14 



Box 1.12 



"Monitoring " 



For marine unconfined or confined 

 open-water disposal, the activities 

 within this particular action box are 

 defined in the next two flow charts. 

 There are two possible routes to arrive 

 at this box. If monitoring is needed as 

 a result of unconfined open-water 

 disposal (via Box 1.9), then the flow 

 chart presented in Figure 2 and 

 explained in Section 4.0 will be 

 followed; if one arrived via Box 1.10, 

 then the flow chart presented in 

 Figure 3 and explained in Section 5.0 

 will be followed. 



The important issue to bear in 

 mind is that the results obtained from 

 activities in the next two flow charts 

 have a feedback function and impact 

 in the overall dredged material 

 management and permit evaluation 

 procedure. 



Box 1.13 



"Acceptable Impacts': 



It is a given that open-water 

 dredged material disposal will cause 

 near-field impacts and possibly could 

 cause far-field impacts (physical, 

 chemical, and biological), just as 

 storms, river flow, or land run-off can 

 cause both localized and system-wide 

 impacts. What constitutes an 

 acceptable or unacceptable impact and 

 the inherent assumptions leading up 

 to that conclusion is explained in the 

 sections to follow. Detection of 

 unacceptable impacts will lead to Box 

 1.15, while detection of acceptable 

 impacts will lead to Box 1.14. 



Box 1.14 



"Status Quo.... " 



If no impacts are detected, one can 

 conclude that either one is measuring 

 the wrong parameters (i.e., one of the 

 previously mentioned sources of 

 uncertainty is causing an undetected 

 bias in the results), the measurement 

 is not sensitive enough to detect 

 adverse impacts, or that one is 

 disposing of dredged material in an 

 environmentally safe and prudent 

 manner. Continuous detection of no 

 impacts under the proposed tiered 

 monitoring schemes also would 

 indicate that reduced monitoring 

 might be warranted. The question of 

 how long repetitive monitoring should 

 be continued will be discussed in the 

 respective sections on unconfined 

 (uncapped) and confined (capped) 

 aquatic disposal below. 



Box 1.15 "Revise the Evaluation and 



Management Process " 



Detection of impacts would lead 

 one to conclude that one or more of 

 the physical/chemical factors has 

 affected the outcome. One very real 

 danger is because of the number of 

 multiple uncertainty factors at several 

 of the above decision points, it is 

 unlikely that a detection of impacts 

 would point clearly to which 

 assumption is false or which source of 

 uncertainty is an important one. If 

 revision of the current evaluation 

 process is required, it would entail 

 restructuring the evaluation criteria 

 down to a finer level of detail to 

 determine exactly where the problem 

 lies by the time-honored technique of 

 inductive inference (Piatt, 1964). The 

 sources of uncertainty outlined above 

 potentially could be eliminated by 

 being approached in the following 



An Integrated, Tiered Approach to Monitoring and Management of Dredged Material Disposal Sites 



