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

T.F. Green Airport Improvement ProgramEnvironmental Impact Statement and Final Section 4(f) EvaluationTable 5-120Comparison of Pollutant Loading ChangesPercentage Change from No–Action AlternativeDrainage Area Alternative B2 Alternative B4Buckeye Brook North 0.7% 0.6%Warwick Pond 5.2% 13.5%Buckeye Brook South 1.9% 1.2%Mill Cove (cumulative) 1.3% 1.2%Tuscatucket Brook -0.4% 11.0%Callahan Brook -0.2% -12.9%Brush Neck Cove (cumulative) -0.3% -0.3%Total 1.0% 0.9%Source: VHB, Inc.Notes: All changes in this table are relative to the No-Action Alternative. Totals rounded.5.11.8 Avoidance and MinimizationFor the T.F. Green Airport Improvement Program, total avoidance of the potential to impact water qualitywould not be possible, as Alternatives B2 and B4 would involve new impervious surfaces, new parking, andincreased aircraft operations. However, the design of Alternatives B2 and B4 includes avoidance andminimization efforts to prevent any risks to water quality.Alternatives B2 and B4 would minimize water quality impacts by reducing roadway and parking areas within theTuscatucket Brook and Brush Neck Cove Watersheds, thereby reducing pollutant loading. In addition,Alternatives B2 and B4 would include improved water quality treatment for the relocation of existing roadways(Airport Road and Main Avenue).The design of Alternatives B2 and B4 includes avoidance and minimization efforts to prevent any risks to waterquality by:• Minimizing the limits of work by keeping access roads as close to the airfield as practicable;• Reusing existing pipes, channels, and outfall structures wherever possible;• Avoiding encroachment onto the former Truk-Away Landfill site, which may contain subsurfacecontamination;• Using a closed stormwater system in the airfield to avoid introduction of any additional contaminants tostormwater runoff; and• Keeping potential pollutant sources such as fuel storage and deicing areas within the same watersheds asunder the baseline condition to avoid affecting any additional receiving waters.Specific water quality mitigation measures for Alternatives B2 and B4 are described in Chapter 6, Mitigation.Chapter 5 - Environmental Consequences 5-224 July 2011\\mawatr\ev\09228.00\reports\FEIS_Final_July_2011\PVD_CH05_Environmental_Cons_JUL_2011.doc