Continuous Turbidity Monitoring and Regression Analysis to Estimate Total Suspended Solids and Fecal Coliform Bacteria Loads in Real Time

Abstract

To obtain timely and continuous water-quality information, the U.S. Geological Survey, in cooperation with State and other Federal agencies, has been using an innovative real-time monitoring approach for several Kansas streams. Continuously recorded data and data from periodic collection of water-quality samples are being used to develop surrogate relations between turbidity and constituents of concern. Regression equations were developed to estimate total suspended solids and fecal coliform bacteria from continuous turbidity measurements collected from 1995 through 1998 on the Little Arkansas River in south-central Kansas. The equations were applied to data collected in 1999 to estimate constituent loads. Estimated total suspended solids loads were 460 and 613 million pounds per year for the two sites in the study. Estimated fecal coliform bacteria loads were 30,000,000 and 32,000,000 billions of colonies per year. Despite some large differences between instantaneous measured and regression-estimated loads, continuous monitoring of turbidity in streams may increase the accuracy of load estimates that may be useful for calculating total maximum daily loads (TMDL's). The availability of this data in real time also may be useful for considering whole-body contact and recreation criteria, for adjusting water-treatment strategies, and for preventing adverse effects on fish or other aquatic life.

Additional information on the TMDL Program in Kansas can be found at: http://ks.water.usgs.gov/studies/TMDL/

Additional information on Real-Time Water Quality in Kansas can be found at: http://ks.water.usgs.gov/studies/qw/

Christensen, V.G., Ziegler, A.C., and Jian, Xiaodong, 2001, Continuous turbidity monitoring and regression analysis to estimate total suspended solids and fecal coliform bacteria loads in real time] in Proceedings of the Seventh Federal Interagency Sedimentation Conference, March 25-29, 2001, Reno, Nevada: Subcommittee on Sedimentation, v. 1, p. III-94 to III-101.

To request a paper copy of this proceedings article, email: vglenn@usgs.gov