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State of Dredging in Long Island Sound

State of Dredging in Long Island Sound


By Steve Sternberg, P.E., Project Manager

Dredging of the harbors in Long Island Sound (LIS) is a vital, yet highly contested, activity necessary to maintain commercial shipping and recreational boating industries in the region, and nationwide. The U.S. Army Corps of Engineers (USACE) is tasked with maintaining 55 authorized and constructed Federal Navigation Projects (FNP) in LIS and adjacent waters, by removing sediments that have accumulated within the waterways. These FNPs include federally authorized channels, anchorages, maneuvering and turning basins. Other non-federally designated local service facilities (LSF) such as marine terminals, port facilities, private marinas and boat yards, and public landings require similar attention to dredging maintenance. At times, improvements to this navigation infrastructure may also be warranted, by deepening or widening areas beyond their historic depths in order to stay present with current boat building and industry trends.

Siltation of these areas is primarily caused by normal coastal processes including tidal currents and wave action, although singular storm events may also burden the areas, requiring that dredging be conducted on a more frequent basis. Riverine flooding, upland runoff and coastal erosion are additional contributors.

From an economic output standpoint, USACE estimates that the contribution of navigation-dependent activity to economic output in the LIS region is approximately $9.5 billion per year. Navigation-dependent activity is estimated to contribute $5.5 billion per year and  ±56,000 jobs to the regional economy of Connecticut, New York, and Rhode Island and accounts for an estimated $1.6 billion per year in Federal and State tax revenues. As such, timely and economical dredging is essential to maintain use by the industrial, commercial, and recreational users of the waterways. 


Historically, and most predominately, material dredged from these areas has been relocated to designated open-water sites in the offshore waters of LIS. This would typically entail a barge mounted crane with clamshell bucket, dredging the area and loading a bottom dump scow. Once at capacity, the scow would be transported to the open-water site, where bottom doors would open, and the material deposited on the sea floor. 


While economical, the restrictions on dredged material placement at these sites was limited until 1972 with the passing of the Clean Water Act (CWA), 33 U.S.C. § 1251, et seq., which established more stringent regulation on discharges, including the disposal of dredged or fill material, to the waters of the United States, landward of the territorial sea baseline. Up until the CWA, the placement of polluted dredged material taken from the industrialized port and harbor areas of the region, would not have been an uncommon occurrence. 


The Marine Protection, Research, and Sanctuaries Act (MPRSA), 16 U.S.C. § 1431, et seq., and 33 U.S.C. § 1401, et seq., further regulated the transportation and dumping of material from the United States into the U.S. territorial sea (seaward of the baseline limit). Since the waters of LIS fall landward of the territorial sea baseline, regulation under the MPRSA would not be expected, however an amendment in 1980, commonly referred to as the “Ambro Amendment”, required that dredged material generated from federal projects or private projects involving more than 25,000 CY, also be regulated under MPRSA. The 25,000 CY limit was determined to be a reasonable limit in which most LSFs could fall, and not have to undertake the increased sediment testing (and therefore costs) associated with MPRSA regulation.  


Under the MPRSA, the U.S. Environmental Protection Agency (EPA) has authorization to designate dredged material disposal sites in LIS, and in 2005 recognizing the need for both economical and environmentally friendly means to dispose of dredged material, issued a Final Rule designating the Central and Western Long Island Sound Dredged Material Disposal Sites (CLDS and WLDS respectively). CLDS is an approximate 3.2 square nautical mile (sq nmi) site located 5.6 nmi south of South End Point, East Haven, CT. WLDS is an approximate 2.0 sq nmi site located 2.8 nmi south of Long Neck Point, Darien, CT. 


As a condition of the designations, the rule required that the USACE in collaboration with the EPA and the states of New York and Connecticut, prepare a Dredged Material Management Plan (DMMP) for LIS. The DMMP is a planning document used to ensure that federal projects are conducted in an environmentally acceptable and cost-effective manner. Although prepared for planning of federally conducted projects, findings within the DMMP can be used as a tool for all dredging projects within the region. A goal of the DMMP per the 2005 ruling, was to, “…reduce or eliminate the disposal of dredged material in Long Island Sound…”

Following years of private and government stakeholder negotiations, the USACE completed the DMMP in 2016. Among other things, the DMMP established a Federal Base Plan for every FNP in the LIS region, defined as the least cost environmentally acceptable alternative for constructing the project. The completion of the DMMP allowed for an amendment to the 2005 rule to incorporate standards and procedures for use of the open-water sites as recommended within the DMMP. The completion and acceptance of this document ensured the continued viability of use of these sites for future projects. While the rule and subsequent amendment allows these sites to be reviewed as an alternative for dredged material relocation, their authorized use was still to remain highly project specific, following an alternatives analysis of other practicable relocation alternatives, and a sediment analysis for suitability. 


As a recognition of the continued need for, both environmentally acceptable and cost-effective dredging and dredged material relocation over a 30-year period as outlined in the DMMP, the EPA further pursued designation of a third long-term disposal site to serve the eastern region of LIS (both CLDS and WLDS are sited significantly west of this region), and to replace the closing, New London Disposal Site (NLDS). In November 2016 subsequent to DMMP issuance, a Final Supplemental Environmental Impact Statement for the Designation of Dredged Material Disposal Site (S) in Eastern Long Island Sound, Connecticut and New York was completed. That December, the EPA issued a Final Rule designating the Eastern Long Island Sound Dredged Material Disposal Site (ELDS) for long-term use with the same restrictions as CLDS and WLDS. ELDS is identified as a 1.3 sq nmi site located 1.1 nmi south of Harkness Memorial State Park, Waterford, CT. 

While most of the users, government bodies, and State and Federal regulatory agencies viewed the ELDS designation as a necessity and environmentally acceptable alternative for dredged material relocation for the region, not all were accepting of the determination. Subsequent to the ELDS designation, the State of New York filed lawsuit against the EPA citing that they, “…acted arbitrarily and capriciously in designating a disposal site for dredged materials in eastern Long Island Sound…” The State of New York notes five Claims for Relief in this lawsuit: 

  1. “EPA arbitrarily inflated the project volumes of dredged materials in order to justify the need for ELDS in violation of the Administrative Procedures Act (APA), 5 U.S.C. § 701 et seq.”

  2. “EPA arbitrarily minimized the ELDS’ potential for interfering with navigation in the Sound in violation of APA.”

  3. “EPA’s designation of an unused and “pristine” site was arbitrarily and capricious in violation of the APA.”

  4. “EPA failed to explain that smaller dredging projects are tested under different, and less stringent, criteria than larger projects and that this would result in greater release of contaminants than described by EPA.”

  5. “The designation of the ELDS was not consistent with New York’s Coastal Zone Management Program and thus is in violation of New York’s Coastal Zone Management Act (CZMA) and the APA."

Acting as the Defendant-Intervenor in the matter for the EPA, the Connecticut Department of Energy & Environmental Protection (DEEP), has filed a memorandum of law in support of the EPA’s findings and ELDS designation, and in opposition to the State of New York complaint.  Among others in the industry that support the EPA decision include both public and private organizations including the U.S. Navy, Electric Boat, Cross Sound Ferry, Connecticut Maritime Coalition (CMC), Connecticut Marine Trades Association (CMTA), and the Connecticut Harbor Management Association (CHMA). 


As the State of New York maintains review authority of dredged material relocation at the open-water sites in LIS under the Coastal Zone Management Act (CZMA), 16 U.S.C. § 1451, et seq., any proposed use of the ELDS at this time, will likely be found inconsistent, and a final permit issuance denied. This will require proposed dredging projects from the eastern LIS region to further explore other dredged material alternatives (beyond those already required), or otherwise not dredge at all. These alternatives may include beneficial use of material in the upland, beach nourishment, landfill placement, or placement at CLDS or WLDS. 


While beneficial use of material in the upland and/or beach nourishment may in-fact be both an economical and environmentally acceptable solution for a given site, among other things, it is highly dependent on the type of material to be dredged. Fine-grained material is not suitable for beach nourishment purposes and has limited upland re-use ability without amending. Even if found suitable for a use in the upland or at a landfill site once amended, the added costs for re-handling ashore, processing, dewatering, transporting and placing the material, may limit the overall viability. Likewise, if open-water relocation is found to be the only practicable solution for a project, the added haul distances to CLDS or WLDS will increase project costs, and may further preclude the project from occurring. 


As of the date of this periodical, the litigation between the EPA and State of New York remains ongoing, and thus use of ELDS likely halted. RACE recognizes the importance of this issue with the LIS maritime industry and will keep abreast of the issues surrounding dredged material relocation in LIS and how it may influence dredging projects throughout the region. Should you require dredge planning, design, hydrographic survey, and/or regulatory permitting services, please feel free to call to discuss your project with us further.

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The U.S. Army Corps of Engineers estimates that the contribution of navigation-dependent activity to economic output in the LIS region is approximately $9.5 billion per year. 

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The Dredged Material Management Plan for LIS is used to ensure that federal projects are conducted in an environmentally acceptable and cost-effective manner.

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The EPA designated the Eastern Long Island Sound Disposal Site in 2016 as a recognition for the continued need for, both environmentally acceptable and cost-effective, dredging for the eastern LIS region.

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