Laserfiche WebLink
Second Semi-Annual Groundwater Monitoring Report - Third Quarter 2017 <br />Former Chevron Service Station No. 94054 <br />December 12, 2017 <br />5.0 DISCUSSION AND RECOMMENDATIONS <br />5.1 DISCUSSION <br />The casing for well MW-4 was bent, therefore a grab sample was taken with a pin bailer. The <br />sample bottles collected from wells MW-1A, MW-1B, MW-1C, and MW-9, MW-9B, MW-9C, and <br />MW-9D on September 25, 2017 were broken. The wells were resampled on September 26, 2017. <br />5.1.1 Groundwater Sampling Results <br />Constituent <br />Frequency <br />of Detection <br />Above the MRL <br />vs. No. of <br />Samples <br />Analyzed <br />Range of <br />Detected <br />Concentrations <br />(pg/L) <br />California <br />Primary <br />Maximum <br />Contaminant <br />Level (pg/L) <br />Frequency of <br />Exceedances <br />Concentration of <br />Exceedances by <br />Well (pg/L) <br />TPH-GRO 16 : 28 51 - 6,100 -- -- <br />Benzene 17 : 28 0.6 - 630 1 15: 17 <br />MW-1A (260), <br />MW-1B (130), <br />MW-2(12), <br />MW-2B (110), <br />MW-3 (80), <br />MW-4 (110), <br />MW-4B (170), <br />MW-4D (42), <br />MW-6 (20), <br />MW-7(1) <br />MW-8 (31), <br />MW-9B (110), <br />MW-12B (10), <br />MW-12C (20), and <br />MW-13B (630) <br />Toluene 7 : 28 0.9 - 14 150 0 : 7 - <br />Ethylbenzene 2 : 28 1 -33 300 0 : 2 - <br />Total Xylenes 7 : 28 1 -20 1,750 0 : 7 - <br />MTBE 3 : 28 2 - 6 13 0 : 3 -- <br />TPH-GRO = Total petroleum hydrocarbons as gasoline as range organics <br />MTBE = Methyl Tert-Butyl Ether <br />MRL = Method Reporting Limit <br />pg/L = micrograms per liter <br />= Not applicable <br />CO Stantec <br />4