Verification of Predictions of Dredged Material Effluent Quality

Abstract

Polluted sediments from harbors are often pumped to confined disposal areas on shore where they are settled. The polluted overflow effluent quality can now be predicted by a recently developed modified elutriate test. Predictions from this test were made for five major dredging jobs, and intensive sampling of the actual confined disposal area influents and effluents was done to check the accuracy of the predictions. Agreement ranged from fair to excellent for various pollutants. The median value of all ratios of predicted to measured total concentration was 1.4, and 23 out of 34 values were within a factor of 2.0. The Corps of Engineers has adopted the predictive method, and descriptions will be included in future Engineer Manuals as design guidance.