501 RIVERSIDE RD REGIONAL DISPOSAL COMPANY EVT TRANSFER FACILITY PHASE 1 SITE IMP Geotech Report 2025-07-28

RDC EVERETT TRANSFER FACILITY Everett,Washington Date Number of Containers Transferred I 2/2013 1,287 3/2013 1,349 I Total 28,450 Daily Average 40.47 CONCLUSIONS AND RECOMMENDATIONS Pavement Recommendations Pavement Design Parameters Based on the historic pavement loading information the following design parameters were used to calculate minimum pavement section thicknesses for new pavement with a 10-year, 15-year, and 20-year design life. • 10-year design life: 36.5 Million ESAL • 15-year design life: 54.8 Million ESAL I in 20-year design life: 73.0 Million ESAL Pavement design was completed following the AASHTO Guide for Design of Pavement Structures (AASHTO, 1993) using a design CBR of 42 for the existing fill and 1.0 for the native soft cohesive soils immediately below the fill, an average 50 trucks per day, and a 200-axle load equivalency I factor. New Hot Mix Asphalt Pavement Based on the results of our analysis, we recommend the new pavement section options summarized in Table 3 for design. Additional variations of new asphalt pavement sections may also be considered, if requested. I TABLE 3. RECOMMENDED PAVEMENT SECTION OPTIONS Pavement 10-Year Design Life Options 15-Year Design Life Options 20-Year Design Life Options Section Material 1 2 3 4 1 2 3 4 1 2 3 4 Asphalt1 7.25 7.25 8.75 8.75 8 8 10 10 8.5 8.5 10.5 10.5 II (inches) CSBC2 12 20 16 8 12 22 18 9 12 24 20 10 (inches) Geogrid3 Yes No No Yes Yes No No Yes Yes No No Yes Notes: 1.Design assumes asphalt consisting of 1/2-inch hot mix asphalt(PG 58-22)or equivalent. Il 2.Crushed surfacing base course(CSBC)should conform to Section 9-03.9(3)of the WSDOT Standard Specifications. 3.Design assumes geogrid such as Tensar®TX160,Mirafi®BXG 120,or equivalent. I GEOENGINEERS June 18,2013 Page 5 File No.4322.002-00 1