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

T.F. Green Airport Improvement ProgramEnvironmental Impact Statement and Final Section 4(f) EvaluationIndirect ImpactsIndirect impacts to existing wetlands are not anticipated. The potential for new commercial development islimited to areas such as the agricultural land and former industrial parcels north of existing Airport Road. Thepotential redevelopment of these properties is not anticipated to result in further significant impacts toremaining wetlands. Indirect impacts can also include impacts that would occur at a later time or in a differentplace, or that would cause changes in wildlife habitat or populations as an indirect consequence of wetland loss.The construction of Fully Relocated Airport Road through Wetland A2 would divide this wetland into half,fragmenting the remaining wetland wildlife habitat not directly impacted by road construction. This action couldindirectly impact the wetland through the discharge of stormwater runoff, potentially affecting water quality. Thefilling of Wetland A5 to accommodate the glide slope area and Perimeter Road would reduce flood storagefunction, potentially increasing flood heights and durations in the wetland above Lakeshore Drive. Theintroduction of traffic along the AMF access road in Wetland A5 could further degrade the wetland wildlifehabitat function of the remaining portion of Wetland A5. Clearing vegetation along portions of the AMF accessroad proximate to Buckeye Brook could lead to undesirable thermal impacts to the stream habitat.The introduction of invasive species at areas disturbed during construction would also be a potential indirectimpact to adjacent wetlands for Alternatives B2 and B4. The presence of an invasive species seed bank and theextent of the wetland disturbance would affect the level of this risk. Monitoring would be required to assess thisindirect impact and determine if mitigation countermeasures would be required.5.10.4.3 Alternative B4This section summarizes the direct, indirect, and short-term construction-related wetland impacts forAlternative B4. Table 5-104 provides information on the impacts to wetland functions and values. Table 5-105provides an overview of waterway impacts by program element. Table 5-106 provides detailed information onimpacts to federal jurisdictional vegetated wetlands while Table 5-107 provides information on impacts tostate-regulated wetlands. All wetland direct wetland impacts associated with Alternative B4 are FAA-requiredsafety enhancements to the Runway 34 RSA, including the relocation of Taxiway C.Direct ImpactsAlternative B4 would impact 5.0 acres of federal jurisdictional vegetated wetlands and approximately 843 linearfeet of waterways. This represents a 2.3 acre decrease from the 7.3 acres of impact to federal jurisdictionalwetlands reported in the DEIS. The additional avoidance and minimization measures incorporated into theRunway 34 design are described in Section 5.10.8, Avoidance and Minimization. Two new culverts are proposedthat would place a total of approximately 340 linear feet of Tributary A11 in structures. The remaining total of503 linear feet of Tributary A11 and Tributary A that would be impacted would be diverted into new channel oropen water wetland areas. The total state-regulated perimeter and riverbank wetland area that would beimpacted under Alternative B4 is estimated to be 6.5 acres, much of which is within the developed Airport area.An additional 0.2 acres of floodplain outside of other freshwater wetland would also be impacted based on theoutput of the HEC-RAS model for Tributary A11. Impacts to state-regulated floodplain are considered in moredetail in Section 5.14, Floodplains. The impacted vegetated wetlands are shown in Figures 5-39 and 5-40.Chapter 5 - Environmental Consequences 5-198 July 2011\\mawatr\ev\09228.00\reports\FEIS_Final_July_2011\PVD_CH05_Environmental_Cons_JUL_2011.doc