Design of CAD Pits in San José Lagoon, San Juan, Puerto Rico

The USACE ERDC has prepared a capping design for disposal of dredged material from two projects in San Juan Bay Estuary, San Juan, PR. Approximately 200,000 cubic yards failed bioassay testing for disposal in the San Juan Ocean Dredged Material Disposal Site (ODMDS). These sediments are to be hydraulically dredged and placed in the largest of the San Jose Lagoon pits. Plans are to cap the deposit with “clean” sediment that passed bioassay testing. In the other project, the Martin Pena Canal will be widened to improve water quality by increasing the flushing of San Jose Lagoon into San Juan Bay. The eastern half of the canal is polluted and has restricted flow due to siltation and accumulation of trash and debris. The channel will be mechanically dredged, resulting in approximately 750,000 cubic yards of sediment, upland fill, and debris. The dredged material will be dumped by barge into three of the San Jose Lagoon pits and capped with clean sand. Consolidation, erosion, and contaminant transport analyses for both projects were done to determine site capacity for dredged material storage and cap design requirements for contaminant isolation. Results determined that pit capacity would be sufficient to accommodate both projects.