WSP05652

• File Number: 8273.300
• Description: Colorado River Basin Salinity Control - Federal Agency Reports - USGS
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 1/1/1997
• Author: USGS
• 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
• Water Supply Pro - Doc Type: Report/Study

STATE LINE
DOTSERO 0
GUNNISON NEAR 0
GRAND JUNCTION
(/J GUNNISON 0 0 0
lLJ TUNNEl..
>-
Cii EAST 0
<9
z
:J
a. GORE 0
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FRENCH 0
DRY 0

BAKER

o N D J
I

FMAMJJ ASONDJ FMAMJJAS
I

1996

1994

1995

Figure 5. Distribution of collection of field blanks, 1995-96.

DATE

The syslematic chloride contamination source
mighr be due to incomplete flushing of Ihe dilute
hydrochloric acid cleaning solution from the cone-
splitter outlet ports. Except for the onC high
value at the Slate Line site, the contamination is
on the order of a few tenths of a milligram per liter
(table 17). Chloride concentrations for the environ-
mental samples within the study unit range from 0.1 to
240 mg/L (U.S. Geological Survey. 1996. 1997). The
interpretation of the environmental data for sites with
low chloride concentrations. collected during the
period of contamination. will need to be qualified.
For future processing. Ihe cone-splitter ports wcre
fully disassembled for rinsing, and further chloride
contamination has not been observed. All of
the other constituents appear to have little or no
contamination.

Nutrients and Organic Carbon

Analytical results of field blanks for water
years 1995-96 for nutrients, dissolved organic carbon.
and suspended organic carbon are listed in table 18.
Constituents listed in table 18 show hllle or
no contamination. Any concentration that was
greater than twice the laboratory reporting limit
is shown in a shaded cell. Results of the dissolved
organic carbon blanks show concentrations in the
0.1 to 0.3 mg/L range. The South Platte NA WQA
study'unit also had dissolved organic carbon
blanks with similar detections (Robert Kimbrough and
Dennis Smits. U.S. Geological Survey. oral commun..
(997). Increasing the amount of blank watcr uscd to
leach the suspended organic filter prior to processing
the sample may reduce the concentrations measured in
these blanks. Future processing methods will include a
100 ml (milliliter) blank-water rinse.

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