This dataset consists of 262 variables which describe various known and suspected point and non-point sources of contaminants and endocrine disrupting compounds (EDCs) throughout the Chesapeake Bay Watershed. Contaminant data was summarized to the NHDPlus Version 2.1 catchment level (1:100K). Contaminant data summarized span a time range of 2001 to 2016 and include regulated facilities, pesticides, manure and biosolids application data, mercury deposition, animal feeding applications, septic systems, landfills, and land use and land cover. These data are presented in a comma separated file, which includes all variables summarized and the NHDPlus Version 2.1 FEATUREID field (also known as COMID). The FEATUREID field can be used to relate these summaries to the NHDPlus Version 2.1 data suite for mapping and other analytical purposes. Total (TOT) and Divergent (DIV) upstream summaries were generated using the NHDPlusV2 Catchment Attribute Allocation and Accumulation Tool (CA3TV2). Using this method, upstreams summaries are generated for 82,263 of the 83,637 NHDPlus catchments in the Chesapeake Bay Watershed. These data will be used to investigate source-sink linkages between contaminant sources, water quality issues, and impacted receptor populations (e.g., smallmouth bass) throughout the Bay Watershed. Information gained from this work may also be used to evaluate the success of mitigation activities and help to prioritize new locations for mitigation, implementation of best management practices, or habitat conservation actions.

Legacy and emerging contaminants were measured in streams and rivers in the District of Columbia and the states of Maryland, Pennsylvania, Virginia, and West Virginia of the Chesapeake Bay watershed between 2005 and 2013. Passive sampling devices, SPMDs and POCIS, were used to sample these waterbodies, providing a time-integrated concentration of contaminants that are potentially bioavailable to native fishes. This data set is a compilation of data from eight separate studies, all focused on determining the potential exposure of organic chemicals to fish which may be responsible for instances of fish kills and intersex that were observed in these waterbodies.

Legacy and emerging contaminants were measured in streams and rivers in the District of Columbia and the states of Maryland, Pennsylvania, Virginia, and West Virginia of the Chesapeake Bay watershed between 2005 and 2013. Passive sampling devices, SPMDs and POCIS, were used to sample these waterbodies, providing a time-integrated concentration of contaminants that are potentially bioavailable to native fishes. This data set is a compilation of data from eight separate studies, all focused on determining the potential exposure of organic chemicals to fish which may be responsible for instances of fish kills and intersex that were observed in these waterbodies.

Each year from 2021 to 2024, teams from the U.S. Geological Survey and the Virginia Polytechnic Institute and State University (Virginia Tech) studied 30 streams with a targeted gradient of land use and conservation practices across the Chesapeake Bay Watershed. The four years of the study cover the following geographic areas and land use characteristics (generally referred to as typologies in associated data sets): Shenandoah Valley and Ridge pasture Delmarva row crop Pennsylvania and Maryland Piedmont mixed agriculture Maryland-Washington, DC-Virginia developed Piedmont The data here provide site names and basic identifiers that are commonly used in the many data releases associated with the larger study and serve as a key to match site ID with locations and data. Specific site location is limited to a HUC12 scale due to requests of privacy from landowners who granted access and permission.

Each year from 2021 to 2024, teams from the U.S. Geological Survey and the Virginia Polytechnic Institute and State University (Virginia Tech) studied 30 streams with a targeted gradient of land use and conservation practices across the Chesapeake Bay Watershed. The four years of the study cover the following geographic areas and land use characteristics (generally referred to as typologies in associated data sets): Shenandoah Valley and Ridge pasture Delmarva row crop Pennsylvania and Maryland Piedmont mixed agriculture Maryland-Washington, DC-Virginia developed Piedmont The data here provide site names and basic identifiers that are commonly used in the many data releases associated with the larger study and serve as a key to match site ID with locations and data. Specific site location is limited to a HUC12 scale due to requests of privacy from landowners who granted access and permission.

The dataset contains estimates for total nitrogen and total phosphorus loads from point sources, combined sewer overflows, wastewater treatment plants that discharge to surface water for selected Chesapeake Bay watersheds. For source information, please refer to the process steps in this metadata report.

The dataset contains estimates for total nitrogen and total phosphorus loads from point sources, combined sewer overflows, wastewater treatment plants that discharge to surface water for selected Chesapeake Bay watersheds. For source information, please refer to the process steps in this metadata report.

Treated effluent from wastewater treatment plants (WWTPs) contains contaminants not fully removed during the treatment process and that may pose environmental health risks when discharged to surface waters. This data release presents inputs for and results from a wastewater reuse model that used data compiled from several sources to calculate the following estimates for each non-tidal, non-coastline, initialized National Hydrography Dataset Version 2.1 (NHDPlus V2) stream segment in the Potomac River watershed: (1) accumulated wastewater as a percent of total streamflow (ACCWW%); and (2) predicted environmental concentrations (PECs, in micrograms per liter) of 69 municipal effluent-derived contaminants. ACCWW% values were calculated for mean-monthly and mean-annual streamflow conditions for both municipal (model results table: Table1_PotomacACCWW_municipal.csv) and industrial-plus-municipal effluent discharges (model results table: Table2_PotomacACCWW_municipal_plus_industrial.csv). PECs were calculated for mean-monthly and mean-annual streamflow conditions for municipal effluent discharges (model results tables: Table3_PotomacPECs.zip, containing comma separated value files of results for mean-monthly and mean-annual conditions). Model estimates at a stream reach of interest represent the combined total upstream wastewater discharges as well as direct discharges into the segment. Model input data included: (1) National Pollutant Discharge Elimination System-permitted facility outfall locations and 2016 average daily effluent discharges linked to a NHDPlus V2 stream Common Identifier (COMID) and facility-specific information on treatment levels and population served per capita (model input table: Table4_PotomacWWTPs.csv); (2) NHDPlus V2 stream geometry and hydrologic attributes (hydrosequence, startflag, terminalfl, divergence, fromnode, tonode, and Enhanced Runoff Method mean-monthly and mean-annual gage-adjusted streamflow and velocity, 1971-2000) (model input table: Table5_PotomacNHDPlusV2.1_flowlines_hydrology.csv); and (3) contaminant-specific data on consumption, fate, and transport compiled from literature sources or estimated from physicochemical properties (see: supplementary table in Larger Work Citation). In Table 4, where information on population served by the facility was missing, this value was estimated by standardizing to 100 gallons per capita per day. Information on population served was only acquired and estimated for municipal facilities. Where treatment level information was missing, the treatment level was assumed to be primary. Ninety-two percent of WWTPs have an assumed treatment as none was reported. R (version 4.0.4) and Python (version 2.7.16) scripts were used to summarize wastewater inputs from outfall locations by COMID and route and accumulate each wastewater and predicted contaminant loads while accounting for in-stream dilution and attenuation of contaminants. Any users of these data should review the entire metadata record and the associated manuscript (see Larger Work Citation). See 'Distribution liability' statements for more information.

Treated effluent from wastewater treatment plants (WWTPs) contains contaminants not fully removed during the treatment process and that may pose environmental health risks when discharged to surface waters. This data release presents inputs for and results from a wastewater reuse model that used data compiled from several sources to calculate the following estimates for each non-tidal, non-coastline, initialized National Hydrography Dataset Version 2.1 (NHDPlus V2) stream segment in the Potomac River watershed: (1) accumulated wastewater as a percent of total streamflow (ACCWW%); and (2) predicted environmental concentrations (PECs, in micrograms per liter) of 69 municipal effluent-derived contaminants. ACCWW% values were calculated for mean-monthly and mean-annual streamflow conditions for both municipal (model results table: Table1_PotomacACCWW_municipal.csv) and industrial-plus-municipal effluent discharges (model results table: Table2_PotomacACCWW_municipal_plus_industrial.csv). PECs were calculated for mean-monthly and mean-annual streamflow conditions for municipal effluent discharges (model results tables: Table3_PotomacPECs.zip, containing comma separated value files of results for mean-monthly and mean-annual conditions). Model estimates at a stream reach of interest represent the combined total upstream wastewater discharges as well as direct discharges into the segment. Model input data included: (1) National Pollutant Discharge Elimination System-permitted facility outfall locations and 2016 average daily effluent discharges linked to a NHDPlus V2 stream Common Identifier (COMID) and facility-specific information on treatment levels and population served per capita (model input table: Table4_PotomacWWTPs.csv); (2) NHDPlus V2 stream geometry and hydrologic attributes (hydrosequence, startflag, terminalfl, divergence, fromnode, tonode, and Enhanced Runoff Method mean-monthly and mean-annual gage-adjusted streamflow and velocity, 1971-2000) (model input table: Table5_PotomacNHDPlusV2.1_flowlines_hydrology.csv); and (3) contaminant-specific data on consumption, fate, and transport compiled from literature sources or estimated from physicochemical properties (see: supplementary table in Larger Work Citation). In Table 4, where information on population served by the facility was missing, this value was estimated by standardizing to 100 gallons per capita per day. Information on population served was only acquired and estimated for municipal facilities. Where treatment level information was missing, the treatment level was assumed to be primary. Ninety-two percent of WWTPs have an assumed treatment as none was reported. R (version 4.0.4) and Python (version 2.7.16) scripts were used to summarize wastewater inputs from outfall locations by COMID and route and accumulate each wastewater and predicted contaminant loads while accounting for in-stream dilution and attenuation of contaminants. Any users of these data should review the entire metadata record and the associated manuscript (see Larger Work Citation). See 'Distribution liability' statements for more information.