Please use this identifier to cite or link to this item: https://hdl.handle.net/11681/6939
Title: Evaluation of dredged material disposal and management for Upper James River Federal Navigation Channel, Richmond, Virginia modeling and testing of contaminant release for expansion of Richmond Deepwater Terminal
Authors: Wade, Roy.
Schroeder, P. R. (Paul R.)
Keywords: Channels (hydraulic engineering)
Dredging
Marine sediments
Publisher: Environmental Laboratory (U.S.)
Engineer Research and Development Center (U.S.)
Series/Report no.: ERDC/EL ; TR-09-17.
Abstract: The Federal Navigation Channel in the Upper James River requires frequent maintenance dredging to ensure safe navigation. One of the shoals is the Federal Channel at Richmond Deepwater Terminal (RDWT). The U.S. Army Corps of Engineers, Norfolk District has proposed expansion of the river basin at RDWT, such that ships arriving at the terminal can turn around and return downriver. Previous investigations determined that RDWT sediments were contaminated with diesel range petroleum hydrocarbons. Dredging and disposal of these sediments into a CDF may result in an adverse impact to water quality from effluent water returned to the James River. Since previous results of a settling test performed on localized material in December 2003 and June 2007, the settling test results were different and no data were collected on zone settling and compression settling. Therefore, ERDC performed an abbreviated settling test (February 2008) on the new work sediment sample to collect compression settling data for predicting storage needs and to verify the sediment settling behavior. Results of this study show the effluent total suspended solids (TSS) concentration to be very dependent on the sediment being disposed. A wide range of TSS concentrations were examined in jar tests to evaluate the effectiveness of chemical clarification. Based on the ERDC column settling test (February 2008), RDWT Expansion sediment underwent zone settling at a rate of 7.2 ft/hr. The areas of both cells are sufficient to allow the dredged material slurry to settle. Screening results showed that only Betz PC 1195 and Nalco 8131 were effective. These two polymers reduced the effluent suspended solids concentration by at least 98%. However, PC 1195 outperformed Nalco 8131. Even though the unit cost of Nalco 8131 is less than PC 1195, the required large dosage rate of Nalco offset that cost. The runoff contaminant pathway showed a potential exceedance of the discharge permit water quality, particularly for the period before the dredged material desiccates, forms a crust or becomes vegetated. Operational controls are required to allow the TSS in the runoff to settle to a concentration below 2.9 g/L before discharging the runoff. The leachate and volatilization contaminant pathway shows no potential for concern.
Description: Technical Report
URI: http://hdl.handle.net/11681/6939
Appears in Collections:Technical Report

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