ARCHIVED REPORTS_XR0003771 - Laserfiche WebLink

Home Browse Search

a r ✓ ^ v 4 n t } 1 } 15 February 2000 AGE-NC Protect No 98-0448 Page 8 of 33 (located approxuriately 10 feet southwest of VW-2) at approximately 0 12 inches of water Minimal induced vacuum measurements were observed from VW-1 (located approximately 15 feet _ _ southwest of VW-2) at approximately 0 03 inches of water and MW-6 (located approximately 67 feet southwest of VW-2) at approximately 0 02 inches of water The vacuum applied at VW-2 and the induced vacuums at VW-1, EW-1 and MW-6 were graphed _ versus distance utilizing a best fit line on a semi-loganthmic scale (Figure 4) Based upon the induced vacuums measured from VW-1, EW-1 and MW-6, a theoretical radius of influence in soils at the site for an induced vacuum of 0 1 inches of water is approximately 13 feet 35 ANALYTICAL RESULTS OF VAPOR SAMPLES ' During the SVE pilot test, TPH-g was detected in vapor samples collected from VW-2 at concentrations ranging up to 1,880 µg11, hydrocarbon vapor concentrations generally decreased as the test progressed BTEX compounds were detected in vapor samples collected from VW-2 at concentrations up to 58 µg/1 Concentrations of benzene were encountered from VW-2 at concentrations as high as 2 5 µg/l, Concentrations of MTBE were encountered at concentrations as high as 1 µg/l, MTBE vapor concentrations were generally stable as the test progressed Analytical results of vapor samples are summarized in'Table 8 The laboratory report (Precision Enviro-Tech Sample I D PE671 3) and chain-of-custody forms are presented in Appendix F 4.0. IN-SITU AIR SPARGING PILOT TEST From 25 through 27 August 1999, an IAS pilot test was performed at the site to evaluate the r k feasibility of IAS as a remediation method at the site 41 PROCEDURES ' AGE designed the IAS pilot test to utilize existing wells screened within the plume of impacted ground water and to assess effectiveness of IAS on wells screened in common geologic interval and , on nearby wells possibly isolated from the sparge zone by an interval of lower permeability (i e silt/clay) For the IAS pilot test, well MW-4B was utilized as a sparging well, wells MW-1, MW-2, MW-6 and EW-1 were utilized as observation points Well MW-4B is screened in a lower sand interval separated from an upper sand interval by a silt/clay interval Wells MW-1,MW-2 and MW-6 Advanced Geo Environmental,Inc I r