The technical and scientific experience of AES professionals is used by our clients to critically review both internal and external technical documents and papers, statistical analyses, ecological models and eco-risk assessments (EcoRA). AES has many years of experience with the effects of a broad range of contaminants, including arsenic, petroleum, mercury, and copper. We combine our technical, scientific and strategic experience to assist in the resolution of issues related to the Total Maximum Daily Load (TMDL), the Endangered Species Act (ESA), the Migratory Bird Treaty Act (MBTA), and particularly Natural Resource Damage Assessments (NRDA). Over the years AES scientists have been invited participants in technical expert panels, scientific oversight committees, and helped to set and assess ecological goals, performance criteria, and standards for a broad range of species, habitats, biotic and abiotic end-points.