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Second Quarter 2006 Groundwater Monitoring Report
<br /> Boyett Petroleum,419 S.Main,Manteca,CA
<br /> Page 2
<br /> . included on the Groundwater Monitoring Field Forms, attached. Groundwater monitoring field measured
<br /> parameters are presented in Table 1.
<br /> Table 1: Groundwater Field Measured Parameters June 27, 2006
<br /> Monitoring pH Specific Dissolved Oxygen Oxidation-Reduction
<br /> Well Conductance S (mg/L) Potential(relative mV)
<br /> MW-2 7.06 913 5.06 34.3
<br /> MW-3 7.02 936 6.57 32.2
<br /> MW-4R 6.95 1,111 2.55 19.0
<br /> MW-6 6.40 621 7.09 108.0
<br /> MW-7 7.30 2,016 6.00 33.0
<br /> MW-8 7.18 1,386 6.29 32.3
<br /> MW-9 7.27 866 1.53 -24.8
<br /> MW 10 7.09 1,083 5.35 17.5
<br /> MW-1 1 7.27 909 2.62 -9.4
<br /> EW-1 7.23 1,221 3.50 17.1
<br /> GROUNDWATER ELEVATIONS AND GRADIENT
<br /> Groundwater elevation data collected during the second quarter 2006 monitoring event indicate an
<br /> average groundwater elevation at the site of 20.98 feet, an increase of 0.43 feet since the previous
<br /> monitoring event (March 2006). Shallow groundwater elevation contours based on the depth to water
<br /> measurements collected on June 27, 2006, indicate the groundwater gradient at the site is very flat and
<br /> that there may be a small groundwater mound near the northeast corner of the site. Groundwater elevation
<br /> data are presented in Table 2, and historical groundwater elevation data are attached.
<br /> • Table 2: Groundwater Elevation Data June 27, 2006
<br /> Monitoring Well TOC Elevation Screened Depth to Groundwater
<br /> Interval b s Groundwater ElevationZ
<br /> MW-2 35.97 15-25 14.96 21.01
<br /> MW-3 36.18 15-25 15.13 1 21.05
<br /> MW-4R 35.21 10-25 14.18 21.03
<br /> MW-6 36.07 10-25 15.11 20.96
<br /> MW-7 36.42 10-25 15.36 21.06
<br /> MW-8 36.43 10-25 15.40 21.03
<br /> MW-9 35.95 40-50 15.08 20.87
<br /> MW-10 36.09 10-25 15.03 21.06
<br /> MW-1 1 36.15 29-39 15.28 20.87
<br /> EW-1 36.23 29-39 15.38 20.85
<br /> 'TOC Elevation: Elevationsare referenced to NAVD88 datum,NGS Benchmark HS 4486.
<br /> 'Groundwater Elevation:Elevatiats are measured from the top of the well casings and are referenced to the benchmark indicated above.
<br /> All measurements are in feet.
<br /> LABORATORY ANALYTICAL RESULTS
<br /> The groundwater samples collected from the monitoring wells were analyzed for benzene, toluene, ethyl
<br /> benzene, total xylenes (BTEX), and selected gasoline oxygenates/additives by EPA Method 826013, and
<br /> for total petroleum hydrocarbons quantified as gasoline (TPH-G) by EPA Method 8015M by Argon
<br /> Laboratories of Ceres, California. The selected oxygenates/additives included MTBE, ethanol (EtOH),
<br /> �_ A "", A, _j: .I aL,. ff-%1T1T:N _. L.A a,_..F: L...c..i ..cL,. /�T'L7C1 4..,.-t: ,1 -rt..,t
<br /> LGIEIaI)-Villai�V� kL"r1j, Ul-I-C I CLu�i wta i,l, u,Y, wiL,uir-vu�), vwvi t.�.,�, ), w..,u:j-u'"j, '" .k.,Y,
<br /> ether(TAME), 1,2-dichloroethane (1,2-DCA), and 1,2-dibromoethane(EDB).
<br /> ti
<br /> t. CONDOR
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