SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

k { lr5 TREVOR SANTOCHI k PAGE 2 in the soil at the site, specifically the tetrachloroeth lene PCE and the 1,2- p Y Y (PCE) c dichloroethane (1,2-DCA). 4 �f k Physical data from other possible sources to the PCE and 1,2-DCA must be i evaluated and discussed in the report. Possible off sitesources to this contamination include the Kearney-KPF facility, located at 1624 East Alpine rand the American Forest Products facility, located at 2801 West Lane. There are files available for review for these two facilities in this office. Another possible source worthy of review is the sewer line that runs down West Lane and possibly East Alpine. You may contact Gene Gillman at the San Joaquin County Public Works Department (209-468- 3038) for more information on the service line in this area. In order to better evaluate the soil lithology/contaminant, distribution patterns identified at the site, please provide a separate cross section, one for each of the following I areas: from monitoring well MW#5 to monitoring well MW#1; ,from monitoring well MW#1 to monitoring well MW#3; and from monitoring well MW#2 to monitoring well MW#6. Please show the location of the tank pit area and include all the analytical soil data generated from the wells and the finished excavation on the cross sections. �h The calculations shown for the mass volume estimate for the'Fremaining hydrocarbons } in the area of the former tank pit are incomplete. It is unclear how the area of i impacted soil was derived and whether the area beneath the ,excavation was included in the calculation. Please calculate a separate mass volume-for each constituent { identified and show all calculations used in the determination;' Legible copies of actual handwritten calculations are acceptable but it is important that they show how ii the determination was derived from start to finish. Please bepadvised that the actual soil sample results from the laboratory should be used in thisidetermination as several errors have been identified in Table 3 and Table 4 from the May 14, 1993 WESTON report that originally reported the data. In addition R for sample results that did not detect contamination and did not achieve the Tri Regional Guideline detection limits, please include the actual detection limit obtained in the calculations, as contamination may have been present but not detected:Il f Monitoring wells MW#1, MW#2, and MW#3 are screened shallower than monitoring wells MW#4, MW#5, and MW#6. The well logs show that monitoring wells MW#1, MW#2, and MW#3 are screened predominantly in the sandy zone and monitoring wells MW#4, MW#5, and MW#6 are screened predomin"antly din the silty zone. An evaluation should be made of the depth to water measurements, the depth of the screen intervals, and the soil lithology in the area of the;!screen intervals. This evaluation should be made to explain how these factors=may;have influenced the contaminant concentration trends documented at the site. A graphic summarization 't :j I� ii