|
1
<br /> Second Quarter 2004
<br /> ' Thrifty 4172
<br /> July 14, 2004
<br /> ' Page 2
<br /> TPHg, BTEX, and MTBE concentrations appear in Table 1, while historical oxygenate and
<br /> alcohol results are presented in Table 2 Copies of groundwater laboratory reports and chain-of-
<br /> custody documents are included in Appendix B TPHg, benzene, and MTBE isoconcentration
<br /> maps are presented as Figures 3, 4, and 5, respectively The highest concentrations of TPHg,
<br /> ' benzene, and MTBE in groundwater were found in monitoring well MW-11 (62,800 ug/L, 1,630
<br /> ug/L, and 25,100 ug/L, respectively) The remaining site wells have very low to non-detectable
<br /> constituent concentrations
<br /> ' Since the third quarter of 1997, Thnft has analyzed for ox -
<br /> Y y oxygenates da isopropyl ether (DIPE),
<br /> ethyl-tert butyl ether(ETBE), tert-amyl methyl ether(TAME), and tert-butanol (TBA), and
<br /> ' MTBE by method 8260B The alcohols (ethanol and methanol) were analyzed by ASTM
<br /> standard D285 The County of San Joaquin Public Health Services (CSJPHS) requested these
<br /> analyses Laboratory results indicate no alcohols or oxygenates (besides MTBE) were detected
<br />' above the laboratory detection limit, with the exception of TAME (323 ug/L) and TBA (5,250
<br /> ug/L) in well MW-11 It has been over three years without detecting the alcohol
<br /> constituents in groundwater samples. Therefore, Thrifty res ectfully repeats its request for
<br /> cessation of the requirement for methanol and ethanol analysis at this site.
<br />' Remediation Status
<br /> Vapor Extraction System
<br />' On April 26, 2001, a new Baker Furnace Thermal Oxidizer Unit was placed into operation with
<br /> the hour meter reading at zero Presently, the remediation system is connected to soil vapor
<br />' extraction wells VW-1, VW-2 (A,B), VW-3, VW-4 (A,B,C), VW-5 (A,B,C), and VW-6 (A,B,C)
<br /> The vapor wells operating during the second quarter of 2004 were VW-3 and VW-5A (100%),
<br /> VW-5B (50%), and VW-5C (25%) During the second quarter of 2004, the soil vapor extraction
<br /> unit(VEU) operated approximately 1,823 hours for a cumulative total of 22,623 hours
<br /> Approximately 4,402 pounds of hydrocarbons were removed during the second quarter 2004 for
<br /> a total of 89,029 pounds as of June 28, 2004 (Table 3) The hydrocarbon mass removal rates via
<br />' vapor extraction were 2 41 lbs/hour during the reporting period and overall 3 94 Ibs/hour as of
<br /> June 28, 2004
<br /> •
<br /> 1
<br />
|