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20 December 2023 AdvancedGeo Project No. 23-7573 CLIENT —ATTORNEY PRIVILEGE An Employee-Owned Company Page 2 of 4 2.0. SCOPE OF WORK AND PROCEDURES AGI proposes to advance four (4) borings at the site. The borings are proposed to be advanced to a total depth of 30 feet below surface grade (bsg). A total of three borings will be advanced to 30 feet bsg and triple-completed soil-vapor wells will be installed to depths of 5, 15 and 30 feet bsg. The remaining location will be single completed with a soil-vapor sampling point to 30 feet bsg. The proposed boring and sub-slab sampling locations are illustrated in Figure 1. 2.1. SOIL BORING ADVANCEMENT, SAMPLING AND ANALYSIS AGI proposes to four (4) borings at the site to 30 feet bsg utilizing a track-mounted Geoprobe direct-push probing unit equipped with 2-inch diameter probing rods. The Geoprobe advances soil probe borings using a hydraulic hammer to drive sampling tools to specified depths. In general soil samples will be collected at two and five feet bsg using hand methods. Soil samples will then be collected continuously from all three borings between 5 and 30 feet bsg using a 2-inch Geoprobe soil sampling assembly with 5-foot acetate liners. Upon sample retrieval, a selected portion of the liner will be cut, and the ends will be covered with Teflon sheets, capped and sealed with tape. All appropriately sealed and labeled samples will be placed in a chilled container with ice and transported under chain-of-custody procedure to a California Environmental Laboratory Accreditation Program (ELAP)-certified laboratory. Each sample will be labeled with boring designation, depth, time, date and sampler's initials. Soils encountered in the borings will be visually classified by AGI personnel in accordance with the Unified Soil Classification System (USCS). Field screening of soil samples shall be performed using an organic vapor meter (OVM), equipped with photo-ionization detector (PID) pre-calibrated to isobutylene. Soil samples will be analyzed for Volatile Organic Compounds (VOCs) in accordance with EPA method 8260B. 2.2. SOIL-VAPOR POINT INSTALLATION, SAMPLING AND ANALYSIS AGI to install proposes ten (10) soil vapor points at the site, within the four completed borings. Following soil sample collection triple completed wells will be installed in each of the locations, except for the location directly in the rear of the former dry cleaning, which will be single completed with one soil-vapor sampling point to 30 feet bsg. A total of 32 feet of/4-inch diameter Teflon® tubing and a 2-inch-long polyethylene soil-vapor implant will be lowered to the bottom of the borehole. A filter pack of#2/12 sand will be added to approximately 29 feet bsg. Following placement of the filter pack, approximately 12 inches of dry granulated bentonite will be placed atop the filter pack to 28 feet bsg. Following the dry bentonite, hydrated bentonite will be used to fill the boring void to 15 feet bsg. At 15 feet bsg a total of 17 feet of 1/4-inch diameter Teflon® tubing and a 2-inch-long polyethylene soil-vapor implant will be lowered to 15 feet bsg. A filter pack of#2/12 sand