ARCHIVED REPORTS_XR0007240 - Laserfiche WebLink

Home Browse Search

I � [ I i-iu1#70(l )0 BI If" Lm II oil tiiuI I I Rc uu di it l-E itiibilm [(,t RLI)OI I Win m 2, 200 i 41 1 Groundwater Sampling ' Groundwater samples were collected before and after AS testing in order to evaluate the effect of AS activities on petroleum hydrocarbon concentrations in the groundwater Prior to initiating AS testing, Blaes Environmental collected groundwater samples from monitor wells MW-3B (located approximately 18 feet north of ASW-1) and MW-3C (located approximately 37 feet west of ASW-1) (Figure 2) ' Groundwater samples were again collected from monitor well MW-3B and 3C following the conclusion of AS testing The non-purge groundwater samples were collected using dedicated disposable bailers The groundwater samples were decanted from the bailers into laboratory supplied sample containers The sample containers were sealed with a teflon lined cap, labeled, and placed on ice in a cooler A written record of each sample was entered onto a chain-of-custody document for transport to Del Mar Analytical in Phoenix, Arizona for laboratory analysis ' • To further assist in evaluating AS effectiveness, on-site monitor wells MW-1C, MW-2C MW-3B MW- 3C, MW-4B and MW-9B were field screened for groundwater depth, temperature, conductivity, and dissolved oxygen concentrations immediately prior to and after the AS test The average depth to groundwater recorded during the remedial program was approximately 57 62 feet below the top of ' individual well casings A summary of the groundwater field parameter data is provided in Table 2 ' 4 12 Air Sparge Test Procedures At the start of the AS test, air pressure was introduced into sparge well ASW-1, screened approximately 10 99 feet below the groundwater surface (screen 69 to 79 feet bgs) at the time of the AS test The ' induced pressure response in the vadose soil horizon was measured at six different lateral monitoring point wells (MW-1C, MW-2C, MW-3B, MW-3C, MW-4B, MW-9B) Magnehelic differential pressure ' gauges were connected and sealed to the top of each of the lateral monitoring points A 200 psi, 30 cfm rated flow meter was located between the manual pressure release bleed valve and the AS test well to ' measure flowrate into ASWA during the test Additionally, a 0 to 30 psi pressure gauge was installed in 8