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

T.F. Green Airport Improvement ProgramEnvironmental Impact Statement and Final Section 4(f) EvaluationAssociated with Construction Activities” is required for all projects with one or more acres of disturbance.Construction activities between one and five acres that also require a RIDEM Freshwater Wetlands Permit areautomatically granted authorization from RIPDES upon departmental receipt of the Freshwater Wetlands Permit.For all construction activities that disturb five or more acres, authorization also requires RIDEM review of theNotice of Intent (NOI) and Stormwater Pollution Prevention Plan (SWPPP) for the project. In the case of T.F. GreenAirport Improvement Program, where each individual project may not exceed this threshold, RIDEM hasindicated that the projects are viewed on a cumulative basis and therefore the filing of a RIPDES NOI and SWPPPwould be required for all projects that do not require a Freshwater Wetlands Permit regardless of the area ofdisturbance from construction activities.The SWPPP would identify all potential sources of pollution that may reasonably be expected to affectstormwater quality discharges, describe practices to be used to reduce pollutants in these discharges, and helpensure compliance with the terms and conditions of the RIPDES permit. The SWPPP would also include amaintenance commitment letter from RIAC regarding long-term maintenance of any structural BMPs that aredesigned as part of the stormwater management system.5.11.2 Significance ThresholdFAA Order 1050.1E defines a significant impact for water quality as one when an action would not meet waterquality standards. Potential difficulty in obtaining a permit or authorization may indicate a significant impact.5.11.2.1 Finding: No Significant Water Quality ImpactsThere would be no significant impacts to water quality, although there would be increases in impervioussurfaces within some drainage areas for Alternatives B2 and B4. Proposed stormwater mitigation measuresdeveloped in compliance with all applicable regulatory standards, including the RIDEM 2010 Stormwater Designand Installation Standards Manual, would address the water quality impacts and ensure the receiving waterswould not be impacted from new discharges. There would be no significant impacts due to Alternatives B2 orB4 because the Improvement Program would be designed to meet stormwater standards. Specifically:• The Project will be designed to meet water quality standards. Stormwater management systems will be designed(during the final design stage) to meet stormwater standards, mitigating the impacts resulting fromincreases to impervious surfaces from either Alternative B2 or B4. Alternative B2 and B4 would eachdecrease roadway and parking areas in the Tuscatucket Brook, and Brush Neck Cove watersheds, therebydecreasing potential pollutants entering downstream waterbodies.• The Project must avoid or mitigate any water quality problems. Alternatives B2 and B4 would avoid water qualityimpacts by reducing roadway and parking areas within the Tuscatucket and Brush Neck Cove Watersheds,thereby reducing pollutant loading. Mitigation measures to ensure that Alternatives B2 and B4 would meetstate stormwater standards would include the proper design of stormwater management systems.5.11.3 MethodologyThis section summarizes the methodology used to determine the Study Area water quality and to assess theImprovement Program’s potential impacts on surface water and groundwater resources.Chapter 5 - Environmental Consequences 5-210 July 2011\\mawatr\ev\09228.00\reports\FEIS_Final_July_2011\PVD_CH05_Environmental_Cons_JUL_2011.doc