Specifications include, but are not limited to: Task I / Watershed Characterization: a. Sub-Task: Develop a watershed characterization for the watershed(s) of interest using ArcGIS ArcMap (10.4.1 or most recent version) that provides an in-depth summary of physical attributes specific to the study area(s) of interest, including on a sub-watershed basis where applicable. The sub-watersheds should be delineated consistently with their land uses, with consideration of jurisdictional boundaries, all available monitoring data, and when possible, should align with 6th order Virginia HUC boundaries. b. Elements - the characterization should include the following elements: (1) Water Resources: A description, associated map(s) and overview of location, size, river basin, hydrologic features (such as dams, reservoirs, water withdrawal activity if applicable, USGS stream gages and the associated drainage area), and land use. (2) Eco-Region/topography: A description of the ecoregion(s) that encompass the watershed. . TASK II - Macro-Invertebrate Stressor Analysis: a. Sub-Tasks: Gather and review all available information / data about potential stressors to benthic macro-invertebrates in the watershed(s) of interest, including, but not limited to: water chemistry, physical habitat, qualitative habitat, and sediment data. b. Approach: (1) Apply a weight-of evidence approach to define the most probable stressor(s) that explain(s) the shift in the benthic community that led to the impaired water listing.