Laserfiche WebLink
Mr.M. Scott Mansholt—CEMC <br /> Second Quarter 2006 Groundwater Monitoring and Sampling Report July 11,2006 <br /> Vernalis Pump Station Page 5 of 5 <br /> laboratory's method detection limit and reporting limit. All qualified data are presented in Table <br /> B-1. <br /> Unless noted otherwise,analytical data collected in support of this investigation are considered <br /> precise, accurate,representative, complete, and comparable, and they may be used for their <br /> intended purposes. <br /> CONCLUSIONS AND RECOMMENDATIONS <br /> Groundwater elevations from the site wells indicate that groundwater flow was to the northeast at <br /> an approximate gradient of 0.001 ft/ft during the second quarter of 2006. No dissolved-phase <br /> TPHg or BTEX appear to be present at the site. TPHd were detected in the samples from MW-5, <br /> MW-7, and MW-7 field duplicate sample during the second quarter of 2006 at concentrations of <br /> 72 Jµg/L, 710 Jµg/L, and 550 J gg/L,respectively. Low concentrations of PAHs were detected <br /> in the samples from wells MW-5,MW-6,MW-7, and MW-7 field duplicate sample and were <br /> below the PRGs for direct exposure to tap water. SPO has been observed in well MW-1 since <br /> 1998. <br /> A Soil and Groundwater Investigation Report for the May 2005 investigation is in progress and <br /> will be submitted during the third quarter 2006. Recommendation regarding the frequency of <br /> groundwater monitoring and sampling will be made in the Soil and Groundwater Investigation <br /> Report to be submitted during the third quarter. The absorbent sock in well MW-1 will be <br /> monitored quarterly and replaced as necessary. When the petroleum sheen has been removed, <br /> SAIC recommends that well MW-1 be incorporated into the quarterly monitoring and sampling <br /> program. <br /> CLOSING <br /> If you have any questions regarding this report,please call Chris Dennis at(916) 979-3866. <br /> Sincerely, <br /> SCIENCE APPLICATIONS INTERNATIONAL CORPORATION <br /> 4,��4 A-�� C <br /> U <br /> Suzette Villanueva Christopher B. Dennis,P.G. <br /> Staff Scientist Senior Geologist ,Or1AL GHQ <br /> Enclosures: 04 CHRISTOPHER <br /> Figure 1: Vicinity Map CL B. <br /> Figure 2: Site Map Is <br /> Figure 3: Potentiometric Surface Map Second Quarter 2006 No.7184 <br /> Figure 4: Petroleum Distribution in Groundwater Second Quarter 2006 9 Q- <br /> Table 1: Groundwater Elevation Data and SPO Thickness Measurements �Op CA, SFO <br /> Table 2: Groundwater Analytical Results—THPd, TPHg, and BTEX <br /> Table 3: Groundwater Analytical Results—PAHs Expires August 3 y ,ZCC <br /> Attachment A: Field Data Sheets <br /> Attachment B: Data Usability Summary and Laboratory Chemical Analytical Report <br />