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MainPlace Mall Transformation Project 12126.001 <br />the site to the maximum depth explored of approximately 51 feet bgs generally <br />consist of silty sand, sand, gravelly sand, sandy silt, silt, clayey silt and clay. <br />2.2 Groundwater Conditions <br />Groundwater was not encountered during our exploratory borings drilled in the <br />site to the maximum depth of 51 Y2 feet bgs (LB-1 through LB-8). According to <br />groundwater information obtained through the California Geological Survey <br />(CGS) and presented in the Seismic Hazard Zone Report for the Orange <br />Quadrangle (CGS, 1997), the historically shallowest groundwater depth in the <br />vicinity of the project site is between 30 and 40 feet bgs in the southernmost <br />portion of the site, and greater than 40 feet bgs in the remaining northern portion <br />of the site. For the purpose of this report, we assume the groundwater depth at <br />the site is 30 feet bgs. <br />In addition, data from the nearest State of California Department of Water <br />Resources (DWR) groundwater monitoring well in the area supports deep <br />groundwater conditions in the area of the project site. State # 04S09W31 B001 S <br />located approximately 0.75 miles to the northeast of the project site indicates <br />groundwater levels ranging from a high of 110 feet bgs 05/05/1969 to a low of <br />186 feet bgs on 12/01 /1977 for recorded monitoring period from 1969 to 1978. <br />Based on the available groundwater data above and the proposed development <br />scheme for the site, groundwater is not expected to pose a constraint for the <br />project as currently planned. <br />Although groundwater is not considered a constraint for the project, seasonal <br />fluctuations in groundwater level, localized zones of perched water including <br />water due to nearby landscaping, and an increase in soil moisture should be <br />anticipated during and following locally intense rainfall or stormwater runoff. <br />2.3 Field Infiltration Test <br />Two (2) infiltration test were performed to evaluate the infiltration characteristic of <br />the site soils. The tests were performed at Parcel 1 (LB-3) and Parcel 6 (LB-6), <br />respectively. Prior to drilling LB-3, we drilled and sampled a 30-foot deep pilot <br />boring 10 feet north of the proposed location of the LB-3 to observe the <br />subsurface soil condition. Based on observation of the soil cuttings retrieved <br />from the pilot boring, it was determined to locate the test zone in LB-3 at depth <br />Ito <br />5 I <br />Leighton <br />