The Bay Program is developing a policy encouraging the use of dredged material to benefit living resources. You have the living resource needs of the Bay, and you have the navigation needs. They are not the same. To some extent, the hope is that there could be a win-win solution found in which materials from the navigation projects could be made available for beneficial use. Sponsors are responsible for finding disposal sites.
Poplar Island is farther from the shipping channels than the deep trough.
Though dredging is typically done in the fall and winter to minimize environmental impacts, some consider the deep trough option unacceptable. Dumping sediment in anoxic conditions tends to pull nutrients out of the sediment and puts them back into the water where they trigger algae blooms that worsen Bay water quality. When that algae dies and sinks to the bottom, it decomposes in a process that further depletes water of the oxygen needed by many aquatic animals. Poplar Island is taking what is regarded by many people as a problem, the deposition of dredged material which has been historically just dumped back into the Bay, and putting that material to beneficial use. Because Poplar Island is more expensive than the least-cost option, it requires a special appropriation from Congress to make it a reality.