ENVIRONMENTAL RISK ASSESSMENT
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 PROJECTS
Tannery Waste Disposal Site Sherwood, Oregon
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.
Lake-side Park Multnomah County, Oregon
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.
Former Battery Facility Portland, Oregon
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.