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Project No 014-95262 Page No 14 Based upon the analytical data from background samples KHP-2 and two other samples (KHP-7 and KHP-8) located some distance from known or potential chloride sources, it appears background concentrations of 540-560 Mmhos/cm EC and 67 to 68 mg/L chloride can be established The samples from the pond vicinity exceed the background values by 3 to 4 tunes and 3 to 6 tunes, respectively The high EC value and associated non detected chloride concentrations for samples KHP-9 is anomalous and unexplained The presence of low concentrations of ammonia in groundwater only in areas hydraulically down- gradient (regionally) of the treatment pond and/or plant may suggest a source at the pond Ammonia could enter the pond via waters coming in contact with the coils/condensers of the ammonia-based cooling system, with ultimate drainage into the pond Due to the low concentrations noted, however, it is only considered as an indicator of possible pond leakage and not as a threat to groundwateruali 9 t3' The concentrations of phosphate, sulfate, nitrate, ammonia and pH in groundwater from the treatment plant and pond vicinity do not exceed any regulatory limit are not considered an environmental concern TRPH was not detected in the pond vicinity 8.6 Former UST Area Three water sampling locations (KHP-7, KHP-8, and KHP-9) were selected to verify the impact of the release from the former Safeway USTs was limited in nature The results for samples from the northern portion of the property (KHP-2 and KHP-3) over 600 feet from this point source, would be used for comparison Results for samples KHP-2 and KHP-3 were 300 and 400 µg/L TPH-D, respectively Sample KHP-8, southeast of the former USTs, also returned a concentration in this range (330µg/L TPH- D) However, sample KHP-9 and KHP-7 both contained TPH-D at a concentration of 1,200 mg/L Further east from the USTs, sample KHP-6 contained TPH-D at a concentration of 1,100 Ag/L The observed distribution of TPH-D suggests that there may be a background concentration of diesel in groundwater in the range of 300 to 400 Mcg/L, not associated with the former Safeway USTs Another source for this "background" diesel may also be from former military operations which occupied the site However, no point sources attributable to the military operations were identified during this investigation The distribution of TPH-D in groundwater both west and northeast of the former Safeway USTs suggests that either, 1) groundwater flow direction has historically varied by over 180°, 2) there is an off- site source for the diesel noted in sample KHP-9, west of the former tanks, or 3) an as yet unidentified military-related point source is present KRAZAN&ASSOCIATES, INC Offices Sernng the Western Unrted States 95262 Piz