Laserfiche WebLink
'} Case Closure Summary Page 2 <br /> Aq oking Underground Fuel Storage Tank Proms <br /> III Release and Site Characterization Information continued .1. i <br /> Maximum Documented Contaminant Concentrations --Before and-After Cleanup <br /> Contaminant Soil Before Soil Water Water Contaminant Soil Soil Water Water <br /> (ppm) After Before After Before After Before After <br /> (ppm) (Ppm) (ppm) <br /> TPH(Gas) 1,900 <1.0 30.6 <.050 MTBE <0.5 <0.005 .0125 <.002 <br /> Benzene 0.075 <0.005 .02 <.0005 Lead -50.5 15 ---- ---- <br /> Toluene 7.3 <0.005 1.4 <.0005 EDB 0.0041 ---- ---- <.002 <br /> Ethylbenzene 18 <0.005 .484 <.0005 1,2-DCA ---- ---- <.002 <br /> a Xylene 120 <0.005 6.06 <.0005 TEPH 5000 ---- ---- <br /> "Soil Before" levels are from MW 1 at 10.5 feet in February 1999, except TEPH which is diesel contamination in the soil <br /> sample collected at 3 feet along the fill line at the time of the tank pull in 1990. "Water Before"levels are from August 1997 <br /> grab water sample from a boring, except MTBE which is from MW 1 in February 1999. "Soil After"levels are from the <br /> monitoring wells installed in February 2001. "Water After"levels are from the monitoring wells on 314102. <br /> Results of soil samples from subsequent investigations of the both diesel UST and the remote fill line in August 1997 <br /> were all non detect. <br /> Only MW-1 groundwater samples had minor levels of BTEX contamin'iiation Between 1999 and 2000. Results of <br /> groundwater samples from all five wells have fallen to non-detect levels over the last 4 quarterly monitoring events in 2001 <br /> { and 2002. Investigation showed minimal impact to soil and groundwater.-! Beneficial uses of groundwater are protected, now <br /> and in the future. i <br /> IV. Closure <br /> ' Does completed corrective action protect existing beneficial uses per the'Regional Board Basin Plan? Yes <br /> , <br /> Does completed corrective action protect potential beneficial uses per the Regional Board Basin Plan? Yes <br /> Does corrective action protect public health for current land use? Yes <br /> Site management requirements: none <br /> Should corrective action be reviewed if land use changes?Yes r <br /> Monitoring wells decommissioned: Yes Number Decommissioned: 5 Number retained:0 <br /> List enforcement actions taken: NOR sent <br /> List enforcement actions rescinded: None <br /> 1 <br /> V. Local Agency Representative Data <br /> �I <br /> Name: Donna anTitle: Director of Environmental Health <br /> Signature: Date: Q3 <br /> VI. Central Valley Regional Water Quality Control Board (RB) Notification <br /> �i <br /> Date Submitted to RB: November 6, 2002 Response Date:-December 2,2002 <br /> RB Staff: Marty Hartzell Response: No Further Action Required <br /> Title: Assoc Eng Geologist <br /> VII. Additional Comments, Data, etc. <br /> MWA to MW-5 destroyed by tremmie and pressure under EHD inspection. <br /> i <br /> This document and the related CASE CLOSURE LETTER, Shall be retained by the lead agency as part of the <br /> official site file. (08124193) Exhibit N Page 2 of 2 <br />