An Approach for Balancing Health and Ecological Risks at Hazardous Waste Sites (original) (raw)

Remediation Actions by a Risk Assessment Approach: A Case Study of Mercury Contamination

Water, Air, and Soil Pollution, 2005

The risk assessment procedure for identifying the remediation actions which may be adopted at a mercury contaminated site, when the plants are upgraded in the future, is proposed. The potentially active exposure/migration pathways in the future arrangement of the area will be due to Hg contaminated subsoil as a primary source (vapor inhalation and groundwater leaching) and to groundwater as a possible secondary source (transport to the point of compliance). The data of mercury concentration in the soil were acquired through environmental monitoring campaigns, and were processed to establish the three-dimensional distribution of contamination in subsoil, to locate sources and to define their geometrical and chemical characteristics. Speciation tests of mercury in the soil indicated that the most abundant species present were poorly leachable under the site-specific environmental conditions, confirming the coefficient distribution value obtained by the leaching tests. Analytical and numerical fate and transport modeling tools were used to locate digging zones in the contaminated subsoil, so as to reduce the possible groundwater contaminant loading and to avoid the down-gradient exceeding the concentration limit according to regulations. Remediation actions additional to civil works were required, which consists of soil digging within one contamination source, for about 22,200 m 3 of soil. In order to evaluate the Hazard Index (HI) for human receptors due to Hg vapor inhalation, the air concentration of volatile mercury at the exposure point was estimated, based on direct measurements carried out at the site. Simulation gave HI values below 1 for all tested scenarios, suggesting that public health is protected without any additional actions to the already scheduled plant upgrading and digging for groundwater protection.

Use of ecological risk assessment to guide remediation at the Teck Pinchi Lake Mercury Mine

2013

The Pinchi Mine roasted cinnabar ore to recover metallic mercury, operating from 1940 to 1944 (historic) and from 1968 to 1975 (modern). After 1975, it was placed under long-term care and maintenance until remediation began in 2002. Waste materials from both operations remain on site, within the lake (historic operation), a Tailings Facility (modern) and other discrete locations. From 2004 – 2009 a terrestrial ecological risk assessment (ERA) was undertaken relying on literature, field investigations, habitat surveys, spatially explicit food chain modeling, and development of toxicity reference values for methylmercury and other metals. Ecological risks were evaluated for 40 wildlife species. Only those species feeding primarily on insects or on small mammals indicated potential risks, mainly from arsenic, inorganic mercury, and methyl mercury from the Mill Site and Tailings Facility. A post-closure risk reduction analysis indicated that remediation of these areas would reduce risks...

Environmental Risk Assessment

NATO Security through Science Series, 2006

This paper presents a current overview of the basic elements of environmental risk assessment within the basic four-step process of hazard identification, exposure assessment, toxicity assessment, and risk characterization. These general steps have been applied to assess both human and ecological risks from environmental exposures. Approaches used to identify hazards and exposures are being refined, including the use of optimized field sampling and more representative, rather than conservative, upper-bound estimates. In addition, toxicity data are being reviewed more rigorously as U.S. and European harmonization initiatives gain strength, and the classification of chemicals has become more qualitative to more flexibly accommodate new dose-response information as it is developed. Finally, more emphasis is being placed on noncancer end points, and human and ecological risks are being weighed against each other more explicitly at the risk characterization phase. Recent advances in risk-based decision making reflect the increased transparency of the overall process, with more explicit incorporation of multiple trade-offs. The end reklt is a more comprehensive life-cycle evaluation of the risks associated with environmental exposures at contaminated sites.

Application of risk assessment and decision analysis to the evaluation, ranking and selection of environmental remediation alternatives

Journal of Hazardous Materials, 2000

A single framework integrating risk assessment and decision analysis methods for evaluating, ranking and selecting preferred remediation alternatives at a contaminated site was developed and demonstrated. The methodology used relies on stakeholder inputs throughout the entire process and employs those inputs to combine the results of multiple risk assessments to arrive at a total impact for each remediation alternative. The total impact values allow the ranking of the alternatives, which in turn, serves as the basis for deliberations among the stakeholders in order to identify the preferred alternative. Six major risk or impact categories were considered in the evaluation of the alternatives: human health and safety, environmental protection, life cycle cost, socio-economics, cultural, archeological and historical resources, and programmatic assumptions. q 0304-3894r00r$ -see front matter q 2000 Elsevier Science B.V. All rights reserved.

A Bayesian Approach to Integrated Ecological and Human Health Risk Assessment for the South River, Virginia Mercury-Contaminated Site

Risk analysis : an official publication of the Society for Risk Analysis, 2017

We conducted a regional-scale integrated ecological and human health risk assessment by applying the relative risk model with Bayesian networks (BN-RRM) to a case study of the South River, Virginia mercury-contaminated site. Risk to four ecological services of the South River (human health, water quality, recreation, and the recreational fishery) was evaluated using a multiple stressor-multiple endpoint approach. These four ecological services were selected as endpoints based on stakeholder feedback and prioritized management goals for the river. The BN-RRM approach allowed for the calculation of relative risk to 14 biotic, human health, recreation, and water quality endpoints from chemical and ecological stressors in five risk regions of the South River. Results indicated that water quality and the recreational fishery were the ecological services at highest risk in the South River. Human health risk for users of the South River was low relative to the risk to other endpoints. Risk...

Ecological assessment of hazardous waste sites: a field and laboratory reference

2018

This document discusses the scientific basis for assessing adverse ecological effects at hazardous-waste sites (HWSs), and presents methods for evaluating the on-site and off-site ecological effects of HWSs. The methods are intended for implementation in the early phases of the HWS evaluation process and should be used as integral parts of HWS evaluations. The document is intended for use by administrative and scientific personnel with a strong background in the environmental sciences, including laboratory and field procedures, and environmental assessment strategies.

Ecological Risk Assessment for Contaminated Sites

CRC Press eBooks, 2000

BACKGROUND 2.2 RISK ASSESSMENT FRAMEWORK 2.3 SOIL REMEDIATION 3 SWEDEN 3.1 LEGAL BACKGROUND 3.2 RISK ASSESSMENT FRAMEWORK 3.3 RISK CLASSIFICATION. 3.4 BASIC RISK ASSESSMENT 3.5 COMPREHENSIVE RISK ASSESSMENT 3.6 SOIL REMEDIATION 4 THE NETHERLANDS 4.1 LEGAL BACKGROUND 4.1.1 Contamination of fresh water and sediments 4.2 RISK ASSESSMENT FRAMEWORK 4.2.1 Environmental risk limits and environmental quality standards 4.2.2 Serious Risk Concentrations (intervention value) 4.2.3 Tiered Risk Assessment 4.3 SOIL REMEDIATION 5 ENGLAND 5.1 LEGAL BACKGROUND 5.1.1 Main actors in the handling of contaminated sites 5.2 RISK ASSESSMENT FRAMEWORK 5.2.1 Assessment of risk to ecosystems 5.3 REMEDIATION OF CONTAMINATED SITES

A framework for ecological risk assessment at the EPA

Environmental Toxicology and Chemistry, 1992

Ecological risk assessments evaluate the likelihood of adverse ecological effects caused by stressors related to human activities such as draining of wetlands or release of chemicals. The term stressor is used to describe any chemical, physical, or biological entity that can induce adverse effects on ecological components (i.e., individuals, populations, communities, or ecosystems). In this review article, a historical perspective on ecological risk assessment activities at the U S . Environmental Protection Agency (EPA) is followed by a discussion of the EPA's "Framework Report," which describes the basic elements for conducting an ecological risk assessment. The "Framework Report" is neither a procedural guide nor a regulatory requirement within the EPA. Rather, it is intended to foster a consistent approach to ecological risk assessments within the Agency, identify key issues, and define terminology.