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David Relos August 30, 2011 Page 2 of 6 concentrations above 100 ppm (two (2) samples analyzed), which was the applicable guideline of the period. However, Benzo (a) pyrene concentrations of 590 ppb and 680 ppb, as reported in the supplemental screening assessment, continued to be above the current RISC Residential criteria of 500 ppb. We also note that the reported Benzo (a) pyrene concentrations were below the RISC Industrial criteria of 1,500 ppb. Although noting that heating oil UST systems used strictly for on -site consumption (as was the case) are exempt from UST requirements; the presence of soil contamination in excess of the RISC Residential criteria could be considered as an indicator of the presence of petroleum contamination, the extents of which were not clearly defined by the 2003 removal sampling or the 2003 supplemental assessment. As such, the possibility exists that any future re- development of the subject site may potentially encounter contaminated soils that may require additional excavation. Phifer Environmental also noted that historical buildings associated with the subject site were known to have heating oil systems, the status of which could not be confirmed. Such UST systems would also be exempt from UST regulations based upon their historical, on -site consumptive use (i.e., 511 Jefferson Blvd.) Phifer Environmental recommended that if during re- development of the property, additional heating oil UST systems or petroleum contaminated soils from historical heating oil systems are encountered, actions for their removal should be undertaken. We note that the City of South Bend and Mr. David Matthews (developer) have reached a tentative Purchase Agreement for the sale of the subject site for the future development of condominium units similar to those being constructed for the nearby, former Rink Riverside site. However, as part of the due diligence process, the City of South Bend and Mr. Matthews are interested in further assessment of the former UST area to determine the extent to which, if any, remnant petroleum impacted soils and /or groundwater remain in the general area of the former heating oil UST location. PROPOSED SCOPE OF SERVICES Ground Penetrating Radar Survey Prior to the initiation of any Phase II Environmental Site Assessment activities, Wightman Petrie will review the prior Phase I Environmental Site Assessment and UST Closure documentation with respect to the location of the former 6,000- gallon former heating oil UST system. Once a general area for the former UST system has been identified, Wightman Petrie will utilize Ground Penetrating Radar as a means for trying to confirm a more exacting location (i.e., presence of disturbed subsurface soils, existing debris associated with UST piping systems, concrete saddles, etc.). Ground Penetrating Radar (GPR) offers the means to detect buried objects that are not otherwise detectable. In addition to the ability to locate metal objects (i.e., underground storage tanks, drums), GPR is able to detect non - metallic objects. The system sends radar pulses into the surface, receives, and processes the reflected energy. Through advanced processing technology, the system calibrates the di- electric constant of the surrounding material. When the signal is reflected from the material having a different di- electric constant, the signal is displayed on the screen as an anomaly. Depth can also be determined by processing the sampling interval and determining the size and comparing relative data to other objects detected. Characteristics of underlying soils effect the penetration of the radar through the ground. Sands and gravel offer the greatest depth penetration and clearest resolution. Whereas, dense saturated clays offer