Laserfiche WebLink
r09 June 1998 <br /> . AGE-NC Project No 95-0104 <br /> Page 4 of 4 <br /> • From Novembei 1997 to February 1998, substantial dissolved hydrocarbon-concentration <br /> decreases were observed from well VW-1 A plot of depth to ground water and TPH-g <br /> concentrations over time (Appendix C) suggests a negative correlation at wells MW-5 and <br /> VW-1 between Increasing/decreasing ground water elevation and Increasing/decreasing <br /> TPH-g concentrations <br /> • Concentrations of benzene detected in samples collected from well VW-1 were above the <br /> State of Califoinia Maximurn Contaminant Level (MCL) for drinking water of 1 0 ppb <br /> • Concentiations of toluene were above the MCL of 150 ppb in well VW-1 <br /> • Utilizing EPA Methods 8020, concentrations of MTBE were not detected above the <br /> laboratory repoitmg limas in samples fiom wells MW-1, MW-5, MW-6 and VW-1 <br /> • The elevated concentrations of petroleum hydrocarbons detected in samples collected from <br /> well VW-1 indicates that this well is within or near the "core area" of the plume of dissolved <br /> petroleum hydrocarbons <br />�• 50 RECOMMENDATIONS <br /> Based upon the results of this Investigation, AGE recommends the following <br /> • Preparation of a soil vapor extraction/air s ar ingPilot test �,voik plan should commence <br /> upon PHS-EHD approval of the AGE recommendation letter submitted on 02 June 1998 <br /> • Continuation of quarteily monitoiing and sampling should next be scheduled for June 199E <br /> 60 LIMITATIONS <br /> Our professional services were performed using that degree of care and skill ordinarily e-,ercised by <br /> environmental consultants practicing in this or similar localities The findings were based upon <br /> analytical results provided by an independent laboratory Evaluations of the geologic/hydrogeologic <br /> conditions at the site for the purpose of this investigation are made from a limited )lumber of <br /> available data points (1 e monrtoiing wells) and subsurface conditions may vary away from these <br /> data points No other warranty, expressed or Implied, is made as to the professional <br /> recommendations contained in this report <br /> • <br /> Advanced GeoEmironmentaI,Inc <br />