FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

. k'q KLEINFELDER from DB-1 and DB-3 (30 foot borings), and three from the 50 foot deep boring (DB-2). A total of eleven soil samples, seven soil samples from the deep soil borings and four from the well borings were submitted to a State of California approved laboratory for the following analyses: • Total Extractable Petroleum Hydrocarbons as referenced to Diesel and Motor oil [TPH-D/MO] by EPA Method 8015M/3015; I • Total Purgeable Petroleum Hydrocarbons as referenced to gasoline [TPH-G] and Benzene, Toluene, Ethylbenzene, Total Xylenes [BTEX] by EPA Method 8015M/8260; • Five Oxygenates (ETBE, DIPE, MTBE; TAME and TBA), by EPA 8260. i A Soil cuttings from deep soil boring DB-2 and well boring MW-4 were contained in 55-gallon drums. Cleaning water and purge water from each of the monitoring wells was also contained in 55-gallon drums pending chemical analysis and disposal by the client. I 4.3 MONITORING WELL DEVELOPMENT AND SURVEYING On October 28, 2003 and greater than 48 hours after insta lation, the four monitoring wells were developed to remove sediment-laden water and to increas the hydraulic radius of the well. The well pack of each well was also surged during well install ition prior to placement of a bentonite and grout seal. Development was performed using a subrr.ersible pump as generally described in Appendix B, Sections B-3.2 through B-3.3. The four new monitoring wells,MW-1 through MW-4 s were subsequently surveyed on November 11, 2003 by Morrow Surveying of West Sacramento. Vertical measurements were surveyed to the nearest 1/100`h of a foot. The measuring point for each well is the north side of the top of the PVC casing pipe. Well GPS survey coordinates are summarized on Plate 2. Copies of the well development logs are included in Appendix C. 4.4 MEASUREMENT OF WATER LEVELS A water level measurement was conducted in each of the four monitoring wells at the beginning of the sampling round prior to purging and sampling of the wells on October 29, 2003. The depth-to-water was measured in each well according to the protocol described in Appendix B, 1 Section B-4. The depths to water, measuring from the north side of the top of the PVC pipe, k ranged from 52.95 (MW-4) to 59.90 (MW-1). The depth-to-water measurements were converted to groundwater elevations and groundwater flow direction and gradient was calculated. Groundwater flow was calculated to be to the southwest with a gradient of 0.012 ft/fl. Because a pumping test was being conducted at the adjacent former Shell Station during the initial water level survey, Kleinfelder conducted a second water level survey on December 18, 2003. During this groundwater survey,the depths to water ranged from 51.45 (MW-4) to 58.11 G 36274/ST03R1919 Page 7 of 19 _g 2004 Kleinfelder, Inc. January 5,2004 I i