Evaluation of Sediment Stability in Surface Water Bodies

This paper describes methods to evaluate the feasibility of monitored natural attenuation (MNA) for remediation of contaminated sediments deposited on the beds of channels and marshes. The feasibility of MNA depends on the erosion potential of contaminated sediments due to channel flows and burial of contaminated sediments due to deposition of cleaner sediments transported by the channel. Because of the empiricism and uncertainty associated with sediment transport formulas and methods to estimate non-scouring velocities, several empirical and semi-analytical methods are presented to estimate the erosion potential of channel bed sediments. Reasonably conservative judgments can be made based on the results obtained from several alternative methods presented in this paper. The potential for deposition of suspended sediments is evaluated by comparing the fall velocities of suspended sediments and flow velocity in the channel.