Laserfiche WebLink
12 October 1995 <br />' AGE-NC Project No. 95-0112 <br /> • Page 2 of 6 <br /> 2.3. QUARTERLY GROUND WATER MONITORING <br />' Wells MW-1 through MW-3 were initially sampled for TPH-g on 13 August 1987 by Weiss <br /> Associates. The wells were again sampled on 8 September 1987 for volatile aromatics (benzene, <br />' toluene, ethyl benzene and xylene: BTE&X). No further sampling was performed between 1987 and <br /> October 1992. <br />' Between October 1992 and April 1995, monitoring at the site was performed on nine occasions. <br /> Petroleum hydrocarbon concentrations have fluctuated in most wells over that period. Past and <br /> current analytical results of ground water samples are included in Table 3. <br /> 2.4. SOIL AND GROUND WATER REMEDIATION <br /> In preparation for soil remediation at the site, boring RW-1 was installed in August 1993 by <br /> GeoAudit. This boring was drilled at a 15' angle from vertical from a surface location near the <br /> southeast corner of the building, and completed as a 4-inch diameter remediation well. A Final <br /> Remedial Plan(FRP) was then prepared by GeoAudit in July 1994, outlining soil and ground water <br /> remediation procedures for the site. <br /> ' 3.0. PROCEDURES <br /> 3.1. DRILLING AND SAMPLING <br /> ' Between 17 to 19 May 1995, two soil borings were drilled using a DH-55 drill rig. The drill rig and <br /> a two-man crew were supplied by Soils Exploration Services, Inc. (SES) of Benicia. Boring SW-1 <br /> ' was installed 20 feet north of MW-1;boring SW-2 was installed approximately 3 5 feet west of RW-1. <br /> The location of the borings is depicted on Figure 2, Boring SW-1 was advanced to a depth of 73.5 <br /> feet; boring SW-2 was advanced to a depth of 75 feet. Soil cuttings were stockpiled on plastic <br /> ' sheeting. <br /> For both borings, discrete soil samples were collected ahead of the drill bit at 5-foot intervals using <br /> ' a split-tube sampler loaded with pre-cleaned 2-by 6-inch brass sleeves. The sampling equipment was <br /> washed in an Alconox solution and rinsed with water prior to each sampling run to avoid cross- <br /> contamination. For each sample, both ends of the lead tube were covered with Teflon sheets, capped <br /> ' --And sealed with tape. _ <br /> Samples were stored on ice and transported under chain-of-custody to Alpha Analytical Laboratories <br /> ' (AAL) for analysis. Selected soil samples were analyzed for TPH-g and BTE&X in accordance with <br /> imethods 5030 and 8020, respectively. <br />