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Stantec <br /> Third Quarter 2010 Status Summary Report <br /> Former Tosco Bulk Terminal No. 10013 <br /> October 26, 2010 <br /> • DIPE was detected in 6 wells at concentrations ranging from 0.63 Ng/L (MW-20) to 18 <br /> pg/L (MW-18C). <br /> • BTEX, ETBE, and TAME were not detected above the laboratory reporting limits in the <br /> samples collected. <br /> • Methanol was not detected in any wells samples during the August 30, 2010 sampling <br /> event. <br /> Reported concentrations of constituents were compared with the analytical results from the <br /> previous quarters for wells MW-2, MW-8, MW-16, MW-17B, MW-20, MW-21B, and MW-22C <br /> with the following results: <br /> • TPH-g and BTEX concentrations have reached non-detectable levels since the previous <br /> quarter. <br /> • TPH-d concentrations increased in 11 wells ranging from 54 Ng/L in MWA to 1,900 Ng/L <br /> in MW-18c. <br /> • MTBE concentrations continue to decline to low or non-detectable levels. <br /> • TBA concentrations decreased to non-detectable levels in MW-8, MW-176, MW-22C <br /> and to low residual levels in MWA 1, MW-16, MW-18C and MW-21B. <br /> DIPE concentrations continued to remain at or near non-detectable levels with minor <br /> decreases during the third quarter 2010. <br /> • Methanol was historically not detected at the site until the first quarter 2010. Methanol <br /> was not detected in any wells samples during the August 30, 2010 sampling event. The <br /> reported concentrations during the first quarter 2010 appear to be anomalous. <br /> Quality Control Data Review <br /> A quality assurance/quality control (QA/QC) review was performed for sample integrity and <br /> analytical methods in the laboratory. Laboratory and field QC sample results were evaluated to <br /> assess the quality of individual sample results and overall method performance. The QA/QC <br /> review included an evaluation of the following: <br /> • Blanks (method) <br /> • Spikes (surrogates, laboratory control samples, and matrix spikes) <br /> • Duplicates (laboratory control spikes, and matrix spikes) <br /> • Sample integrity (chain-of-custody documentation, sample preservation, and holding <br /> time compliance) <br /> 5 <br />