Laserfiche WebLink
1 <br /> • ranged from a high of 2600 ppb in groundwater sample GP-8, which was located offsite <br /> of the subject property to the northeast to a low of 6 7 ppb in sample GP-4 The highest <br /> 1 MTBE detections were from the offsite locations <br /> In February 2002, four additional groundwater monitoring wells were installed on the <br /> subject property Three of the wells were placed on an offsite property to the north in <br /> order to test the horizontal limits of MTBE impact, and one of the wells was placed on the <br /> 1 subject property to test the vertical limits of MTBE impact to groundwater in one deep <br /> well The three wells installed north of the subject property were non detect for TPH and <br /> MTBE The deep well located on the subject property detected MTBE at a concentration <br /> of 570 ppb Based on the available data it appears that the horizontal limits of impact is <br /> limited. There appears to be in impact at depth, however, until further monitoring is <br /> M performed, a determination of whether the MTBE has or has not impacted the deeper <br /> horizon cannot be made <br /> 2.1 Purpose <br /> The purpose of this investigation was to determine the extent of the MTBE plume <br /> both on and offsite <br /> 2.2 Methodology <br /> . All work was performed in accordance with the "Scope of Work," prepared and <br /> submitted to the client and to the San Joaquin County Environmental Health <br /> Department Site Mitigation Unit (SJCEHD) by Avalon on August 17, 2001 <br /> (Appendix VI and V11) Prior to conducting subsurface exploration and soil <br /> sampling, Underground Service Alert was contacted in order to clear the boring <br /> 1 locations from underground utilities Three wells were drilled on the adjacent <br /> property to the northeast and one well was drilled on the subject property The <br /> three offsite wells were completed at a depth of 20 feet bgs, and the one onsite <br /> well was completed at 30 feet bgs All groundwater samples and select soil <br /> samples were analyzed for oxygenate compounds and lead scavengers Methanol, <br /> Ethanol, Tertiary Butanol, Methyl Tertiary Butyl Ether (MTBE ), Di-isopropyl Ether <br /> (DIPS), Ethyl Tertiary Butyl Ether (ETBE), Tertiary Amyl Methyl Ether (TAME), 1,2 <br /> Dlchloroethane and 1, 2 Dibromoethane and TPH as Gasoline by EPA <br /> Method 82606 Samples were placed on ice in a portable cooler for transport <br /> under chain of custody to Kiff Analytical Laboratory <br /> i Avalon Environmental Consultants 9627-001 7 <br /> Joe's Truck Plaza <br /> May 15,2D02 15600 S Harlan Road <br /> Lathrop,California <br /> 3 <br />