ARCHIVED REPORTS_XR0012457 - Laserfiche WebLink

Home Browse Search

' 13 September 2001 • AGE-NC Project No. 98-0450 Page 3 of 6 ' stream_ These samples were labeled,placed in a pre-chilled cooler and transported under chain-of- custody to Associated Laboratories in Orange, California. ' Three sets of samples were collected during June, July and August 2001. Samples were collected on 21 June, 17 July and 09 August 2001 in Tedlar vapor bags using a vacuum pump attached to the influent and effluent stream.The samples were labeled,placed in a pre-chilled cooler and transported under chain-of-custody to MAI. The samples were analyzed for; ' 0 TPH-g in accordance with EPA Method 8015 Modified and ' • BTEX and MTBE in accordance with EPA Method 8020. ' The results of the laboratory analysis are summarized in Table 4. , . 3.0. FINDINGS Ground water elevation, flow direction and gradient were determined from field data collected on ' 06 June 2001. Ground water flow direction was determined by contouring the water elevations on a scaled site plan(Figure 3). The contaminant impact to ground water was assessed from the ground water laboratory data. From field data collected at the SVE remediation system between early May and early August 2001, AGE determined the average TPH-g concentration, the average flow rate and calculated the ' approximate mass and volume of gasoline removed. ' 3.1. RELATIVE GROUND WATER ELEVATION AND GRADIENT The depths to ground water from the tops of the monitoring well casings were measured at 46.34 to 47.70 feet. The corresponding ground water elevations ranged from 1.27 to 1.67 feet below mean sea level. ' - Since the last quarterly monitoring event,ground water elevation has decreased an average 0.74 feet - - at the site. The ground water elevation data for the well network during the latest ground water Ilemonitoring event is depicted in Figure 3. The ground water flow direction determined during this monitoring event was toward the south to southwest, with a hydraulic gradient of approximately 0.004 (Figure 3). 1 Advanced GeoEnvironmental,Inc.