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File: 218267 November 30, 2018 B - We observed hairline to '/4 inch wide cracks in the concrete driveway and patios, with up to %z inches of vertical offset. These cracks were most likely caused by a combination of the root systems of the nearby large trees and the expansive site soils. C - The exterior house walls were covered with wood siding at the front and left side, and stucco at the right side and back. The stucco walls were generally in fair condition. There were hairline to 1116-inch wide cracks at the corner of many openings in the walls. D - We consider the drainage around the house to be poor. The ground surface near the house, and over much of the lot, is flat without sufficient slope away from the house to adequately carry water away from the house. "Trapped"planters and low areas also exist near the house foundations. Additionally, the roof downspouts discharge collected water onto the ground surface near the house foundations. Water which is discharged, collected, or trapped by the house foundations may seep into the crawlspace. Geologic Map Review We reviewed the Geology of the Onshore Part of San Mateo County, California: Derived from the Digital Database Open-File 98-137, by Earl E. Brabb, R.W. Graymer, and D.L. Jones (1998), and the State of California Seismic Hazards Zone Map; Palo Alto Quadrangle (10118106) . The relevant portions of the Brabb, Graymer,and Jones map and State map have been reproduced in Figures 3 and 3a. The Brabb, Graymer,and Jones map indicates that the site is underlain by Flood Plain Deposits (map symbol "Qhfp"). These materials are described as consisting of"medium to dark gray, dense sandy to silty clay. Lenses of coarser material (silt, sand, and pebbles) may be locally present. Flood Plain deposits usually occur between levee deposits and basin deposits." Our subsurface exploration (see below) encountered clay and sand materials which we judged to be consistent with the mapping. The Seismic Hazards Zone Map indicates the site is outside of the areas where: 1) there is a historic occurrence of liquefaction; 2) there have been previous occurrences of landslide movement; and 3) there are local topographic, local geological, geotechnical, and groundwater conditions would indicate a potential for permanent ground displacement such that mitigation, as defined in Public Resource Code Section 2693(c),would be required. The active San Andreas Fault is mapped approximately 5.6 miles (9.0 km) southwest of the site, and the potentially active Monte Vista-Shannon Fault is mapped approximately 3.7 miles (6.0 km) to the southwest. 3