Plume Study for Disposal of Dredge Material from KCT Expansion, Jamaica
The Dredge Disposal Report formed an Addendum to the study undertaken by Environmental Solutions Limited (ESL), entitled ‘An Environmental and Social Impact Assessment of the Proposed Development of Infrastructure Capacity at Kingston Harbour: Channel Upgrade’ (ESIA). The ESIA, among other elements, addressed the impacts of dredging the inner harbour and eastern channel and disposing of the dredge spoil in deep water east of the Port Royal Cays.
National Environmental and Planning Agency (NEPA) guidelines recommend disposal of dredge spoil at the 1000m water depth contour. The project proponents, Kingston Freeport Terminal Limited (KFTL), determined that cost and time-savings could be achieved if a disposal site in shallower water, closer to the dredge location, could be identified. This required a study to demonstrate that the impacts of using a closer site would be no worse than those resulting from releasing the dredged material at the 1000m contour.
The assessment which was undertaken applied computer-based analysis of the behaviour of dredge spoil after dumping in the ocean, using state-of-the-art modelling software calibrated by measurements of ocean processes at two locations. The behaviour of dredge spoil deposited in three water depths at 500, 750 and 1000 meters was modelled for both summer and winter conditions over 30 day model-run periods.