Concord, NH – The New Hampshire Department of Environmental Services (DES) and New Hampshire Department of Transportation (DOT) today announced the issuance of final state environmental approvals for improvements to Interstate 93 from the Massachusetts border to the junction with Interstate 293 in Manchester. DES has issued the Wetlands Permit and the 401 Water Quality Certificate.
This project will improve the safety, capacity and efficiency along 19.8 miles of I-93. The project will include rebuilding and widening I-93, improvements to five existing interchanges and cross roads, construction of three new Park and Rides at Exits 2, 3 and 5, expanded bus service at Exit 4 and space to accommodate a future transit service within or along the highway corridor rail corridor between the Massachusetts/New Hampshire state line northerly to the Exit 5 interchange.
Approximately 76 acres of wetlands will be impacted by the project. As a part of the wetlands permitting process, DES and DOT have worked cooperatively to develop a mitigation plan that compensates for the loss of wetlands and aquatic resources associated with the construction of this project. The mitigation plan includes the construction of 31 acres of new wetlands, preservation of 1,000 acres of upland/wetland complexes, and construction of stormwater treatment areas. The mitigation plan also includes a $3 million contribution to the NHDES Drinking Water Supply Grant Program for funding aquatic resource protection within the Massabesic Lake watershed project area and the establishment of a $3.5 million fund for the Community Technical Assistance Program to help area communities within the project area plan for growth.
Water quality monitoring by DES, DOT, and the US Environmental Protection Agency during the past 3 winters has documented concentrations of chlorides that do not meet water quality standards in water bodies located in four watersheds through which I-93 passes. The high chloride concentrations are largely due to winter road maintenance of paved surfaces, including I-93, state, municipal and private roads and parking lots on all roads in these watersheds. To address this issue, the 401 Water Quality Certificate incorporates a process by which DES and DOT will perform a water quality and load reduction study, called a Total Maximum Daily Load (TMDL) study, in four watersheds to further assess road salt impact, and then develop a comprehensive plan for winter salt use reduction. These studies will be performed with monitoring concurrent with the final design and early construction of the highway improvements. This work will be completed before the new I-93 improvements are put into operation.
DES Commissioner Michael Nolin commented, "I want to commend the DES and DOT staff along with our Federal partners for the collaborative effort that occurred over the past three years to ensure that protection of our surface waters goes hand-in-hand with the benefits to the public’s safety that is expected by the expansion improvements to of I-93."
DOT Commissioner Carol Murray quote "The cooperative efforts of many State and Federal agencies working together to move a needed highway safety improvement project forward in an environmentally responsible manner is the reason that these final State environmental approvals have been issued today."