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Scope of Work and Cost Estimate Soil Vapor Survey Main Street Corridor Development - Centerville, Minnesota Page 2 Site File Review In conjunction with the MPCA determination of site file status at the 1724 Main Street Property, Pro Source will perform a detailed file review of the available environmental reports on file with the MPCA, in an effort to obtain additional information pertaining to the petroleum release and investigative and corrective actions taken. Results of the file review will be conducted prior to start of field work and incorporated into the Soil Vapor Survey Report. Subsurface Investigation Weare proposing the installation of up to ten soil vapor probes along the corridor. Three probes will be advanced in the right-of-way north of Main Street, spaced at approximately 125 foot intervals. An identical set of three will also be advanced along the south right-of-way of Main Street. Based on site reconnaissance, most of these areas are unpaved. If utility and traffic patterns allow, ProSource also recommends the advancement of up to two borings through the paved roadway to address conditions below the impervious surfaces. One of the remaining two vapor borings is proposed to be advanced west of Centerville road and south of Main Street. The final boring would be proposed in what is currently the parking area located between Kelly's Bar and the Noble Welding building. ProSource assumes that access to these areas will be granted/provided by the City of Centerville (City). If some of these areas are not accessible, boring locations will be adjusted accordingly. Soil vapor probes are proposed to be advanced to 14 feet below grade to assess the soil vapor conditions through the corridor using direct push technology. This method utilizes a small drill rig which employs a hydraulically-powered probe that utilizes static force and percussion to advance sampling tools into the subsurface for the collection of soil vapor samples. Upon advancement, the tubing used for sampling will be purged and immediately connected to a sampling canister under a pre-determined vacuum. Soil vapor sampling will be conducted in accordance with MPCA Guidance Document 4-0Ia "Vapor Intrusion Assessments Performed During Site Investigations". Soil gas samples will be submitted to a MPCA certified laboratory for chemical analysis using the Environmental Protection Agency (EPA) TO-I5 method for volatile organic compounds (VOC's) in the Minnesota Soil Gas List. Soil Vapor Survey Report Following completion of the above-identified tasks and upon receipt of the analytical testing results, ProSource will prepare a Soil Vapor Survey Report. In short, the report will include: . A discussion of field methods and results of the subsurface investigation; . Results and discussion of the laboratory analytical data, site figures, tables, etc; . Recommendations and conclusions as to whether additional work will be necessary at the Site; and . Applicable tables, figures and supporting data (i.e. field forms, analytical reports, etc.). ProSource Technologies, Inc. ~tiJ June 9, 2008