ARCHIVED REPORTS_XR0002885 - Laserfiche WebLink

Home Browse Search

1 5 4.0 SUMMARY OF RESULTS 1 A summary of the analytical results from current and past well sampling is presented in Table 1. Based i� on the water-level data for September 18, 2000, ATC has interpreted the groundwater gradient and flow direction for the upper aquifer, as shown on Figure 3. In the upper aquifer (monitoring wells MW-5, MW-6, and MW-7), the groundwater elevation decreased from the previous quarter an average of 1.15 feet, ranging from 1.13 feet in monitoring well MW-7 and MW-6 to 1.18 feet in monitoring well MW-5. The apparent groundwater flow direction in the upper aquifer was southeasterly at a gradient of ' approximately 0.005 (Figure 3). ' Based on the water-level data for September 2000 (Table 1), ATC has interpreted the groundwater gradient and flow direction for the lower aquifer, as shown on Figure 4. In the lower aquifer (monitoring ' wells MW-1R, MW-2, MW-3, MW-4), the groundwater level decreased from the previous quarter an average of 1.18 feet, ranging from 1.23 feet in monitoring well MW-2 and MW-3 to 1.13 feet in monitoring well MW-6 and MW-7. The apparent groundwater flow direction in the lower aquifer was southeasterly at a gradient of approximately 0.00 17 (Figure 4). ' As part of construction activities for widening West Hammer Lane, the casing of MW-8 was cut and the well box lowered by V&W Drilling. The well was recently paved over preventing access to it. Therefore, the groundwater elevation could not be calculated for well MW-8 this quarter. ATC will re-survey the well when it is located so that groundwater elevations can be accurately calculated. Laboratory analysis of the water sample collected on September 18, 2000 indicates that TPH-G and BTEX was not detected in any of groundwater samples collected from monitoring wells with the rexception of MW-2, where benzene was detected in a concentration of 25 micrograms per liter (µg/1). TPH-G was detected in the groundwater samples from monitoring well MW-1R, MW-2 and MW-5. Laboratory results of fuel oxygenate compounds by USEPA Method 8260 indicates that MTBE was detected in the groundwater samples from monitoring wells MWAR (31µg/1), MW-2 (3,600 gg/1), and ' MW-5 (2,900 µg/1). Tert-butanol (200 µg/1) and TAME (30 }ig/1) were detected in samples collected from monitoring well MW-5. The next quarterly groundwater sampling is scheduled for the fourth quarter of 2000. 2W0 Third Quarter Groundwater Monitoring Report 51Ple3santon�projrcts\1n ProgreWQU1KSTOPSQS 1321R8PORTSUOOO\3rd0tr2000rpt.&w 1