SITE INFORMATION AND CORRESPONDENCE

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I KL NFELDER engmrtoar..xrgnexmno.. • underlain by an approximate 5-10 foot thick layer of silt or clayey silt. The silt layer is underlain by a silty sand which may contain interbedded layers of clay or clayey silt. In November 1998, ten backhoe test pits were advanced on the nursery property. The lithology encountered in the test pits and previous borings show a broad stratigraphy of gravels, sands, silts and clays. The orientation and grading of the deposits coupled with the topography of the nursery property suggests an alluvial and overbank depositional environment. Therefore, channel deposits would be sporadic in their occurrence and generally be within finer grained overbank sediments as noted in Kleinfelder's past logs of borings and test pit logs. In November 1999, three deep groundwater monitoring wells were drilled at various locations on the nursery property. In general, the subsurface geology encountered in the deep borings showed varied lithology ranging from clays, silts, sands, and gravels. Groundwater was encountered at approximately 135 feet below the ground surface. On October 27, 1998, Kleinfelder's revised proposal for "Additional Subsurface • Investigation" (dated October 8, 1998) was submitted to the State of California Central Valley Region of the Regional Water Quality Control Board (CVRWQCB) and the San Joaquin County Public Health Services Department Environmental Health Division (PHS/EHD) for approval. That proposed investigation includes the installation of an additional groundwater monitoring well on the nursery property and the excavation of ten shallow backhoe pits on the property. The purpose of the third monitoring well is to help provide additional perched groundwater gradient information for the nursery. The purpose of the proposed backhoe pits is to provide additional information regarding the shallow subsurface stratigraphy beneath the site. This workplan was approved and field work was conducted on November 5, 1998. The following is a general summary of Kleinfelder's conclusions: • The ten shallow backhoe pits were excavated between 6'/z feet to 10 feet below ground surface (bgs). Four of the ten pits encountered perched water from 3'/z to 7 feet bgs. The four pits were located in topographically high areas in the southeast and northwest portions of Norman's Nursery. Groundwater was not encountered in test pits located in the central portion of the nursery. • The origin of the perched water encountered on the southeast and northwest portions of • the nursery are unknown. The lack of perched water noted in the central portion of the nursery in addition to the historical lack of water noted in nested monitoring wells MW- 117226.E02/ST012R0696 Page 12 of 43 September 14, 2012 Copyright 2012 Kleinfelder