This data set compiles regulatory information about river and stream impairments within the Chesapeake Bay watershed as part of a Chesapeake Bay watershed multi-stressor meta-analysis project. Data are contained in a single combined and name-harmonized dataset originating from a snapshot of the Environmental Protection Agency's Assessment and Total Maximum Daily Load Tracking and Implementation System (ATTAINS) obtained in Spring of 2020. These data were clipped to only waterbodies contained in the Chesapeake Bay watershed and were designated to be free-flowing (e.g., rivers and streams). This compiled dataset contains information on a waterbody's designated uses, parameter impairments, and potential sources of that impairment. Be aware, as data on potential sources were joined to parameter impairments in a "one-parameter to many-sources" format, individual impairments might have multiple rows in this dataset, with one row for each potential source. Use of this dataset to evaluate only unique parameter impairments necessitates retaining only unique parameter and assessment unit information.

This data release contains relevant datasets used in the analysis for the Chesapeake Bay stressor identification project, for which results are described in Fanelli and others (in review). For this project, two existing information sources were compiled and summarized to identify key in-stream stressors reported by the scientific literature or through regulatory assessments to be likely affecting benthic macroinvertebrate community metrics in the Chesapeake Bay region: 1) the peer reviewed multi-stressor literature, in which the effects multiple in-stream stressors on benthic macroinvertebrate community metrics are simultaneously assessed; and 2) reported causes of biological impairment as listed by state or district regulatory agencies in the Environmental Protection Agency's Assessment and Total Maximum Daily Load Tracking and Implementation System (ATTAINS). This data release contains three child items: 1) "Data from the Assessment, Total Maximum Daily Load (TMDL) Tracking and Implementation System (ATTAINS) for evaluating multiple stressors affecting Chesapeake Bay Watershed rivers and streams": The ATTAINS dataset is for the Chesapeake Bay region, which was summarized for the jurisdictional impairment analysis (jurisdictions include the states of Maryland, Pennsylvania, Virginia, West Virginia, New York, and Delaware, as well as the District of Columbia). This compiled dataset contains information on a waterbody's Designated Uses, parameter impairments, and potential sources of that impairment. 2) "Multi-stressor literature summary information for Chesapeake Bay stressor identification project": A summary table of the peer-reviewed literature that was considered for the literature review meta-analysis. This dataset includes basic identifying information regarding the report, geographic location of the study, type of field study, the major source or driver that was the focus of the study, and which in-stream stressors were measured. 3) "Results from the literature review meta-analysis for the Chesapeake Stressor Identification Project": The results from the literature review meta-analysis. The dataset includes basic identifying information regarding the report, the response metric for which results were reported, the major source or driver that was the focus of the study, and whether or not the study found the stressor to be important.

This dataset includes information compiled for the literature review meta-analysis portion for the Chesapeake Bay Stressor Identification Project. The dataset includes basic identifying information regarding the publication (last name of the first author, year published, study type, and number of observational units included in the study), the response metric for which results were reported, and the major source or driver that was the focus of the study. The dataset denotes for each stressor category whether a stressor was measured and whether the study’s analysis found it to be an important factor influencing the response metric. The results are reported for both coarse and fine stressor levels, since two stressor categories (geomorphology and toxic contaminants) were subdivided into finer scale categories (habitat and sediment for geomorphology, and pesticides, mercury, metals, and other for toxic contaminants).

The Water Quality Assessment TMDL Tracking And Implementation System (ATTAINS) stores and tracks state water quality assessment decisions, Total Maximum Daily Loads (TMDLs) and other watershed plans designed to restore impaired waters.

This data release includes metrics from the Regional Stream Quality Assessment (RSQA) from the Southeast Region for habitat stressors related to water-quality and habitat substrate. The goals of RSQA are to characterize multiple water-quality factors that are stressors to aquatic life ‐ contaminants, nutrients, sediment, and streamflow alteration – and to develop a better understanding of the relation of these stressors to ecological conditions in streams throughout the region. In order to characterize water-quality variables and stream-habitat measurements as an aggregation of multiple measurements over a sampling period, and in support of ecological stressor modelling, metrics (summary statistics or indices) were computed from individual results by site using consistent methods over a consistent time frame. Water-quality metrics are based on discrete samples as well as long-term deployed passive samplers.

This data release includes metrics from the Regional Stream Quality Assessment (RSQA) from the Southeast Region for habitat stressors related to water-quality and habitat substrate. The goals of RSQA are to characterize multiple water-quality factors that are stressors to aquatic life ‐ contaminants, nutrients, sediment, and streamflow alteration – and to develop a better understanding of the relation of these stressors to ecological conditions in streams throughout the region. In order to characterize water-quality variables and stream-habitat measurements as an aggregation of multiple measurements over a sampling period, and in support of ecological stressor modelling, metrics (summary statistics or indices) were computed from individual results by site using consistent methods over a consistent time frame. Water-quality metrics are based on discrete samples as well as long-term deployed passive samplers.

Nitrogen, phosphorus, and suspended-sediment loads, and changes in loads, in major rivers across the Chesapeake Bay watershed have been calculated using monitoring data from the Chesapeake Bay River Input Monitoring (RIM) Network stations for the period 1985 through 2020. Nutrient and suspended-sediment loads and changes in loads were determined by applying a weighted regression approach called WRTDS (Weighted Regression on Time, Discharge, and Season). The load results represent the total mass of nitrogen, phosphorus, and suspended sediment that was exported from each of the RIM watersheds.

Nitrogen, phosphorus, and suspended-sediment loads, and changes in loads, in major rivers across the Chesapeake Bay watershed have been calculated using monitoring data from the Chesapeake Bay River Input Monitoring (RIM) Network stations for the period 1985 through 2020. Nutrient and suspended-sediment loads and changes in loads were determined by applying a weighted regression approach called WRTDS (Weighted Regression on Time, Discharge, and Season). The load results represent the total mass of nitrogen, phosphorus, and suspended sediment that was exported from each of the RIM watersheds.

Nitrogen, phosphorus, and suspended-sediment loads, and changes in loads, in major rivers across the Chesapeake Bay watershed have been calculated using monitoring data from the Chesapeake Bay River Input Monitoring (RIM) Network stations for the period 1985 through 2020. Nutrient and suspended-sediment loads and changes in loads were determined by applying a weighted regression approach called WRTDS (Weighted Regression on Time, Discharge, and Season). The load results represent the total mass of nitrogen, phosphorus, and suspended sediment that was exported from each of the RIM watersheds.

Nitrogen, phosphorus, and suspended-sediment loads, and changes in loads, in major rivers across the Chesapeake Bay watershed have been calculated using monitoring data from the Chesapeake Bay River Input Monitoring (RIM) Network stations for the period 1985 through 2022. Nutrient and suspended-sediment loads and changes in loads were determined by applying a weighted regression approach called WRTDS (Weighted Regression on Time, Discharge, and Season). The load results represent the total mass of nitrogen, phosphorus, and suspended sediment that was exported from each of the RIM watersheds.