ARCHIVED REPORTS_XR0004477 - Laserfiche WebLink

Home Browse Search

1 1 2005 3rd Quarter Groundwater Report • Frontier Transportation,Ine, ' December 5,2005 Page 2 In January of 1998, Blakely Environmental Investigations, Inc (BEI) advanced four(4) ' groundwater monitoring wells(MW4 through MW-7)to assess the extent of subsurface contamination beneath the site (See Figure 2, Site Layout Map) Soil samples were collected every five feet Laboratory analysis of soil samples identified no detectable concentrations of TPH-g,BTEX,or MTBE Groundwater samples were subsequently collected and results are tabulated in Table 1 ' In January 2000,BEII advanced two borings (B-5 and B-6), installed four additional groundwater monitoring wells (MW-8 through MW-11), and collected nine soil vapor samples for a soil vapor survey as part of an additional site assessment(See Figure 2, Site Layout Map for well locations). Soil sample analysis identified no detectable concentrations of petroleum hydrocarbons with the exception of boring B-6. Maximum contaminant levels in B-6 were t identified 100 mg/kg as TPH-g,2,343 µg/kg as BTEX, and 10,600 µg/kg as MTBE at 10' bgs. Maximum soil vapor concentrations were identified at sample point V5 at 4' bgs. Groundwater samples were subsequently collected from all monitoring wells. Groundwater results are ' tabulated in Table 1 In May 2002, BER installed two additional groundwater monitoring wells(MW-12 and ' • MW-13) screened from 30' bgs to 40' bgs. Soil sample results identified maximum TPH-g, BTEX,and MTBE concentrations of 700 mg/kg, 115,000 µg/kg, and 25,000 gg/kg in soil collected from MW-13 at 10' bgs Soil concentrations attenuate by 99%at 15' bgs. No ' detectable TPH-g,BTEX,and MTBE were identified in MW-12. Also,monitoring well MW-3 was abandoned prior to excavation and removal of 325 tons of impacted soil and replaced by MW-3R In June 2003, BER installed an additional groundwater monitoring well (MW-14) screened from 30' bgs to 44' bgs Soil sample results identified a maximum MTBE ' concentration ofd—,920 µg/kg at 10'-bgs using EPA Method 8260B. No detectable TPH-g and BTEX were identified nn MW=14- �rr�I�a e-1 a cr" rn' ' In January 2004, BEII installed four additional groundwater monitoring wells. Deep monitoring wells MW-15, MW-16 and MW-18 were advanced to 40' bgs and screened from 30' ' bgs to 40' bgs. Shallow monitoring well MW-17 was advanced to 20' bgs and screened from 5' bgs to 20' bgs. Soil sample results identified a maximum MTBE concentration of 1,310 pg/kg at 10' bgs in MW-15 using EPA Method 8260B No other oxygenates or lead scavengers were ' detected. The maximum TPH-gas detected was 1.7 mg/kg at 10' bgs in MW-15 using EPA Method 8015M No detectable BTEX was identified in the soil column for MW-15 through MW-18. See Figure 2 for well locations. 1 •