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• System Operation Details
<br /> The C-SpargeM system was started on December 26, 2002 The C-SpargeTM control panel was
<br /> programmed and scheduled to inject ozone cyclically into each injection point for 14 minutes Based on
<br /> this programming, each injection point will have ozone injection in 18 cycles for 4 2 hours every day
<br /> During the third quarter 2005 (between July 12, 2005 and September 8, 2005), a Stratus technician
<br /> conducted eight site visits to collect field and laboratory parameters, and to conduct operation and
<br /> maintenance of the ozone injection system Field data sheets presenting field parameters collected during
<br /> the third quarter 2005 are included in Appendix A Certified analytical reports with chain-of-custody
<br /> documentation are included in Appendix C Analytical data were submitted to the State Water Resources
<br /> Control Board as required by A82886 The electronic delivery receipt is attached in Appendix C
<br /> Ozone Iniection Monitoring Plan
<br /> Monitoring wells MW-3 through MW-10 are used as observation wells to monitor the performance of the
<br /> ozone injection system Monitoring wells MW-1 and MW-2 are used as background wells to evaluate and
<br /> monitor for natural geo-chemical changes in the groundwater
<br /> During the third quarter 2005, field parameters were collected on a monthly basis and select laboratory
<br /> parameters were collected on a quarterly basis During the third quarter 2005 monitoring event, all
<br /> samples were collected after purging three volumes of well casing The ozone injection monitoring plan is
<br /> listed below and a summary of frequency and significance of field and laboratory parameters is presented
<br /> in Table 3
<br /> Field Parameters (Monthly) pH, Dissolved Oxygen (DO), and Specific Conductivity
<br /> Laboratory Parameters (Quarterly) GRO, BTEX, five oxygenates, 1,2-DCA, EDB, ethanol, Chemical
<br /> Oxygen Demand (COD), Total Iron, and Heterotrophic Plate Count
<br /> Laboratory Parameters (Annually) Total Organic Carbon (TOC), Nitrates, Sulfates, Orthophosphates, and
<br /> Total Dissolved Solids (TDS)
<br /> Results
<br /> Results of field and analytical parameters collected to date to evaluate and optimize the performance of
<br /> the ozone injection system are presented in Tables 4 and 5 The GRO, benzene, and MTBE
<br /> concentrations reported in all the groundwater monitoring wells during the third quarter 2005 are
<br /> presented in Figure 4 Change in DO concentrations for select observation and background monitoring
<br /> wells are presented in Figure 5 The average DO concentration variation with distance since the operation
<br /> of ozone injection system is presented in Figure 6 The historical GRO, benzene, MTBE, and depth to
<br /> water concentration variation over time at select monitoring wells (MW-4 through MW-8) are illustrated
<br /> graphically in Figures 7 through 11
<br /> During the third quarter 2005, GRO was reported for groundwater samples collected from wells MW-5 (55
<br /> pg/L), MW-6 (5,300 pg/L), MW-8 (6,900 pg/L), and MW-10 (83 pg/L) Benzene was reported only in
<br /> groundwater sample collected well MW-4 at a concentration of 53 pg/L MTBE was reported at wells MW-
<br /> 1 (4 0 pg/L), MW-3 (0 89 pg/L), MW-4 (2,100 pg/L), MW-5 (57 pgll-), MW-6 (7,500 Pg/L), and MW-8
<br /> (9,500 pg/L) DIPE (2 0 pg/L) was reported in well MW-10 1,2-DCA was reported in wells MW-7 (0 67
<br /> pg/L), MW-9 (2 0 pg/L), and MW-10 (6 3 pg/L) TBA, ETBE, TAME, EDB, or ethanol were not reported in
<br /> any of the wells The petroleum hydrocarbon concentrations generally appear to have decreased since
<br /> the operation of ozone injection Analytical data were submitted to the State Water Resources Control
<br /> Board as required by AB2886 The electronic delivery receipt is attached in Appendix C Historical
<br /> •, groundwater monitoring and chemical analytical data back to 2000 are included in Appendix D
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