SU0000568 SSNL - Laserfiche WebLink

Home Browse Search

File No. 20-3514-01 K L E I N F E L D E R September 11, 1991 The field explorations were performed under the direction of an engineering geologist from our firm. Continuous logs of the soils - encountered in the borings were maintained, and relatively undisturbed samples of the soils encountered were obtained at various intervals for visual observation, classification, and laboratory testing. Soil samples were obtained by driving a 2- inch inside diameter sampler into the soil using a 140-pound hammer falling approximately 30 inches. The number of blows required to advance the sampler into the soils is presented on the Logs of Borings, Appendix, Plates A-3 through A-6, at the corresponding sample location. The septic system suitability study was performed according to San Joaquin County requirements. The residence surveys were performed on August 13 , 1991 by a field technician from our firm. The percolation tests were performed on August 22 , 1991 following San Joaquin County guidelines, and the procedure and results are discussed in a following section of this report. SOIL CONDITIONS The surface and near-surface soils encountered at the locations explored generally consisted of very loose to medium dense silty - sands that extended to depths of approximately 3-1/2 to 6 feet below existing ground surface. The sandy soils were underlain by stiff to hard and partially cemented silt soils that extended to depths of approximately 7 to 12 feet in Borings B-1, B-3 and B-4 , and to the maximum depth explored of 10 feet in Boring B-2 . The silt soils were underlain by alternating layers of silty sand, silty clay and relatively clean sand that extended to the maximum depths explored. No free groundwater was encountered in the borings drilled for - this investigation. However, we understand that after heavy rains water stands at the surface on the south portion of the site for several days. In our opinion, the standing water is likely = perched on the silt soils encountered at depths of approximately 3-1/2 to 4 feet beneath the south portion of the site. It is possible however, that groundwater conditions at the site could change at some time in the future due to variations in rainfall, groundwater withdrawal, irrigation, construction activities or other factors not apparent at the time our borings were drilled. The above is a general summary of the soil and groundwater conditions encountered in the borings drilled for this investigation. More detailed descriptions of the soils encountered in the borings are noted on the Logs of Borings. All soils have been classified according to the Unified Soil Copyright 1991 KLeinfelder, Inc. Page 3 of 13