ARCHIVED REPORTS_2015 SITE INVESTIGATION WORK PLAN

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30 January 2015 AGE Project No. 14-3154 Page 7 of 9 All field procedures will be overseen by an AGE representative under the supervision of a California Professional Geologist. 2.1. PRE-FIELD WORK PREPARATIONS Applicable excavation/trenching permits/approval will be obtained from SJCEHD. An update to the health and safety plan presently on-file will be prepared in accordance with Occupational Safety and Health Guidance Manual for Hazardous Waste Site Activities (National Institute for Occupational Safety and Health Administration, U.S. Coast Guard and U.S. Environmental Protection Agency, 1985). Prior to mobilization, the area of excavation will be clearly marked and a utility clearance obtained through Underground Service Alert. The SJCEHD will be contacted at least 48 hours prior to conducting any field work. 2.2 PROJECT TASKS During the investigation of the former PNA site, a sampling location reference grid will be established and tied to a benchmark at the site. Relocation of planned sampling locations may be performed and the location referenced to the reference grid. Sampling at a location will involve use of the backhoe, which will trench down to native soil beneath any waste discovered and the current soil cap. AGE anticipates that approximately 20 trenching (sampling) locations will be required to adequately define the horizontal and vertical extent of the waste (see sampling location map). Additional trenches will be established in quadrants surrounding areas of waste discovery; thus increasing the total number of trenches, to generate a more accurate location and thickness (topology) of the potentially buried waste. Under the sampling protocol, AGE field staff may change individual sampling locations based on site- specific field conditions (including unforeseen obstructions, visible signs of contaminated soils or other factors). The trenches are proposed to be 18 inches wide, ten feet in depth bsg and approximately 25 feet in length north to south; producing a volume of 375 cubic feet or approximately 13.9 cubic yards of exposed soil and potential waste. If no more than 1 cubic yard of waste is encountered, then the excavation spoil waste will be considered de minimus. Soil samples will be field-screened using a Thermo 580B organic vapor meter and RKI methane (four-gas) meter. The trenches excavated by the backhoe will be screened using a RKI methane (four gas) meter capable of measuring concentrations of methane, hydrogen sulfide, oxygen, lower explosive limit and potentially carbon monoxide. The trenches will be backfilled with native soil. Advanced GeoEnvironmental Inc.