50 Ways We’ve Saved The Bay: Improving Dredge Policy in Rhode Island
by Chris Cassaday, communications intern
Commercial and recreational vessels rely on shipping channels and marinas for safe navigation and use of Narragansett Bay. As the size of vessels using the Bay increased, channel depth had to increase with it, and the natural depths of the Bay no longer allowed vessels to reach Providence. By the 1990s, the Providence River shipping channel had silted in, making navigation significantly more dangerous. When Save The Bay learned about dredge disposal plans that posed a direct threat to the Bay, we sprang into action. Our advocacy against these plans, and for alternatives that would better protect the Bay, forever changed the way dredging projects take place throughout Rhode Island. Now, rather than being dumped throughout the Bay, dredge material is reused when possible, and properly disposed of in other cases.
A Unique Habitat Near Hog Island
Nestled in the middle of the Bay between Bristol and Portsmouth, Hog Island is surrounded by benthic (bottom) habitats that dot the mid and upper Bay. Benthic habitats support a diverse community of invertebrates, crustaceans, and shellfish that live in and on the sediments. A 70-foot depression southwest of Hog Island, roughly 30 feet deeper than the surrounding area, provides a unique refuge for many species that rely on the colder, deeper water.
In 1998, the U.S. Army Corps of Engineers was planning to dredge 5.6 million cubic yards of the Providence River and dump nearly all of it into the depression, creating a mound 430 acres—roughly 325 football fields—wide and 25 feet thick. The Corps predicted that the disposal area would recover over time, but Save The Bay and our allies met that prediction with great skepticism. The Hog Island habitat is intensively fished, and knowledgeable fishermen pointed to the site as a critical habitat for juvenile tautog. Filling it in would irrevocably jeopardize its value as a temperature refuge.
The Army Corps plan was met with stiff opposition from Save The Bay, as well as several East Bay communities, fishermen and environmental groups. Senator John Chafee, Congressman Patrick Kennedy, and Governor Lincoln Almond joined the rising tide of opposition. “I am gravely concerned about the possible threats to our natural habitat,” said Congressman Kennedy. “…the proposal to dump dredge material into the so-called Hog Island site… is simply unacceptable.”
New Alternatives, New Policy for Dredge Disposal
Several important events followed. First, an offshore dredge disposal site, known as “69B,” was established nine miles south of the Rhode Island coast to accept dredge material deemed environmentally safe for disposal. But state and federal regulatory agencies deemed much of the Providence River shipping channel material too contaminated for open water disposal. As the river continued to silt in, pressure mounted for an alternative. Finally, the Army Corps of Engineers proposed a unique new approach: creating giant depressions below the Providence River shipping channel, where the contaminated dredge spoils would be dumped and then covered up with cleaner, suitable material. These subterranean sites, known as Confined Aquatic Disposal cells, or CADs, became the solution.
The CAD solution also provided short term relief for marinas, saving them the time and money it would have taken to barge their dredge material out to 69B. But CADs did not address the underlying challenge of preventing future “Hog Island” proposals. Save The Bay set out to change dredging policy so that Narragansett Bay would be the absolute last resort for dredge disposal. A years-long standoff between Save The Bay and the Rhode Island Marine Trades Association ended when the two organizations worked together with the Rhode Island General Assembly to establish, in law, a “hierarchy” of dredge disposal options. At the top of the hierarchy was “beneficial use” of dredge material on land, for landfill cover and other projects. For example, dredged material was used as a base for the athletic fields of Johnson and Wales University near the Save The Bay Center in Providence
Dredging shipping channels is essential for the maritime economy. Done correctly, with the environment in mind, it can be done in a way that protects Bay habitat and water quality, while also providing material for other projects. Save The Bay has fought to protect the Bay from dredge plans that would have damaged the environment for many years, and will continue to do so to protect the Bay and its habitats from being buried in sedimentary spoils.