10122 7TH AVE SE 2018-02-12 - Laserfiche WebLink

Considering option 3. BM10.50 Downspout dispersion, gravel-fillI trenches are not feasible as well due to the size of trench required and the requirement of having a vegetated flowpath of at least 25 feet in length. Splash blocks are proposed to be used for two of the downspouts locate at the southeast and southwest of the duplex structure discharging to a vegetated flow path toward north (see plans). A shallow awale will be installed on the north side of the driveway. A berm will line the property line and the east end of the swale (see plans). **Please Note:At a minimum,you must establish good soil quality and depth in all areas that will remain vegetated after your project is complete, including lawn and landscaped areas. One of the three following options must be chosen(Select Check Boxes as applicable) per BMP 12.20: © OPTION 1- Amend Existing Soils in Place: Scarify or till existing subgrade to 4 inches depth (or to depth needed to achieve a total depth of 12 inches of uncompacted soil after calculated amount of amendment is added,see specific subsections below). Entire surface should be disturbed by scarification. Do not scarify within drip line of existing trees to be retained. Within Stormwater Drainage System locations or Landscaped Areas (10percent organic content)- Place and rototill 3 inches of composted material into 5 inchesof soil(a total depth of about 9.5 inches,for a settled depth of 8 inches). As noted previously, subsoils below this layer should be scarified at least 4 inches,for a finished minimum depth of 12 inches of uncompacted soil. Rake beds to smooth and remove rocks largerthan 2 inches diameter. Mulch areas with 2 inches of organic mulch. Within Lawn Areas (5percent organic content)- Place and rototill 1.75 inches of composted material into 6.25 inches of soil(a total amended depth of about 9.5 inches,for a settled depth of 8 inches). As noted previously,subsoils below this layer should be-scarified at least 4 inches,for a finished minimum depth of 12 inchesof uncompacted soil. Water or roll to compact soil to 85 percent of maximum. Rake to level, and remove surface woody debris and rocks largerthan 1 inch in diameter. II OPTION 2- Stockpile Site Topsoils Prior to Grading for Reapplication: If placed topsoil plus compost or other organic material will amount to less than 12 inches: scarify or till subgrade to depth needed to achieve 12 inches of loosened soil after topsoil and amendment are placed. Entire surface should be disturbed by scarification. Do not scarify within drip line of existing trees to be retained. Stockpile and cover soil with weed barrier material that sheds moisture yet allows air transmission, in approved location,prior to grading. Replace stockpiled topsoil prior to planting. Within StormwaterDrainage System locations or Landscaped Areas (10percent organic content)- Place and rototill 3 inches of composted material into 5 inches of replaced soil (a total depth of about 9.5 inches,for a settled depth of 8 inches). Subsoils below this layer should be scarified at least 4 inches,for a finished minimum depth of 12 inches of uncompacted soil. Rake beds to smooth and remove rocks larger than 2 inches in diameter. Mulch areas with 2 inches of organic mulch or stockpiled duff. Page 4 of 8 CITY OF EVERETT 13200 Cedar Street I Everett, WA 98201 1425-257-8810 jeverettwd.guv