|
to be functioning normally since then Field data sheets presenting field parameters collected between
<br /> October 11, 2004 and December 23, 2004 are included in Appendix A Certified analytical reports with
<br /> chain-of-custody documentation are included in Appendix C Analytical data were submitted to the State
<br /> Water Resources Control Board as required by AB2886 The electronic delivery receipt is attached in
<br /> 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 infection 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 fourth quarter 2004, field parameters were collected on a monthly basis and select laboratory
<br /> parameters were collected on a quarterly basis During the fourth quarter 2004 monitoring event, all
<br /> samples were collected after purging three volumes of well casing The modified ozone infection
<br /> monitoring plan is listed below and a summary of frequency and significance of field and laboratory
<br /> parameters is presented in Table 3
<br /> Field Parameters (Monthly) pH, Dissolved Oxygen (DO), and Specific Conductivity
<br /> Laboratory Parameters (Quarterly) GRO, BTEX, five oxygenates, Chemical Oxygen Demand (COD),
<br /> Ferrous Iron, Total Iron, and Heterotrophic Plate Count
<br /> Laboratory Parameters (Annually) Total Organic Carbon (TOC), Nitrates, Sulfates, Phosphates, and Total
<br /> Dissolved Solids
<br /> Results
<br /> Results of field and analytical parameters collected to date to evaluate and optimize the performance of
<br /> the ozone infection system are presented in Tables 4 and 5 The GRO, benzene, and MTBE
<br /> concentrations observed in all the groundwater monitoring wells during the fourth quarter 2004 are
<br /> presented in Figure 4 Change in DO concentrations for select observation and background monitoring
<br /> wells are presented in Figure 5 The historical GRO, benzene, and MTBE concentration variation over
<br /> time at select monitoring wells (MW-4 through MW-8) are illustrated graphically in Figures 6 through 10
<br /> During the fourth quarter 2004, GRO concentrations appeared to have generally decreased in all the
<br /> monitoring wells with the greatest decrease observed in well MW-4 (from 32,000 pg/L to 13,000 pg/L)
<br /> GRO was also reported in wells MW-5, MW-6, and MW-8 at concentrations of 130 µg/L, 3,000 pg/L, and
<br /> 13,000 µg/L, respectively GRO was not reported in wells MW-1 through MW-3, MW-7, MW-9, and
<br /> MW-10
<br /> During the fourth quarter 2004, benzene was reported in wells, MW-4 and MW-8 Benzene
<br /> concentrations had remained the same (2,500 pg/L) in well MW-4, and had increased (from 420 µg/L to
<br /> 1,400 jig/L) in well MW-8, since the previous sampling event (September 14, 2004) Benzene was not
<br /> reported in wells MW-1 through MW-3, MW-5 through MW-7, MW-9, and MW-10
<br /> During the fourth quarter 2004, MTBE concentrations appear to have decreased in wells MW-4, MW-5,
<br /> MW-6, MW-9, and MW-10, while concentrations appear to have increased in wells MW-1, MW-3, MW-7,
<br /> and MW-8 The greatest decrease in MTBE (from 12,000 µg/L to 7,700 µg/L) was observed in well MW-6,
<br /> while the greatest increase (from 20,000 pg/L to 23,000 µg/L) was observed in well MW-8 MTBE was not
<br /> reported in wells MW-2 and MW-9
<br /> 1,2-DCA was reported in wells MW-7 (1 7 pg/L) and in well MW-9 (2 7 pg/L) DIPE, TSA, ETBE, TAME,
<br /> EDB, or ethanol were not reported in any of the wells Analytical data were submitted to the State Water
<br /> K\Bp-Arco for URS\5469\QuarterlyUO041Arco_5469_4Q04 doe 0rRAW5
<br />
|