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Project No. 034-17016 Site-Specific Health& Safety Plan Page No.6 within the northward trending rough channel; however, areas of somewhat darker soil were observed. Otherwise,no obvious evidence of a potential impact from hazardous materials or hazardous waste was noted within the on-site stormwater retention basins, and no odors, surface staining, or other evidence of the disposal of hazardous materials or hazardous waste was observed within or adjacent to the on-site stormwater drains. However, given the presence of the valley gutter discharge point,the referenced northern trending rough channel, and associated areas of the retention basin within 50 to 150 feet of the fuel USTs,oil UST, waste oil UST,and the truck maintenance shop hazardous waste and hazardous materials use/storage areas, coupled with the fact that the valley gutter has presumably been discharging stormwater runoff with dissolved and/or entrained engine drip-related petroleum hydrocarbons and other contaminants potentially residing on paved surfaces served by the drainage system for approximately 26 years,the potential exists that the valley gutter discharge area and the unpaved basin area located immediately adjacent to the discharge point and immediately east of the truck maintenance shop/truck wash bay have been impacted by constituents of concern. For a higher level of due diligence relative to the referenced potential for impacts to the on-site stormwater retention basins,Krazan recommended that a limited soil assessment be conducted to assess the presence or absence ofsignificant concentrations ofthe constituents ofconcern in soils associated with the stormwater management system. Potential Historical Farming Operations USTs Krazan's review of historical aerial photographs indicates that a rural residence, including a dwelling-type structure,a barn-type structure,and at least one outbuilding,were located in the northwestern portion of the subject site near/on the northern property boundary from at least 1937 until at least 1968. Additionally, historical aerial photographs of the subject site indicate that much of the subject site and the northern adjacent property were utilized for agricultural purposes during this time interval. Historical uses of the subject site prior to 1937 were not reasonably ascertainable utilizing the standard historical references consulted during this assessment,and it is therefore unknown how long the subject site was occupied by the rural residence and utilized for agricultural purposes prior to 1937. The current owners of the subject site have no knowledge of the presence of underground storage tanks (USTs) being located in the historical residential area (northwestern portion of the subject site)during the 1937 to 1968 time interval,and no records of USTs for the subject site are on file with the local regulatory agencies other than those associated with the four existing USTs which are located in the central-eastern portion of the subject site. However,during the 1937 to 1968 time interval,USTs on rural or agricultural properties typically would have been exempt from requirements for registration with regulatory agencies. Krazan's experience with such properties has shown that it is not uncommon for agricultural property owners/operators to install USTs for their convenience,especially in the vicinity of structures, which are undocumented and whose presence would remain unknown in spite of the standard data research conducted in the course of this Phase I ESA. A portion of the former residential area has been redeveloped with a paved parking area and it is presumed that any USTs located within the footprint of the parking area would have been properly removed from the subject site in conjunction with this redevelopment. However,the remainder of the former residential area is occupied by minimally developed stormwater retention basin corridors. Therefore, it is possible that subsurface features such as unregistered USTs may exist in the vicinity of the historical on-site rural residential structures which were not removed from the subject site during the early-1990s redevelopment of the parking area and stonnwater retention basin and which remain unknown based upon the absence of any regulatory,municipality,interview data,or other evidence indicating their presence or location. Consequently, despite an absence of data suggesting their presence, the presence or absence of USTs associated with the former rural residence and farm structures historically located in the northwestern portion of the subject site prior to the current owner of the subject site is unknown. For a higher level of due diligence, Krazan recommended conducting a limited geophysical survey in the inferred location of the former on-site farm structures to assess the presence or absence of subsurface KRAZAN&ASSOCIATES,INC. With Offices Serving the Western United States 03417016 SSI Lathmp HASP Fiml.doc