Environmental Sampling and Modeling Results to Characterize Surface-Water Quality at 32 Sites Across the Potomac River Watershed, 2022 (ver. 2.0, September 2024)
Dates
Publication Date
2024-07-30
Start Date
2022-07-28
End Date
2022-09-01
Revision
2024-09-20
Citation
Miller, S.A., Faunce, K.E., Burns, D.W., Barber, L.B., Jasmann, J.R., Roth, D.A., Fleck, J.A., Hansen, A.M., Hladik, M.L., and De Parsia, M.D., 2024, Environmental Sampling and Modeling Results to Characterize Surface-Water Quality at 32 Sites Across the Potomac River Watershed, 2022 (ver. 2.0, September 2024): U.S. Geological Survey data release, https://doi.org/10.5066/P9DUC4L1.
Summary
This data release presents chemical results from investigations of surface-water quality in the Potomac River watershed (encompassing Washington, D.C. and parts of West Virginia, Virginia, Pennsylvania, and Maryland) conducted during low-flow conditions in July through September of 2022 and modeling results that support interpretative products. Water-quality sampling: A sampling campaign was conducted at 32 stream sites throughout the watershed (Table 1). A suite of field parameters and inorganic and organic chemical characteristics at each site were characterized using seven separate analytical methods at five laboratories (Table 2). The water-quality results are presented in Table 3. Analytical methods and laboratories used were [...]
Summary
This data release presents chemical results from investigations of surface-water quality in the Potomac River watershed (encompassing Washington, D.C. and parts of West Virginia, Virginia, Pennsylvania, and Maryland) conducted during low-flow conditions in July through September of 2022 and modeling results that support interpretative products. Water-quality sampling: A sampling campaign was conducted at 32 stream sites throughout the watershed (Table 1). A suite of field parameters and inorganic and organic chemical characteristics at each site were characterized using seven separate analytical methods at five laboratories (Table 2). The water-quality results are presented in Table 3. Analytical methods and laboratories used were (1) major anions by ion chromatography at the U.S. Geological Survey Integrated Water Chemistry Assessment Laboratory in Boulder, Colorado (USGSIWCAL); (2) excitation-emission-matrix (EEM) fluorescence spectroscopy dissolved organic carbon (DOC), and total dissolved nitrogen (TDN) at the U.S. Geological Survey California Water Science Center Organic Matter Research Laboratory in Sacramento, California (CAWSCOMRL); (3) per-and polyfluoroalkyl substances (PFAS) using liquid chromatography with tandem mass spectrometry (LC-MS/MS), at the U.S. Geological Survey National Water Quality Laboratory in Denver, Colorado (USGSNWQL); (4) pesticides (PEST) by LC-MS/MS or gas chromatography with tandem mass spectrometry (GS-MS/MS) at the U.S. Geological Survey Organic Research Laboratory (USGSOGCA); (5) pharmaceuticals (PHARM) using LC-MS/MS at the USGSNWQL; and (6) Major elements and trace elements (TEs) using inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma-optical emission spectrometry (ICP-OES) at the USGSIWCAL. Enzyme-Linked Immunosorbent Assay (ELISA) analyses were additionally performed at the U.S. Geological Survey Strategic Laboratory Science Branch in Boulder, Colorado (USGSSLSB) for the herbicides atrazine and glyphosate, the insecticide imidacloprid, and the consumer product chemical linear alkylbenzene sulfonate. Three analytes (atrazine, piperonyl butoxide, thiabendazole, and the thiabendazole surrogate standard thiabendazole-d4) were analyzed by the U.S. Geological Survey National Water Quality Laboratory (USGSNWQL) included with the pharmaceutical data in addition to being analyzed by the USGSOGCA with the pesticide data. The USGSNWQL results for these analytes were coded as replicate samples and additional time offsets were applied to create distinct times for these sample results. Samples were collected according to U.S. Geological Survey (USGS) protocols and procedures. A field blank and field replicate was collected for every analytical method, a matrix spike for PFAS, PHARM, and PEST was performed at three sites for quality assurance. Most sites were only sampled once for each parameter with the exception of four sites that had to be resampled due to samples arriving too warm to be processed for PFAS and PHARM parameters. Therefore samples for the remaining parameters were collected twice at these four sites.
Water-quality modeling: This data release also contains inputs for and results from a wastewater reuse model that used data compiled from multiple sources to calculate the following estimates for each non-tidal 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 nanograms per liter) of 14 pesticides. ACCWW% values were calculated for mean-monthly and mean-annual streamflow conditions for municipal wastewater treatment plants (model results table: Table6_PotomacACCWW_municipal.csv). The term ‘municipal’ is used here to represent National Pollutant Discharge Elimination System (NPDES)-permitted facilities with the Standard Industrial Classification code 4952 (‘sewerage systems’). PECs were calculated for mean-monthly and mean-annual streamflow conditions for municipal effluent discharges (model results tables: Table7_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) NPDES-permitted facility outfall locations and 2021-2022 median effluent discharge rates obtained from discharge monitoring reports from August 2021 to September 2022 linked to a NHDPlus V2 stream Common Identifier (COMID; model input table: Table5_Potomac_municipal_WWTPs.csv); and (3) contaminant-specific data on reported wastewater concentrations, fate, and transport compiled from literature sources (see: supplementary table in Larger Work Citation). NHDPlus V2 stream geometry and hydrologic attributes were obtained from Faunce et al., 2022 (Table5_PotomacNHDPlusV2.1_flowlines_hydrology.csv). R (version 4.4.1) and Python (version 3.9.16) 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. 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.
Click on title to download individual files attached to this item.
prw_sampling_2022_version2.xml Original FGDC Metadata
View
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application/fgdc+xml
sampling-site-map.jpg “Potomac River watershed boundary with sampling locations.”
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Table1_sampling_sites.csv
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Table2_parameter_metadata.csv
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Table3_results.csv
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Table4_EEMs_vector_data.csv
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Table5_Potomac_municipal_WWTPs.csv
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Table6_PotomacACCWW_municipal.csv
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Table7_PesticidePECs.zip
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version_history.txt
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Related External Resources
Type: Related Primary Publication
Miller, S.A., Faunce, K.E., Barber, L.B., Fleck, J.A., Burns, D.W., Jasmann, J.R., and Hladik, M.L., 2024, Factors contributing to pesticide contamination in riverine systems: The role of wastewater and landscape sources: Science of The Total Environment, p. 174939, https://doi.org/10.1016/j.scitotenv.2024.174939.