ARCHIVED REPORTS_XR0012129 - Laserfiche WebLink

Home Browse Search

1 ,ARCADISGERAGHTY&MILLER detected a 60 4 f t the ft bgs depth ( ,200 ug/L} As with TPHg, the sampled concentrations o ' benzene declined sequentially at sample depths below 60 feet, to a concentration as low as 9 9 ug/L at the 100 ft bgs depth Sampled benzene concentration then increased to 38 ug/L at the 110 ftbgs depth Sunilar patterns are observed in the sample concentration depth distribution for toluene, ethylbenzene, and total xylenes MTBE, when detected by Method 8020, was confirmed using Method 8260 and was ' nondetect for all soil and groundwater samples ' Analytic results derived from groundwater samples extracted in boring NP-1 using the Sirnulprobe and analyzed in an on site mobile laboratory are summarized in Table 5-1 and ' illustrated in Figure 54 Detailed mobile laboratory results, fixed-lab MTBE confirmation results (also summarized in Table 5-2), QA/QC records, and Cham-of-Custody records for the field water sampling results are included in Appendix F 5.4.2 Boring NP-2 ' Attempts were made to collect groundwater samples at 10 foot depth intervals ' between 30 and 118 feet bgs, inclusive, using the Simulprobe sampling device Samples were successfully collected at the depths of 40, 60, 70, 80, 90, 110, and 118 ft bgs (Table 5-3, ' Figure 5-5) Insufficient quantities of water were collected, over the 30 minute collection time period, due lack of formation yield at sample depths of 30 and 50 ft bgs The concentration of TPHg (EPA Method 8015) in water samples collected at discrete ' depths in NP-1 was greatest at the 60 ft depth(4,000 ug/L) The 65 ft bgs depth was the depth at which the highest concentration of TPHg in soil was detected TPHg concentration in water ' collected at the 70 ft depth (3,600 ug/L) was similar to that at the 60 ft depth The TPHg ioconcentration in the sample collected at the 80 ft bgs depth decreased by an order of magnitude ' 25