220 OLYMPIC BLVD VA OUTPATIENT CLINIC 2023-02-09

► I The site is bound by apartment buildings to the north, Elm Street to the west, Olympic Boulevard to I the east, and W Mukilteo Boulevard to the south with a gas station occupying the southeast corner of the lot. It is zoned B-2, Community Business. The surrounding zoning is B-2 to the south and east, I R-1 to the west, and R-3 to the north. Per the Geotechnical Engineering Report by Terracon, dated May 15, 2020, existing fill wasI observed at the exploration locations to depths of 6 to 15 feet below ground surface (bgs); loose to medium dense sand silt to about 15 bgs; and very stiff to hard sand with silt below about 15 bgs. The groundwater table ranges from approximately 5 to 10 feet bgs. I EXISTING STORMWATER RUNOFF The project site is divided into two on-site storm drainage sub-basins and two off-site tributary sub- I basins as shown in Figure 5 below. Please see further below for a general description of the two on- site basins and the off-site tributary basins. (kJ .....- -----j f., ,e ' / -, - -1/(5P/ ,.---‘----. I EXISTING BASINS 1 /�r.�/� 1: 105,741 SF (2.42 ACRES) ` / SOUTH BASIN ,7 f 34.951 SF (0.80 ACRES) ;,-�'.. �� 1 ', 1' ,,', § I NORTH BASIN 3,, ' - /_ 4, ,; 63,496 SF (1.45) ACRES) .��, � I OLYMPIC BASIN: / /, 1 2,928 SF (0.07 ACRES) 4 �w MUKILTEO/ELM BASIN: �, f 4,366 SF (0.10 ACRES) .. 111 \, -tr . - � , . tot,. ti 7LO IV" y Figure 5: Existing Sub-Basins Map I South Basin: Drainage from the southern portion of project site (South Basin) is conveyed through I catch basins and closed conveyance pipes to the basin's connection point to the existing municipal conveyance system in Elm Street. From there, the stormwater runoff flows southerly to the intersection of Elm Street and Mukilteo Boulevard. The runoff is then conveyed easterly to an existing stormwater manhole on the southeast corner of the project site where it converges with I NAVIX Everett VA Clinic— Everett, WA 16 I