Laserfiche WebLink
P <br /> + Ms. Vicki McCartney <br /> Project 880-040.1A/0107 ! <br /> November 25, 2003 <br /> Page 3 <br /> 8015GRO/8021 and 8260B. Field and laboratory procedures are presented in <br /> Attachment A. Certified analytical reports, chain-of-custody documentation, and field data <br /> sheets are presented in Attachment B. Sa 7/1'" w"e_ AVs o f y z 41t/ 4r �� z•bG� <br /> D B "Iff-MoAhoil 4co 8. vrn o 1 <br /> a Fourth Quarter Groundwater Monitoring Results <br /> I <br /> Groundwater elevation at the site decreased approximately 0.95 feet since the previous <br /> sampling event conducted on July 21, 2003. During the fourth quarter groundwater flow r <br /> was to the east-northeast at an average gradient of 0.002 ft/ft, which is consistent with <br /> previous sampling events. Groundwater elevation data are presented in Table 1. <br /> A groundwater elevation contour map based on the October 13, 2003, data is shown on <br /> Figure 1. a mi MW-3 M <br /> Owl °q <br /> i <br /> TPHg range hydrocarbons were reported in well MW-1 at concentrations of ' <br /> 4,600 micrograms per liter (µg/L). Benzene was reported in well MW-I at a concentration <br /> of 700 µ /L. MtBE was reported in all wells sampled at concentrations ranging g p p g g from <br /> 22 µg/L in well MW-3, to 9,900 µg/1L in well MW-4. TBA was reported in well MW-1 at a <br /> concentration of 5,800 µg/L. Groundwater analytical data are presented in Table 1. A <br /> TPHg, benzene, and MtBE concentration map based on October 13, 2003, data is shown on <br /> Figure 2. <br /> DISCUSSION <br /> Groundwater levels have decreased approximately 0.95 feet since the third quarter 2003 <br /> sampling event. Groundwater analytical data for the fourth quarter 2003 sampling event are <br /> consistent with historical data. Since groundwater monitoring began in September 2000, <br /> MtBE concentrations have declined in all wells. Shaw has prepared and will submit a report <br /> during the fourth quarter 2003 presenting the results of the CPT investigation conducted in <br /> September 2003. In addition to the recommendations made in that report, Shaw <br /> recommends continued monitoring of the existing five wells (MW-1 through MW-5) to <br /> further evaluate the dissolved hydrocarbon plume at the site. <br /> Shaw Environmental,Inc. <br /> N!:-,acDP120031Prj188018800401A.3ae.doc <br /> t <br />