A.51 Naval Station - McAllister Point Landfill, RI
A.51.1 Summary
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Environment: |
Landfill/marine |
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Scale: |
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Contaminants of Concern: |
PCBs, PAHs, copper, nickel, anthracene, fluorine, and pyrene
Near shore area contains: ash, glass, pottery, brick, metal pieces, and larger debris (metal, concrete, and submarine netting). |
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Final Remedy: |
Approximately 895,540 gallons of water from water collection pond treated and discharged to Newport publicly-owned treatment works.
Approximately 20% of dredged material (rocks more than 6 inches in diameter) decontaminated and reused.
Small fraction of dredged material (≈500 tons) decontaminated and sent off site for recycling or disposal.
Remaining dredged material dewatered and disposed at McAllister Point Landfill or another off-site location. |
A.51.2 Site Description
Year: 1996
Water Depth: 3 ft at mean low water line
Target Volume: 34,000 yd3
Actual Volume Removed: 2,700 m2
A.51.3 Remedial Objectives
Copper: 52.9 (ppb in pore waterWater located in the interstitial compartment (between solid-phase particles) of bulk sediment.)
Nickel: 33.7 (ppb in pore water)
Anthracene: 513 (ppb in sediment)
Fluorine: 203 (ppb in sediment)
Pyrene: 2,992 (ppb in sediment)
Total PCBs: 3,634
Landfill materials estimated up to 15 ft thick at revetment in central portion of the landfill and taper to less than 1 ft at north and south ends.
Contaminated area: ≈ 47 acres adjacent to the landfill
A.51.4 Remedial Approach
Mechanical clamshell. Installation of multi-media, low-permeability1) Characteristic of a material or membrane that allows liquids or gases to pass through it; 2) The rate of flow of a liquid or gas through a porous material. capA covering over material (contaminated sediment) used to isolate the contaminants from the surrounding environment. over landfill. Passive gas vent system installed during construction of cap to dissipate potential for gas buildup that could disturb the cappingTechnology which covers contaminated sediment with material to isolate the contaminants from the surrounding environment. materials.
A.51.5 Monitoring
Turbidity curtains were installed at the perimeter of the near shore and elevated risk offshore areas to minimize the migration of sediments during the dredging activities. Turbidity curtains were also used as the dredging progressed to separate confirmed clean areas from active dredging areas.
After an area was confirmed clean, area was backfilled with materials appropriate to the area and graded. The surface of the cap is vegetated and graded to promote runoff of precipitation1) The formation of a solid in a solution or inside another solid during a chemical reaction or by diffusion in a solid; or 2) rain, sleet, hail, snow and other forms of water falling from the sky., thus minimizing potential infiltration that could cause further leachingLeaching is the extraction of certain materials from a carrier into a liquid; usually, but not always, a solvent.. Non-contaminated areas were capped with a RCRA Subtitle C multi-layer cap.
RAOs/project objectives achieved? Targeted cleanup goals were met at all locations.
A.51.6 References
USEPA Superfund Record of Decision: Newport Naval Education & Training Center EPA ID: RI6170085470. Sep 1993. http://www.epa.gov/superfund/sites/rods/fulltext/r0193081.pdf.
USEPA. Final Five-Year Review Report for Naval Station Newport. Dec 1999. http://www.epa.gov/region1/superfund/sites/netc/34986.pdf.
USEPA. Five-Year Review for Naval Station Newport. Dec 2004. http://www.epa.gov/region1/superfund/sites/netc/213065.pdf.
Publication Date: August 2014