9409

• UCREFRP Catalog Number: 9409
• Author: Spahr, N. E. and R. W. Boulger.
• 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.
• USFW Year: 1997.
• USFW - Doc Type: 97-4227,
• Copyright Material: NO

program requires that quality-control samples be
collected at sites within the surface-water network
(T.L. Miller, U.S. Geological Survey, written
commun.,1996).
Quality-control samples provide part of the
information needed to estimate the bias and variability
that result from sample collection, processing, and
analysis. The results are used to evaluate possible
effects of bias and variability on the interpretation

of environmental data. Two specific objectives for
evaluating bias and variability are to determine the
extent to which (1) sampling methods and equipment
introduce contaminants (bias) into water-quality
samples; and (2) sample processing and handling
affect the variability of measured constituent concen-
trations (T.L. Miller, U.S. Geological Survey, written
commun.,1996).

Upper Colorado River Basin
study unit

UTAH

T9

EXPLANA nON
SAMPLING SITE AND NUMBER

o
I
o

20 40 MILES

Figure 1. Location of sampling sites (numbers refer to table 1).

20 40 KILOMETERS

2 Interim Results of Quality-Control Sampling of Surface Water for the Upper Colorado River National Water-Quality
Assessment Study Unit, Water Years 1995-96