|
rj It
<br /> MWI contained benzene, toluene, ethylbenzene, xylenes, and TPHG at 5 2, 1 0, 1 7, 6 4, and
<br /> 220 parts per billion (ppb), respectively, MW3 contained ethylbenzene, xylenes, and TPHG at
<br /> 2 6, 4 2, and 430 ppb, respectively, MW4 contained xylenes at 2 0 ppb, and MW5 contained
<br /> benzene, toluene, ethylbenzene, xylenes, and TPHG at 15,000, 6,800, 1,400, 7,700, and 90,000
<br /> ppb, respectively MTBE was not detected in well MW5 at a detection limit of 50 ppb The
<br /> detection limit was raised on MTBE due to dilution factors No petroleum hydrocarbons were
<br /> detected in samples collected from well MW8 Samples were not collected from wells MW2,
<br /> MW6, or MW7. Analytical results for the reporting period are summarized in Table 2
<br /> Laboratory data sheets and chain of custody documentation are included in Attachment B
<br /> Figure 3 shows the estimated extent of dissolved benzene in groundwater.
<br /> San Joaquin County Public Health Services, Environmental Health Division (PHSIEHD)
<br /> previously approved modifications to the groundwater monitoring and sampling program at the
<br /> site as follows wells MW6 and MW7 would be temporarily removed from the sampling
<br /> program, wells MW3 and MW5 would be sampled on a semi-annual basis during first and third
<br /> quarters, wells MW2 and MW4 would be sampled on a semi-annual basis during second and
<br /> fourth quarters, and wells MWI and MW8 would be sampled on a quarterly basis However,
<br /> PHSIEHD later requested the groundwater monitoring and sampling program be modified as
<br /> follows wells MWI, MW4, MWS, and MW8 sampled quarterly, MW3 sampled semi-annually,
<br /> MW2 sampled annually, and MW6 and MW7 removed from the sampling program
<br /> The next quarterly monitoring and sampling is scheduled for May 1996
<br /> Please contact John Lane or Greg Stahl at your convenience if you have any questions or
<br /> comments regarding the site
<br /> Sincerely,
<br /> Ground Zero Analysis, Inc
<br /> � ,��RED GEp!
<br /> John P Lane
<br /> Seni r Geologist GREGORY P.
<br /> STAHL
<br /> No 5023
<br /> f
<br /> Gregory P Stahl �T£OF CAI�F���
<br /> CA Registered Geologist No 5023
<br /> CA Certified Hydrogeologist No 264
<br /> Attachments
<br /> PC Mr Carl Knowles
<br /> Mr. David Isola, Riddle & IsoIa
<br /> • Ms Elizabeth Thayer, CRWQCB Sacramento
<br /> gromdzellmawles hamllgm1996 2
<br />
|