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
DEP-15: For infiltration basin and trench sizing, MassDOT will need to submit information to conservation
commissions and MassDEP that runoff from at least 65% of the catchment's impervious cover is directed to the
recharge practices. This needs to be considered on a catchment basis to each recharge practice in order to ensure
that sufficient runoff volume is directed to the recharge practices to achieve the annual recharge target.
Redevelopment components need to meet this requirement to maximum extent practicable and improve existing
conditions.
Response: Calculations and graphics have been provided to each conservation commission in
support of the NOI applications to demonstrate that at least 65% of the new development portion of
the project has been diverted to the proposed recharge BMPs. Recharge BMPs for the
redevelopment portion of the project have been incorporated to the maximum extent practicable.
DEP-16: MassDEP agreed to allow MassDOT to use the macro-approach to achieve compliance with stormwater
standards in recognition of their efforts to improve quality of runoff from state highways, including reduced road
salting in watersheds where public drinking water supplies are located. As reduction of winter deicers to roads within
public drinking water areas was a consideration for allowing use of the macro-approach, MassDEP requests that the
Secretary require MassDOT to evaluate the application of road deicers at the reduced rates in the all public drinking
water watersheds located along the 4.25 mile project route, Stormwater recharge within Zone II is specifically
required, by both MassDEP Drinking Water (3 10 CMR 22.21(2)(b)(7)) and Wetland (310 CMR I0.05(6)(k)(6))
regulations.
Response: As a general practice, MassDOT continues to update snow and ice material procedures
from a cost savings and efficiency perspective as well as to be better environmental stewards. Over
the past few years, a number of technologies and practices have been implemented to help achieve
the aforementioned goals. These technologies and practices, briefly described here, will be used in
these watersheds to address the concern with salt application.
MassDOT acknowledges that it will be necessary to provide sufficient deicer material on roadways to
provide reasonably safe roads to the traveling public, while at the same time improving stormwater
runoff and infiltration for recharge to the public water supply areas. An evaluation of our winter
maintenance practices can have the overall benefit of reducing salt application for comparable storm
events. It should be noted that the Zone II for the Salisbury wells overlaps the northern project limits
by approximately 1,500 feet. A review and modification of the road salt application will be aimed at
the salt spreader routes covering the entire project limit, which includes a number of municipal wells.
This approach is different from formally designating a reduced salt zone which adds sand to the
deicer and which, per MassDOT‘s Standard Operating Procedure, is based on review of scientific
data. MassDOT has been striving to reduce sand use for a variety of reasons including its inability to
work as a deicer or provide traction on high speed roads, its environmental impact, and the costs
associated with handling and disposal. A copy of MassDOT‘s Standard Operating Procedure for
considering municipal wells for a reduced salt zone can be viewed at:
http://www.mhd.state.ma.us/downloads/environ/ENV-01-30-1-000.pdf.
In lieu of a designated reduced salt zone along this section of I-95, MassDOT will review and
implement the following best management practices for winter maintenance:
a) Provide annual snow and ice training to the MassDOT personnel working in this area. The
training will include a component that will describe the environmental setting and public water
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