Reports
Poplar Island sediment quality monitoring
2002, Hill, J.M.; Wikel, G.
File Reports, Coastal and Estuarine Geology, File Report 2001-04
Executive Summary
The Poplar Island Environmental Restoration Project (PIERP) is an innovative approach to the disposal of dredged material. The facility was constructed to produce a combination of low elevation upland disposal sites in conjunction with the formation of tidal wetlands. Potentially, this facility will establish new habitats for a wide range of aquatic and terrestrial wildlife. Depending upon the success of the operation of this facility, other facilities based upon this design will most likely be built. Because this is a prototype facility in the Chesapeake Bay, it is crucial to assure the integrity of the environment of the Chesapeake Bay is not diminished by the placement of dredge material. This study reports the results of the exterior monitoring of the sedimentary environment surrounding the PIERP, based on grain size, metals, and total carbon, nitrogen, and sulfur analyses of samples from eleven sites around the island.
The environment has changed around the island due to changes in the hydrodynamic regime of area. Prior to construction the area had high current velocities, which swept the shallow platform where the island is located. The high energy stabilized coarse sandy sediment in the area. The project has created a sheltered area in Poplar Harbor, which has produced a low energy environment. Lower current velocities allow finer sediments to become stable in the exterior sediments; finer sediment has higher metals content. This has been documented in this study. Although the sediment distribution pattern has changed, the material is indistinguishable from baseline main Chesapeake Bay sediments.
The scale and pattern of the grain size and associated metals changes can not be assessed with the current 11 bottom sediment sampling stations because of the insufficient spatial coverage in the area. More detailed mapping of these changes in the area would require sampling at additional sites, such as the 16 sediment quality stations included in the baseline survey. The inclusion of these samples will provide adequate spatial coverage to map the changes in sedimentation patterns in the area. Knowledge of the sedimentation pattern would provide information on where materials of concern may focus as a result of PIERP operation.
