I-93 Exit 4A

TFMoran Engineers are providing stormwater management and monitoring services for the new exit 4A off I-93 in Londonderry. The project, nearing completion of its first phase, is intended to reduce congestion on Route 102, improve safety, spark economic growth, and relieve traffic on secondary and residential roads.

Along with the on-going SWPPP related services, TFM designed the stream diversion plans and bypass pumping system to divert the flow of the Wheeler Pond Tributary to allow for the relocation of the brook. These plans included the development of a monitoring program for the in-stream work and monitoring the turbidity of the construction water discharge for compliance with NHDES surface water quality rules.

Additionally, TFM designed several water diversions to allow for the construction of new stormwater infrastructure, designed and permitted a flocculation treatment system, and performed drinking water well monitoring to support the rock blasting activities required on the project.

The project is located about a mile North of Exit 4 and will provide access to the east side of I-93 via a new connector road between the interchange in Londonderry and Folsom Road in Derry. The project also includes upgrades to surrounding roads including Folsom Road, Tsienneto Road, and NH Route 102 (Chester Road).

The project, including all phases, is expected to be completed in 2026.

  • Client: Weaver Brothers Construction
  • Services: Stormwater Monitoring