1707 SCENIC DR SNO CO PUD 2025-07-28

Recommended fill and crushed rock descriptions Page 2 of 2 The existing site will be strip of organic and stockpile the excavated material for landscaping. Imported Structural Fill meeting the following gradation will be imported, spread and compacted to subbase/subgrade level. Import Structural Fill - Modified U.S. Standard Sieve Size Percent Passing by Dry Weight 1 1/2 inch 100 ' inch 56 - 100 'A inch 40- 78 No. 10 22 - 57 No. 40 8 - 32 No. 200 Less than 2 Once all underground works are done,the area for the Substation Rock will be fine graded and compacted before placing the 4-inch Substation Rock material.The Substation Rock shall conform to the requirements of State Specification Section 9-03.12 (5), Gravel Backfill for Drywells, with the following gradation requirements: Substation Rock U.S. Standard Sieve Size Percent Passing by Dry Weight 1-1/2 inch square opening 100 1-inch square opening 50-100 3/4-inch square opening 0-20 3/8-inch square opening 0-2 No. 200 0-1.5 *Substation rock shall have a minimum void ratio of 30%. Crushed Surfacing As an option to promote better driving surface, a layer of crushed surface top course or base course can be added between the structural fill and the substation rock. Crushed surfacing top course and crushed surfacing base course shall conform to the requirements of state specification section 9-03.9(3)with the exception that the percent passing the U.S. No. 200 sieve shall not exceed 2 percent based on that fraction passing the U.S. No. 4 sieve. Per your email,the lower end gradation of the crushed surfacing and district standard import fill have been modified to promote better drainage;the substation rock gradation is fine as is. Hoson Lau (425)783-4338 Hllau@snopud.com !DSPAM:48,4c0d7fbe8744082639869! 6/10/2010