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A study of trends in dissolved oxygen and fecal coliform bacteria at NASQAN stations

Open-File Report 82-1019

By:
,

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Abstract

Most stations in the U.S. Geological Survey's National Stream Quality Accounting Network show no significant trend in either dissolved oxygen concentration or fecal coliform bacteria population for the period October 1974. through October 1981. Of the stations which do show trends, however, most show improved water quality: thirty-one of a total of 276 stations show rising dissolved oxygen concentrations, while only 17 show decreasing concentrations. Decreases in fecal coliform populations have occurred at 21 stations while increases have occurred at only 12 stations. Approximately half of the stations showing improving trends in dissolved oxygen and fecal coliform bacteria are in the Missouri-Mississippi-Ohio River system. Decreases in dissolved oxygen have occurred at scattered locations in the Western and South-Central States. Rising bacterial populations occur most frequently in the Eastern and Central States Trends in dissolved oxygen concentration resulting from temperature changes occurring during the study period can be separated from trends caused by chemical or biological processes by analyzing computed values of dissolved oxygen deficit. About half of the observed trends in dissolved oxygen appear to be the result of changes in water temperature.

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
A study of trends in dissolved oxygen and fecal coliform bacteria at NASQAN stations
Series title:
Open-File Report
Series number:
82-1019
Edition:
-
Year Published:
1982
Language:
ENGLISH
Publisher:
U.S. Geological Survey,
Description:
[i], 8 p. maps ;28 cm.