This metadata record contains 6 tables used to assess sources of Polychlorinated Biphenyls (PCB) in the Back River watershed, Baltimore City, Maryland. Included in the dataset are PCB concentrations of surface water and porewater passive samplers from Herring Run, Moores Run, tidal Back River, and Back River Wastewater Treatment Plant; PCB concentrations of bed sediments and other solids, Fat, Oil, and Grease (FOG) samples, and road sediments; dissolved organic carbon (DOC), total suspended solids (TSS), and particulate organic carbon (POC) concentrations of grab samples; and PCB concentrations of passive samplers from pump stations collected in 2018-2020.

Two types of passive samplers for polychlorinated biphenyl (PCB) analysis were deployed in the Clinton River Area of Concern in 2019: semipermeable membrane devices for water and in-stream sediment samplers. Samplers were deployed in July 2019 and retrieved in August 2019. Additionally, bank sediment samples for PCB analysis were collected by the U.S. Geological Survey (USGS) in August 2019 and catch basin bottom material samples for PCB analysis were collected by LimnoTech in November 2019 under contract with the U.S. Army Corps of Engineers. These data are a part of a larger study and associated USGS report (https://doi.org/10.3133/sir20235030).

Two types of passive samplers for polychlorinated biphenyl (PCB) analysis were deployed in the Clinton River Area of Concern in 2019: semipermeable membrane devices for water and in-stream sediment samplers. Samplers were deployed in July 2019 and retrieved in August 2019. Additionally, bank sediment samples for PCB analysis were collected by the U.S. Geological Survey (USGS) in August 2019 and catch basin bottom material samples for PCB analysis were collected by LimnoTech in November 2019 under contract with the U.S. Army Corps of Engineers. These data are a part of a larger study and associated USGS report (https://doi.org/10.3133/sir20235030).

This metadata record consists of 3 tables containing per-and-poly-fluoroalkyl substances (PFAS) and polychlorinated biphenyls (PCB) concentration data of wastewater and biosolid samples from wastewater treatment plants within the Patapsco and Potomac watersheds. The PCB concentration data was used to assess the occurrence and fate of PCB in wastewater treatment plants within the Patapsco watershed, from December 2021 to December 2022; The PFAS concentration data was used to assess the occurrence and fate of PFAS within the Patapsco and Potomac watersheds, from 2021-2023. The PFAS total oxidizable precursors (TOP) assay data were used to investigate PFAS fate in the wastewater treatment process of plants within the Patapsco watershed from March and September of 2022.

These data were collected as part of a study that used a sediment fingerprinting model to better understand sources of PCB-contaminated suspended sediments within stormflow in the Back River watershed. This metadata record contains 4 tables of data used to model and assess the source of storm sediment collected within the Back River watershed in Maryland in 2023. Included in the dataset are analytical results from sediment samples collected from the landscape, in stream banks, during storms using passive samplers, and intact cores, and analyzed for (1) PCB, (2) elemental metals and carbon content, and (3) grain size. Also included are calculated PCB concentrations in porewater using sediment concentration from storm and core samples.

Water-borne polychlorinated biphenyls (PCBs) were sampled in three tributaries of the Niagara River Area of Concern (AOC) in 2018 and 2019 using semipermeable membrane devices (SPMDs). This data set is a compilation of data from two sampling efforts, focused on determining the presence and distribution of total and congener PCBs in these tributaries.

Water-borne polychlorinated biphenyls (PCBs) were sampled in three tributaries of the Niagara River Area of Concern (AOC) in 2018 and 2019 using semipermeable membrane devices (SPMDs). This data set is a compilation of data from two sampling efforts, focused on determining the presence and distribution of total and congener PCBs in these tributaries.

The sampling of the riverine-to-marine transect (Penobscot River, Penobscot Bay, and the Gulf of Maine) took place in 2008. Water samples were collected and filtered in the field using 0.45 micrometer capsule filters (Versapor membrane), silicon tubing, and a peristaltic pump. Water samples were then shipped on ice to the U.S. Geological Survey in Boulder, Colorado and chilled to approximately 4 degrees Celsius until analysis. Dissolved organic matter (DOM) was separated into fractions by an isolation method that passes aqueous sample through Amberlite XAD8 and XAD4 resins using low pressure liquid chromatography. The hydrophobic organic acid (HPOA) fraction is the eluate from the XAD8 fractionation column and the transphilic organic acid (TPIA) fraction is the eluate from the XAD4 fractionation column. Dissolved organic carbon (DOC) was either analyzed on a Shimadzu TOC-Vcph total organic carbon analyzer by combustion-infrared or an OI700 Analytical total organic carbon analyzer by wet-oxidation; each sample was measured in replicate and the average was reported. Ultraviolet (UV) absorbance at the wavelength of 254 nm was measured with an Agilent HP8453 UV-Vis spectrophotometer. Specific UV Absorbance (SUVA) at 254 nm is a calculated parameter defined as the UV absorbance at a wavelength of 254 nm in absorbance units per centimeter divided by the DOC concentration in milligrams per liter and then multiplied by 100. SUVA 254 nm is reported in units of liters per milligram carbon per meter and correlates with the percent aromatic carbon of the DOM. Associated laboratory quality assurance and quality control measures have been taken to produce final data.

The sampling of the riverine-to-marine transect (Penobscot River, Penobscot Bay, and the Gulf of Maine) took place in 2008. Water samples were collected and filtered in the field using 0.45 micrometer capsule filters (Versapor membrane), silicon tubing, and a peristaltic pump. Water samples were then shipped on ice to the U.S. Geological Survey in Boulder, Colorado and chilled to approximately 4 degrees Celsius until analysis. Dissolved organic matter (DOM) was separated into fractions by an isolation method that passes aqueous sample through Amberlite XAD8 and XAD4 resins using low pressure liquid chromatography. The hydrophobic organic acid (HPOA) fraction is the eluate from the XAD8 fractionation column and the transphilic organic acid (TPIA) fraction is the eluate from the XAD4 fractionation column. Dissolved organic carbon (DOC) was either analyzed on a Shimadzu TOC-Vcph total organic carbon analyzer by combustion-infrared or an OI700 Analytical total organic carbon analyzer by wet-oxidation; each sample was measured in replicate and the average was reported. Ultraviolet (UV) absorbance at the wavelength of 254 nm was measured with an Agilent HP8453 UV-Vis spectrophotometer. Specific UV Absorbance (SUVA) at 254 nm is a calculated parameter defined as the UV absorbance at a wavelength of 254 nm in absorbance units per centimeter divided by the DOC concentration in milligrams per liter and then multiplied by 100. SUVA 254 nm is reported in units of liters per milligram carbon per meter and correlates with the percent aromatic carbon of the DOM. Associated laboratory quality assurance and quality control measures have been taken to produce final data.

In June 2019, the U.S. Geological Survey Maryland-Delaware-District of Columbia Water Science Center (MD-DE-DC WSC) team began to collect and inventory available information on toxic contaminants within the Chesapeake Bay Watershed. State agencies were contacted to determine available data. Also, the National Water Information System (NWIS) and National Water Quality Database (NWQD) were queried to gather relevant data for the compilation. The resulting tables contain records for available sites where specific analyte groups, Hg (mercury), PCB (polychlorinated biphenyls), or pesticides, have been collected with appropriate supplemental metadata including media, method, time frame, and frequency of collection. Sample results span 1972-2019. Files included in the data release: Basic_Table.csv Detailed_Table.csv NWIS_PCodes.csv State_Result_Totals.csv NWIS_Result_Totals.csv