Filters: Tags: Fluoride (X)
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In 1991, the U.S. Geological Survey (USGS) began a study of more than 50 major river basins across the Nation as part of the National Water-Quality Assessment (NAWQA) project. One of the major goals of the NAWQA project was to determine how river water quality has changed over time. To support that goal, long-term consistent and comparable monitoring has been conducted by the USGS on streams and rivers throughout the Nation. Outside of the NAWQA project, the USGS and other Federal, State, and local agencies also have collected long-term water-quality data to support their own assessments of changing water quality. In 2017, data from these multiple sources were combined to support one of the most comprehensive assessments...
In 1991, the U.S. Geological Survey (USGS) began a study of more than 50 major river basins across the Nation as part of the National Water-Quality Assessment (NAWQA) project. One of the major goals of the NAWQA project was to determine how river water quality has changed over time. To support that goal, long-term consistent and comparable monitoring has been conducted by the USGS on streams and rivers throughout the Nation. Outside of the NAWQA project, the USGS and other Federal, State, and local agencies also have collected long-term water-quality data to support their own assessments of changing water quality. In 2017, data from these multiple sources were combined to support one of the most comprehensive assessments...
This data release documents time-series analyses of aqueous-chemistry data from public-supply wells (PSWs) and associated potential explanatory factors to characterize responses of groundwater quality to drought and recovery periods in California’s San Joaquin Valley (SJV) during 2000-2022. Annual median nitrate values were computed for PSWs throughout the SJV during the period of study. Median annual nitrate values were calculated at all PSWs with available data in the SJV, resulting in a total of 698 PSWs with complete annual records after single-year linear gap imputation. A total of 237 of these records were classified as “low variance” because they contained proportions of identical values exceeding 80 percent...
Data from 38,105 wells were used to characterize fluoride occurrence in untreated United States groundwater. The data were retrieved from the U.S. Geological Survey (USGS) National Water Information System (NWIS). Groundwater samples were collected from 1988 to 2017 in the conterminous United States. Data for groundwater included in this dataset are pH, water temperature, and concentrations of dissolved oxygen, calcium, magnesium, potassium, sodium, alkalinity, chloride, fluoride, silica, sulfate, aluminum, iron, manganese, and total dissolved solids.
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