thumbnail

Water-quality assessment of south-central Texas : comparison of water quality in surface-water samples collected manually and by automated samplers

Fact Sheet 172-99

By:

Links

Abstract

Surface-water sampling protocols of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program specify samples for most properties and constituents to be collected manually in equal-width increments across a stream channel and composited for analysis. Single-point sampling with an automated sampler (autosampler) during storms was proposed in the upper part of the South-Central Texas NAWQA study unit, raising the question of whether property and constituent concentrations from automatically collected samples differ significantly from those in samples collected manually. Statistical (Wilcoxon signed-rank test) analyses of 3 to 16 paired concentrations for each of 26 properties and constituents from water samples collected using both methods at eight sites in the upper part of the study unit indicated that there were no significant differences in concentrations for dissolved constituents, other than calcium and organic carbon.

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Water-quality assessment of south-central Texas : comparison of water quality in surface-water samples collected manually and by automated samplers
Series title:
Fact Sheet
Series number:
172-99
Edition:
-
Year Published:
1999
Language:
ENGLISH
Publisher:
U.S. Geological Survey,
Description:
1 folded sheet (6 p.) : col. ill., col. map ; 28 x 64 cm. folded to 28 x 22 cm. col. ill., col. map ;