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<br /> Ms Margaret Lagono
<br />' July 16, 2004
<br /> Page 2
<br /> NP-1 were analyzed for fuel oxygenate compounds methyl tertiary butyl ether (MtBE),
<br /> tertiary-amyl methyl ether (TAME), tert butanol (TBA), dusopropyl ether (DIPE), ethyl tertiary butyl
<br /> ether (EtBE) using EPA Method 8260B Additionally, groundwater samples collected from wells
<br /> MW-1 through MW-11, MW-17 through MW-20 and NP-1 were analyzed for lead scavengers
<br /> 1,2 -dibromoethane (EDB), and 1,2-dichloroethane (1,2-DCA) using EPA Method 8260B
<br /> Cumulative groundwater sampling analytical results are summarized in Table 1 and Table 2
<br /> Dissolved concentrations of benzene, TPHg, MtBE, and 1,2-DCA in groundwater for second
<br /> quarter 2004 are presented in Figure 5 and Figure 6 Copies of the groundwater sampling
<br />' information sheets are included in Attachment B Laboratory analytical results with chain-of-
<br /> custody documentation are included in Attachment C Concentrations of MtBE were not
<br /> reported at or above laboratory reporting limits in any of the groundwater samples submitted for
<br /> analysis during the second quarter 2004
<br /> TPHg Concentrations
<br /> • Concentrations of TPHg decreased since February 2004 in wells MW-2 and MW-15
<br /> • Concentrations of TPHg increased since February 2004 in wells MW-3, MW-6, MW-10, MW-
<br /> 11, MW-12, MW-14, MW-16, and MW-18, through MW-21
<br /> • TPHg has not been reported in well NP-1 at or above laboratory reporting limits since
<br /> October 2002
<br />' Benzene Concentrations
<br /> • Concentrations of benzene decreased since February 2004 in well MW-2
<br /> • Concentrations of benzene increased since February 2004 in wells MW-3, MW-6, MW-10,
<br /> MW-11, MW-12, MW-14 through MW-16, MW-18, MW-19, and MW-21
<br /> • Benzene has not been reported in well NP-1 at or above laboratory reporting limits since
<br />' November 2000
<br /> 1,2 DCA Concentrations
<br />' Concentrations of 1,2-DCA, ranged between 2 0 micrograms per liter (Ng/L) and 78 pg/L, and
<br /> were reported in wells MW-4, MW-5, MW-10, MW-11 MW-17, MW-18, and MW-19 during the
<br /> second quarter 2004
<br /> Ozone Microsparge System Description
<br />' The C-SpargeTM system includes an ozone generator, air compressor, and a programmable
<br /> timer/controller The C-SpargeTM system utilizes ozone microspargmg a process where ozone
<br /> is entrained in air and introduced into groundwater The ozone is injected at low flow rates of 2
<br />' to 6 cubic feet per minute through specially designed sparge points to create "microbubbles " As
<br /> these microbubbles rise within the column of water, dissolved volatile organic compounds
<br /> (VOCs) including petroleum hydrocarbons are oxidized The system cycles ozone/air injection
<br /> between eight micro-sparge points (SP-1 A, SP-IB, SPA C, SP-2A, SP-2B, SP-2C, SP-3A and
<br /> J 1Prolects10694012859 357\RnaRReportsl2nd Qtr 04 QMR RSR12nd Qtr 04 QMR doc
<br />' i Over 30 Years of Excellence in Environmental Services
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