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Marsh Creek segment is located 66 km west of the site and is segmented into a northern and southern section. The frequency of occurrence of earthquakes on the Greenville -Marsh Creek -Arroyo fault is estimated using the fault parameters listed in Table 1 and a characteristic magnitude recurrence model (Youngs and Coppersmith, 1985). The 100 -year probability of at least one earthquake of magnitude M or larger is shown in Figure 1. Based on the long term slip -rate, there is about a 1/3 chance of having a magnitude 5.5 earthquake or larger on the Green Valley - Concord Fault in the next 100 years. The recommended MPE is a magnitude 5.5 at a distance of 66 km. Green Valley - Concord Fault The Green Valley - Concord fault is located 80 km west of the site. This fault has been segmented into three segments: Green Valley North, Green Valley South, and Concord faults. Combined, the three segments have a total length of 56 km and a slip rate of 4-5 mm/year (WGEP, 2003). The estimated maximum magnitude for the combined rupture is 6.7. Although there are many small earthquakes along the Green Valley Fault, no historical earthquakes over magnitude 5 have occurred on the Green Valley Fault. The frequency of occurrence of earthquakes on the Green Valley Fault is estimated using the fault parameters listed in Table 1 and a characteristic magnitude recurrence model (Youngs and Coppersmith, 1985). The 100 -year probability of at least one earthquake of magnitude M or larger is shown in Figure 1. Based on the long term slip - rate, there is about a 1/3 chance of having a magnitude 6.75 earthquake or larger on the Green Valley - Concord Fault in the next 100 years. The recommended MPE is a magnitude 6.75 at a distance of 80 km. Calaveras Fault The Calaveras Fault is located 85 km west of the site. The total fault length of the fault is approximately 123 km, however, it is often segmented into the northern and southern segments. The southern segment, 78 km long, extends from Hollister to the Calaveras Reservoir. The northern segment, 45 km long, extends from north of the Calaveras Reservoir to Danville. The site is closest to the northern segment.