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

Whittier Bridge/I-95 Improvement Project FEIR
Chapter 3.0: Mitigation and Commitments
provided through the implementation of the SWPPP to be prepared in accordance with the EPA
Construction General Permit.
The wetland mitigation in Amesbury and Salisbury will be performed in conjunction with the widening
of the I-95 corridor, during the initial project stages. The cost associated with the mitigation is
expected to be $135,000.
Summary of Fisheries Impacts
There are two fish species with special status known to use the project area, the shortnose sturgeon
and the Atlantic sturgeon. Due to the presence of these species a Section 7 consultation regarding
potential impacts and impact avoidance measures with the National Marine Fisheries Service
(NMFS) under the federal Endangered Species Act (ESA) has been conducted. There may be some
temporary impacts related to construction noise and activity and MassDOT has coordinated with
NMFS and the Massachusetts Division of Marine Fisheries (DMF) in their review of the proposed
demolition, construction and dredging activities.
Fisheries Mitigation
DMF has determined, in a letter dated December 9, 2011, that if the project avoids the simultaneous
installation of cofferdams, no time of year restrictions are required.
MassDOT has coordinated extensively with NMF Northeast Region to implement conservation
recommendations within essential fish habitat and anadromous fish runs within the Merrimack River
in the project vicinity. As such, MassDOT has accepted NMFs recommendations as follows:
All in water work will take place within cofferdams. Installation of cofferdams will only be
conducted one at a time to minimize noise and/or turbidity impacts.
From April 1 through June 30 of any year, at least one of the two navigation channels will remain
unobstructed at all times to minimize impacts to the Atlantic salmon migration.
From April 1 through June 30 of any year, an observer will be present on-site at the time of the
installation of cofferdams. If the Atlantic salmon or other anadromous species are observed in
the work area, the in-water work (i.e., cofferdam installation) will be delayed until they have
passed through. Prior to the commencement of any cofferdam installation, MassDOT will submit
an observer plan to NMFS for approval.
Schedule and Cost
The overall construction duration is expected to be 48 months, including a 42-month in-water work
period for demolition and construction. Construction is scheduled to begin in 2013 and end in 2016.
It is expected that the removal of all existing bridge components will begin in November 2014 and be
completed within 24 months by November 2016.
For the new structures, the in-water work will include installing piles, piers, and footings; in-water
demolition activities will require removing the existing bridge piers. The removal of the existing
Whittier Bridge will occur during the second phase of construction when the new northbound bridge
is complete and all I-95 traffic is shifted to the new bridge.
The cost of the cofferdams and observer is estimated at $7.5 million.
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