Interim results of quality-control sampling of surface water for the Upper Colorado River National Water-Quality Assessment Study Unit, water years 1995-96

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Title Interim results of quality-control sampling of surface water for the Upper Colorado River National Water-Quality Assessment Study Unit, water years 1995-96
Creator Spahr, N. E.; Boulger, R. W.
Subject Water quality; Water quality biological assessment; Water quality -- Measurement
Spatial Coverage Colorado River (Wyo.-Utah); Colorado
Description Quality-control samples provide part of the information needed to estimate the bias and variability that result from sample collection, processing, and analysis. Quality-control samples of surface water collected for the Upper Colorado River National Water-Quality Assessment study unit for water years 1995-96 are presented and analyzed in this report. The types of quality-control samples collected include pre-processing split replicates, concurrent replicates, sequential replicates, post-processing split replicates, and field blanks. Analysis of the pre-processing split replicates, concurrent replicates, sequential replicates, and post-processing split replicates is based on differences between analytical results of the environmental samples and analytical results of the quality-control samples. Results of these comparisons indicate that variability introduced by sample collection, processing, and handling is low and will not affect interpretation of the environmental data. The differences for most water-quality constituents is on the order of plus or minus 1 or 2 lowest rounding units. A lowest rounding unit is equivalent to the magnitude of the least significant figure reported for analytical results. The use of lowest rounding units avoids some of the difficulty in comparing differences between pairs of samples when concentrations span orders of magnitude and provides a measure of the practical significance of the effect of variability. Analysis of field-blank quality-control samples indicates that with the exception of chloride and silica, no systematic contamination of samples is apparent. Chloride contamination probably was the result of incomplete rinsing of the dilute cleaning solution from the outlet ports of the decaport sample splitter. Silica contamination seems to have been introduced by the blank water. Sampling and processing procedures for water year 1997 have been modified as a result of these analyses.
Publisher U. S. Geological Survey
Date 1997
Type Text
Format application/pdf
Digitization Specifications pdf file copied from USGS website (http://water.usgs.gov/pubs/wri/wri97-4227/). Uploaded into CONTENTdm version 3.7.
Identifier http://water.usgs.gov/pubs/wri/wri97-4227/
Source Spahr, N. E.; Boulger, R. W., Interim results of quality-control sampling of surface water for the Upper Colorado River National Water-Quality Assessment Study Unit, water years 1995-96, Denver, Colorado: U.S. Geological Survey Water Resources Investigations Report 97- 4227, 34 p.
Language eng
Rights Management Public Domain, Courtesy of the USGS
Holding Institution University of Utah
Metadata Cataloger Kristin Willmore
ARK ark:/87278/s60z727s
Setname wwdl_er
Date Created 2005-08-10
Date Modified 2005-08-10
ID 1145883
Reference URL https://collections.lib.utah.edu/ark:/87278/s60z727s
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