INDICATOR BACTERIA CONCENTRATIONS OF TWO NORTHWEST ARKANSAS STREAMS IN RELATION TO FLOW AND SEASON

Concentrations of indicator bacteria such as fecal coliform (FC) and fecal streptococcus (FS) are often used to assess the suitability of waters for their intended use(s) and to allocate resources for water quality improvement measures. There is evidence, however, that concentrations of FC and FS can be influenced by variables such as season and flow rate during sampling, which could lead to biased results. The objective of this study was to assess the impacts of season and flow rate on concentrations of FC and FS. Fecal indicator bacteria concentrations were measured for approximately three years at five sites on two Northwest Arkansas streams. Flow data were collected at two of the five sites. Land use in the basins draining the streams was primarily pasture (57-90%) and forest (6-40%). Significant seasonal influences on FC and FS concentrations were detected for all sampling sites, with the highest concentrations occurring in summer. On the two sites with flow data, flow rate generally had a significant effect on FC and FS concentrations during all seasons, with FC and FS concentrations increasing with flow rate. Ratios of FC and FS, which have been used in the past to differentiate between animal and human sources of fecal pollution, did not appear to reliably indicate the major sources of fecal indicator bacteria. The findings of this study suggest a potential for fixed sampling intervals to contribute to biased results. The issue of biased results might be avoided by sampling during times of year and flow conditions that support the intended use(s) of the waters.

[1]  K. E. Saxton,et al.  The Effect of Cattle Grazing on Indicator Bacteria in Runoff From a Pacific Northwest Watershed , 1982 .

[2]  T. C. Sturgis,et al.  Reliability Problems With Indicator Organisms for Monitoring Overland Flow Treated Waste Water Effluent 1 , 1979 .

[3]  Awwa,et al.  Standard Methods for the examination of water and wastewater , 1999 .

[4]  J. S. Schepers,et al.  Chemical and bacteriological quality of pasture runoff , 1981 .

[5]  J. R. Miner,et al.  Bacterial Pollution from Agricultural Sources: A Review , 1983 .

[6]  Charles M. Milne,et al.  Effect of a Livestock Wintering Operation on a Western Mountain Stream , 1976 .

[7]  E. Geldreich,et al.  The bacteriological aspects of stormwater pollution. , 1968, Journal - Water Pollution Control Federation.

[8]  Charles P. Gerba,et al.  Fate of Wastewater Bacteria and Viruses in Soil , 1975 .

[9]  M. D. Harper,et al.  Soil survey of Washington County, Arkansas. , 1969 .

[10]  S. M. Morrison,et al.  Multiplication and growth of selected enteric bacteria in clear mountain stream water , 1967 .

[11]  E. McCoy,et al.  Use of fecal streptococci as indicators of pollution in soil , 1978, Applied and environmental microbiology.

[12]  Douglae R. Hamilton.  U. S. National Oceanographic Data Center National Environmental Satellite Data and Information Service National Oceanic and Atmospheric Administration , 1961 .

[13]  L. V. Street,et al.  Bacterial Variations in Streams from a Southwest Idaho Rangeland Watershed , 1978 .

[14]  Alan A. Beetle,et al.  Effect of Summer Use of a Mountain Watershed on Bacterial Water Quality 1 , 1974 .

[15]  James A. Moore,et al.  Resuspending Organisms from a Rangeland Stream Bottom , 1988 .

[16]  Stanley L. Ponce,et al.  Cattle grazing impact on surface water quality in a Colorado front range stream , 1983 .

[17]  H. R. Sanderson,et al.  Bacterial Water Quality Responses to Four Grazing Strategies—Comparisons with Oregon Standards , 1988 .

[18]  J. I. Sewell,et al.  Water Quality in a Stream Receiving Dairy Feedlot Effluent , 1982 .

[19]  Robert L. Blevins,et al.  An Assessment of Water Sources Related to Major Systems of Agricultural Land Use in Kentucky , 1995 .

[20]  J. Niemi,et al.  Bacterial pollution of waters in pristine and agricultural lands , 1991 .

[21]  J. Doran,et al.  Bacteriological Quality of Runoff Water from Pastureland , 1979, Applied and environmental microbiology.

[22]  Mark S. Coyne,et al.  Fecal bacteria in agricultural waters of the bluegrass region of Kentucky , 1995 .

[23]  Martha W. Gilliland,et al.  Bacterial Pollution in Runoff from Agricultural Lands , 1988 .

[24]  Edwin E. Geldreich,et al.  Fecal coliform and fecal streptococcus density relationships in waste discharges and receiving waters , 1976 .