Yates Environmental Sciences Inc.
Areas of Expertise
Yates Environmental Sciences consulting offers various areas of expertise
Ecological Risk Assessment
Over a decade of experience in conducting ecological risk assessments (ERA). Sites range from small streams adjacent to underground storage tank to industrial facilities along large rivers with over a hundred Areas of Concern. The ERA process begins at the screening level, by identifying Contaminants of Potential Ecological Concern, migration pathways and environmentally sensitive areas. If all three are present, the sensitive habitat is sampled for contaminants. Based on the results, a decision is made as to whether a baseline ERA is needed. If so, we will incorporate various lines of evidence, such as tissue analysis, food chain modeling, community surveys, and/or pore water analysis to characterize risks. Ecological risk assessment is an excellent tool for evaluating impacted habitats and has resulted in collective cost savings of millions of dollars in avoided remedial costs. ​
Contaminated Sediments
Has extensive expertise in the characterization and evaluation of contaminated sediments. The approach used for evaluating contaminated sediments depends upon the objectives of each project, the regulatory arena, and other site-specific factors. Bioavailability can often be evaluated using the results of equilibrium partitioning (e.g., AVS/SEM, organic carbon and USEPA models). As needed, modeling results are validated with additional lines of evidence, such as pore water data, sediment toxicity testing, and/or benthic community surveys. The “Sediment Quality Triad” (i.e., analysis of contaminants, toxicity, and community) is often a useful method for Ecological Risk Assessments
Groundwater- to- Surface Water Investigations
Groundwater-to-surface water studies have received considerable attention over the past decade. In our experience, this pathway is best assessed through the collection of pore water data along the edge of the environmentally sensitive natural resource (piezometers often make sense if long-term monitoring is required). Depending on the results, we will use conventional eco-risk tools such as pore water toxicity testing and/or benthic surveys within the groundwater discharge area. If contaminants exceed human health criteria, we develop site-specific exposure models that account for reasonably conservative exposure scenarios (e.g., incidental ingestion, direct contact), depending on the nature of the receiving water body.
Risk Management Decisions
In many cases, a full-blown risk assessment is not necessary due to the localized nature of the discharge and steep concentration gradients. In these cases, YES will develop site-specific management options ranging from “no action” to remediating all locations with exceedances of screening criteria, and comparing risk reduction to the amount of habitat impacted. Based on those relationships, a management option is selected that maximizes risk reduction while minimizing habitat impacts. This decision is made based on the nature and extent of contamination, the quality of the habitat, and the technical practicability of restoring said habitat.
Natural Resource Damage Assessment
Natural Resource Damage Assessment involves quantifying the impacts of contamination on an ecological resource. Damages are assessed based on the nature of the habitat prior to, and after contamination. The model used to assess damages depends upon the nature of the site, the contaminants and their concentrations, the spatial extent of the impacts, and natural attenuation processes. A “whole ecosystem” approach is often appropriate based on the loss of certain trophic levels/feeding guilds relative to background. On-site remediation and restoration is supplemented, when necessary, with the completion of within-watershed mitigation projects.