The Navy is in the final planning and design stages for an unusual remedial project at the base. Rather than cleaning up soil with chemicals and petroleum products, contractors will remove shotgun pellets in the sediment offshore of an old skeet range.
There are tens thousands of pellets in the sediment off Carr Point due to the presence of a skeet range there from 1967 to 1989, with the Aquidneck Island Military Rod and Gun Club taking it over from the Navy in 1975.
The danger of lead pellets in the sediment is that bottom feeding birds ingest them when they plow the sediment with their bills. Another form of near-shore life, benthic invertebrates, or animals without backbones, are also at risk.
The first testing of the site took place in 2013, with surveying done until 2018. A decision was then made to dredge offshore sediment extensively the to render the site safe for marine life.
There are also pellets in the soil of the narrow strip between the shoreline and the area where the shooters fired their shotguns. During the site survey, a small area with unacceptable levels of manganese and PCBs was also discovered.
In the fan-shaped area that extends 900 feet from the shore and widens as it goes deeper into the bay, three feet of sediment will be removed. Closer to the beach, one foot will be stripped off. The total area to be dredged is about 240,000 square feet.
Once the sediment is removed, it will be treated onshore, first to dewater it before testing it for chemical contaminants. The sediment will then be trucked to a disposal facility. The team expects to dredge up about 42,000 tons of sediment.
The water that drains out of the sediment will be tested for chemicals and, should it be acceptable, will go through a filtering process before being put back into the bay. Onshore, the soil with pellets and chemicals will be hauled off and the excavated areas filled in with clean soil.
Where the sediment is removed near shore the contractor will fill in the excavated space with clean material. A little further offshore, the bay will be allowed to replace the pellet laden sediment which has been removed with the natural flow of dirt.
The onshore soil will be remediated this summer and fall. When the weather allows in 2024, the offshore sediment will be addressed.
Will it solve the problem? Further testing after the sediment is removed will tell. If, after dredging down to the planned levels of up to three feet there are still unacceptable levels of pellets, “Our shoulders will slump, but then we will get back at it,” Jamie Greacen of Tetra-Tech, the lead contractor for the remediation effort, told the Restoration Advisory Board on May 17.