Judi L. Durda

Creosote Site Assessment, Southeastern and Midwestern U.S — Evaluated potential human health and ecological risks associated with PAH and other constituents present in sediments at former wood treatment facilities. Designed sampling programs to address potential human health and ecological risks.

Feasibility Study Support and Post-remediation Monitoring, New Jersey — Provided technical support to assess risk reduction associated with different remedial alternatives.  Also led efforts to develop biological metrics to assess system response post-remedy.  Chemicals of interest included mercury and PCBs.

Remedial Design, Contaminated Sediment Site, Michigan — Assisted in development of the remedial design for a contaminated sediment site in Michigan. Constituents of concern included mercury, PCBs, and PAHs.

RI/FS and Risk Assessment for a Watershed, New Jersey — Led risk assessment for an RI/FS conducted for the Berry’s Creek watershed, a Superfund site located in the Meadowlands.  One of the principal authors of the remedial investigation report for the site.  Chemicals of interest included mercury and other metals and PCBs.

Feasibility Study and Risk Assessment Support, Mining Site, Midwest — Principal-in-charge of technical team that conducted the feasibility study at a former mining site.  Constituents of concern included lead and other metals.

Mercury and PCB Uptake in a Marsh Food Web, New Jersey — Designed studies to assess chemical accumulation in insects and invertebrates inhabiting a marsh adjacent to a tidal estuary.

RI/FS at a Dioxin Waste Site, Gulf Coast — Provided technical support as part of the overall RI/FS to assess potential risks and remedies for a dioxin waste site on the Gulf Coast.  Evaluations included source evaluations, fate and transport analysis, bioaccumulation modeling, and risk assessment.

Regulatory and Trustee Negotiations, Texas — Led a multi-consultant technical team in negotiations with state environmental regulators and state and federal trustees to address sediment contamination in a Texas bayou.

Human Health and Ecological Risk Assessment, Maryland — Led human and ecological risk assessment efforts at a former steel mill site located in Baltimore Harbor.  Chemicals of potential interest included lead, cadmium, chromium, zinc, PAHs, and benzene.  Developed a field investigation program to assess potential contributions to offshore surface water and sediment from stormwater and groundwater releases from the site.

Human Health and Ecological Risk Assessment, Maryland — Led human and ecological risk assessment efforts at a former manufacturing site located in Baltimore Harbor.  Chemicals of potential interest include industrial solvents.  Assessed potential risks from groundwater discharge to surface water.

Litigation Support, Baltimore Harbor Redevelopment, Maryland — Evaluated human and ecological risks associated with sediment contamination in a proposed redevelopment area under legal dispute.

Expert Witness, Texas — Retained as an expert witness to assess health and ecological risks associated with organochlorines, metals, and other chemicals present in sediments and waters of a bayou in Texas.  Work included design of biological sampling programs, risk analysis, and participation in technical mediation.

Ecological Risk Assessment of Creosote-Contaminated Sediments in the St. Johns River, Florida — Conducted an assessment that focused on potential ecological impacts of PAHs in river sediments.

Sediment Quality Triad and Weight-of-Evidence Evaluation, Nationwide — Led technical efforts associated with weight-of-evidence evaluation of benthic community impacts potentially associated with sediment contamination with PAHs, metals, pesticides, and other constituents at a variety of contaminated sediment sites.

PFAS Assessment at a Publicly Owned Treatment Works (POTW), Confidential Location — Assisted in evaluation of the potential risks associated with disposal of treated landfill leachate at a POTW.

PFAS and Firefighting Foams — Served as technical advisor on the study of PFAS and non-PFAS compounds in firefighting foams.

Ecological Risk Assessment at a RCRA Regulated Facility, Ohio — Evaluated ecological risks associated with land disposal of wastewater treatment sludge.  Evaluation included statistical spatial evaluation of residual metal concentration in soils along with screening-level risk calculations.  Constituents of concern included cadmium, copper, chromium, nickel, and zinc.  Evaluation conducted using Ohio EPA ecological risk assessment guidance.

Human and Ecological Risk Assessment at RCRA Sites, Southeast — Leading risk assessment and response strategy to address PFAS at 14 sites located in the southeast United States. Work includes developing site-specific risk-based screening values to support site delineation and management and developing a programmatic approach for human health and risk assessment for all sites.

Regulatory Standards Review and Comment, Nationwide — Reviewed and prepared technical comments on PFAS regulations and guidance values. Reviews included evaluation of the adequacy and applicability of laboratory toxicology data and human epidemiology data, interpretation and use of biomonitoring data, appropriateness of exposure assumptions, and analytical chemistry considerations. Prepared technical comments on regulatory docket and served as technical representative of clients in regulatory and public meetings.  Work conducted in multiple states (including New Jersey, Illinois, Michigan, Minnesota, New York, and North Carolina) and on federal initiatives (EPA and Agency for Toxic Substances and Disease Registry).

Short-Chained PFAS, Consumer Product Safety — Led technical team evaluating the safety of short-chained PFAS used in consumer product manufacturing.  Support included compilation, review, analysis, and reporting on toxicology, fate and transport, and health effects data.

Human and Ecological Risk Assessment, Nationwide — Prepared technical evaluations of human health and ecological risks of PFAS in groundwater, soils, sediment, and surface water.  Support included risk and toxicological evaluations, calculation of cleanup levels, and peer reviews.

PFAS Assessment, Agricultural Operations, Confidential Location — Assisted in evaluation of potential risks to an agricultural operation from PFAS in a regional aquifer.

PFAS Assessment at a Publicly Owned Treatment Works (POTW), Confidential Location — Assisted in evaluation of the potential risks associated with disposal of treated landfill leachate at a POTW.

Toxicology Support for Legacy PFAS — Led team engaged in in-depth toxicological reviews for legacy PFAS compounds, including perfluorooctanoic acid, perfluorooctane sulfonic acid, and perfluorononanoic acid.  Evaluations addressed mode of action, toxicokinetics, and laboratory animal and epidemiological data review.

PFAS Biomonitoring — Reviewed and analyzed biomonitoring data for PFAS in blood.  Evaluated studies included site-specific studies of local populations near a suspected source and national biomonitoring programs.

PFAS Environmental Investigation — Led design and implementation of multimedia sampling program for legacy PFAS.  Studies included groundwater, soil, surface water, sediment, and sediment porewater.

PFAS Replacement Chemistry Evaluations — Supported evaluation of the toxicology, fate, and risk of replacement PFAS chemistry.

PFAS Litigation Support — Provided technical support for litigation involving PFAS compounds.

PFAS and Firefighting Foams — Served as technical advisor on the study of PFAS and non-PFAS compounds in firefighting foams.

Natural Resource Damage Assessment — Evaluated natural resource damages under state law related to perfluorinated chemicals in groundwater, rivers, and lakes.  Used resource equivalency and other economic methods to assess damages.  Supported negotiations with trustees.

Coal Ash Risk Assessment, Confidential Location — Evaluated ecological risks potentially associated with releases at a coal-fired power plant.  Constituents of concern included selenium and arsenic.

Human Health and Ecological Risk Assessment at a Former Wood Treatment Site, Virginia — Principal in charge of human and ecological risk assessments at a former wood treatment site. 

Biotic Ligand Modeling at Superfund Site, Pennsylvania — Evaluated potential aquatic toxicity of copper using biotic ligand model and other tools.

Regulatory Analysis and TSCA — Provided technical support to clients regarding risk assessment and risk management issues under TSCA.

Wood Treatment Sites, Nationwide — Provided technical support to multiple clients to address human health and ecological risks at former wood treatment sites where creosote and pentachlorophenol were used.  Sites regulated under CERLCA and RCRA.

Ecological Risk Assessment at a RCRA Regulated Facility, Ohio — Evaluated ecological risks associated with land disposal of wastewater treatment sludge.  Evaluation included statistical spatial evaluation of residual metal concentration in soils along with screening-level risk calculations.  Constituents of concern included cadmium, copper, chromium, nickel, and zinc.  Evaluation conducted using Ohio EPA ecological risk assessment guidance.

Perchlorate Risk Assessment to Support Remediation and Redevelopment, Virginia — Evaluated human health and ecological risks from perchlorate at a former rocket fuel manufacturing facility.  Used evaluation to support remediation and redevelopment designs at the site.

Risk Assessment of Mercury in a Marine Environment, Confidential Location — Led human health and ecological risk assessments of mercury present in a marine environment.

Risk Assessment at a Petroleum Site, Montana — Principal-in-charge for human health and ecological risk assessment for a former petroleum storage site in Montana.  Groundwater contamination and potential discharge to a nearby creek were evaluated along with other pathways.  Used risk-based assessments in support of remedy development.

Risk Assessment of PCBs and Beef, Confidential Location — Conducted an evaluation to examine potential human health risks from exposure to beef from cattle that have grazed on pasture containing PCBs.  Assessment included evaluation of distribution of beef in the commercial marketplace.  Supported alternative risk-based remedy design for the site.

Ecological Risk Assessment, New York — Led ecological risk assessment efforts for a creek in upstate New York.  Key constituents were arsenic and DDT.

Ecological Risk Assessment, Landfill, Massachusetts — Prepared environmental risk characterization report consistent with the Massachusetts Contingency Plan.  The key element of the risk characterization was differentiation between impacts caused by hazardous constituents versus physical habitat alterations.  Phthalates were a principal hazardous constituent of concern.

Risk Assessment, Mining Site, Illinois — Conducted human and ecological risk evaluations for a former mining site in Illinois and oversaw residential soil cleanup.  Lead and other metals are of potential interest.  Work is being conducted under the state’s Tiered Approach to Corrective Action Objectives (TACO) program.

Human Use Surveys at Waste Site, Mid-Atlantic Region — Designed and implemented a camera survey to document human use at a Superfund site in the mid-Atlantic region.  Information on the frequency of use, types of activities, and exposed population gathered to support development of site-specific exposure assumptions in the risk assessment.

Vapor Intrusion Risk Assessment, Baltimore, Maryland — Evaluated human health risks from vapor intrusion at a Brownfields redevelopment site.  Work has included soil vapor sampling program design, exposure modeling, and risk assessment.

Human Health and Ecological Risk Assessment, Nevada — Technical and strategic lead to address human health and ecological risks associated with groundwater and surface soil contamination at an industrial complex in Nevada.  Key issues include perchlorate and volatile organic compound contamination of groundwater and pesticide bioaccumulation and exposure in the terrestrial and ephemeral aquatic environments.

Waste Site Human Health and Ecological Risk Assessments, Nationwide — Assessed risks to humans and terrestrial and aquatic wildlife posed by waste sites regulated under CERCLA, RCRA, and state regulatory programs.  Assessments involved field identification of potential receptor species and human activity patterns, quantitative evaluation of human and wildlife exposure, interpretation of toxicity data, and application of ecological and toxicological principles.  Conducted deterministic and probabilistic (e.g., Monte Carlo) assessments.  Lead investigator or technical director for more than 100 site investigations.  Types of facilities evaluated include pesticide and organic chemicals manufacturing facilities; chlor‑alkali plants; PCB and dioxin waste sites; hydrocarbon waste sites; wood treatment facilities with copper, chromium, and arsenic contamination; Department of Defense facilities; railyards; metal finishing and processing sites; mining sites; municipal and hazardous waste landfills; mixed industrial waste sites; and contaminated rivers and estuaries.

Multistressor, Regional Risk Assessment, Pennsylvania, Delaware, and New Jersey — Co‑principal investigator of a regional-scale risk assessment conducted to identify, analyze, and rank the impacts of various stressors on overall ecological health in the Delaware Estuary.  Stressors evaluated included physical (e.g., salinity, sedimentation, wetland loss), biological (e.g., invasive species), and chemical (e.g., petroleum, PCBs, mercury) forms. 

Arsenic Risk Assessment, Tennessee — Evaluated potential ecological risks associated with residual sediment contamination resulting from an arsenic acid spill in a river.  Assessment utilized sediment sampling data and a detailed analysis of arsenic speciation and sediment chemistry to assess aquatic life risks.

DDT and Mercury Waste Site Evaluation, Alabama — Evaluated potential ecological impacts associated with DDT and mercury waste sites in a southern bottomland wetland habitat.  Comprehensive assessment involved evaluation of tissue residue data and bioassay data.  A trophic model was constructed for the site to interpret chemical accumulation within the food web.  Risks were assessed for a variety of wetland birds (e.g., heron, wood stork, osprey), mammals, amphibians, fish, and invertebrates.

DDT Bioaccumulation Assessment — Critically reviewed and compiled literature data on the biological accumulation of DDT and its metabolites in aquatic and terrestrial systems.  Prepared database of sediment to organism bioaccumulation factors for multiple species across trophic levels.  Data were compiled to support Monte Carlo evaluation of DDT accumulation in terrestrial and aquatic food webs.

Ecological Assessment of Uranium Enrichment Plant Construction, Louisiana — Evaluated environmental impacts associated with construction and operation of a uranium enrichment plant in Louisiana.  Task involved a detailed description of the ecology of the area and an evaluation of the potential impacts associated with emissions from the facility. 

Australian Olympics Risk Assessment, Sydney, Australia — Assisted in the preparation of and provided quality assurance oversight of an ecological risk assessment conducted in Sydney, Australia, at the site of the Year 2000 Olympics.  Activities included assessment of risks in saltwater, estuarine, freshwater, and rare upland environments; identification of remediation needs; development of mitigation strategies; and negotiation with Australian regulatory agencies.

Equine Risk Assessment, Western United States — Assessed reproductive and other health risks to horses exposed to accidental and long-term chemical air emissions from a manufacturing plant.  Evaluated both acute and chronic health risks under routine and upset operating conditions.  Particle deposition and subsequent ingestion exposures also evaluated.  Evaluation conducted as part of a series of evaluations to quell community concerns regarding plant emissions.

Risk Assessment Peer Reviews, Nationwide — Conducted risk assessment peer reviews for private sector clients to determine if the assessments conformed to applicable guidance yet incorporated recent scientific advances in the areas of exposure assessment, toxicity assessment, and uncertainty analysis.

Occupational Exposure Evaluations in Baltimore Harbor, Maryland — Evaluated potential exposures and risks in workers constructing a tunnel in Baltimore Harbor.  Potential exposure to PAHs and metals were of particular concern.  Acute and long-term health risks were evaluated.

Risk Assessment Lectures — Assisted in the development and teaching of training courses in risk assessment.  Courses included detailed lectures on hazard assessment, dose-response evaluation, exposure assessment, and risk characterization.

Regulatory Review — Reviewed and commented on proposed regulations on behalf of private clients.

Antibiotic Resistant Microorganism and Genes (ARM/ARG), Nationwide — Led team conducting research on monitoring the presence of ARM/ARG in sludge and in the environment.  Developed framework for preliminary risk evaluations.

Municipal Sludge Application, Ohio — Conducted risk and exposure analyses to assess degree of risk posed by land application of municipal sludge.  Both chemical and pathogenic risks considered.  Evaluated potential for impacts on local residents from sludge-associated odors.  Case settled.

Lagoon Remediation Risk Assessment, Ohio — Evaluated human health risks associated with various technologies proposed for remediation of former wastewater treatment lagoons at an industrial facility in Ohio.  Risk assessment included an evaluation of exposures resulting from lagoon dewatering, sludge excavation, and sludge incineration.

Remedial Technology Risk Evaluation, California — Evaluated potential human health exposures and risks associated with land farming of waste sludges in California.  The assessment included evaluations of worker exposures during sludge application, offsite air exposure resulting from dust transport, and dietary exposures associated with consumption of beef and vegetables produced in the farmed area.

Incinerator Risk Assessment, United States and Canada — Evaluated potential ecological impacts associated with emissions from proposed municipal and solid waste incinerators and cement kilns that use waste as fuel.  Multipathway, multichemical assessments included evaluation of food chain exposures to mercury, dioxin, and PCBs in terrestrial wildlife species and surface water exposures to multiple organic and inorganic chemicals in aquatic species.  Conducted risk assessments for more than a dozen facilities.

Ecological Risk Assessment for a Waste-to-Energy Facility, Florida — Conducted ecological risk assessment for a facility in Florida.  Evaluation focused on exposures to bioaccumulative compounds (methylmercury, dioxin) in federally endangered and threatened species, including the Florida panther and wood stork.

Ecological Risk Assessment of a Carbon Regeneration Facility, Arizona — Evaluated ecological risks associated with emissions from a carbon regeneration facility in Arizona.  Constituents of concern included mercury and dioxin and more than 200 other chemicals.

Co-Chair, Special Session on Antibiotic Resistance in the Environment, SETAC Europe Annual Meeting, May 2018, Helsinki, Finland — Co-chaired technical session to evaluate human health risks from the presence of antibiotic pharmaceuticals and antibiotic resistant genes in the environment.

Human Health Risk Assessment of Veterinary Antibiotics, Europe — Conducted probabilistic risk assessment of veterinary antibiotics released to the environment from cattle feedlots.  Considered fate, environmental transport, release, and effect probabilities.

Pharmaceutical Product Evaluation, New Jersey — Evaluated safety of pharmaceutical product inadvertently released to groundwater.  Conducted detailed reviews of clinical, epidemiologic, toxicity, and pharmacokinetic data to establish acceptable groundwater concentration limits.  Relied on dose-response and incidence data to develop a probability-based concentration limit.

Pharmaceutical Site Litigation, Cost Allocation, New Jersey — Provided technical support to counsel to address cost allocation and liability issues at an operating pharmaceutical manufacturing facility where hazardous wastes had been disposed.  Cases settled.

Antibiotic Resistant Microorganism and Genes (ARM/ARG), Nationwide — Led team conducting research on monitoring the presence of ARM/ARG in sludge and in the environment.  Developed framework for preliminary risk evaluations.

Municipal Sludge Application, Ohio — Conducted risk and exposure analyses to assess degree of risk posed by land application of municipal sludge.  Both chemical and pathogenic risks considered.  Evaluated potential for impacts on local residents from sludge-associated odors.  Case settled.

Microbiological Risk Assessment of Food Safety, U.S. Nationwide — Conducted risk assessment to evaluate potential for human disease from exposure to zoonotic pathogens in food.  Assessment included evaluations of microbial ecology, dose-pathogen response assessments, and analysis of exposure pathways along commercial food distribution networks.

Risk Assessment of West Nile Virus Incidence and Control, New York — Led the risk assessment effort to evaluate comparative risks on human and wildlife populations of disease versus pesticide use and other management actions.  West Nile Virus is an arthropod-borne disease associated with specific viruses from the Flaviviridae family.  Work was used to assist in development of a vector management program in Suffolk County, New York.

Potential Radiological Risks, Chesapeake Bay Watershed — Evaluated adequacy of data to assess potential radiological risks at a site managed under the Formerly Utilized Sites Remedial Action Program managed by the U.S. Army Corps of Engineers.

Chemical and Radiological Risk Assessment, New York — Conducted an assessment of health and ecological risks associated with mercury, PCBs, pesticides, and radiological constituents in a river in Long Island, New York.

Radiological Assessment, Western United States — Evaluated potential ecological risks associated with radiation at a U.S. Army test facility and research laboratories.

Tritium Risk Assessment, California — Evaluated potential human health risks from tritium in groundwater.

Selenium — Conducted toxicological and ecological assessments of potential impacts of selenium.  Evaluations included assessment of potential impacts of coal ash releases at a power plant and selenium releases associated with phosphate mining.

Mercury — Evaluated ecological and human toxicology and risk at multiple Superfund sites.  Work has included the design and conduct of field studies to address mercury bioaccumulation and toxicity in aquatic systems, food web modeling and assessment, fish consumption evaluations, air monitoring, risk assessment, cleanup level development, and forensic evaluations.

Copper — Evaluated potential aquatic toxicity and risks associated with copper releases at a variety of waste sites.  Work has included biotic ligand modeling, benthic toxicity testing, and risk assessment.

Arsenic — Evaluated potential ecological and human health risks associated with arsenic released via spills or associated with historical activities from former wood treatment or other industrial facilities.  Work has included human health risk assessment, ecological risk assessment, and field studies to assess bioavailability and form of arsenic in biological tissue.

Zinc — Evaluated potential ecological risks and damages related to zinc in aquatic systems.  Evaluations have included toxicity assessments and forensic evaluation of historical releases.

Lead — Evaluated potential ecological risks and damages at numerous mining sites, landfills, and former firing range locations.

Manganese — Evaluated source, bioavailability, and ecological risk associated with manganese in aquatic and wetland settings.

Cadmium — Evaluated ecological risks associated with cadmium in aquatic, wetland, and terrestrial environments.  Work has included toxicity testing, source evaluation, and fate assessment.

Chromium — Evaluated human health and ecological risks of chromium at former industrial facilities.  Work has included fate and transport evaluations and exposure and toxicity assessments.

Natural Resource Damage Assessment, Confidential Location, New Jersey — Led evaluations of potential natural resource damages in wetlands, lakes, and uplands at a former manufacturing facility in New Jersey.  Constituents of concern included lead and arsenic.

Natural Resource Damage Assessment, Tidal Urban River, Mid-Atlantic — Led technical efforts related to potential natural resource damage claims for a former manufactured gas plant.  Constituents of concern included PAHs.

Natural Resource Damage Assessment, Landfill, Confidential Location — Led technical efforts related to potential natural resource damage claims at a former landfill.  Constituents of concern included metals and PCBs.

Natural Resource Damage Assessment, U.S. Research Facility, Western United States — Led technical evaluations of potential natural resource damage claims for a former research facility in the western United States.  Constituents of concern included radionuclides.

Natural Resource Damage Assessment, Former Manufacturing Site, Virginia — Led technical evaluations of potential natural resource damage claims for a former industrial site.  Constituents of concern included PCBs, mercury, zinc, arsenic, and antimony.

Natural Resource Damage Assessment, Mining Site, Western United States — Led technical efforts related to potential natural resource damage claims for a mining site in the western United States.  Constituents of interest included selenium and other naturally occurring metals.

Natural Resource Damage Assessment, Mining Site, Western United States — Provided technical and strategic support to address potential natural resource damage claims for a mining site in the western United States.  Constituents of interest included naturally occurring minerals.

Natural Resources Damage Assessment, Petroleum Release, Colorado — Led technical efforts related to potential natural resource damage at a refinery site in Colorado where petroleum has been released to groundwater and is potentially discharging into a river.

Natural Resource Damage Assessment, Mining Site, Midwestern United States — Led technical efforts related to potential natural resource damage claims for a mining site in the Midwest.  Addressed ecological and human use issues.  Constituents of interest included lead, cadmium, nickel, and zinc.

Groundwater Natural Resource Damage Assessment, Confidential Location — Provided technical and strategic consultation for natural resource damage settlement discussions and potential litigation on a matter involving widespread presence of manufactured chemicals in an urban/suburban area’s groundwater.

Groundwater and Wetlands Natural Resource Damage Assessment, Petroleum Site, Minnesota — Provided technical and strategic advice to an industry client on a pending groundwater natural resource damage claim involving alleged injuries to groundwater and a wetland.

Natural Resource Damage Assessment, Delaware — Provided technical and strategic support for a natural resource damage assessment for tidal wetlands containing creosote associated with a former wood treatment facility.

Natural Resource Damage Assessment and Restoration, Texas — Led a joint natural resource damage assessment and ecological services analysis for a Texas bayou, with a focus on benthic community injury from chlorinated solvents and pesticides.  Restoration efforts focused on identification and evaluation of restoration projects for salt marsh and other types of wetlands.

Consulting Expert for Petroleum Spill, Confidential Location — Retained as a consulting expert to address fate, transport, and natural resource damages associated with a petroleum spill.

Natural Resource Damage Assessment and Restoration, Alabama — Provided strategic and scientific support to address natural resource injury issues in a wetland and river in Alabama as part of a cooperative assessment process with state and federal trustees.  Injuries in fish, birds, and the benthic community potentially associated with sediment in food-web contamination were evaluated.  Restoration efforts focused on identification and evaluation of restoration options in forested wetland systems, including hydrological modifications, reforestation, and invasive species control.

Trustee Oversight, Alabama — Provided technical oversight support of natural resource damage studies conducted by the U.S. Fish and Wildlife Service (USFWS) at a DDT Superfund site in Alabama.  Provided critical review and comment on behalf of a PRP of studies designed to assess DDT accumulation in the aquatic and terrestrial food web and potential impacts on breeding populations of neotropical migrant bird species.  Assisted in the design of a parallel study designed to address avian population risks.

Ecological Risk Assessment and Natural Resource Damage Assessment in an Estuary, Louisiana — Assisted an industry consortium in developing a statement of work to address ecological risks and natural resource damages in an estuary in Louisiana.  Efforts included developing a framework for studies designed to assess the impacts of multiple chemical and nonchemical stressors from point and non-point sources.  An important goal of the study was to maximize the integration of natural resource damage assessment and RI/FS activities and thereby reduce redundant or contradictory data demands.

Injury Assessment and Habitat Equivalency Analysis, Southeastern United States — Conducted assessments of injury to natural resources at a Superfund site.  Developed the framework for service flow model to account for seasonal dynamics on the presence, nature, and extent of habitat in a river floodplain and led technical negotiations with state and federal trustees.

Natural Resource Damage Assessment, Minnesota — Provided strategic and technical support to address natural resource damage claims for a lake in Minnesota.  Key constituents of concern included PAHs, lead, cadmium, zinc, and chromium.

Natural Resource Damage Assessment Support at a Superfund Site, Virginia — Provided strategic support to a PRP during the initial stages of damage assessment activities initiated by natural resource trustees.  Assisted in the development of a technical strategy for addressing trustee concerns.

Injury Assessment and Habitat Equivalency Analysis, Southeastern United States — Conducted assessments of injury to natural resources at a Superfund site. Worked in conjunction with resource economists to conduct habitat equivalency analysis.

Natural Resource Damage Assessment Support at a Superfund Site, Ohio — Provided strategic support to a PRP.  Activities included development of technical strategy for addressing trustee concerns.

Natural Resource Damage Assessment, New York — Provided strategic support to PRPs during the initial stage of damage assessment activities for a river in New York.  Conducted injury assessments in conjunction with habitat equivalency analyses.

Critical Review of the Toxicity of p-Toluic Acid to Inform Regulatory Standard, North Carolina — Conducted a technical review of the toxicity basis for regulatory standard for p-toluic acid. Review utilized a weight-of-evidence approach that evaluated in vivo and in vitro test results, chemical surrogates, and metabolically relevant compounds.

Toxicity Review of Hexachlorocyclohexane (HCH) Isomers to Support Revision of Regulatory Standards, North Carolina — Prepared documents to support revisions of regulatory drinking water standards in North Carolina.

Mercury Toxicity in Songbirds — Conducted literature review and developed toxicity criteria for assessment of reproductive toxicity in songbirds exposed to mercury via the diet.

Mercury Toxicity in Fish — Conducted literature review of toxicity of mercury in fish and used dose-response models to develop residue-based toxicity criteria with which to assess mercury risks in fish.

Carcinogenicity Assessment of HCH Isomers and Petition to Change Regulatory Toxicity Criteria, Nevada — Headed a team of toxicologists investigating the carcinogenicity of alpha-HCH, beta-HCH, and gamma-HCH (lindane).  Toxicological data indicate that these compounds are either not carcinogenic or are carcinogenic in rodents, but operate via a threshold-based mechanism.  Current regulatory toxicity criteria are derived using the linear low-dose response model, which is the default cancer dose-response model adopted by EPA.  Conducted analysis that indicated that beta- and gamma-HCH are not carcinogenic, and that alpha-HCH is potentially carcinogenic but operates via a nonlinear mode of action.  The alternate toxicological evaluations were accepted by the State of Nevada for use in assessing risks and setting cleanup levels.

Human Health Toxicological Criteria Development for Organic Acids, Nevada — Led technical efforts to develop human health toxicological criteria for a series of five organic acids that are of concern in groundwater at a site in Nevada.  Work involved evaluation of biochemical mechanisms of action, analysis of structure-activity relationships, and review of available in vivo and in vitro toxicological data.  Criteria were accepted by the state regulatory agency for use.

Regulatory Toxicology Reviews, Texas — Conducted critical reviews of the toxicological basis of human health regulatory criteria used by the state of Texas for DDT, BHCs, hexachlorobenzene, and chlorinated benzene products.  Assessed feasibility of petitioning for change in criteria.

Drinking Water Standards Review — Prepared a petition on behalf of an industry consortium requesting a change to the federal drinking water standard for lindane.  Petition was submitted as comments in response to EPA’s 5-year national review of drinking water standards.

Derivation of Site-Specific Water Quality Criteria for BHC Pesticides, North Carolina — Derived site-specific aquatic life criteria for gamma-BHC and other BHC isomers to support risk assessment and remedial design activities at a waste site where BHC groundwater discharge to surface water was at issue.  Site-specific criterion for gamma-BHC was 40 times greater than the promulgated state criterion.  Site-specific criteria for other BHC isomers were more than 2,000 times those originally considered by regulatory agencies.  Site-specific criteria were accepted by both EPA and the state.

DDT Carcinogenicity Evaluation — Evaluated carcinogenicity data for DDT using 1996 proposed EPA guidelines for carcinogen assessment.  Considered epidemiological, genotoxicity, bioassay, and mechanistic data, focusing importantly on the role of gap‑junction inhibition in DDT carcinogenesis.  Compiled weight-of-evidence assessment of DDT carcinogenicity.  Assessment was conducted to support modifications of a fish consumption advisory that was posted in a water body near a hazardous waste site where DDT had been manufactured.

DDT Ecotoxicological Evaluation — Critically reviewed toxicity data related to the effects of DDT and its metabolites on avian reproduction.  Derived toxicity reference values based on a combination of laboratory and field data and structure-activity relationships.  Evaluated toxicological data statistically to support Monte Carlo assessment of ecotoxicological risks.

Mirex and Kepone Ecotoxicological Evaluation — Critically reviewed ecotoxicological, fate, and bioaccumulation literature for the organochlorine pesticides mirex and kepone.  The purpose of the review was to derive toxicity reference values and bioaccumulation factors for use in site-specific ecological risk assessments.  The approach considered toxicity data related to ecologically relevant endpoints (i.e., reproduction, survival) and utilized a weight-of-evidence approach to data interpretation.

BHC Toxicity Assessment — Conducted comprehensive review of toxicity literature for the organochlorine pesticide lindane and other BHC isomers on behalf of an industry consortium.  Efforts were part of a process to solicit changes to regulatory toxicity values listed in EPA’s IRIS database.

Organ-Specific Toxicological Evaluations — Developed acceptable exposure limits for air pollutants based on organ-specific toxicity.  Task involved critical review of the available toxicological data and the use of selected scientifically valid data, conversion factors, and appropriate uncertainty factors in the calculation of exposure limits.

Environmental Criteria Development — Developed acceptable exposure limits for hazardous chemicals in drinking water and air.  Task involved review and evaluation of toxicity data and synthesis of pertinent data to derive concentration limits.

Chemical-Specific Toxicological Evaluations, Nationwide — Prepared toxicity profiles for chemicals present at Superfund hazardous waste sites, focusing on potential carcinogenic effects and other irreversible toxic effects of the chemical.

Forensic Assessment and Source Allocation, Mercury, PCBs, Dioxin, Confidential Location — Directed a forensic assessment to evaluate sources of mercury, PCBs, and other chemicals present in river sediments and wetlands in a southern estuary.  Assessments included visual (e.g., fingerprinting, source mapping) and statistical forensic techniques (e.g., principal component analysis), coupled with historical source evaluation and fate and transport modeling.

Mercury Study, Galveston, Texas — On behalf of a PRP group, developed a monitoring study to assess mercury concentrations in fish and crab to address EPA concerns about potential health risks for recreational users of a lake downgradient of a Superfund site.  The study design took into account the likely multiple sources of mercury in the industrialized area surrounding the site, fish and crab movement into and out of the lake from the nearby estuary, and fate and transport pathways for mercury from the site.

Groundwater Risk Management, Texas — Retained as a technical expert to address the potential contribution of groundwater to surface water and sediment at a Texas bayou.  Led technical analyses, as well as negotiations with the state and trustees.

Probabilistic Techniques Applied toward Derivation of Performance Standard, Southeastern United States — A probabilistic exposure analysis model was developed within a risk-based framework to determine safe levels of the organochlorine pesticide DDT in the prey of wading birds foraging in freshwater wetlands.  The novel approach developed as part of this probabilistic model offered the distinct advantage of incorporating the inherent variability in behavior that occurs within natural wading bird populations, such that the range of theoretically possible exposures could be evaluated.  The output of this model was a performance standard based on plausible exposure, assessed through quantification of the inherent variability and uncertainty in biological attributes of wading birds.

BHC Environmental Fate Assessment — Directed literature review and analysis conducted to characterize the likely fate of BHC pesticides in groundwater and surface water.  Analysis was conducted to evaluate the feasibility of natural attenuation as a remediation option at a waste site where BHC was present in the groundwater.  Aquatic life was the principal receptor of concern in adjacent waters.

Evaluation and Management of Groundwater–Surface Water/Sediment Interactions, New Jersey, Kentucky, West Virginia, Texas, and Maryland — Directed efforts to evaluate the risk consequences and management needs to address the release of contaminants in groundwater discharging to surface waters.  The focus of investigations included fate and transport assessments, loading and discharge modeling and monitoring, forensic source allocation, toxicity assessment, and risk evaluation.  Sites addressed are located throughout the United States.

Remedy Design Support, Alabama — Served on a project team that designed supplemental remediation to address residual DDT present in the sediments of the river floodplain. Evaluated DDT uptake in fish under different remediation scenarios to determine the necessary scale of remedial actions. Modeling included evaluation of accumulation changes in response to variable flooding regimes.

Long-Term Monitoring of DDT Bioaccumulation, Alabama — Provided long-term support to a post-remediation monitoring effort at a DDT waste site. Efforts included evaluation of yearly sediment, fish tissue, and sediment bioassay data and preparation of annual monitoring reports to EPA.

Mercury Cleanup Level Evaluation, New York — Conducted extensive review of the ecotoxicological, statistical, and regulatory basis of a sediment remediation level established by EPA in a record of decision for a mercury waste site located in an embayment of a large river in New York. The review took advantage of recent toxicological data for mercury, state and federal sediment management strategies, and statistical evaluations of sampling data to develop a remediation strategy.

Perchlorate Persistence and Risk in Soil, Virginia — Designed and executed a study to assess perchlorate in soils at a former rocket fuel manufacturing facility.  Used data to support risk assessment and remedial design.

Stream Mitigation: Assessment and Design, Confidential — Assisted in the development of a plan to characterize and mitigate in-stream impacts from mining operations.

Remedial Technology Risk Evaluation, California — Evaluated potential human health exposures and risks associated with land farming of waste sludges in California.  The assessment included evaluations of worker exposures during sludge application, offsite air exposure resulting from dust transport, and dietary exposures associated with consumption of beef and vegetables produced in the farmed area.

Risk Assessment Support for U.S. Army Corps of Engineers, Nationwide — Principal-in-charge for human and ecological risk assessments conducted as part of site inspection reports at formerly used defense facilities under subcontract agreement with Alion Science and Technology Corporation.  Provide senior review and technical input on all human and ecological risk assessment activities.  Senior technical resource on toxicological evaluations and assessments of munitions and related compounds.

Aberdeen Proving Ground Risk Assessment, Maryland — Evaluated ecological and human health risks associated with past chemical agent testing, munitions testing, pesticide use, and waste disposal at a U.S. Army facility located on the Chesapeake Bay.  The facility covered 80,000 acres and contained more than 700 individual waste sites.  The primary focus of the assessment was potential impacts on the Chesapeake Bay fishery and shellfishery, although impacts on other ecological resources also were evaluated.  Surface water, sediment, and soil ecological risks were evaluated along with potential impacts from groundwater discharge to the Bay.  Chemicals of concern included munitions, chemical warfare agents, mercury, arsenic, and other heavy metals, chlorinated pesticides, and volatile organic chemicals.  The risk assessment was the first conducted at Aberdeen under the base cleanup program. 

Aberdeen Proving Ground Biological Assessment, Maryland — Headed a team of scientists tasked with developing comprehensive field and laboratory studies to evaluate ecological impacts associated with various hazardous waste sites at Aberdeen Proving Ground.  The study area consisted of more than 80,000 acres of relatively undeveloped coastal plain uplands, wetlands, and estuary.  The biological assessment program was designed to evaluate potential impacts at various trophic levels within both aquatic and terrestrial communities.  Five basic types of bioassessment techniques were incorporated into the program:  toxicity tests; residue analyses; histological studies; community analyses; and harvest surveys.

Baseline Risk Assessment at Military Installations, Nationwide — Conducted baseline human health and ecological risks assessments at military installations nationwide as part of RI/FS‑related activities.  Installations evaluated included North and South Tooele Army Depots in Utah, Umatilla Chemical Depot in Oregon, Fort Dix in New Jersey, and the St. Louis Ordnance Plant in Missouri.  Evaluations included toxicological and exposure assessments for a number of military-specific compounds (munitions, chemical warfare agents) as well as other hazardous substances.

Alameda Naval Air Station, California — Assisted in the development of a sampling and bioassessment plan to evaluate hazardous chemical contamination at the Alameda Naval Air Station in California.  Provided recommendations regarding sample type, number, location, and the timing of sampling events.  Recommended specific species and bioassays appropriate for evaluating potential impacts in estuarine environments.

Bioassessment Plan Design at Munitions Facility, Missouri — Developed bioassessment plan to investigate potential ecological impacts associated with past disposal of process wastewater from a munitions manufacturing facility.  The bioassessment plan included bioassays using surface water and sediment from the adjacent creek system and residue analysis of soil invertebrates inhabiting uplands adjacent to former wastewater treatment ponds.