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

T.F. Green Airport Improvement ProgramEnvironmental Impact Statement and Final Section 4(f) EvaluationTable 5-113 Alternative B2: Impervious Roadway and Parking Areas by Drainage Area 1Drainage AreaNo-ActionAlternativeAlternative B2Change in Roadway and Parking Area (acres) 2Required for Voluntary LandConstruction 3 Acquisition Areas 4 TotalBuckeye Brook North 106.8 124.3 +15.9 +1.6 +17.5Warwick Pond 0.8 0.9 +0.1 0.0 +0.1Buckeye Brook South 50.5 53.5 +3.0 0.0 +3.0Mill Cove (cumulative) 5 158.1 178.7 +19.0 +1.6 +20.6Tuscatucket Brook 21.0 18.2 (2.8) 0.0 (2.8)Callahan Brook 19.1 19.1 0.0 0.0 0.0Brush Neck Cove40.1 37.3 (2.8) 0.0 (2.8)(cumulative) 6Total 198.2 216.0 +16.2 +1.6 +17.8Source: VHB, Inc.1 The areas in this table represent the portions of the watersheds that fall within the maximum combined footprint of the Alternatives (including both on- andoff-Airport areas). Totals are rounded. Existing roadways were assumed to remain impervious.2 The roadway and parking areas are a subset of the impervious areas referred to in Table 5-112 (e.g., 216.0 acres of the 549.4 acres total impervious acres areattributed to parking and roadway surfaces).3 Construction elements include EMAS, parking, roadways, taxiways, and RSA and RPZ clearing, depending on drainage area.4 Associated with the Completed and Current Part 150 VLAP.5 The Mill Cove drainage area consists of the combined Buckeye Brook North, Warwick Pond, and Buckeye Brook South drainage areas evaluated in this analysis.6 The Brush Neck Cove drainage area consists of the combined Tuscatucket Brook and Callahan Brook drainage areas evaluated in this analysis.Alternative B2 would decrease the amount of road and parking lot impervious surfaces by 2.8 acres in the BrushNeck Cove watershed, improving water quality by removing potential pollutant sources. The 20.6-acre increasein roadway, including Fully Relocated Airport Road and parking lot impervious surfaces in the Mill Covewatershed, would include mitigation measures designed to meet state stormwater requirements and would notadversely affect water quality in the receiving waters of Spring Green Pond, Buckeye Brook, or Warwick Pond.Table 5-114 shows that Alternative B2 would result in a 1.0 percent increase to the total pollutant load whencompared to the No Action Alternative. Infiltrating stormwater BMPs and pervious surfaces located betweenimpervious surfaces, such as taxiways and runways, and the stormwater collection system would beimplemented to effectively mitigate pollutant loading impacts in receiving waters of Spring Green Pond,Buckeye Brook, and Warwick Pond.Alternative B2 would decrease the amount of pollutant loading by 0.3 percent in the Brush Neck Covewatershed, improving water quality by removing potential pollutant sources. The 1.3 percent increase topollutant loads in the Mill Cove watershed would include mitigation measures designed to meet statestormwater requirements and therefore would not adversely affect water quality.Alternative B2 would increase the use of glycol for aircraft deicing proportionate to the increase in departingflights, as shown in Table 5-115. The average use of glycol (depending on weather) would increase by8.8 percent in 2020 and 8.3 percent in 2025 relative to the No-Action Alternative. Without the proposed deicermanagement system which will be in place by 2015, increased glycol usage could impact water quality.However, the use of the glycol blending facility and deicer management system (both constructed as part of theNo-Action Alternative) would not substantially increase glycol use or discharge.Chapter 5 - Environmental Consequences 5-215 July 2011\\mawatr\ev\09228.00\reports\FEIS_Final_July_2011\PVD_CH05_Environmental_Cons_JUL_2011.doc