215 DORN AVE 2022-01-24 - Laserfiche WebLink

Executive Summary This project proposes the construction of two duplex structures and paved driving access. The site consists of a single tax parcel that has a gross area of 12,715 sf(0.292 acres). The site address is 215 Dorn Ave,Everett,WA 98208,with tax parcel number 392500001700. The site elevations range between 543 and 542,and appears to be nearly flat throughout the entire site with limited sloping from the northwest to the southeast. Vegetation on site is limited to grass. There are no trees, or other significant vegetation on-site. Existing impervious areas include gravel and concrete. An existing single family house has been recently demolished and removed from the property. The Geotechnical Engineering Evaluation for this site was performed by Nelson Geotechnical Associates, INC. Soils on site were identified as gray fine to course sands at depths within 6", and gray fine to course sand with silt and gravel trace at depths greater than 6". An infiltration rate of 0.9 in/hr was used in the sizing of this project's bioretention facility. This project is subject to the requirements of EMC Chapter 14.28, and the 2014 DOE Stormwater Management Manual of Western Washington. This project proposes greater than 5,000 sf of new and replaced impervious surface, and will evaluate minimum requirements#1-9 of both the DOE and EMC. This project proposes to route stormwater from all impervious surfaces into a bioretention facility designed to meet the low impact development performance standard, and flow control for this project. The 13 Elements of Stormwater Pollution Prevention Plan(SWPPP) are addressed on the drawing sheet titled Storm Water Prevention Plan and as well as in this report. Post construction soil in the disturbed areas,not covered by impervious surface, are to be installed in accordance to BMP T5.13.Post-construction Soil Quality and Depth. 3