|
TABLE 7
<br /> TOTAL AND HEXAVALENT CHROMIUM RESULTS EVALUATION
<br /> 2012 SEMIANNUAL GROUNDWATER MONITORING REPORT
<br /> FORMER MARLEY COOLING TOWER SITE
<br /> STOCKTON,CALIFORNIA
<br /> Total Chromium and Chromium VI(µg/L) Percent Change in
<br /> Monitoring Well Screened Water- 2nd Qtr and 4th Qtr and 4th Qtr Supplemental Chemical Name Q 3rd Qtr and PP 1st Qtr Compliance 2nd Qtr Compliance Supplemental Ma Supplemental June 3rd Qtr Compliance Supplemental(August 4th Qtr Compliance 1st Qtr Compliance 2nd Qtr Compliance Concentration from
<br /> Location bearing Zone Q Q P Q P PP (May PP ( Q P PP ( g Q P Q P Q P
<br /> g Compliance(April Compliance(October Sampling(December Maximum***
<br /> 2010) Compliance(July 2010) 2010) 2010) (January 2011) (April 2011) 2011) 2011) (July 2011) 2011) (October 2011) (January 2012) (April 2012)
<br /> MW-323 Intermediate Chromium 9 14 16 NS 11 7J NS NS 10 NS <10 7.1 8J -72%
<br /> Chromium VI <lOUJ <10 <10 NS 4.73 4.04 NS NS <10 NS <0.5 6.6 6.44 -36%
<br /> MW-324(I-10) Intermediate Chromium 1 22 17 14 12 16 15 15 1 15 12 14 18 571/o
<br /> Chromium VI I0'1V 10 <10 10.4 10.6 10.5 10 10 10 12.1 12.4 13.7 15.1 0%
<br /> MW-361 Deep Chromium 3 3 4J NS <10 <10 NS NS <10 NS <10 <10 <10 NM
<br /> Chromium VI <IOUJ <10 <10 NS <0.5 <0.5 NS NS <10 NS <0.5 <0.5 <0.5 NM
<br /> MW-363 Intermediate Chromium NS NS 5J NS 3J NS NS NS NS NS NS NS NS NM
<br /> Chromium VI NS NS <10 NS 1.91 NS NS NS NS NS NS NS NS NM
<br /> MW-4475 Intermediate Chromium NS 7,090 7,700 6,990 6,650 6,020 5,910 5,130 4,950 815 2,630 2,240 2,160 -72%
<br /> Chromium VI NS 7,080 7,670 6,510 5,740 5,980 5,880 5,200 3,350 753 2,630 2,200 1,990 -74%
<br /> MW-447D Intermediate Chromium NS 29530 39350 2,960 39460 19620 2,130 2,600 2,370 2,040 2,290 2,650 2,290 -34%
<br /> Chromium VI NS 2,360 3,120 2,730 3,110 1,600 1,920 2,290 1,870 1,950 2,280 2,580 2,150 -31%
<br /> MW-448S Intermediate Chromium NS 2,300 2,120 2,170 2,280 1,370 1,350 1,570 1,820 2,240 2,230 2,400 2,570 0%
<br /> Chromium VI NS 2,220 2,110 2,010 2,030 1,210 1,150 1,570 1,530 2,150 2,230 2,370 2,540 0%
<br /> MW-448D Intermediate Chromium NS 49110 12,800 10,800 99790 7,870 99240 99770 99170 8,320 4,440 29910 29460 -81%
<br /> Chromium VI NS 4,060 12,500 10,300 8,410 7,500 9,040 9,000 8,570 8,220 4,440 2,800 2,360 -81%
<br /> EW-3 Intermediate Chromium NS NS NS 31,700 37,100 10,100 NS NS 5,210 NS 12,400 4700 NS -87%
<br /> Chromium VI NS NS NS 28,800 33,300 8,510 NS NS 3,580 NS 12,400 4650 NS -86%
<br /> EW-4 Intermediate Chromium NS NS NS 29 194 38 NS NS 23 NS 15 NS NS -92%
<br /> Chromium VI NS NS NS 28 232 26 NS NS 10 NS 13.6 NS NS -94%
<br /> EW-5 Intermediate Chromium NS NS NS 55 54 18 NS NS 16 NS 13 NS NS -76%
<br /> Chromium VI NS NS NS 54.6 52.7 8.4 NS NS 10 NS 13.2 NS NS -76%
<br /> MW-4 Intermediate Chromium NS NS NS 770 800 524 691 686 586 589 521 NS NS 35%
<br /> Chromium VI NS NS NS 696 765 516 620 660 360 559 520 NS NS -32%
<br /> MW-212 Intermediate Chromium NS NS NS 132 140 87 100 99 80 76 95 NS NS -32%
<br /> Chromium VI NS NS NS 131 136 82 100 110 60 72 94.5 NS NS -31%
<br /> MW-7 Shallow Chromium 7 3 13 NS 91 13 NS NS 8J NS <10 6J 8J -859/o
<br /> Chromium VI <10 <10 <10 NS 3.03 3.77 NS NS <10 NS 0.88 5.24 5.35 -73%
<br /> MW-201 Shallow Chromium 11 32 15 NS 21 23 NS NS 10 NS 13 17 14 -78%
<br /> Chromium VI <10 10 <10 NS 8.98 10 NS NS <10 NS 9.74 9.4 10.7 0%
<br /> MW-202 Shallow Chromium 26 8 15 NS 12 7J NS NS 6J NS 3J 5J 10 -709/o
<br /> Chromium VI <10 <10 <10 NS 3.36 2.67 NS NS <10 NS 1.57 4.08 4.46 0%
<br /> MW-210 Shallow Chromium 12 10 17 NS 6J 8.1 NS NS 4.1 NS <10 3J 5J -71%
<br /> Chromium VI <IOUJ <10 <10 NS 1.26 1.31 NS NS <10 NS <0.5 1.26 1 -24%
<br /> MW-302 Shallow Chromium 14 9 10 NS 6J 8J NS NS 3.1 NS 4J <10 <10 -86%
<br /> Chromium VI QO QO QO NS 2.04 1.59 NS NS QO NS 2.11 1.47 1.35 36%
<br /> MW-304 Shallow Chromium 8 27 20 NS 27 15 NS NS 17 NS 6J 10 12 -66%
<br /> Chromium VI <10 10 <10 NS 8.06 8.04 NS NS <10 NS 3.13 9.03 8.27 -17%
<br /> MW-401 Shallow Chromium 7 4 5J NS <10 M NS NS <10 NS <10 <10 <10 -55%
<br /> Chromium VI <lOUJ <10 <10 NS 0.98 0.74 NS NS <10 NS <0.5 <0.5 1.11 0%
<br /> MW-310 100-Foot Sand Chromium 12J 30 26 NS 19 14 NS NS 17 NS <10 81 10 -78%
<br /> Chromium VI <lOUJ <10 <10 NS 7.44 7.04 NS NS <10 NS <0.5 5.12 8.36 0%
<br /> MW-211 Intermediate Chromium 13 11 10 NS 5J 5J NS NS 4 NS <10 3J 3J 82%
<br /> Chromium VI <10UJ 10 QO NS 1.78 2.07 NS NS <10 NS 0.61 2.09 1.96 -6%
<br /> MW-325 Intermediate Chromium 14 12 14 NS 12 8J NS NS <10 NS <10 81 81 -74%
<br /> Chromium VI <lOUJ <10 <10 NS 6.13 3.55 NS NS <10 NS <0.5 7 7.82 0%
<br /> Notes:
<br /> *=April 2007 data from Dudek M&S Report
<br /> **=baseline samples
<br /> ***=The comparison is between the most recent concentration and the maximum concentration reported since the baseline sampling event in 2008. A value of zero indicates the current concentration is the highest.
<br /> Bold=Concentration greater than Water Quality Objective(WQO)
<br /> J=Estimated laboratory value
<br /> µg/L=microgram per liter
<br /> NM=not meaningful because the chemical has not been detected above the laboratory analytical reporting limit.
<br /> NS=not sampled
<br /> UJ=Non-detect value is estimated
<br /> (Page 4 of 4)
<br />
|