Long Island Sound DMMP PEIS — Addressing Concerns

The U.S. Army Corps of Engineers released the Long Island Sound Draft Dredged Material Management Plan (DMMP) and Draft Programmatic Environmental Impact Statement (PEIS) for public review and comment on Monday, August 17, 2015. The DMMP and PEIS can be found on the Corps website at: www.nae.usace.army.mil/Missions/ProjectsTopics/LongIslandSoundDMMP.aspx. The public comment period will run through Oct. 16, 2015.

Based on feedback received from the public at six recent public hearings, the New England District of the Corps would like to address some confusion about the project.

The DMMP and PEIS are not decision documents.

The Long Island Sound DMMP & PEIS are not decision documents, nor do they recommend locations for dredged material placement. They examine and present a variety of placement options. Recent concerns that the Corps is recommending placing millions of cubic yards of dredged material into Long Island Sound are simply incorrect. The post-screening alternatives listed are just possible options for potential future dredge material management. As each dredging project is evaluated in the future, a more detailed study must be performed to evaluate the Federal Base Plan (FBP), i.e. the least costly, environmentally sound alternative, and practicable alternatives that may be available since the completion of the DMMP. The alternative FBPs listed in this draft DMMP and PEIS will change over time, and actual future placement recommendations may be different as new studies for future projects are completed.

Beneficial use is a primary focus in identifying potential alternatives.

Since 1986, there has been a major evolution of law and policy concerning the beneficial use of dredged material. As such, the Corps looks at beneficial use potential for every project. Several programs exist that allow the Corps to team up with non-Federal cost-sharing partners to implement beneficial use projects that are not the FBP. Often, sandy dredged material is repurposed as beach renourishment or placed near shore to reduce wave energy and subsequent erosion of beaches. Educating the public and potential Corps-partners for beneficial use opportunities remains one of our greatest challenges.

Federal law requires the least costly, environmentally acceptable management option.

People frequently suggest that the Corps select dredged material use options other than open water placement. However, the Corps is required by Federal law to evaluate all potential alternatives and to select the least costly, environmentally acceptable management alternative as its base plan. As mentioned above, the Corps has programs that allow partnership with non-federal sponsors to support environmental restoration or hurricane and storm damage reduction projects. Locally preferred alternatives may be implemented if non-federal partners contribute funds for the additional costs of those projects.

Dredged material is tested to insure compatibility with placement sites.

Before any material is dredged, it is always thoroughly analyzed chemically, biologically, and physically (grain size). Testing includes comparing the dredged material to the material in the proposed disposal location to ensure that the material is environmentally acceptable. The required testing is very conservative and includes risk assessments that the material must pass before the dredged material is determined to be suitable for ocean placement. The test results and suitability determination must be independently reviewed and confirmed by the U.S. Environmental Protection Agency. Material that does not pass the testing (i.e. material that is declared unsuitable) cannot be placed in open water under Federal law.

The physical characteristics of dredged material is key to how, or if, it can be used beneficially.

Dredged material must meet specific particle size requirements for certain beneficial use options. For example, dredged sand can be placed on beaches and dunes, if the sand size and particle distribution is close to that of the proposed placement location. This is why silt, which has a much smaller particle size than sand, cannot be placed on beaches. Silty material – a very common product of dredging – can be used for marsh creation, but generally has limited beneficial use options as it usually is not compatible with beach renourishment, is not an appropriate construction material, and has a salt content too high for landscaping.

Dredged material placed in open water containment sites remains where it is placed.

Over the years, many studies have been performed on the placement of suitable dredged material in open water. These studies clearly demonstrate that dredged material can be placed where it is intended at open water containment sites, and that the dredged material does in fact remain within the sites, unless a site is specifically chosen to achieve dispersive effects. Very little dredged material (~1%) is suspended when the material is placed at the site. Additionally, none of the final alternatives in the DMMP/PEIS evaluated placement of dredged material in “the Race” or similar fast current areas. The Corps’ Disposal Area Monitoring System (DAMOS) Program has continuously monitored open water placement sites for decades. Information on the DAMOS Program and DAMOS reports are available on the Corp’s website: http://nae.usace.afpims.mil/Missions/DisposalAreaMonitoringSystem(DAMOS).aspx.

The amount of projects to be dredged in the next 30 years will be less than identified.

The DMMP estimates the amount of material that could potentially be dredged from each Federal Navigation Project (FNP) over the next 30 years if all the projects were funded for dredging. However, history shows us that it is extremely unlikely that all of the FNPs will be dredged during this time frame due to fiscal constraints, both federally and non-federally, and limited need. The DMMP simply includes all potential projects, and identifies a maximum potential quantity of dredged material, not a guarantee of what will be dredged.

Open water placement has reduced over the past 10 years.

Contrary to perception, there has actually been a 35% average reduction in the amount of dredged material placed at Long Island Sound ocean sites between 2006 and 2014, when compared to those sites between 1984 and 2004. This is due in large part to New York and Connecticut’s efforts to beneficially use sandy dredged material for coastal resiliency projects. As described previously, beneficial use is always a preferred option for Corps dredging projects.

Public comments on the Draft DMMP and Draft PEIS should be forwarded no later than October 16, 2015 to the U.S. Army Corps of Engineers, New England District, (ATTN: LIS DMMP/PEIS Project Manager Meghan Quinn), 696 Virginia Road, Concord, MA 01742-2751.

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