421 85TH PL SW 2018-01-02 MF Import

0 designed to the standards and requirements of the City of Everett Drainage Ordinance (514-78). This generally requires that the peak runoff from the site during a 25-year design storm, after development, not exceed the calculated present peak runoff rate during a 10-year design storm. Project sponsors are also coordinating runoff detention design with the develope"s of the Andrea Terrace site to the east. It is hoped that the proper- ties can utilize the existing bog area (Figure 2) as a common detention site amenity as well. Some drainage improvements may be necessary off -site, where the vacant lot on Casino Road (Figure 2) has been partially filled, diverting the natural drainage course. Rain fal.ing on paved surfaces will pick up pollutants and will not be filtered through soils. Some pollutants, such as grease, oils and suspended sediments can be re- moved from the runoff before it leaves the site, by the incorporation of specially designed catch basins, with a commitment to their :egular, ongoing maintenance. Removal of these pollutants is of greatest benefit to the efforts to maintain the fish population in the creeks in Southwest Everett (Ref.: Kenilworth Hills FEIS). It may be desireable and feasible, defending upon the thickness and slope of permeable soil layers, to design permeable drainage systems to maximize groundwater re- charge. Though the groundwaters from this site are not known to feed into an important aquifer, probably resur- facing into Merril -Ring Creek, additional potential for removal of pollutants through soil filtration and b'_o- logic action, gained through groundwater recharge, may be desirable.