T.F. Green Airport Improvement Program - FEIS Chapters - PVD

T.F. Green Airport Improvement ProgramEnvironmental Impact Statement and Final Section 4(f) EvaluationRunway 23Airport design engineers and the FAA reviewed safety and efficiency design requirements closely beforedeveloping Alternative B2 with an 8,700-foot long runway as a practicable alternative that would avoid most ofthe undesirable aquatic and terrestrial habitat impacts associated with extending Runway 5-23. Alternative B2would impact approximately 142 linear feet of stream at Runway 23 End and 12.1 acres of terrestrial habitat.These impacts could be avoided (or minimized) if the glide slope critical area were eliminated, but this levelsurface is required as a navigational aid to airplanes landing at Runway 23. Alternative B4 would avoid allimpacts to aquatic and terrestrial habitats at the Runway 23 End by extending the runway to the south only.Fully Relocated Airport RoadFor Alternative B2, the full relocation of Airport Road between Post Road and Warwick Avenue is necessary toallow Runway 5-23 to be extended northward across existing Airport Road. Fully Relocated Airport Roadwould impact approximately 14.4 acres of terrestrial habitat (primarily agricultural land). Other cover typesimpacted would include forested wetland (1.8 acres), shrubland (2.7 acres), and upland forest (2.1 acres).Alternative roadway alignments were investigated but were found to have significant adverse impacts toresidential neighborhoods or because they would create undesirable traffic conditions on Warwick Avenue.The use of a flyover structure was investigated to avoid impact to forested wetland habitat in the vicinity of PostRoad. Preliminary cost estimates were approximately $4 million to avoid 0.5 acres of wetland habitat impact. Itwas determined that the flyover would not be practicable based on cost.Under Alternative B4, Fully Relocated Airport Road is not proposed thereby avoiding any impacts to biologicalcommunities associated with this program element.5.12.8.2 MinimizationWhere possible, Alternatives B2 and B4 were designed to minimize impacts to biotic communities, particularlywetlands and aquatic habitats. Additional minimization measures may be feasible and would be evaluated forthe Preferred Alternative as it proceeds into the final design phase.Runway 34The Runway 34 safety enhancements (including relocating Taxiway C) would have unavoidable impacts toterrestrial habitats. These impacts have been minimized by shifting Runway 16-34 north to the maximum extentpracticable and by installing EMAS to reduce the length of the RSAs from 1,000 feet to 600 feet, and by locatingthe Perimeter Road within the ROFA between the runway end and EMAS. Impacts associated with the fillslopes for the runway were reduced from those reported in the DEIS Level 5 analysis by steepening the slopesfrom 4:1 to 3:1.Runway 23Alternative B2 would minimize disturbance to forested wetlands by routing the AMF Access Road over anexisting Airport security road. Alternative alignments were considered, including filling the north end ofWetland A5 and crossing Buckeye Brook on a structure midway between Lakeshore Drive and existingChapter 5 - Environmental Consequences 5-240 July 2011\\mawatr\ev\09228.00\reports\FEIS_Final_July_2011\PVD_CH05_Environmental_Cons_JUL_2011.doc