A Framework for Field and Laboratory Studies for Ecological Risk Assessments in Wetland and Terrestrial Habitats: Two Case Studies

Abstract

Field surveys are frequently required during an ecological risk assessment for a hazardous waste site. Depending upon habitat type, field and laboratory methods that were developed for hazard evaluation lend themselves directly to the ecological risk assessment process. For example, wetlands are frequently impacted by various anthropogenic chemicals, and field and laboratory methods have been developed to help focus laboratory testing routinely planned in site evaluation. Here we compare and contrast the field and laboratory methods used in evaluating wetlands that occurred in markedly different geographic settings and were impacted by two different, but relatively simple contaminant sources. Both field studies were completed as part of the baseline ecological risk assessment process, one being located at Milltown Reservoir wetlands in western Montana and the other in the high desert of south central Oregon. In conjunction with chemical analyses of soil, sediment, and water samples, biological and ecological evaluations yielded an integrated evaluation of ecological effects and exposure at each site, which is critical information for any baseline ecological assessment. Overall, the field activities at each site illustrate the role that laboratory and field screening methods play in ecological management of waste sites.