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Non-Water Release Corrective Action Plan <br />North County Recycling Center and Sanitary Landfill <br />AU24.1294.00 | Non-Water Release Corrective Action Plan Update 5 <br />October 2024 <br />acceleration assuming that the nearest fault ruptures nearest to the site), using an attenuation <br />relationship from Boore, et. al. 1997 for a Vs30 of approximately 275 m/s (USGS, Vs30 website), <br />the MCE event on these faults is expected to produce a horizontal Probable Ground <br />Acceleration (PGA) at the site of 0.1g. <br />TABLE 1 - MAXIMUM CREDIBLE EARTHQUAKE <br />SEISMIC PARAMETERS FOR ACTIVE FAULTS (BLAKE, 2004; CALTRANS, 2017; USGS, 2008/2019) <br />FAULT APPROXIMATE DISTANCE <br />FROM FAULT TO SITE (MILES) <br />MCE MOMENT <br />MAGNITUDE <br />PEAK GROUND <br />ACCELERATION, (GRAVITY) <br />Great Valley 6-7 (Midland, <br />Vernalis, Midway, Black Butte, <br />San Joaquin Fault Zone) <br />29.8 6.8 0.1 <br />Great Valley 5 (Vaca, Kirby <br />Hills, Davis) 35.1 6.5 0.09 <br />Concord/Mount Diablo 40.5 6.7 0.09 <br />Marsh Greek/Greenville 41.4 6.9 0.08 <br />San Andreas 78.4 7.9 0.08 <br /> <br />Using the newer attenuation relationships of the Next Generation of Attenuation (NGA) <br />Relationship Project in 2008 (Abrahamson, et.al, 2008, Boore, et. al, 2008, Campbell, et.al, <br />2008, and Chiou, et. al, 2008), and considering the faults, distance to the site, and site-specific <br />configurations, a PGA of 0.10g is calculated for the Great Valley 6-7 Fault (Appendix A). A shear <br />wave velocity (Vs30) of the upper 30 meters of the site was taken to be 275 m/s for the <br />underlying alluvium at the site (USGS, 2014). <br />Review of previous data indicates that the seismic characterization of the site by Abrahamson <br />(1994) used a PGA of 0.06g and a PGA of 0.1g in Abrahamson (2007) for the Maximum Probable <br />Earthquake (MPE) event at the site using the older attenuation relationships. <br />A search of historic earthquake events by the program EQSEARCH (Blake, 2000) indicates that <br />the largest calculated historic peak ground acceleration (PGA) at the site in the last 200+ years <br />was 0.13g from the 1906 San Francisco Earthquake of a Magnitude 8.25 approximately 81 miles <br />from the site. That earthquake was also the largest recorded earthquake magnitude within 100 <br />miles of the site. <br />Review of the Department of Water Resources (DWR) comments to the vertical expansion <br />report prepared by Shaw (2009) indicates that the DWR recommends a minimum PGA of 0.15g <br />due to the “height of the embankment, the results of the simplified USGS analyses performed <br />by DWR, and the possibility that a small earthquake, such as a M 5.5 or 6, can occur almost <br />anywhere in California”. <br />For purposes of this evaluation, seismic impacts to the landfill will use a PGA of 0.15g to be <br />conservative and to exceed the largest predicted MCE at the site. The results of the seismic