Posted on

EXH AR026116: Memo — Modeled Area and Hydrus Model Results Draft Interim Deliverables

Document Library
Sea-Tac Airport
Third Runway
PCHB
Box 10

A June 2001 technical memo from Pacific Groundwater Group to the Port of Seattle outlines groundwater modeling work related to the proposed Sea-Tac Airport third runway construction. The memo defines areas to be analyzed using Hydrus/Slice modeling software instead of the standard HSPF model, focusing on how new runway fill in the Miller Creek and Walker Creek basins will affect groundwater recharge. It also describes the selection of three representative hydrogeologic cross sections and methods for calculating effective recharge, accounting for runoff from impervious runway surfaces into surrounding pervious fill areas.

Open full document

Notes

Memorandum dated June 25, 2001 from Charles Ellingson of Pacific Groundwater Group to Keith Smith, Port Of Seattle, presenting draft interim deliverables for Hydrus/Slice modeling of third runway fill at Sea-Tac Airport. Covers definition of areas modeled by Hydrus/Slice instead of HSPF, effective recharge calculations (recharge 1 and recharge 2 algorithms), selection of three hydrogeologic cross sections (Slice 1, Slice 2, Slice 3), fill thickness, and soil definitions. Addresses Miller Creek Basin (3,030,620 sq ft pervious fill area; 1,833,928 sq ft impervious) and Walker Creek Basin (450,630 sq ft pervious; 260,743 sq ft impervious). References AquaTerra HSPF regional parameters, Hart Crowser 1999 cross sections, Parametrix SMP Figure B2-2, and Mechanically Stabilized Earth (MSE) wall. Administrative Record number AR 026116.

Sidebar On/Off
V V