Subaqueous Dredge Material Capping
- Objectives
- Reduce mobility of contaminated
sediment/dredged material
- Reduce mobility of contaminants
- Isolate contaminants from benthic organisms --
food chain
- Advantages
- Historical sediment contaminants generally low
mobility
- Cap provides further isolation
and mass transfer resistance
- Metals tend to be less mobile in reducing
environments
- Avoids enhanced mobility if
exposed at surface
- Avoids cost, containment and effectiveness issues of
upland treatment
- Disadvantages
- Contaminant losses during dredging operations
- Placement of contaminated dredged material and
cap layer difficult in high energy environments
- Retains contaminants in potentially dynamic
environment
