ARCHIVED REPORTS XR0007833 - Laserfiche WebLink

Home Browse Search

MN. Ms Lon Duncan Apri14, 2000 . Page 4 of 6 Soil Analytical Results No detectable concentrations of petroleum hydrocarbons, gasoline oxygenate additives or VOCs were found in the samples collected from borings S134, SB5, SB7 or SB8 In boring SB 6, the sample collected at 15 feet bgs contained low levels of toluene and xylenes At 20 feet bgs, TPHg, TPHd, and TRPH were detected at 1,100 ppm, 1,800 ppm, and 4,800 ppm, respectively BTEX and VOCs ranged from non detectable to 14 ppm Total lead detected in borings SB4 through SB8 ranged from non- detectable concentrations to 8 8 ppm, and appears to be representative of background levels Figure 3 presents the estimated extent of soil contamination in the vicinity of the former UST Analytical results of soil samples are summarized in Table 2 Laboratory reports and chain of custody documentation are included in Attachment B Groundwater Analytical results The grab groundwater samples collected from borings SB4 through SB8 contained lead, petroleum hydrocarbon constituents as well as various solvent related VOCs, however, neither TRPH or gasoline oxygenate additives were detected No TPHg was detected in borings SB4, SB6, SB7, or SB8 However,boring S135 contained 340 parts per billion (ppb)TPHg TPHd was detected in borings SB4, S135 and SB6 at concentrations of 110 ppb, 820 ppb, and 160 ppb, respectively Boring SB8 contained toluene near non-detectable concentrations and benzene was detected exclusively in the sample collected . from boring S135, at 7 8 ppb VOCs were not detected in bonngs SB4, SB6, or S138, but boring SB5 had concentrations ranging from 14 to 32 ppb Total lead in the shallow groundwater ranged from 9 9 ppb in boring SB4 to 550 ppb in boring SB5 Figure 4 presents the estimated extent of groundwater contamination in the vicinity of the former UST Analytical results of groundwater samples are summarized in Table 3 Laboratory reports and chain of custody documentation are included in Attachment B SUMMARY AND CONCLUSIONS Summary • Soil encountered at the site generally consisted of sand, silts and clays Thickness of the fine grained material in borings SB4 through SB8 range from 24 5 feet to 31 feet, and overlies a bed of well graded sand approximately 4 5 to 6 feet thick Underlying the sand, clay (SB4, SB7) and silty clay (SB6) was present to the termination point Stratigraphy of borings SB4 through SB8 generally correlates to soil classified from previous investigations at the site • Initial depth to groundwater ranged from 24 to 29 feet bgs and rose to depths ranging from 10 5 to 22 feet bgs • Soil discoloration and significant petroleum odors were only evident in the samples collected from 20 feet and 25 feet bgs in boring SB6 • Detectable concentrations of petroleum hydrocarbons and VOCs in the soil were found only in groundzelgabbardladd_bonng_rpt doc