a toxicity assessment and risk characterization. A final HRA report was prepared by SCS and submitted to California EPA for review.
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| RCRA FACILITY INVESTIGATION
KENNAMETAL MANUFACTURING FACILITY
Bedford, Pennsylvania
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SCS Engineers (SCS) has provided environmental consulting services at Kennametal’s Bedford, Pennsylvania plant since 1987. The plant manufactures tungsten carbide tools. A summary of our services includes providing oversight and design during RCRA closure of two lagoons containing pentachlorophenol (PCP) compounds; conducting a waste minimization study; and performing a RCRA Facility Investigation (RFI). A major component of the RFI focused on the possibility of PCP, trichloroethane, and polychlorinated biphenyls releases.
Two lagoons formerly used for wastewater treatment were determined PCP containing following environmental sampling and analysis. SCS prepared construction plans and provided construction oversight, eventually certifying closure in accordance with the plans.
In response to an Administrative Order issued by the U.S. Environmental Protection Agency (EPA) SCS prepared a detailed summary of the site’s conditions, reviewed preliminary corrective action technologies, and prepared a work plan. The work plan included sampling and analysis procedures, quality assurance methods, data management, and community relations plans.
As part of the RFI, SCS has provided the following services:
- Groundwater, surface water, soil, and sediment monitoring and analysis;
- A soil-gas survey;
- An ecological risk assessment, which included a wetlands assessment, a characterization of dominant-site vegetative communities, and semi-quantitative analysis of the upstream and downstream benthic macroinvertebrate communities; and
- A human health risk assessment.
SCS recently helped Kennametal negotiate conditions for termination of the Administrative Order. SCS currently is overseeing closure of selected monitoring wells and is implementing the EPA-required annual groundwater monitoring program. Kennametal’s existing groundwater pump and treat system will continue to operate until the groundwater monitoring results support ending its operation. A land declaration was recorded by Kennametal in the County records as a condition for termination of the Administrative Order. No additional measures were required by EPA.
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| HUMAN HEALTH AND ECOLOGICAL RISK ASSESSMENT
FORMER LEACH CORPORATION FACILITY
Los Angeles, California
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The former Leach Corporation facility in Los Angeles, California is an inactive industrial facility with varying levels of soil and groundwater contamination due to chlorinated solvents. The former Leach Corporation facility was used for the manufacture of electronic relays for aerospace and related applications since the early 1940's. The facility was decommissioned in 1991. The project is currently under the jurisdiction of the Los Angeles Regional Water Quality Control Board, who is overseeing site remediation activities.
After an extensive site investigation program from late 1992 through 1994, SCS Engineers (SCS) discovered significant soil and groundwater contamination beneath the site due to releases of chlorinated solvents. Based on the extent and magnitude of the contamination, it was established that a human health and ecological risk assessment was necessary to evaluate potential health risks to human receptors and possible adverse impacts to sensitive biological receptors. As such, SCS completed a baseline human health and ecological risk assessment for the site in 1995 and 1996.
The risk assessment included an evaluation of potential health impacts to on- and off-site human and ecological receptors. Risk assessment techniques utilized by SCS on this project included:
- Vadose zone fate and transport modeling to evaluate the potential migration of soil-bound contaminants to groundwater.
- Groundwater fate and transport modeling to evaluate the migratory path of contaminated groundwater and potential impaction of municipal drinking water supplies.
- Qualitative and quantitative analyses of groundwater monitoring data for the site, as derived from groundwater monitoring wells installed for this purpose.
- Air dispersion modeling to assess the off-site migration and human inhalation of airborne contaminants.
- Ambient air monitoring to determine potential health impacts to potential on-site receptors, such as industrial tenants.
- Calculation of carcinogenic and non-carcinogenic risk values using methodologies prescribed by the California EPA.
- An ecological risk assessment to evaluate potential adverse impacts to sensitive plant and animal species located within the vicinity of the project site.
Based on the results of our risk assessment, SCS was able to show that adverse health impacts were only of potential concern for on-site residents due to contamination of drinking water supplies. If soil contamination could be mitigated before it impacted groundwater, these risks would be manageable. Therefore, SCS devised a soil remediation system using vapor extraction that is currently in operation at the site. Clean-up levels were established based on risk assessment results and protection of groundwater quality. The risk information is currently being used for risk management purposes in support of redevelopment and re-occupancy of the site.
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| BASELINE HEALTH RISK ASSESSMENT
ANGELES CHEMICAL COMPANY FACILITY
Santa Fe Springs, California
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The Angeles Chemical Company (ACC) facility in Santa Fe Springs, California is an active chemical manufacturing plant, with significant soil and groundwater contamination due to chlorinated and oxygenated solvents as well as aromatic hydrocarbons. The site occupies approximately 1.8 acres in a predominantly industrial area. ACC has conducted chemical manufacturing operations on-site since 1976. Thirty-four underground storage tanks (USTs) and nine aboveground tanks (AGTs) are presently in use at the facility. A total of 14 volatile organic compounds (VOCs) were identified in soil and groundwater at the ACC site:
- Acetone
- Benzene
- 2-butanone (MEK)
- 1,1-Dichloroethane (1,1-DCA)
- 1,2-Dichloroethane (1,2-DCA
- 1,1-Dichloroethene (DCE)
- Ethylbenzene
- Methylene Chloride
- 4-Methyl-2-Pentanone (MIBK)
- Tetrachloroethylene (PCE)
- Toluene
- 1,1,1-Trichloroethane (1,1,1-TCA)
- Trichloroethene (TCE)
- Xylenes
The ACC site is currently undergoing site mitigation under the CERCLA, with oversight provided by the California EPA. A remedial investigation (RI) was previously prepared for the site by SCS Engineers (SCS) and approved by California EPA.
In order to provide estimates of the potential human health and ecological impacts that could occur due to chemicals detected in soil and groundwater, SCS prepared a baseline human health risk (HRA) for the site following approval of the RI. The purpose of a baseline HRA was to evaluate the probability and magnitude of potential health effects posed to human and ecological receptors by substances at the site under existing site conditions.
As part of the HRA, analytical data from the RI was summarized and evaluated for inclusion in the HRA. Following data validation, chemicals of potential concern were identified for inclusion in risk calculations. These chemicals of potential concern were further evaluated as part of the exposure assessment, including identification of exposed populations, identification of exposure pathways, and estimation of exposure point concentrations. The exposure assessment was followed by a toxicity assessment and risk characterization.
A final HRA report was prepared by SCS and reviewed and approved by California EPA. Currently, the HRA is being used to evaluate potential remedial actions as part of the Feasibility Study (FS). Future project activities will include the establishment and negotiation of site-specific remediation goals and a post-remediation residual risk assessment.
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