3003 W CASINO RD BLDG 45-12 2016-10-20

STATIC TEST FACILITY PRELIMINARY STORM DRAINAGE REPORT EVERETT,WASHINGTON SECTION 1: PROJECT OVERVIEW Boeing Company is proposing to construct a 115,000 square foot building and associated improvements in support of the Static Testing for the 777-9X Airplane. The site is located at the intersection of 94'Street SW and 29'Avenue W, Everett, Washington. The project is bound by the Boeing Flightline to the west,Paine Field Airport Property and the perimeter road to the south, 94'j' Street SW to the north and 29' Avenue W. to the east. More generally, the project site is located at the southeast quarter of Section 15,Township 28N, R4W,WM in Everett, Washington. See Vicinity Map on the following page. The project area is approximately 6.84 acres and includes the removal of the temporary S4 parking lot and approximately 125,000 cubic yards of spoil material used as preload. The existing land use areas can be characterized as S4 parking lot and a mix of pervious fill and existing pond and grass lined swale. The site is adjacent to a jurisdictional ditch that was mapped by the United States Army Corps of Engineers. The ditch receives stormwater from the pipe that is connected to the recently constructed drainage system for the S5 Parking Lot to the east. At this time, the jurisdictional ditch is unaffected by the proposed development. The proposal is to construct a 115,000sf, 120ft tall building and surrounding concrete paved surfaces and utilities. The building will house a not fueled 777-9X airplane,where a series of static tests on the airplane will be performed. Externally, the paved surfaces will be used to wheel the airplane from the flightline into the building,as well as,provide storage of raw materials(i.e. steel, aluminum, etc.) used for the manufacturing of fixtures and structures in support of the testing operations. Stormwater from the site will be collected by concrete swales, trench drains, catch basins and conveyed by a pipe system. The stormwater will enter the existing flightline storm drainage system and generally conveyed in a northwest direction where it will discharge into the existing stormwater wetlands and Alpha Pond located adjacent to the main runway at Paine Field Airport. Ultimately,the stormwater enters Japanese Gulch and discharges into Possession Sound. The stormwater runoff from the project site will be treated by onsite water quality treatment devices reviewed and approved by the Paine Field Airport (Snohomish County) and detained at Alpha Pond,through an agreement between Snohomish County,Boeing Company and the City of Everett. Basic Stormwater water quality treatment for the developed areas must comply with the latest 2012 Washington State Department of Ecology's Stormwater Management Manual for Western Washington(2012 DOE Manual). -0 Go Amite c :4-1 y `�t'a-F- enc)C+)/ft%P A,, V4— ��S �1pv�' � G�C • 5► c� rl CC & o Cf ru rl 0 � a� c�ec�Lf ane rrvn 1-5 vyluS+ 6-9- CEI Project#141001 Pg. 1