Amoret L. Bunn

Scientific Opportunities for Monitoring at Environmental Remediation Sites (SOMERS): Integrated Systems-Based Approaches to Monitoring

Through an inter-disciplinary effort, DOE is addressing a need to advance monitoring approaches from sole reliance on cost- and labor-intensive point-source monitoring to integrated systems-based approaches such as flux-based approaches and the use of early indicator parameters. Key objectives include identifying current scientific, technical and implementation opportunities and challenges, prioritizing science and technology strategies to meet current needs within the DOE complex for the most challenging environments, and developing an integrated and risk-informed monitoring framework.

Phospholipid fatty acid biomarkers in a freshwater periphyton community exposed to uranium: discovery by non-linear statistical learning

Phospholipid fatty acids (PLFA) have been widely used to characterize environmental microbial communities, generating community profiles that can distinguish phylogenetic or functional groups within the community. The poor specificity of organism groups with fatty acid biomarkers in the classic PLFA-microorganism associations is a confounding factor in many of the statistical classification/clustering approaches traditionally used to interpret PLFA profiles. In this paper we demonstrate that non-linear statistical learning methods, such as a support vector machine (SVM), can more accurately find patterns related to uranyl nitrate exposure in a freshwater periphyton community than linear methods, such as partial least squares discriminant analysis. In addition, probabilistic models of exposure can be derived from the identified lipid biomarkers to demonstrate the potential model-based approach that could be used in remediation. The SVM probability model separates dose groups at accuracies of ∼87.0%, ∼71.4%, ∼87.5%, and 100% for the four groups; Control (non-amended system), low dose (amended at 10 μg UL⁻¹), medium dose (amended at 100 μg UL⁻¹), and high dose (500 μg UL⁻¹). The SVM model achieved an overall cross-validated classification accuracy of ∼87% in contrast to ∼59% for the best linear classifier.

Functional remediation components: A conceptual method of evaluating the effects of remediation on risks to ecological receptors.

ABSTRACT Governmental agencies, regulators, health professionals, tribal leaders, and the public are faced with understanding and evaluating the effects of cleanup activities on species, populations, and ecosystems. While engineers and managers understand the processes involved in different remediation types such as capping, pump and treat, and natural attenuation, there is often a disconnect between (1) how ecologists view the influence of different types of remediation, (2) how the public perceives them, and (3) how engineers understand them. The overall goal of the present investigation was to define the components of remediation types (= functional remediation). Objectives were to (1) define and describe functional components of remediation, regardless of the remediation type, (2) provide examples of each functional remediation component, and (3) explore potential effects of functional remediation components in the post-cleanup phase that may involve continued monitoring and assessment. Functional remediation components include types, numbers, and intensity of people, trucks, heavy equipment, pipes, and drill holes, among others. Several components may be involved in each remediation type, and each results in ecological effects, ranging from trampling of plants, to spreading invasive species, to disturbing rare species, and to creating fragmented habitats. In some cases remediation may exert a greater effect on ecological receptors than leaving the limited contamination in place. A goal of this conceptualization is to break down functional components of remediation such that managers, regulators, and the public might assess the effects of timing, extent, and duration of different remediation options on ecological systems.

A Methodology to Evaluate Ecological Resources and Risk Using Two Case Studies at the Department of Energy’s Hanford Site

An assessment of the potential risks to ecological resources from remediation activities or other perturbations should involve a quantitative evaluation of resources on the remediation site and in the surrounding environment. We developed a risk methodology to rapidly evaluate potential impact on ecological resources for the U.S. Department of Energy’s Hanford Site in southcentral Washington State. We describe the application of the risk evaluation for two case studies to illustrate its applicability. The ecological assessment involves examining previous sources of information for the site, defining different resource levels from 0 to 5. We also developed a risk rating scale from non-discernable to very high. Field assessment is the critical step to determine resource levels or to determine if current conditions are the same as previously evaluated. We provide a rapid assessment method for current ecological conditions that can be compared to previous site-specific data, or that can be used to assess resource value on other sites where ecological information is not generally available. The method is applicable to other Department of Energy’s sites, where its development may involve a range of state regulators, resource trustees, Tribes and other stakeholders. Achieving consistency across Department of Energy’s sites for valuation of ecological resources on remediation sites will assure Congress and the public that funds and personnel are being deployed appropriately.

Summary of TPH Monitoring Conducted at 100-NR-2- 2008 through 2010

A summary of TPH monitoring conducted along the 100-N shoreline and the 100-NR-2 operable unit

The costs of delaying remediation on human, ecological, and eco-cultural resources: Considerations for the Department of Energy: A methodological framework

Remediation and restoration of the Nations nuclear legacy of radiological and chemical contaminated areas is an ongoing and costly challenge for the U.S. Department of Energy (DOE). For large sites, such as the Hanford and Savannah River Sites, successful remediation involves complex decisions related to remedies, end-states, timing, and sequencing of cleanup of separate and related contaminated units within a site. Hanford Site cannot clean up every unit simultaneously due to limits in funding, personnel, and technology. This paper addresses one of the major considerations - the consequences of delaying remediation of a unit on different receptors (e.g. people, ecological, and eco-cultural resources), using the DOE Hanford Site as a case study. We develop a list of attributes that managers should consider for successful remediation, examine how delaying remediation could affect workers, the public and ecological resources (including water resources), and use some examples to illustrate potential effects of delays. The factors to consider when deciding whether and how long to delay remediation of a unit include personnel, information and data, funding, equipment, structural integrity, contaminant source, and resource vulnerability. Each of these factors affects receptors differently. Any remediation task may be dependent on other remediation projects, on the availability of transport, containers, interim storage and ultimate disposition decisions, or the availability of trained personnel. Delaying remediation may have consequences for people (e.g. workers, site neighbors), plants, animals, ecosystems, and eco-cultural resources (i.e. those cultural values that depend upon ecological resources). The risks, benefits, and uncertainties for evaluating the consequences of delaying remediation are described and discussed. Assessing the advantages and disadvantages of delaying remediation is important for health professionals, ecologists, resource trustees, regulators, Tribal members, recreationists, fishermen, hunters, conservationists, and a wide range of other stakeholders.

100-OL-1 Operable Unit Field Portable X-Ray Fluorescence (XRF) Analyzer Pilot Study Plans

A pilot study is being conducted to support the approval of the Remedial Investigation/Feasibility Study (RI/FS) Work Plan to evaluate the 100-OL-1 Operable Unit (OU) pre-Hanford orchard lands. Based on comments received by the U.S. Environmental Protection Agency (EPA) and Washington State Department of Ecology, the pilot study will evaluate the use of field portable X-ray fluorescence (XRF) spectrometry measurements for evaluating lead and arsenic concentrations on the soil surface as an indicator of past use of lead arsenate pesticide residue in the OU. The work will be performed in the field during the summer of 2014, and assist in the planning for the characterization activities in the RI/FS.

Integrated Systems-Based Approach to Monitoring Environmental Remediation

The US Department of Energy (DOE) is responsible for risk reduction and cleanup of its nuclear weapons complex. Remediation strategies for some of the existing contamination use techniques that mitigate risk, but leave contaminants in place. Monitoring to verify remedy performance and long-term mitigation of risk is a key element for implementing these strategies and can be a large portion of the total cost of remedy implementation. Especially in these situations, there is a need for innovative monitoring approaches that move away from the cost and labor intensive point-source monitoring. A systems-based approach to monitoring design focuses monitoring on controlling features and processes to enable effective interpretation of remedy performance.

Summary of TPH Monitoring Conducted at 100-NR-2 during CY 2008 and 2009

This report covers a variety of environmental monitoring activities that were conducted over an 18 month period to provide characterization of a TPH-diesel contamination plume in the 100-NR-2 OU

Uranium in the Near-shore Aquatic Food Chain: Studies on Periphyton and Asian Clams

The benthic aquatic organisms in the near-shore environment of the Columbia River are the first biological receptors that can be exposed to groundwater contaminants coming from the U.S. Department of Energys Hanford Site. The primary contaminant of concern in the former nuclear fuels processing area at the Site, known as the 300 Area, is uranium. Currently, there are no national clean up criteria for uranium and ecological receptors. This report summarizes efforts to characterize biological uptake of uranium in the food chain of the benthic aquatic organisms and provide information to be used in future assessments of uranium and the ecosystem.