EXH1253050603

Observed Groundwater Levels in Monitoring Wells near Pond A FIGURES Site and Exploration Plan Cross Section A-A' Pond A Detail Cross Section B-B' APPENDIX A SUBSURFACE EXPLORATIONS FIGURES A-1 Key to Exploration Logs A-2 and A-3 Boring Log HC99-B38 and HC99-B39 A-4 Hand-Auger Log HC00-A300 and HC00-A301 APPENDIX B GROUNDWATER SEEPAGE ANALYSIS B-1 Approach B-1 Model Setup B.I HartCrowser Page i4978-06June18,2001 AR 050605 CONTENTS (Continued) PaRe Assumptions B-4 Results B-4 Data Sources for Appendix B B-5 FIGURES B-1 Groundwater Modeling Area, Pond A B-2 SimulatedAverageWater Table,ExistingConditions without PondA B-3 SimulatedAverageWaterTable,PondA with SheetPiles B-4 SimulatedAverageWater Table, PondA with Sheet Pilesand DiversionDrain B-5 SimulatedLateSummerWater Table,ExistingConditions without Pond A B-6 Simulated LateSummerWater Table,Pond A with Sheet Pilesand Diversion Drain APPENDIX C SHEET PILE DESIGN AND CONSTRUCTION C-1 Design C-1 Construction C-3 TABLE C-1 Soil ParametersUsed in Design Hart Crowser Page ii 4978-06 June 18, 2001 AR 050606 AVOIDANCE OF WETLAND IMPACTS TEMPORARY STORMWATER POND A SEA-TAC THIRD RUNWAY SUMMARY The design and construction of Temporary Stormwater Pond A at the Sea-Tac Third Runway project has been analyzed to avoid potential effects on groundwater flow and wetland hydrology. This report examines the hydrogeologic and geotechnical issues related to design, construction, and operation of Pond A. Potential impacts to the hydrology of riparian wetlands between Pond A and Miller Creek can be mitigated through appropriate engineering design. Pond A will be excavated about 6 to 10 feet in wetland soils, and would have an operating water level roughly 0 to 10 feet below the current…

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Add to CalendarMWednesday Mar 11, 9:00am - 11:35am
1904 3rd Avenue, Suite 105, Seattle, WA 98101
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 [...]