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

Whittier Bridge/I-95 Improvement Project FEIR
Chapter 1.0: Changes Since the Draft Environmental Impact Report and Resolution of Additional Issues
applicant shall demonstrate the restoration or mitigation has been successfully completed for
at least two growing seasons.
MassDOT will monitor the RFA mitigation and restoration for two growing seasons following the
completion of the mitigation and restoration work.
RFA mitigation in Newburyport is summarized in Table 1-3 and in Table 1-4 for Amesbury. RFA
impacts in Newburyport are illustrated on Figure 1-7 and for Amesbury in Figure 1-8.
Meader Brook in Salisbury also has a 200-foot RFA, but because the existing culvert under I-95 is
greater than 200 feet in length, the RFA starts and ends at the culvert headwalls. The highway
widening in this vicinity would not affect the RFA; therefore, no impacts would occur.
1.4.5 Wetland Mitigation
The project will result in 4,960 square feet of direct impacts to jurisdictional wetlands (Wetlands I and
H) in Amesbury, including 3,560 square feet of permanent impact. To mitigate for permanent
impacts, the Bordering Vegetated Wetland (BVW) replication proposed in Amesbury will consist of
expanding Wetland H by excavating approximately 4,960 square feet of upland near its northern end
within the ROW, establishing grades to match the grades in Wetland H and planting with a variety of
wetland species, including Black Chokeberry, Highbush Blueberry, Winterberry and Grey Dogwood.
Temporary impacts to Wetland H (1,400 square feet), as well as to Isolated Vegetated Wetland M
(240 square feet in Salisbury), will be mitigated at each wetland location by restoring to preconstruction
grades and stabilizing substrates with a seed mix of annual rye and native wetland
species.
Site Selection
The WPA requires compensation for impacts to BVW after all avoidance and minimization measures
have been taken (310 CMR 10.55(4)(b)). Because permanent BVW impacts for the project are less
than 5,000 square feet, site selection was guided by the following criteria as listed in the DEP‘s
Massachusetts Inland Replication Guidelines (2002):
1. Surface area must be equal to the lost area;
2. The replication area must have similar ground water and surface elevation as the lost area;
3. The replication area must have a similar location relative to the bank as the lost area;
4. The replication area must have an unrestricted hydraulic connection to the same water body
or waterway as the lost area; and
5. The location of the replication area must be in the same general area as the lost wetland.
The search for a replication site was confined to the MassDOT ROW within Amesbury to facilitate
access and to provide compensation close to, and similar to, the impact areas.
After reviewing field notes, aerial photography and project-specific topography, several sites were
identified as having the potential to provide suitable restoration opportunities. These included the
south end of Wetland G, two sites at the north end of Wetland H, and Wetland J. The four sites were
investigated with the following findings:
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