DAMOS CAPPING MODEL 



BACKGROUND 



At present, the primary management tool used by the New England Division (NED) 

 of the US Army Corps of Engineers in dealing with the disposal of contaminated dredged 

 material in the marine environment is capping. Several capping experiments have been 

 conducted in Long Island Sound to confirm and demonstrate the viability of this alternative to 

 upland disposal of contaminated dredged material. In order to better manage the disposal of 

 contaminated dredged material and the subsequent capping, regulators at NED required a 

 simple model that could predict the configuration of a disposal mound and help estimate the 

 amount of clean material needed to adequately cap the mound. Although models predicting 

 the behavior of disposed dredged material already existed (Koh and Chang 1973, Brandsma 

 and Divoky 1976), the level of complexity and the amount of information required to run 

 them precluded their frequent use by managers. To provide a model that could be useful 

 incorporating the theory and processes used in the above models, the DAMOS Capping 

 Model was developed. 



THEORY 



The DAMOS Capping Model is based on two published reports (Koh and Chang 

 1973, Brandsma and Divoky 1976) dealing with the subject of dredged material disposal. 

 These reports contain a complete mathematical description of the models operations and 

 include extensive equations and formulas that will not be repeated here. Koh and Chang 

 (1973) included of models describing the dilution and transport of dredged material under 

 several discharge conditions: 



1. simple overboard dumping; 



2. jet discharged; 



3. discharge into barge wake. 



Brandsma & Divoky (1976) included descriptions of the first two cases above but also 

 considered a number of different receiving water conditions typical of estuaries such as: 



1. strongly stratified/ salt wedge conditions; 



2. two layer flow; 



3. partially mixed estuary (vertically); 



4. completely mixed estuary (vertically). 



Both reports described the process of material settling to the bottom in distinct phases. 

 The first phase, called convective descent, describes the dilution due to the momentum 



