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

T.F. Green Airport Improvement ProgramEnvironmental Impact Statement and Final Section 4(f) Evaluation5.10.5 Short-Term Impacts from Temporary Construction ActivitiesConstruction activities associated with Alternatives B2 and B4 could potentially affect wetlands that are notdirectly impacted. Construction of new navigational aids at the Runway 34 End in Wetland A10 and A13 underAlternative B2 may require equipment to enter wetlands and temporarily disturb existing vegetation.Alternative B2 would also include temporary impacts to install utility conduits to provide electrical andcommunication service to navigational aids north of Airport Road for Runway 23. This would involve work inWetland A4 and Upper Buckeye Brook and Wetland A2 and the Spring Green Pond Inlet stream. Methods ofavoiding and minimizing this impact, such as directional drilling or jacking will be evaluated. Any disturbedarea would have wetland substrates restored in place after work is completed with vegetation largely returningto a pre-disturbance condition within one growing season. Alternative B4 would not require the installation ofnew navigational aids at the Runway 34 or Runway 23 Ends. There are no wetlands at the Runway 5 End wherenew navigational aids would be installed under Alternative B4.Construction activities within or close to wetlands are likely to affect habitat utilization patterns of wildlife,temporarily impacting the wetland wildlife habitat function. Wildlife species currently utilizing these habitatshave habituated to typical Airport operations but may abandon these areas when disturbed by nearby heavyequipment operations. Predisturbance habitat utilization patterns are anticipated to reestablish some periodafter construction has been completed.Without appropriate erosion and sedimentation controls, areas of exposed soils created during constructionactivities could contribute to temporary increases watercourse sediment loads. Construction best managementpractices, such as installing hay bales and silt fences, would be implemented to avoid and minimize thesetemporary construction impacts. The erosion and sedimentation control practices will be consistent with themost recent edition of the Rhode Island Soil Erosion and Sediment Control Handbook and Minimum Standard 10 ofthe Rhode Island Stormwater Design and Installation Standards Manual. 4045.10.6 Cumulative ImpactsFigure 5-41 shows the cumulative impacts to wetlands for Alternatives B2 and B4. Based on a review ofhistorical aerial photographs, there has been a substantial loss of wetland area (approximately 70 percent) since1939 within the Project Area. 405 Under Alternative B2 and B4 there would be an additional one percent loss(approximately) of this historical wetland area.Under Alternative B2, there would be an additional loss of 1.5 acres of Wetland A5, the relocation ofapproximately 112 feet of Buckeye Brook and extension of the existing 80-foot long culvert at Lakeshore Drive by30 feet to 110 feet. Under current conditions the culvert is a restriction to river herring spawning runs into SpringGreen Pond. Impact to this important fish run would represent a further cumulative loss of wetland functions andvalues provided by the Buckeye Brook/Spring Green Pond wetland system north of Warwick Pond. Wetland A2has suffered the loss of hydrology through artificial drainage, encroachment by residential development, andwater quality degradation through the discharge of untreated stormwater. Alternative B2 requires the constructionof Fully Relocated Airport Road, which would fill an additional 1.1 acre of this 7.6 acre forested wetland. Further,404 RIDEM and CRMC, December 2010.405 Estimated 397 acres of wetland in the Project Area in 1939 versus 118 acres in the baseline.Chapter 5 - Environmental Consequences 5-202 July 2011\\mawatr\ev\09228.00\reports\FEIS_Final_July_2011\PVD_CH05_Environmental_Cons_JUL_2011.doc