Final Environmental Impact Report - Whittier Bridge/I-95 ...

Whittier Bridge/I-95 Improvement Project FEIR
Chapter 2.0: Response to Comments on the Environmental Assessment/Draft Environmental Impact Report
Response: NMFS indicated the following in a letter dated June 8, 2011: ―Based on the analysis that
any effects to shortnose sturgeon from the proposed action will be insignificant or discountable,
NMFS is able to concur with the determination that the proposed reconstruction of the Whittier
Bridge in Amesbury, Massachusetts is not likely to adversely affect any listed species under NMFS
jurisdiction.‖
2.3.3 Massachusetts Division of Marine Fisheries
The DMF submitted a letter dated December 9, 2011.
DMF-1: Marine Fisheries previously recommended in a letter dated September 8, 2011 that the installation and
removal of the cofferdams occur outside of the March 1 to November 1 time-of-year (TOY) restriction period. This
recommendation was designed to ensure safe passage for a variety of diadromous fish species including American
shad (Alosa sapidissima), Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus), and shortnose sturgeon (Acipenser
brevirostrum). Based on additional project information, cofferdam installation will be staged to reduce impact by only
installing a single cofferdam at any given time. By avoiding simultaneous installation of multiple cofferdams, this
project design would limit the area of impact to less than 5% of the river width at any given time. This staging
approach combined with the nature of the river bottom at the project site (predominantly bedrock) should allow for
safe passage of diadromous fishes during the construction process. If the project avoids simultaneous installation of
multiple cofferdams, Marine Fisheries does not recommend any TOY restrictions on the construction process.
Response: As noted in the comment, MassDOT has committed to construction procedures which
will limit the installation or removal of temporary cofferdams to a single location at any one time.
2.3.4 Massachusetts Coastal Zone Management
Massachusetts Coastal Zone Management (MCZM) submitted a letter dated December 21, 2011.
CZM-1: Based on the information included in the DEIR, it appears that the Preferred Alternative limits impacts to
resource areas such that it may not require a variance from the Wetlands Protection Act as discussed in the ENF and
may restore an area of salt marsh that is currently impacted by a stormwater outlet.
Response: The comment is noted. Construction of the project will not require a Variance from the
Wetlands Protection Act or Wetland Regulations. No alterations to salt marsh are required to
construct the project. The relocation of the existing stormwater outfall, the placement of suitable
substrate and the installation of a biodegradable mat planted with salt marsh vegetation is proposed
to be provided as an enhancement for the salt marsh to re-establish itself.
CZM-2: Resource Area Impacts - CZM notes that the flood zones, resource areas, and resource impact estimates
included in the DEIR appear to be based on available GIS overlays, not actual delineations. While these mapping
tools are adequate to generally characterize these features, use of appropriate FEMA flood maps, field delineation of
resource boundaries, and quantification of impacted resources and associated mitigation will be required as the
project proceeds through permitting.
Response: The wetland resource areas were delineated in the field, mapped on the project
topographic survey plans and the delineations accepted by the conservation commissions through
the issuance of ORADs. Current FEMA flood insurance rate maps and flood studies were consulted
for 100-year floodplain and floodway elevations and boundaries and located on the topographic
mapping. All mapping of resources and impact assessments in the EA/DEIR is based on the field
delineations and mapping.
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