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k" KLEINFELDER j SCOPE OF WORK Vertical Soil Contamination Extent and Ground Water Assessment This section contains a description of the drilling and soil sampling; monitoring well construction, development, water sampling, and surveying, chemical analysis, and reporting associated with the soil and ground water assessment Additional work may be required beyond this scope of work if ground water has been impacted or if SJCEHD requires additional soil assessment. Task 1: Drilling and Sampling Initially, four bonngs will be drilled at the approximate locations shown on Plate 3 MW-1, 2, and 3 will be constructed as ground water monitoring wells Boring B-3 will be continuously cored from a depth of 5 feet to the terminus of the boring B-3 will be terminated if any of the following occur ground water is encountered; field observations indicate an absence of petroleum hydrocarbons, drilling refusal, or a maximum depth of 40 feet Each of the monitoring wells will be sampled at 5-foot intervals from ground surface to the terminus of the boring The monitoring wells will be terminated 15 feet beyond first encountered ground water The wells may be terminated if drilling refusal is encountered, or a maximum depth of 55 feet is reached Additional monitoring wells may be installed to assess the impact to ground water if the initial analytical results indicate that ground water is impacted. The boring and monitoring wells will be drilled using a truck-mounted drill rig • equipped with 8-inch hollow stem augers The borings will be drilled, logged, and sampled following the protocol described in Attachment A, Sections A-2 1 through A-2 4 Two-inch wells will be constructed in three of the four borings Each of the wells will be installed as described in Attachment A, Section A-3 1 Task 2 Well Development Twenty-four to 48 hours after installation, the three ground water monitoring wells will be developed to remove sediment-laden water and to increase the hydraulic radius of the wells Development will be performed as described in Attachment A, Sections A-3 2 through A-3 3 Once the wells are installed, the top of each well casing will be surveyed so that depth- to-ground water measurements in the wells can be converted to ground water elevations used to estimate ground water gradients The wells will be surveyed relative to a local benchmark If a local benchmark is not available near the site, the wells will be surveyed relative to an on-site, assumed, benchmark with an assigned elevation The wells will be surveyed as described in Attachment A, Section A-3.4. Task 3 Measurement of Water Levels To assess the ground water gradient at the time of sampling, water level measurements will be made in the three wells prior to purging and sampling the wells. The depth-to- water will be measured in each well according to the protocol described in Attachment A, Section A-4 1 The depth-to-water measurements will then be converted to relative ground water elevations by subtracting them from the surveyed casing elevations FWP2-92-25 Page 2 of 4 24-220152-DOO Copynght 1992 Kleinfelder, Inc