Highway Environmental Impact Statement & Environmental Design Services - Parksville
NYS Route 17 (I-86), Sullivan County, NY |NYSDOT
Project received a 2013 ACEC-NY Engineering Excellence Diamond Award and also received an Evergreen Certification through NYSDOT's GreenLITES Program.
This project involves construction of approximately 4.6 kilometers of controlled access expressway to interstate standards, on new alignment. The project is being conducted as part of the conversion of NYS Route 17 to I-86. The new highway will bypass an existing section of Route 17 that includes at-grade intersections and driveway access. The project area is in close proximity to the Little Beaverkill, a high quality trout fishery. The new alignment traverses an area of groundwater seeps that provide a thermal refuge for trout in the Little Beaverkill.
Services provided for this project included environmental studies and analyses for the Environmental Impact Statement (EIS), permitting, design services associated with wetland mitigation, landscape plans and Stormwater Pollution Prevention Plans (SWPPP). Detailed environmental studies included a visual impact assessment, wetland delineation, noise and air quality studies, socio-economic impact analyses, and water quality monitoring during construction.
Final mitigation plans were prepared for two sites totaling 2.6 acres. The mitigation will be accomplished by creating a composite of forested, emergent and scrub shrub wetlands adjacent to existing wetlands. Grading plans, planting plans, cross sections, sequence of construction and construction specifications were prepared.
The SWPPP addressed stormwater quantity and quality, and included additional measures to minimize thermal impacts. The stormwater management strategy included separation of offsite runoff from disturbed areas, bioretention design, stormwater pond design (with consideration for thermal impacts), open channel design, extensive use of TRMS for slope stability, TRM lined drainage channels to promote infiltration & 'greening', protection of riparian buffers, minimizing clearing limits, development of extensive landscaping plan for ponds & bioretention areas, protecting natural areas, minimizing project footprint, development of detailed E&SC plans to protect water quality during construction, pollutant loading analysis, and development of a water quality monitoring plan. Avoidance, minimization, and Low Impact Development strategies played a key role in designed measures contained in the SWPPP. Coordination of the SWPPP implementation with the highway and bridge construction phasing and drainage design was a key challenge during development of the SWPPP.