SITE INFORMATION AND CORRESPONDENCE FILE 1

Home Browse Search

N l 16 April 1997 AGE-NC Project No. 95 -0121 Page 4 of 9 are depicted in Figure 4 - Proposed Soil Vapor Extraction Well Locations. During drilling activities, soil borings will be advanced to depths of approximately 20 feet bsg . All hollow stem augers will be steam-cleaned prior to advancement in each borehole. Cuttings and rinseate generated during drilling activities will be containerized in properly labeled D . O . T. model 17H 55 -gallon drums, and stored on- site in an area inaccessible to the general public . Soil borings will be completed as 2- inch diameter SVE wells using both 0 . 020-inch screened and schedule 40 blank poly vinyl chloride (PVC) casing. A Lonestar #3 sand will be utilized as a filter pack in and slightly above the screened interval . Bentonite chips will be utilized as an approximate five-foot annular sea! located above the filter pack, while a Portland Type Il cement will be utilized as a grout to surface grade. A proposed as- built construction diagram is illustrated in Figure 5 - Proposed Soil Vapor Extraction Well Diagram . 3 . 1 .2 . PROPOSED SYSTEM LOCATION AIND DESIGN The location of the VES unit is proposed near the southeast corner of the Nomellini Construction Company building. This location will reduce the amount of trenching and piping needed to install the system. A gated enclosure, approximately 15 by 20 feet, will secure the VES unit. One-inch diameter PVC piping will be installed underground from the proposed SVE well head locations to a vapor dropout drum . The PVC piping will carry hydrocarbon vapors from the SVE well heads to the VES unit. A brass flow control valve will be installed in each line so that vapors can be drawn from each well independently. A plan of the proposed piping system and enclosed VES unit location are depicted in Figure 6 - Proposed Piping System. 3 . 1 .3 . PROPOSED SUPPLEMENTAL FUEL Supplemental fuel is proposed for the operation of the selected VES unit. An automatic air dilution module adjusts for the optimal combustion parameters by adding oxygen and/or supplemental fuel . Natural gas is readily available on- site. A dedicated gas line could be installed by representative of P .G. & E. that would connect directly to the VAS unit. Furthermore, a meter would be installed to monitor supplemental fuel consumption . 3 . 1 .4. PROPOSED MONITORING ACTIVITIES The VES unit will be monitored weekly using a photo-ionization detector (PID) to ensure optimal destruction of recovered hydrocarbon vapors, and to monitor cleanup progress. The PID readings will be recorded from the influent end of the VES unit, and recorded before and after catalytic