EXH1304052531

TO: Muffy Walker, U.S. Army Corps of Engineers FROM: Elizabeth Leavitt, Port of Seattle RE: Army Corps 404 Review of On-Site Borrow Areas TABLE OF CONTENTS Page I. OVERVIEW OF NEED FOR ON-SITE BORROW AREAS ............................................ 2 II. ANALYSIS OF BENEFITS FROM USE OF THE ON-SITE BORROW SOURCES ........................................................................................................................... 3 A. Reduction in Traffic Impacts ................................................................................... 3 B. Reduction in Air Quality Impacts ............................................................................ 5 C. Cost Savings from Use of the On-Site Borrow Sources .......................................... 5 III. DESCRIPTION OF CHANGES TO THE BORROW AREA PROPOSALS SINCE ISSUANCE OF THE MASTER PLAN IMPROVEMENT EISs ........................... 6 A. Borrow Areas 3 and 4 .............................................................................................. 6 B. Borrow Area 1.......................................................................................................... 7 IV. ENVIRONMENTAL ANALYSIS AND MITIGATION MEASURES ............................. 7 A. Summary .................................................................................................................. 7 B. Borrow Area Limits of Excavation and Groundwater ............................................. 8 C. Borrow Material Haul Methods ............................................................................. 10 D. Project Design Changes to Borrow Areas 3 and 4................................................. I 1 E. Managing Borrow Area Stormwater ...................................................................... 12 F. Managing ASARCO Smelter Arsenic Concentrations in Borrow Area 4 Soils ....................................................................................................................... 13 G. Preserving Wetlands within the Borrow Areas ...................................................... 14 H. Reclamation of Borrow Area Excavation Sites ..................................................... 15 V. REFERENCES .................................................................................................................. 16 AR 052531 1304 Page2 In response to your request, this Memorandum provides information on the Port of Seattle's purpose and need for the on-site borrow sources and explains the environmental review and project refinements that have occurred since issuance of the FAA's Record of Decision. I. OVERVIEW OF NEED FOR ON-SITE BORROW AREAS From the initial stages of…

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Call to order – Roll Call – Quorum Established – Land Acknowledgement We would like to acknowledge that our Agency operates in four present-day counties, which are the traditional lands of the Coast Salish people, past and present. This acknowledgement does not take the place of authentic relationships with indigenous communities in our jurisdiction and [...]