ARCHIVED REPORTS_XR0003878 - Laserfiche WebLink

Home Browse Search

(BTEX) and total petroleum hydrocarbons as gasoline (TPHG) by Sequoia Analytical (DHS cert. #1210) utilizing EPA methods 8020 and 8015, respectively Laboratory results detected low levels of BTEX in both soil samples. No TPHG was detected at or above method detection limits. Analytical results are summarized on Table 1. 3.1.2 Monitoring Well Construction Soil boring MWl was subsequently completed as a groundwater monitoring well. The ' monitoring well was installed to assess groundwater quality beneath the site. Figure 3 shows the location of the well. The well was constructed with 2-inch F480 polyvinyl chloride(PVC) screen/casing. The ' screened interval of the well was positioned from approximately five feet above to fifteen feet below the encountered water table to allow for seasonal water level fluctuations. A well screen slot size of 0 01 was used The boring for the monitoring well was advanced with 8-inch outside diameter hollow stem augers. When the augers were advanced to the desired depth of the well, the well ' casing was lowered down the center of the augers and set to the appropriate depth. The annular space between the augers and the screened portion of the well was backfilled ' with Lonestar #2-12 sand. As the filter pack was placed, the augers were withdrawn from the borehole so the sand flowed from the augers into the annular space of the borehole. The filter pack was extended to approximately two feet above the top of the screened portion of the casing. A two foot seal of bentonite clay was placed in the annular space above the filter pack. Since the bentonite seal was positioned above the ' water table, five gallons of potable water was added to allow the bentonite to gel. The remaining annular space was backfilled to the surface with neat cement using the ' tremmie method. R-060392 TIL 4