Antarctica A Keystone in a Changing World · 1995 · 21 citations · 1 references
Natural ResourcesEnvironmental SciencesWater Resources ManagementGroundwater HydrologyGroundwater ManagementWater Resources HydrologyGroundwater ContaminationGroundwater QualityGroundwater Resource AssessmentWater PollutionWater QualityConcentrationGroundwater Nutrient ContaminationGroundwater Quality AssessmentLand Use Impacts On Groundwater QualityNitrate ContaminationNitrate Contamination In Drinking WaterNitrate RegulationWater Quality Baseline Assessment
The U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program is designed to assess the status of and trends in the quality of the Nation's wj ter resources, and to gain a better understanding of the natural and human factors that affect water quality. The Central Columbia Plateau is one of 60 NAWQA study units (major river basins and parts of aquifer systems) located throughout the Nation. In the Central Columbia Plateau, nitrate concentrations for 19% of the 573 wells shown below exceed the U.S. Environmental fflrotection Agency (EPA) maximum contaminant level (MCL) for drinking water. These concentrations include USGS samples from 1942-94, although 93% of the data are from 1980-94. one analysis was available for a well, this document refers to the mean concentration as the nitrate concentration for the well.
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E. F. Winton, Robert G. Tardiff, Leland J. McCabe · American Water Works Association · 1971 · 128 citations