ARCHIVED REPORTS_XR0004870 - Laserfiche WebLink

Home Browse Search

n Second Quarter 2005 Monitoring Report • Quik Stop Market No 121 Page 3 this quarter (Figures 2 and 3) All three of the deep wells, MW-6, MW-9 and MW-10, screened from 65 to 75 feet within the B-aquifer, were reported to be free of detectable TPHg/BTEX One of the three B-aquifer wells was reported to contain MTBE Monitoring well MW-6 was reported to contain 1 5 ug/L MTBE No other compounds were detected in MW-6 or wells MW-9 and MW-10 The results of the groundwater analysis are summarized in Table 2 A graph for well MW-3 and RW-1, summarizing MTBE concentrations over time, are also presented herein The analytical reports from STL, chain-of-custody documents and field notes are attached in Appendix B Discussion Groundwater measurements taken in nine of the ten shallow A-aquifer wells this quarter indicated the depth-to-groundwater ranged from approximately 17 68 to 18 67 feet below the top of the well casings The water level in monitoring well MW-4 was measured at 17 68 feet below the top of the well casing The water table in the A-aquifer has risen approximately 3 feet during the last three months The current groundwater table at the site shows a slight flow direction to . the north (Figure 4) Groundwater measurements taken in the three B-aquifer wells indicated the depth-to-groundwater ranged from approximately 19 20 to 20 17 feet below the top of the well casings The water table in the B-aquifer has risen approximately 2 feet during the last three months A groundwater gradient map for the B-aquifer was created and indicates a gradient of 0 001 feet per foot to the southwest (Figure 5) Dissolved oxygen (D 0 )readings were collected this quarter The D 0 readings for all of the wells are summarized in Table 3, and also show D O readings from previous sample rounds Based on the groundwater data obtained during the quarter, it appears TPHg and BTEX compounds have been eliminated from all the site wells The MTBE plume has been eliminated from the area around monitoring well RW-1 The previous MTBE concentration reported in well RW-1 has dropped from 160,000 ug/L on August 16, 2002 to non-detect this quarter Minor concentration of MTBE was detected in one of the three B-aquifer wells this quarter Monitoring well MW-6 was reported to contain 15 ug/L MTBE No other fuel oxygenates were detected in the B-aquifer wells A summary of the data collected during the operation of the System is presented in Table 3 To summarize the results, with the exception of MW-6, no TPHg/BTEX or fuel oxygenates were detected in any of the wells sampled this quarter The KVA C-Sparge system has operated with some problems this quarter, but continues to have a positive impact on the groundwater conditions at the site CCI will continue to work on and monitor the System during the next . quarter Based on the last two quarters of non-detect groundwater results, CCI requests that the