Concentrations and annual fluxes for selected water-quality constituents from the USGS National Stream Quality Accounting Network (NASQAN), 1996-2000

By Valerie J. Kelly, Richard P. Hooper, Brent T. Aulenbach, and Mary Janet

List of Figures and Tables

Figures

1. Location of sampling stations and major reservoirs in NASQAN basins
2. Hydrographs and samples collected at four NASQAN stations during water years 1996-2000
3. Contamination, measured by blank detections only where they exceed twice the MRL, as percent of ambient data for nutrients, major ions, and trace elements for NASQAN data during 1996-2000
4. Comparison of rank distribution for blank/ambient ratios, in percent, with associated ambient concentrations, only where blank concentrations exceed twice the MRL for ammonia-nitrogen and orthophosphate
5. Comparison of rank distribution for blank/ambient ratios, in percent, with associated ambient concentrations, only where blank concentrations exceed twice the MRL for dissolved organic carbon and zinc
6. Comparison of standard deviations for NASQAN ambient data and replicates for selected constituent groups
7. Comparison of NASQAN sediment concentrations from various USGS District Sediment Laboratories and from the Georgia District Sediment Chemistry Laboratory
8. Distribution of NASQAN field-spike recovery data for 1996-2000
9. Comparison of sum of ambient pesticide concentrations; and field-spike recoveries, categorized by ambient concentration for individual pesticide constituents for NASQAN data, 1996-2000(/a>

1. Sampling stations
2. Water-quality stations descriptions