Here we report optical data collected as part of a collaborative study between USGS Pennsylvania Water Science Center, Pennsylvania Department of Environmental Protection and Water Mission Area Proxies Project. The optical measurements reported here were collected to aide in the characterization of water sources and mixtures and establish proxies (surrogates) for per- and poly-fluorinated alkyl substances within the Neshaminy Creek basin. Data are compiled into three tables: 1) full fluorescence spectra in vectorized format, 2) full absorbance spectra, and 3) summary file of commonly extracted optical indicators and field-based sensor arrays.

Fluorescence and absorbance spectra were measured in discrete surface water samples collected during three sampling campaigns (Nov 2022, Mar/Apr 2023, Jul 2023) on the Illinois Waterway (IWW) and Chicago Area Waterway System (CAWS), which are the primary drainage of the Illinois River Basin (IRB). Water sampling was conducted concurrently with a boat-based water quality mapping effort using the Fast Limnology Automated Measurement (FLAMe) system (Crawford et al., 2015). Each campaign began in the Chicago metropolitan area, and after having sampled Lake Michigan, entered into the upper extent of the IWW, sampling through the CAWS into the lower reaches of the Des Plaines River and finally the Illinois River. After 8-10 days of traveling downriver through the IWW, sampling ended in the Mississippi River upstream of St Louis, Missouri. Discrete water quality samples were collected from various sites that include main channel, tributaries, and off-channel areas (e.g., backwaters) from a depth of 1 meter (m), typically in the center of the channel or aquatic feature. Between 25 and 40 sites were sampled per campaign dependent upon river conditions and boat accessibility. Data reported here are compiled into three tables: 1) full fluorescence spectra in vectorized format, 2) full absorbance spectra, and 3) summary optical measurements commonly used in statistical analyses.

Optical spectra reported here are collected from 17 surface water sampling sites within the Fraser River, a headwaters drainage of the Upper Colorado River Basin in the central western United States. The sample collection was conducted as part of the partnership between the United States Geological Survey’s (USGS) Next Generation Water Observation System (NGWOS) and Proxies Project, in coordination with the USGS Colorado Water Science Center and California Water Science Center, and the East Grand Water Quality Board.

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 Tables 3 and 4. 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) full fluorescence spectra in vectorized format, 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%) from municipal as well as municipal plus industrial PFAS wastewater treatment plants; and (2) predicted environmental concentrations (PECs, in nanograms per liter) of 14 pesticides and eight PFAS as well as the sum of the eight PFAS. ACCWW% values were calculated for mean-monthly and mean-annual streamflow conditions for municipal wastewater treatment plants (model results table: Table5_PotomacACCWW_municipal.csv) as well as

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 Tables 3 and 4. 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) full fluorescence spectra in vectorized format, 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%) from municipal as well as municipal plus industrial PFAS wastewater treatment plants; and (2) predicted environmental concentrations (PECs, in nanograms per liter) of 14 pesticides and eight PFAS as well as the sum of the eight PFAS. ACCWW% values were calculated for mean-monthly and mean-annual streamflow conditions for municipal wastewater treatment plants (model results table: Table5_PotomacACCWW_municipal.csv) as well as

Water quality and optical absorbance data for journal article entitled, "The removal kinetics of dissolved organic matter and the optical clarity of groundwater" by Francis H. Chapelle, Yuan Shen, Eric W. Strom, and Ronald Benner.

Water quality and optical absorbance data for journal article entitled, "The removal kinetics of dissolved organic matter and the optical clarity of groundwater" by Francis H. Chapelle, Yuan Shen, Eric W. Strom, and Ronald Benner.

This data release contains the results from a study that characterized the concentration and quality of dissolved organic carbon (DOC) in the McKenzie River, a relatively pristine watershed in western Oregon, and its link to forming disinfection by-products (DBPs) in treated drinking water. The study aimed to identify the primary source(s) of DOC in source water for the Eugene Water and Electric Board’s (EWEB) conventional treatment plant on the McKenzie River near river mile 11, upstream of Hayden Bridge. The two classes of regulated compounds examined—trihalomethanes (THMs) and haloacetic acids (HAAs)—form when organic carbon in raw source water reacts with chlorine and (or) bromine during water treatment. The data release includes six general types of data: 1) the concentration of dissolved organic carbon in filtered water samples; 2) the concentration of disinfection by-products (DBPs) in finished (treated) drinking water; 3) raw absorbance data for filtered water samples; 4) fluorescence excitation-emission matrices in vectorized format; 5) Parallel factor analysis (PARAFAC) component loadings for the fluorescence excitation-emission matrices; and 6) the percentages of different land cover for the watersheds draining to the sampled sites.

The goal of this study was to develop a suite of inter-related water quality monitoring approaches capable of modeling and estimating the spatial and temporal gradients of particulate and dissolved total mercury (THg) concentration, and particulate and dissolved methyl mercury (MeHg), concentration, in surface waters across the Sacramento / San Joaquin River Delta (SSJRD). This suite of monitoring approaches included: a) data collection at fixed continuous monitoring stations (CMS) outfitted with in-situ sensors, b) spatial mapping using boat-mounted flow-through sensors, and c) satellite-based remote sensing. The focus of this specific Child Page is to present laboratory measured spectral data associated with discrete surface water samples collected as part of both the CMS and boat mapping sampling efforts. All laboratory-based measurement presented herein were conducted by the U.S. Geological Survey (USGS) Organic Matter Research Laboratory (OMRL) in Sacramento, Calif. The machine-readable (comma separated value, *.csv) files presented herein include spectral data collected using two different instruments: 1) Laboratory-based absorbance and fluorescence measurements on filtered water using an Aqualog (Hansen and others, 2018) and 2) Laboratory-based absorption measurements using a Varian Cary spectrophotometer on particulate samples collected on glass fiber filters (Kishino and others, 1985; Roesler, 1998). The reported spectral data includes: 1) fluorescence intensities across a wide range of excitation (240 to 800 nm) and emission (250 to 800 nm) wavelengths expressed as an excitation-emission matrix (EEM), 2) absorbance of light (from 239 nm to 800 nm) due to dissolved and colloidal substances, and 3) absorption coefficients (from 350 nm to 715 nm) for particulates using the quantitative filter technique (QFT).

The goal of this study was to develop a suite of inter-related water quality monitoring approaches capable of modeling and estimating the spatial and temporal gradients of particulate and dissolved total mercury (THg) concentration, and particulate and dissolved methyl mercury (MeHg), concentration, in surface waters across the Sacramento / San Joaquin River Delta (SSJRD). This suite of monitoring approaches included: a) data collection at fixed continuous monitoring stations (CMS) outfitted with in-situ sensors, b) spatial mapping using boat-mounted flow-through sensors, and c) satellite-based remote sensing. The focus of this specific Child Page is to present laboratory measured spectral data associated with discrete surface water samples collected as part of both the CMS and boat mapping sampling efforts. All laboratory-based measurement presented herein were conducted by the U.S. Geological Survey (USGS) Organic Matter Research Laboratory (OMRL) in Sacramento, Calif. The machine-readable (comma separated value, *.csv) files presented herein include spectral data collected using two different instruments: 1) Laboratory-based absorbance and fluorescence measurements on filtered water using an Aqualog (Hansen and others, 2018) and 2) Laboratory-based absorption measurements using a Varian Cary spectrophotometer on particulate samples collected on glass fiber filters (Kishino and others, 1985; Roesler, 1998). The reported spectral data includes: 1) fluorescence intensities across a wide range of excitation (240 to 800 nm) and emission (250 to 800 nm) wavelengths expressed as an excitation-emission matrix (EEM), 2) absorbance of light (from 239 nm to 800 nm) due to dissolved and colloidal substances, and 3) absorption coefficients (from 350 nm to 715 nm) for particulates using the quantitative filter technique (QFT).