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Foothill Sanitary Landfill – Seismic Characterization 2 03.18.2015 and the USGS Quaternary Fold and Fault Database were also used to verify fault parameters. Faults / fault zones located within 150 km of the Landfill were screened for location and magnitude. From this screening it was the determined that eight (8) faults / fault zones would have the greatest impact based on their magnitude and location. Listed below are the eight faults / fault zones shown with their maximum moment magnitudes (Mw) and approximate closest distance from the Landfill site: Great Valley 7 (Central Valley Coast Range): Mw of 6.90, and ~ 59.33 km from site; Greenville Connected: Mw of 7.00, and ~ 74.36 km from site; Mount Diablo: Mw of 6.70, and ~ 84.55 km from site; Ortigalita: Mw of 7.10, and ~ 89.41 km from site; Green Valley Connected: Mw of 6.80, and ~ 93.43 km from site; Calaveras (CN+CC+CS): Mw of 7.03, and ~ 94.56 km from site; Hayward / Rodgers Creek (RC+HN+HS): Mw of 7.33, and ~ 102.52 km from site; and N. San Andreas (SAO+SAN+SAP+SAS): Mw of 8.05, and ~ 132.99 km from site. Figure 1 shows the locations of these faults relative to the Landfill site. Next the horizontal ground motions at the Landfill site were assessed via empirical attenuation relationships. To be conservative, the ground motions at the site were assessed to ½ standard deviation above the median ground motion. Because this seismic characterization method utilizes the maximum earthquake a fault is currently believed capable of producing, which is already considered a conservative scenario, a ½ standard deviation increase from the median ground motions based on the MCE is very conservative. To estimate the ground response at the Landfill site, the MCE is to be located at the seismic source’s closest location to the site. The horizontal ground motions (or peak ground accelerations [PGA]) at the Landfill site were determined by using the Pacific Earthquake Engineering Research Center (PEER) - 2008 Next Generation Attenuation (NGA) Model (PEER 2008) and the 2014 NGA West-2 Model (PEER 2014). 3.0 Des c r i p t i o n o f Fau l t s Th at Si g n i f i c an t l y In f l u en c e t h e MCE Gr o u n d Mo t i o n s Based on the assessment of site response utilizing the NGA models, the eight (8) faults / fault zones that will have the greatest impact on the ground motions at the Landfill Site were determined. Brief descriptions of the eight faults / fault zones are provided below. 3.1 Great Valley 7 The Great Valley 7 is one fault segment of the Great Valley Fault system. The Great Valley 7 Fault is a thrust fault, characterized by a total fault length of 45 km, a fault plane width of approximately 11.2 km, and a reported slip rate of 1.5 mm/year (USGS, 2008). The Great Valley 7 Fault is approximately 59.3 km from the Landfill site with a reported maximum moment magnitude earthquake of 6.90 (USGS, 2008). The maximum moment magnitude of 6.90 has been selected as the MCE for this fault zone. 3.2 Greenville The Greenville Fault is a strike-slip fault, characterized by a total fault length of 50.0 km, a fault plane width of approximately 14.2 km, and a reported slip rate of 2.0 mm/year (USGS, 2008). The Greenville Fault is approximately 74.4 km from the Landfill site with a reported maximum