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One soil sample (MW3-50) was submitted for microbial enumeration and physicochemical laboratory
<br /> analysis. The results of the analysis indicated that hydrocarbon-degrading microorganisms were
<br /> detected at 260,000 CFU (colony forming units) per gram. The laboratory indicated that these
<br /> physicochemical conditions at the site were well within the range necessary to support microbial
<br /> growth and bioremedial activity. Three soil samples (MW1-50, MW2-20 and MW2-35)were submitted
<br /> for laboratory analysis of permeability, porosity, moisture and total organic content. Analysis of MW1-
<br /> 50 (silty clay/clayey silt) reported an average permeability of 8 x 10-7 , porosity at 38.99 percent,
<br /> moisture at 22.7 percent and organic content at 2.2 percent.Analysis of MW2-20(sandy clayey silt/silty
<br /> clay)reported an average permeability of 8 x 10-7, porosity at 48.65 percent, moisture at 33.6 percent
<br /> and organic content at 2.3 percent . Analysis of MW2-35 (sandy silt/silty sand) reported an average
<br /> permeability of 2 x 10-6, porosity at 43.15 percent, moisture at 25.6 percent and organic content at 1.6
<br /> percent.
<br /> • 27 November 2000-AGE conducted a sensitive receptor survey to locate potential vertical conduits
<br /> within a 2,000-foot radius of the site. The sensitive receptor survey located one operational municipal
<br /> water well (Station No.77) located approximately 300 feet south of the site, a second non-operational
<br /> municipal water well (Station No.3) located approximately 1,000 feet southeast of the site and a third
<br /> operational municipal water well(Station No.21) located approximately 2,500 east of the site. Results
<br /> of the sensitive receptor survey are summarized in Table 5. Results of the investigation were reported
<br /> in Sensitive Receptor Survey, dated 27 November 2000, prepared by AGE.
<br /> • 09& 10 October 2003-Five soil borings(P-8 through P-12)were advancement at the site to depths of
<br /> 68 feet bsg. Soil borings P-8, P-10, P-11 and P-12 were advanced to depths of 50 feet bsg, while
<br /> boring P-9 was advanced to a depth of 65 feet bsg. Soil samples were collected at 5-foot intervals,
<br /> and a grab water sample was collected from P-9 at a depth between 65 and 68 feet bsg. Laboratory
<br /> analysis of soil samples detected TPH-mo at 5-feet bsg from borings P-8 and P-9 at concentrations of
<br /> 3.1 mg/kg and 3.8 mg/kg, respectively. TPH-g, TPH-d, toluene, ethylbenzene and xylenes were not
<br /> detected in the analyzed soil samples. However, benzene was detected at 15-feet bsg from borings
<br /> P-10 and P-12 at concentrations of 0.092 mg/kg and 0.21 mg/kg, respectively.The fuel additive MTBE
<br /> was detected at15-feet and 25 feet soil samples collected from borings P-10 and P-12 and the 25- foot
<br /> soil sample collected from boring P-9 at concentrations as high as 0.14 mg/kg (P12-15). Laboratory
<br /> analysis of the P-9 grab water sample detected TPH-d and TPH-mo at concentrations of 3,600
<br /> micrograms per liter(pg/1)and 17,000 pg/l, respectively. TPH-g was not detected from the grab ground
<br /> water sample analysis. BTEX compound benzene was detected at a concentrations of 0.64 pg/l. BTEX
<br /> compounds toluene, ethylbenzene and xylene were not detected from the analysis. The fuel additive
<br /> MTBE was detected at a concentration of 0.59 pg/l; 1,2-DCA was detected at a concentration of 1.2
<br /> pg/l. Analytical results of soil and grab water samples are summarized in Tables 1, 2 and 6. Results
<br /> of the October 2003 investigation were reported in Site Assessment Report-December 2003, dated 30
<br /> December 2003, prepared by AGE.
<br /> • 24 & 25 October 2005- Two ground water monitoring wells (MW-4 and MW-5) were installed at the
<br /> site to maximum depths of 70 feet bsg(Figure 2).A total of five soil samples were collected from MW-5
<br /> and submitted for laboratory analysis of TPH-g, TPH-d, TPH- mo, BTEX, MTBE, ETBE, TAME, DIPE,
<br /> TBA, 1,2-DCA, EDB, methanol and ethanol. None of the above mentioned fuel components were
<br /> detected by laboratory analysis. Results of the October 2005 investigation were reported in Monitoring
<br /> Well Installation Report, dated 02 May 2006, prepared by AGE.
<br /> • 30 March 2006 - Immediately following installation of well MW-5, grout intrusion was suspected by
<br /> AGE due to significant pH values encountered during well development activities and due to a well
<br /> obstruction encountered at 65 feet bsg. Therefore, well MW-5 was destroyed under SJCEHD permit
<br /> and replaced with well MW-5R. No soil samples were collected during installation of MW-5R. Results of
<br /> the March 2006 investigation were reported in Monitoring Well Installation Report, dated 02 May 2006,
<br /> prepared by AGE.
<br /> • 06& 29 February 2008-Cone penetration testing (CPT)borings P-16 and P-17 were advanced at the
<br /> site to depths of 68 feet bsg; CPT boring P-18 was advanced off-site to 70 feet bsg;three on-site soil
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