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

Whittier Bridge/I-95 Improvement Project FEIR
Chapter 3.0: Mitigation and Commitments
Exit 57 Newburyport Park-and-Ride lot through to the Ghost Trail in Salisbury (which connects to
U.S. Route 1):
Providing for the eventual hub connection to the Amesbury Powow Riverwalk and Salisbury
Point Ghost Trail;
Providing connections to existing and planned trails; and
Improving access to and interconnections between Moseley Woods and Maudslay State Park
and other regional recreational resources.
The incorporation of the Shared-Use Path will be consistent with the USDOT Policy Statement on
Bicycle and Pedestrian Accommodation Regulations and Recommendations (March 15, 2010) and
MassDOT‘s GreenDOT initiatives policy. The Shared-Use Path will be constructed during all
construction stages since it is directly related to the I-95 northbound bridge and roadway approach
sequencing. Cost to construct the path is expected to be $8.5 million.
Schedule and Cost
Permanent lighting, fendering, and a navigation buoy will be constructed during the last phase of the
project when bridge work is complete. Temporary aids to navigation during in-water work (42
months) will be used as needed. The cost to provide temporary and permanent navigation aids is
expected to be $100,000.
3.16.6 Section 401 Water Quality Certifications – MassDEP
A combined Water Quality Certification Application for the project was prepared to include: Major
Project Certification for dredging and disposal of more than 5,000 cubic yards of material within the
Merrimack River (BRP WW07); a Major Project Certification for the discharge of more than 5,000
square feet of fill within Land Under Ocean of the Merrimack River; and three vegetated wetlands
(Series H, I and M) north of the river (BRP WW10).
Summary of Dredging Activities (BRPWW07)
Dredging is associated with the installation of cofferdams around the six new permanent piers during
construction, around each of the four existing Whittier Bridge piers during demolition and from
construction of two temporary support structures during construction of the I-95 northbound bridge.
Approximately 7,150 cubic yards of material will be dredged within Land Under the Ocean (LUO) of
the Merrimack River. Dredging activities are limited to the Merrimack River and will include the entire
area within the cofferdams (45,620 square feet); it does not include the removal of the existing piers
(10,130 square feet outside of new pier footprints), which will be considered restoration of LUO.
Work within the cofferdams, outside of the footprint of the existing and proposed piers, is considered
a temporary alteration to LUO and totals 28,520 square feet. Cofferdams will be constructed at each
proposed pier location to provide work access and allow work to be performed in the ―dry.‖
Avoidance and Minimization
Measures to minimize the suspension of solids during dredging will include conducting all dredging
activities within water tight sheet pile cofferdams. Dredging will be conducted with a clamshell
excavator located on a barge moored or spudded adjacent to the cofferdam. Dredged material will
be allowed to drain much of the entrained water within the confines of the cofferdam before the
material is deposited on a barge for transport to an intermediate facility. No open water disposal or
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