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TREADWELL & ROLLO o the lack of any observable indication of on-site chemical usage together with the absence of any apparent effects on the near-surface soil indicate that any constituents that may affect the site would be expected to be waterborne; the direction of the local flow gradient suggests that any potential sources would be to the south or southeast o the analytical chemical results from samples taken from the monitor wells indicate that no volatile petroleum hydrocarbons, volatile organic compounds, pesticides, herbicides or PCBs are present in the near-surface groundwater; the concentrations of metals detected were within ranges considered to be "background" levels in the western conterminous United States; petroleum hydrocarbons as diesel were detected at levels ranging from 230 to 450 ppb in the initial sampling and confirmation sampling performed at well MW-1 and at levels ranging from below method reporting limits to 290 ppb in monitor well MW-2; no diesel was detected in monitor well MW-3 o since MW-1 and MW-2 are "upgradient" wells and MW-3 is a "downgradient" well, and since there are no historical records which indicate the presence of a potential on-site source, we believe that the diesel that was detected originated from off site. 7.0 LIMITATIONS The conclusions and recommendations presented in this report are professional opinions based on the specific activities conducted and information obtained, some of which was developed by others, and are therefore dependent upon the quality of the information obtained. Treadwell & Rollo makes no guarantees nor warranties with respect to the accuracy nor completeness of this information. Opinions and recommendations presented herein apply to site conditions existing at the time of the investigation and cannot necessarily be taken to apply to site changes or conditions of which we are not aware and have not had the opportunity to evaluate. 9 1107A201.CRJ 5 November 1991