Risk-Assessment Projects
ENW’s Risk Assessment Division has successfully completed highly visible risk-assessment projects. Our regulatory and project experience and modeling capabilities with contamination investigation and remediation projects are well proven with state agencies. Our risk assessments are firmly grounded in scientific toxicology studies and highest quality environmental data from a site.
A risk assessment is an analysis that uses information about toxic substances at a site to estimate a theoretical level of risk for people who might be exposed to these substances. Risk assessments are used to determine if levels of toxic substances at hazardous waste sites pose an unacceptable human health or ecological risk as defined by regulatory standards and requirements. The risk assessment helps property owners, regulatory officials, and prospective property owners and developers determine hazardous site cleanup strategies that will ensure overall protection of human health and the environment.
A Risk Assessment begins with an evaluation of contamination sources and proceeds to identification of potentially impacted media such as shallow soil, subsurface soil, groundwater, surface water, and indoor air quality. These processes require high quality field and laboratory data acquired with an effective Quality Assurance and Quality Control program. The Assessment then evaluates land use and beneficial uses of water to identify which human and ecological receptors might be exposed to the contamination. A conceptual site model is developed to identify complete exposure pathways by which contaminants may reach potential receptors. Each contaminant identified at a site is then evaluated for fate in the environment, transport characteristics, toxicity, and concentration. The findings of this assessment are used to establish site-specific cleanup standards and identify materials and volumes that require remedial measures, or, alternatively, to identify land uses and activities that are appropriate for a site.
Prominent Risk-Assessment Projects
Tannery Waste Disposal Site, Sherwood, OR
Lynn Green conducted a human health and ecological risk assessment for a former farm site that historically received wastes from a tannery facility historically located in Sherwood, Oregon. The scope of work for this project included statistical analysis, standard four-part risk assessment, hot spot evaluation, uncertainty analysis, and the development of preliminary remediation goals. The primary constituents of concern were heavy metals, particularly mercury, lead and chromium. An ecological risk assessment was provided after supervising and reviewing the ecological data collected for the project.
Federal Superfund Closure Evaluation, Sherwood, OR
Lynn Green conducted a human health and ecological risk assessment for a former leather tannery facility historically located in Sherwood, Oregon. The scope of work for this project included statistical analysis, standard four-part risk assessment, and regulatory closure assessment regarding impacts to both soil and ground water associated with a former underground storage tank location. The primary constituents of concern were petroleum hydrocarbons, heavy metals, polyaromatic hydrocarbons, and volatile aromatic hydrocarbons (including TCE).
Former Battery Facility, Portland, OR
Lynn Green conducted a human health risk assessment for a former battery servicing site that historically serviced automotive batteries in Portland, Oregon. The scope of work for this project included statistical analysis, standard four-part risk assessment, hot spot evaluation, uncertainty analysis, the development of preliminary remediation goals and regulatory closure assessment. The primary constituents of concern were heavy metals, particularly lead, and petroleum constituents. The site subsequently received formal regulatory closure.
Federal Superfund Legal Suit, Multnomah County, OR
Lynn Green provided toxicological and litigation support for this case. He reviewed records and data extending back over twenty years in order to characterize the nature and extent of the contamination on the site, and determine its impact on the activities of adjacent property owners. He used analytical and historical data to assist in the creation of a database for risk calculations.
Hazardous Waste Permit Application, Tri-Cities area, WA
Lynn Green provided toxicological support and guidance on regulatory compliance in support of a Hazardous Waste Permit Application for a gasification/vitrification facility to handle low-level radioactive wastes from Hanford and other Department of Defense sites. The project included developing a list of potential chemicals and radionucleides of concern, and modeling emissions data and meteorological data for the surrounding area. A pre-construction risk assessment was required as part of the permit application. He participated in developing appropriate scenarios for direct and indirect exposure pathways for human health as well as ecological receptors. The Preliminary Risk Assessment was submitted to the Environmental Protection Agency Region X and the Washington Department of Ecology in February 1999.
Lake-side Park, Multnomah County, OR
Lynn Green worked with a team conducting a risk analysis for a city in support of the development of a recreational city park. The analysis included a review of historical uses of the property, data Quality Assurance/Quality Control (QA/QC) and statistical analysis, a modified risk-assessment scenario development, and calculation of potential risks to adjacent residents and park users. The risk analysis was used by the City to support the proposed park development. Constituents of potential concern were dieldrin, chlordane, heptachlor epoxide, endosulfan I, endosulfan II and endosulfan sulfate.
Ranger Station, Lake County, OR
Lynn Green assisted a consulting firm in a human health and ecological risk assessment for a ranger station in a national forest area in southern Oregon. The scope of work for this project included data QA/QC and statistical analysis, standard four-part risk assessment, hot spot evaluation, uncertainty analysis, and the development of preliminary remediation goals. The primary constituents of concern were petroleum hydrocarbons, BTEX, and volatile aromatic hydrocarbons (including TCE and PCE). An ecological risk assessment was provided after supervising and reviewing the ecological data collected for the project.
Industrial Plastics Manufacturer, Washington County, OR
Lynn Green assisted a consulting firm in a human health risk assessment for an industrial plastics manufacturer in Oregon. The scope of work for this project included data QA/QC and risk analysis referencing Oregon’s Risk-Based Decision-Making for Remediation of Petroleum-Contaminated Sites guidance document, and in the development of risk-based concentrations. The primary constituents of concern were petroleum hydrocarbons and volatile aromatic petroleum-hydrocarbons (BTEX). Lynn also assisted in conducting an ecological screening assessment as part of this project.
Numerous Underground Storage Tank Sites, OR
ENW has been very successful in completing closures for impacts to soil and ground water resulting from releases from underground storage tanks using Oregon’s Risk-Based Decision-Making for Remediation of Petroleum-Contaminated Sites guidance document.
Numerous Underground Storage Tank Sites, WA
ENW has been very successful in completing closures for impacts to soil and ground water resulting from releases from underground storage tanks using Washington’s Model Toxics Control Act regulations and associated risk-based assessment guidance documents.