The St. Croix Environmental Association (SEA) thanks Senator Wayne James and the St. Croix Renaissance Group LLLP (SCRG) for seriously considering depositing dredge spoils from the St. Thomas Harbor dredging project on SCRG’s industrially-zoned St. Croix property. According to initial conversations with Myron Allick, VP Operations, SCRG, while a final decision depends upon permit approvals, results of spoils test results, and other considerations, SCRG is considering placement of the dredge spoils on the bauxite tailings (red mud) on SCRG property. This SCRG alternative to depositing the dredge spoils in Lindbergh Bay would appear to provide environmental benefits to both St. Thomas and St. Croix:
• St. Thomas’ Lindbergh Bay benthic habitats include sea grass beds, important habitat for queen conch and juvenile yellow tail snappers, grunts, and many other marine species; forage grounds for sea turtles; and critical hard bottom habitat for Acropora coral along outer bay shores. Lindbergh bay beaches, as we have seen recently, are nesting ground for the federally endangered Leatherback Sea Turtle. Marine habitats and species are threatened by movement of deposited dredge spoils and turbidity, especially during storm events.
• St Croix would benefit from spreading dredge spoils on the red mud, helping to cover and stabilize that industrial dumpsite and reducing erosion of bauxite tailings into wetland and marine habitats. It is our understanding that SCRG would use the dredge spoils directly over the red mud, and would cover the spoils with topsoil or caliche (limestone soil) or a combination of both to protect the dredge spoils from erosion by wind and rainfall, and provide a final ground cover that would support vegetation. Once spread on the red mud and covered with topsoil, there would be minimal risk of heavy metals or other toxic materials in the dredge spoils to leach from the disposal site or be exposed to erosion and transported away from the site.
St. Croix Environmental Association has examined analyses of sediment samples taken by CH2MHill and Environmental Resource Management Puerto Rico (ERM). Two of 21 samples collected contained heavy metals at or above concentrations at which adverse effects frequently occur, according to National Oceanic and Atmospheric Administration (NOAA) sediment quality guidelines. In addition to potential impacts of suspended solids in the Lindbergh Bay water column, on coral and sea grass habitats, or on shorelines (including nesting beaches for federally-listed sea turtles), SEA is concerned about distribution of heavy metals within marine ecosystems. The St. Croix Environmental Association recommends that dredge spoils from St. Thomas Harbor be deposited in a terrestrial (not marine) environment; SEA endorses use o f the Saint Croix Renaissance Group bauxite tailings (red mud) industrially-zoned site for the dredge spoils disposal.
Editor’s note: Paul Chakroff is the managing director St. Croix Environmental Association, which is a chapter of the Virgin Islands Conservation Society.
