This dataset describes (a) concentrations of nutrients and related constituents, and (b) discharge in the lower Boise River (Idaho) and its primary tributaries for Water Years 1994 through 2023 and 1969 through 2024, respectively. Constituents include water column concentrations of suspended sediment, total phosphorus, dissolved phosphorus, orthophosphate as phosphorus, total nitrogen, nitrite and nitrate as nitrogen, ammonia and ammonium as nitrogen, Escherichia coli (E. coli) bacteria, and total coliform bacteria; and concentrations of periphyton biomass and chlorophyll a on submerged rocks. Sites with water quality and periphyton results include five mainstem Boise River locations (at Eckert Road, Glenwood Bridge, Middleton, Caldwell, and Parma) and nine tributary locations (Conway Gulch, Dixie Drain, Fivemile Creek, Tenmile Creek, Fifteenmile Creek, Indian Creek at its mouth and upstream at Caldwell, Mason Creek, and Mill Slough. Data are also reported for Sand Hollow Creek, which is not a tributary to the Boise River but is generally considered to be part of the lower Boise River system. Discrete and daily mean discharge data are also provided, when available. This dataset is a compilation of water quality and discharge data from different entities including the U.S. Geological Survey, U.S. Bureau of Reclamation, Idaho Department of Water Resources, City of Boise, and Idaho Power Company. The sampling agency and collection and analysis methods are described in the Processing Steps section of the metadata.

Soil data were collected from catchments of USGS edge-of-field (EOF) monitoring sites in Great Lakes Restoration Initiative (GLRI) priority watersheds. As part of this release, soil data from 2016 through 2019 are provided from 14 sites spanning 5 Great Lake States (Wisconsin, Michigan, Ohio, Indiana, and New York). The data collected are from private farms representing a variety of agronomic systems, landscapes settings, soil types, and climate regimes. These data can be used to investigate relationships among microbial properties (e.g. soil microbial biomass, activity, diversity, and enzymes), general soil structure (e.g. bulk density, soil aggregate structure, soil water holding capacity, soil texture, and infiltration rates), soil resources (e.g. organic matter, reactive carbon, total carbon, nitrogen, water extractable phosphorus, cations), and exported resources (e.g. runoff volume, phosphorus loads). Water quality data, site descriptions, and management are provided in a companion data release (Komiskey and others, 2021).

Dissolved pesticides were measured in weekly water samples from 100 wadeable freshwater streams across eleven states in the Midwestern U.S. during May-August, 2013, as part of the Midwest Stream Quality Assessment study conducted by the U.S. Geological Survey's (USGS) National Water Quality Assessment (NAWQA) Project. Of the 100 stream sites, 12 were urban indicator sites and the remaining 88 sites were located along an agricultural gradient of watershed land use. Twelve depth- and width-integrated water samples were collected at each site within the 14-week study period. Water samples were filtered (0.7 micrometers) and analyzed for 227 pesticide compounds by direct-injection liquid chromatography with tandem mass-spectrometry, and for glyphosate by Enzyme-Linked Immunoassay in a separate analysis. Potential aquatic toxicity was evaluated using the Pesticide Toxicity Index and by comparison to U.S. Environmental Protection Agency aquatic-life benchmarks. This data release provides sampling site locations, method information, summaries of quality-control data, and concentration data for pesticide compounds in environmental weekly water samples, in support of the journal article, "Complex mixtures of dissolved pesticides show potential aquatic toxicity in a synoptic study of Midwestern U.S. streams," by Nowell, L.H., Moran, P.W., Schmidt, T., Norman, J.E., Nakagaki, N., Shoda, M.E., Mahler, B.J., Van Metre, P.C., Stone, W.W., Sandstrom, M.W., and Hladik, M.L.

Dissolved pesticides were measured in weekly water samples from 100 wadeable freshwater streams across eleven states in the Midwestern U.S. during May-August, 2013, as part of the Midwest Stream Quality Assessment study conducted by the U.S. Geological Survey's (USGS) National Water Quality Assessment (NAWQA) Project. Of the 100 stream sites, 12 were urban indicator sites and the remaining 88 sites were located along an agricultural gradient of watershed land use. Twelve depth- and width-integrated water samples were collected at each site within the 14-week study period. Water samples were filtered (0.7 micrometers) and analyzed for 227 pesticide compounds by direct-injection liquid chromatography with tandem mass-spectrometry, and for glyphosate by Enzyme-Linked Immunoassay in a separate analysis. Potential aquatic toxicity was evaluated using the Pesticide Toxicity Index and by comparison to U.S. Environmental Protection Agency aquatic-life benchmarks. This data release provides sampling site locations, method information, summaries of quality-control data, and concentration data for pesticide compounds in environmental weekly water samples, in support of the journal article, “Complex mixtures of dissolved pesticides show potential aquatic toxicity in a synoptic study of Midwestern U.S. streams,” by Nowell, L.H., Moran, P.W., Schmidt, T., Norman, J.E., Nakagaki, N., Shoda, M.E., Mahler, B.J., Van Metre, P.C., Stone, W.W., Sandstrom, M.W., and Hladik, M.L.

This data release provides computed rainfall (rain total, duration, intensity, erosivity and antecedent rainfall) and flow (flow volume, flow-weighted mean concentrations, total loads, and total yields) metrics from monitored precipitation, discharge, and water quality (nutrients and sediment concentrations) data collected at U.S. Geological Survey edge-of-field (EOF) monitoring sites located in five Great Lakes States (Wisconsin, Michigan, Ohio, Indiana, and New York). EOF monitoring sites are installed at the edge of agricultural fields, either on the field surface or using subsurface tiles, where runoff can be intercepted and channeled through monitoring equipment before it enters the natural stream system. The methods used to collect this data followed USGS EOF monitoring methods (https://pubs.usgs.gov/of/20081015/). These EOF monitoring sites are located at private farms under a variety of farming systems, landscape settings, drainage areas, soil types, and climates. Site information is provided in the ‘EOF_Site_Table.csv’ data table. Rainfall metrics were computed for EOF site locations and are provided in the ‘All_EOF_RainEvents.csv’ data table. Rainfall was directly monitored at many, but not every EOF monitoring site. EOF monitoring sites without on-site rainfall data were associated to rainfall data measured at a nearby EOF monitoring site or meteorological site. Rainfall was combined into a single event if it occurred within 2 hours of the previous rainfall. Flow data were computed for each flow event at each EOF monitoring site and are available in the ‘All_EOF_StormEventLoadsFormatted.csv’ data table. A flow event was defined as any period of flow at a site that was classified as a storm and represents flow that was related to rainfall or snowmelt. There were occurrences of continuous flow between rain events, which were not associated with a period of rainfall or snowmelt, likely due to excessive soil saturation or shallow groundwater discharge. These periods of intermittent tile discharge were not classified as a storm. Multiple precipitation and flow events were combined if they occurred within two hours of each other to account for similar rainfall/runoff characteristics. Rainfall metrics and flow data were then calculated for these combined events at each EOF monitoring site and available in the ‘All_EOF_StormEventLoadsRainCalculated.csv’ data table.

This data release contains nutrient and sediment concentrations, loads, and yields from a USGS subsurface-tile edge-of-field (EOF) agricultural monitoring site. Sampling and flow monitoring were performed at the outlet of a subsurface-tile that drains 14.7 acres of cultivated cropland. The site is located in South Central Michigan and discharges into a headwater stream of the Maumee watershed. Through a cooperative agreement between the USGS and the USDA Natural Resources Conservation Service (NRCS) in Michigan, data was collected from May 22, 2019, through March 19, 2023. Water quality and rainfall metrics are summarized by individual flow events to evaluate the contribution of EOF losses to a headwater stream. The methods used to collect this data followed USGS EOF monitoring methods (https://pubs.usgs.gov/of/20081015/) and the contents of this data release are consistent with a related EOF data release (Komiskey et. al 2023). Flow data, including total flow volume, flow-weighted mean concentrations, total loads, and total yields, were computed for each flow event. A flow event was defined as any period of flow at a station that was classified as a storm and represents flow that was related to rainfall or snowmelt. In the combined flow and rain table, multiple flow events were combined if they occurred within 2 hours of each other, to account for similar rainfall/runoff characteristics. Linked to each flow event, rainfall metrics were computed (rain total, duration, intensity, erosivity, and antecedent rainfall). Rain metrics were also computed for the entire rainfall record, which are in the rain event table. Similar to the combined flow-related rain metrics, rainfall was combined into a single event if it occurred within 2 hours of the previous rainfall. There were occurrences of continuous flow between rain events, which were not associated with a period of rainfall or snowmelt, likely due to excessive soil saturation or shallow groundwater discharge. These periods of intermittent tile discharge were not classified as a storm. Monitoring was conducted year-round to evaluate flow characteristics among seasons and variation in weather, field conditions, and agricultural activities.

Four dichloroacetamide herbicide safeners (AD-67, benoxacor, dichlormid, and furilazole) and two co-applied herbicides (acetochlor and metolachlor) were measured in water samples from 7 streams across Iowa and Illinois. Iowa water samples were collected from March 2016 to June 2017, and Illinois water samples were collected from September 2016 to June 2017. The compounds studied are applied to corn, and Iowa and Illinois are the two largest corn producing states in the U.S. The seven stream sites are all adjacent to agricultural fields in corn production. Water samples (1-L) were collected in amber glass bottles using a grab or depth weighted approach. With the exception of one site, Iowa River at Wapello (USGS Site ID 05465500), all water samples were collected using a hydrologic based sampling approach. This means that samples were collected near peak flow during storm events and periodically during base flow conditions. Water samples were filtered (0.7 micrometers), extracted via solid phase extraction (Oasis® MAX cartridge), and analyzed for each herbicide and safener by gas chromatography with mass-spectrometry.

Four dichloroacetamide herbicide safeners (AD-67, benoxacor, dichlormid, and furilazole) and two co-applied herbicides (acetochlor and metolachlor) were measured in water samples from 7 streams across Iowa and Illinois. Iowa water samples were collected from March 2016 to June 2017, and Illinois water samples were collected from September 2016 to June 2017. The compounds studied are applied to corn, and Iowa and Illinois are the two largest corn producing states in the U.S. The seven stream sites are all adjacent to agricultural fields in corn production. Water samples (1-L) were collected in amber glass bottles using a grab or depth weighted approach. With the exception of one site, Iowa River at Wapello (USGS Site ID 05465500), all water samples were collected using a hydrologic based sampling approach. This means that samples were collected near peak flow during storm events and periodically during base flow conditions. Water samples were filtered (0.7 micrometers), extracted via solid phase extraction (Oasis® MAX cartridge), and analyzed for each herbicide and safener by gas chromatography with mass-spectrometry.

Data in this release were collected and computed to evaluate the occurrence of pesticides in shallow groundwater in the state of Alabama. Additionally, these data support interpretation in Gill (2023) for a cooperative project between the U.S. Geological Survey and the Alabama Department of Agriculture and Industries. During 2009-2020, samples were collected from twenty-four wells located near agricultural land use in Alabama and evaluated for concentrations of agricultural pesticides and pesticide degradates. Most data produced from the sampling effort are available from the publicly accessible USGS National Water Information System (NWIS; U.S. Geological Survey, 2023). For certain pesticide compounds, data were combined from multiple analytical methods to provide a longer period of record in order to evaluate changes in concentrations and occurrence through time. All groundwater quality data used in Gill (2023), including supporting quality assurance datasets, are included in this data release. References: Gill, A.C., 2023, Pesticide occurrence in shallow groundwater near areas of agricultural land use in Alabama, 2009-2020: U.S. Geological Survey Scientific Investigations Report 2023-xxxx, xx p., https://doi.org/xxxx. U.S. Geological Survey, 2023, National Water Information System data available on the World Wide Web (USGS Water Data for the Nation), accessed April 21, 2023, at http://dx.doi.org/10.5066/F7P55KJN.

Data in this release were collected and computed to evaluate the occurrence of pesticides in shallow groundwater in the state of Alabama. Additionally, these data support interpretation in Gill (2023) for a cooperative project between the U.S. Geological Survey and the Alabama Department of Agriculture and Industries. During 2009-2020, samples were collected from twenty-four wells located near agricultural land use in Alabama and evaluated for concentrations of agricultural pesticides and pesticide degradates. Most data produced from the sampling effort are available from the publicly accessible USGS National Water Information System (NWIS; U.S. Geological Survey, 2023). For certain pesticide compounds, data were combined from multiple analytical methods to provide a longer period of record in order to evaluate changes in concentrations and occurrence through time. All groundwater quality data used in Gill (2023), including supporting quality assurance datasets, are included in this data release. References: Gill, A.C., 2023, Pesticide occurrence in shallow groundwater near areas of agricultural land use in Alabama, 2009-2020: U.S. Geological Survey Scientific Investigations Report 2023-xxxx, xx p., https://doi.org/xxxx. U.S. Geological Survey, 2023, National Water Information System data available on the World Wide Web (USGS Water Data for the Nation), accessed April 21, 2023, at http://dx.doi.org/10.5066/F7P55KJN.