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KLEINFELDER File No. 20-3978-01.WR9 December 9, 1996 2. SCOPE OF WORK The activities discussed in this section are structured to locate and characterize the landfills in a cost effective manner that will provide information to support subsequent meetings with and submittals to regulatory agencies and also to support preparation of specific corrective actions measures that may have to be taken at each landfill site. Since the number, size, and locations of the suspected landfills are not clearly defined, the first task is to use geophysical techniques to field locate suspected landfill locations. After the geophysical work is complete, the landfills will be trenched to find the lateral and vertical extent of the landfills as well as to document the landfills contents. Once the landfills have been physically located in the field, soil and groundwater samples will be collected to assess if contaminants have migrated from the landfills. Landfill gas measurements will also be made since decomposing waste in landfills may generate explosive landfill gas. After the data on the size, location, content , and evidence of contaminant migration for each landfill has been assembled, a series of meetings with regulatory agencies will be held to discuss the results and to receive guidance on what forms of corrective action will be acceptable to the regulators and if additional investigation will be necessary. Once input from the regulators has been solicited, a corrective action report will be prepared that documents the results of the investigation and regulatory contacts, and describes what additional actions (if any) should be taken to formally close the landfills. Note that this scope of work and the associated costing is based on a "worst case" assumption that seven separate landfills will be located and each landfill area will require a full investigation. The scope of work and associated costs will be reduced if less landfills are located or if less investigation is deemed to be necessary (such as reducing the number of monitoring wells at a landfill site from three to two). 2.1 Geophysical Investigation Two complementary surface geophysical methods will be used, electromagnetic induction (EM), and magnetrometry. EM can detect landfilled waste (both metallic and nonmetallic) generally to a depth of 20 feet. The magnetometer detects metallic waste. Typically a single 55 gallon drum can be detected at a depth of up to 18 feet and a large cluster of drums can be detected at depths of up to 60 feet. A trained engineer or geologist will walk the suspected landfill sites first with the EM unit and then the magnetometer. Readings will be recorded at intervals as each area is walked. The location of each reading will be established using a GPS (global positioning system) unit. The reads and corresponding locations will then be processed and turned into a map showing the approximate extent of waste (as indicated by fluctuations in either 20-3978-01.WR9/MP960143 Page 2 of 9 01996, Kleinfelder, Inc.