|
Second Semi-Annual 2021 Groundwater Monitoring, Batch Extraction Results Report & Supplemental Site Investigation
<br />Waterloo Food and Fuel
<br />3032 East Waterloo Road, Stockton, California
<br />Page 6
<br />Analyses Performed
<br />Groundwater samples were transported, under chain-of-custody (COC) documentation, to California
<br />Laboratory Services of Rancho Cordova, California, a state-certified analytical laboratory, for
<br />analysis of the following constituents:
<br />Analysis Abbreviation Designation USEPA Method No.
<br />Total Petroleum Hydrocarbons
<br />as Gasoline TPHg Gas Range
<br />Hydrocarbons 8260B
<br />Total Petroleum Hydrocarbons
<br />as Diesel TPHd Diesel-Range
<br />Hydrocarbons 8015M
<br />Benzene
<br />BTEX
<br />Aromatic
<br />Volatile
<br />Organics
<br />8260B
<br />Toluene
<br />Ethylbenzene
<br />Xylenes (Total)
<br />Tertiary Butyl Alcohol TBA
<br />Five Fuel
<br />Oxygenates
<br />Methyl Tertiary Butyl Ether MTBE
<br />Di-isopropyl Ether DIPE
<br />Ethyl Tertiary Butyl Ether ETBE
<br />Tertiary Amyl Methyl Ether TAME
<br />1,2-Dichloroethane 1,2-DCA Lead
<br />Scavengers 1,2-Dibromoethane EDB
<br />Naphthalene Naphthalene
<br />Volatile
<br />Organic
<br />Carbons
<br />Analytical results are summarized in Tables 3 and 5. Copies of the laboratory analytical results and
<br />COC documentation are presented in Appendix D.
<br />GROUNDWATER MONITORING RESULTS
<br />Shallow Zone
<br />According to the laboratory analytical report, concentrations of TPHg was reported at wells MW-1,
<br />MW-3, MW-4, MW-7A, EW-2, EW-3, EW-4, and EW-5, with a maximum concentration of
<br />5,200 micrograms per liter (µg/L) in well MW-2. TPHd was reported in wells MW-1, MW-2,
<br />MW-7A, EW-2, and EW-3, with a maximum concentration of 33,000 µg/L at well MW-2.
<br />Benzene was reported in wells MW-1, MW-2, MW-3, MW-4, MW-5A, MW-7A, EW-2, EW-3,
<br />EW-4, EW-5, and EW-7 with a maximum concentration of 700 µg/L at well MW-2. MTBE was
<br />reported in wells MW-2, MW-3, MW-4, MW-7A, EW-2, EW-3, EW-4, and EW-5, with a maximum
<br />concentration of 160 µg/L at well MW-2 (Table 3, Figures 5 through 8).
<br />Groundwater elevations decreased an average of 6.80 feet compared to the last sampling event.
<br />Groundwater flow direction was reported to be to south 55° west with a gradient of 0.001 ft/ft
<br />(Figure 4a). Floating liquid hydrocarbon (Free Product) was observed in EW-1. The thickness of
<br />the Free Product was measured to be 0.33 inches. Based on that observation, the well was not
<br />sampled. A sample of the free product was collected and analyzed along with addressing potential
|