6133 LAKE CHAPLAIN RD 2025-08-19

On-Site Stormwater Management BMPs for MR#1-5 Projects (continued). Category 2 — Roofs (continued) Simplified infeasibility criteria Feasible/infeasible? Check box if criterion is true. Only one box needs to be checked to Provide justification if Priority BMP indicate that the BMP is infeasible. infeasible. 1 BMP T5.30: ❑ Flow control exempt as site directly discharges to Puget Sound ❑ Not applicable since Full or Snohomish River;or in a storm drainage system that is site is flow control Dispersion entirely manmade from the site to one of these water bodies. exempt(direct ❑ <65 to 10 ratio of forested or native vegetation area to discharge) impervious area. ❑ Infeasible ❑ <100 feet(<25 feet for sheet flow from a non-native pervious ❑ Feasible surface)forested or native vegetation flow path length. ❑ Dispersion area located in a critical area buffer. Justification: ❑ Dispersion area located on slope>20 percent. ❑ Dispersion area contains septic systems. ❑ Site setbacks and design criteria provided in BMP T5.30 (SWMMWW Section V-3)cannot be achieved. 2 BMP T5.14: Selection of any of the following criteria does not require input ❑ Not applicable since Rain Gardens from a licensed professional,although some may require site is flow control professional services: exempt(direct ❑ Flow control exempt as site directly discharges to Puget Sound discharge) or Snohomish River;or in a storm drainage system that is ❑ Infeasible entirely manmade from the site to one of these water bodies. ❑ Feasible ❑ Evaluation of infiltration is not required per the Infiltration Infeasibility data available on Map Everett. Justification: ❑ BMP is not compatible with the surrounding drainage system. ❑ Within a designated erosion hazard or landslide hazard area. ❑ Site cannot be reasonably designed to locate rain gardens on Attach supporting slopes<8 percent. documentation if this ❑ Within 50 feet from the top of slopes>20 percent and >10 BMP is feasible: feet of vertical relief. ❑ USDA Custom Soil ❑ Site has known soil or groundwater contamination(typically Report federal Superfund sites or state cleanup sites under the ❑ Small-scale Pilot Model Toxics Control Act[MTCA)).See Volume V of the Infiltration Test SWMMWW for specific setbacks. (PIT)results per ❑ Within 100 feet of a closed or active landfill. SWMMWW ❑ Within 10 feet of an UST and its connecting underground pipes specifications (capacity of the tank and pipe system is<_1,100 gallons). ❑ USDASoilType(s) ❑ Within 100 feet of an UST and its connecting underground ❑ Measured pipes(capacity of the tank and pipe system>1,100 gallons). Infiltration Rate in ❑ Within 100 feet of a drinking water well,or a spring used for in/hr(from PIT) drinking water supply. ❑ Separation to ❑ Within 10 feet of small on-site sewage disposal drainfield, groundwater and including reserve areas,and grey water reuse systems. hardpan ❑ Field testing indicates the site has a measured infiltration rate<0.30 inches per hour. ❑ <1 foot to from the proposed rain garden bottom to seasonal high groundwater or another impermeable subsurface layer. City of Everett Public Works Small Project Stormwater Site Plan/Report—Sept.2023 Page 23 of 40