Laserfiche WebLink
L & M OPERABLE UNIT- FIRST QUARTER 2012 SITE STATUS, REMEDIAL SUMMARY, <br />AND GROUNDWATER MONITORING REPORT <br />Groundwater Monitoring and Sampling <br />April 30, 2012 <br />I:\Tidewater\TW Stockton (P2A)\QMRs\2012\1Q12\1Q12 QSSR QRSR QMR Stockton_FINAL.doc 2.20 <br />Well 2AMW-14 was not assessed during the third through fourth quarters of 2004 due to its <br />connection to a free product removal system. However, well 2AMW-14 has been accessible in <br />recent quarters and has contained sheen only. SPH or sheen has historically been reported in <br />well MW-10 since February 2004 and has ranged in thickness from 0.01 to 3.09 ft (February <br />2007; Table 3). Well MW-10 was abandoned in November 2008 due to the city of Stockton’s <br />excavation activities. <br />Historical measurable thickness of SPH in wells DPE-1 through DPE-13 and MW-40 has ranged <br />from 0.01 ft (DPE-12, February 2005) to a shallow zone maximum thickness of 11.72 ft (DPE-1, <br />November 2003). Well MW-40 was abandoned in November 2008 due to the city of Stockton’s <br />excavation activities. All DPE wells contained only sheen during 1Q12. <br />A summary of 1Q12 SPH thickness and SPH sheen in comparison to the 4Q11 is provided in <br />the following table. <br />SPH removal activities are scheduled to be conducted quarterly (at a minimum) for on and off <br />Site wells which repeatedly contain measurable thickness of SPH and are not connected to a <br />free product removal system. It should be noted that these SPH removal activities are typically <br />performed between quarterly monitoring events (as noted on the table), and are likely to <br />influence reported SPH thickness.