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

STATIC TEST FACILITY PRELIMINARY STORM DRAINAGE REPORT EVERETT,WASHINGTON SECTION 3: OFFSITE ANALYSIS Upstream: The project located is located on an existing preload/spoil pile site and therefore does not receive any surface run-on stormwater, however, a culvert located at the northeast corner discharges stormwater into the existing ditch at the northeast corner of the site. The ditch has been recently reconstructed as a part of the remediation efforts to remove contaminated soils. The ditch mostly receives stormwater from the detention facility for the newly constructed S5 Parking Lot to the east. This stormwater flows westward within the ditch approximately 170' where it enters into a 12" CMP culvert. Stormwater flows northward through the culvert under 94"' St. SW and discharges into Wetland #13. The ditch has been preliminary jurisdictional determination from the Department of Army Engineers. JVb 8c e i Downstream: J Inspector: Dean A.Furr Dates of Field Inspection: 1/6/15 at 11:30am Weather Conditions: Partly cloudy with temperatures in the range of upper 40's to low 50's. The site currently has the temporary S4 parking lot to the west adjacent to the flightline and a large spoil pile to the east. Stormwater discharges from the project area at 3 Discharge Points (DP). DP#1, located at the northwest corner, receives surface water from the majority of the north half of the parking lot and the north half of the spoil pile. The stormwater is conveyed through a pipe network in westerly direction for approximately 1,400 LF where it enters an Oil Water Separator #EV-157. The stormwater continues northward for approximately 170LF where it enters a 54" SD Main. DP#2, receives stormwater from the south half of the parking lot and the spoil pile. The stormwater enters a 12" SD at the west end of the sediment pond located in the southwest corner of the site. The stormwater is conveyed westward for approximately 1,000LF along south side of the Flightline and turns northward. The stormwater is conveyed within a 36"SD for approximately 90OLF where it converges with stormwater from POC#2 at the entrance into Oil Water Separator#EV-157. DP#3, receives stormwater from the emergency overflow of Pond D and the discharge form the east as described in the Upstream portion of this section. Stormwater flows in a northwest direction for approximately 90OLF through Wetland#13 and Boeing Lake where it enters the 54"SD main as described in POC#1. Stormwater flows westward for approximately 750LF where it converges with stormwater form POC's#1 and#2. See the Offsite Analysis Exhibit 1 at the end of this Section. CEI Project#141001 Pg.5