Proceedings of the Federal Interagency Workshop on Turbidity and other Sediment Surrogates, April 30-May 2, 2002, Reno, Nevada

U.S. Geological Survey Circular 1250
Edited by John R. Gray and G. Douglas Glysson
Sponsored by the Federal Interagency Subcommittee on Sedimentation

A pdf is available for this report.


The April 30-May 2, 2002, Federal Interagency Subcommittee on Sedimentation Workshop on "Turbidity and Other Sediment Surrogates," held in Reno, Nevada, brought together a diverse group from local, State, and Federal agencies, academia, and the private sector with common interests in turbidity and other sediment-surrogate measurements used for estimation of water clarity and (or) selected characteristics of suspended sediment. The general goals of the workshop were to (1) propose a technically supportable, unambiguous definition of turbidity, and (2) describe the proper use, capabilities, and limitations of turbidimeters and other instruments operating on bulk-optic, digital-optic, laser, acoustic and pressure-differential principles for providing reliable surrogate data to characterize selected properties of suspended sediment and associated flux computations.

Findings and recommendations from the workshop were derived through two plenary sessions, four breakout sessions, a blind reference sediment-sample measurement session, and a pre-workshop questionnaire on "Uses of Turbidity by States and Tribes." Among the findings of the workshop were the conclusion that there is considerable ambiguity in the definition, meter calibration, and measurement of turbidity; and that turbidity measurements can be unreliable and relatively inaccurate. Workshop recommendations included calls for a new standard method for measurement of the optical properties of natural water and wastewater; and standard and reliable procedures for measuring and storing data on water clarity and suspended sediment, and for computing sediment fluxes.

Table of Contents

Executive summary

Introduction to the proceedings of the Federal Interagency workshop on turbidity and other sediment surrogates

Breakout Session 1: Definition of optical methods for turbidity and data reporting

Breakout Session 2: Use of optical properties to monitor turbidity and suspended-sediment concentration

Breakout Session 3: Computing suspended-sediment records using surrogate measurements

Breakout Session 4: Other fluvial-sediment surrogates

Summary of blind sediment reference sample measurement session

Uses of turbidity by states and tribes


Appendix 1: List of registrants and respective affiliation for the “Turbidity and Other Sediment Surrogates Workshop,” April 30-May 2, 2002, Reno, NV

Appendix 2: Papers submitted as part of the, “Turbidity and Other Sediment Surrogates Workshop,” April 30-May 2, 2002, Reno, NV

Appendix 3: Questionnaire used to provide information on “Uses of Turbidity by States and Tribes,” as part of the “Turbidity and Other Sediment Surrogates Workshop,” April 30-May 2, 2002, Reno, NV

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