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f 2.0 GROUNDWATER INVESTIGATION AND CONFIRMATORY SOIL SAMPLING ( The following sections describe the field and laboratory procedures employed during the ! groundwater investigation and confirmatory soil sampling. The findings of the investigations are described in Section 3.0. 2.1 MONITORING WELL INSTALLATION Prior to initiating Feld activities, SEACOR applied for and obtained well construction permits from the SJPHS. In addition, because one of the well locations was located in a public right-of-way, SEACOR applied for and obtained an encroachment permit from the City of Lodi. Copies of the permits are included in Appendix A. Two groundwater monitoring wells, identified as MW-2 and MW-3, were installed at the locations shown on Figure 2. Monitoring well MW-2 was located within the northwestern corner of the parking lot and well MW-3 was located in the parking lane on the north side of Hutchins Street. These locations were selected based on the anticipated groundwater flow direction, and access limitations presented by on-site structures. Monitoring well drilling and installation was performed by Spectrum Exploration Inc. on January 12, 1993, under the direct supervision of a SEACOR engineer. Boreholes were advanced using hollow 1P I stem auger drilling equipment. During borehole advancement, relatively undisturbed soil samples were collected continuously from five feet below ground surface to total depth for lithologic description and possible chemical analysis. Soil samples were collected using a clean unlined 5-foot long split barrel core sampler. The SEACOR engineer described soils according to the Unified Soil ' Classification System (USCS)and maintained a continuous boring log. A representative sample from each 5-foot core interval was screened in the field for the presence of volatile organic compounds (VOCs) using a photo-ionization detector (PID). The results of the PID screening in parts per ' million (ppm) isobutylene equivalents were recorded directly on the boring log. Boring logs are provided in Appendix B. ' Soil samples collected during advancement of the borehole did not exhibit elevated PID readings or other signs of hydrocarbon contamination (e.g., discoloration or odors). As requested by Ms. Mary Meays of the SJPHS, two soil samples from each wellbore from depths of 30 and 45 feet were ' retained for chemical analysis. Soil samples for chemical analysis were retained by driving a clean 6-inch long brass tube into the desired interval of the soil core. Care was taken to minimize disturbance of the soil in order to prevent potential contaminant loss. The ends to the brass tube I were immediately covered with aluminum foil, fitted with plastic end caps and sealed with tape. Sample tubes were labeled to designate boring location, sample depth, and date collected and stored in an ice-filled cooler. Soil samples were submitted to the Superior Precision Analytical Inc. (Superior) of Martinez, California with a completed chain-of-custody record and analyzed for total = petroleum hydrocarbons as gasoline (TPHg) and benzene, toluene, ethylbenzene, and xylenes (BTEX) in accordance with EPA methods modified 8015 and 8020, respectively. MARDEE.RPT 50014-003-01 MD04 5 1 �.