SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

Mr. Robert Donovan • - 2 - • 28 March 2001 2. The isoconcentration maps need to show all contour lines. Several isoconcentration maps contour to 1,000 parts per billion (ppb) and the next contour line is less than 50 ppb or less than 0.5 ppb. 3. Isoconcentration maps must reflect reported concentrations. Examples of discrepancies are: • Figure 6 has two separate values of 1,700 ppb on the 10,000 ppb contour line; • Figure 6 has a value of 420 ppb contoured closer to the <50 contour line than a 100 ppb value; • Figure 10 has no 100,000 contour line; • Figure 12 has a value of 5,700 contoured within the<50 contour line; • Figure 12 has values of 74 ppb, 140 ppb, 170 ppb, and 930 ppb equidistance from the<50 contour line; and • Figure 13 has concentrations from 120 ppb to 11,000 ppb, but there is only a<50 contour line. 4. In Table 2 of the Report, the list of duplicates provided at the bottom does not correspond to the duplicates shown on the field data sheets. 5. The lateral and vertical extent of groundwater contamination is not defined. Please see our comments to the Groundwater Investigation Report provided under different cover. Please include these changes in the next quarterly monitoring report, which is due 30 April 2001. If you have any questions, you may contact Devra Lewis at(916) 255-3119 or lewisd(@,rbSs.swrcb.ca.gov. E Y L. COHEN Chief, Site Cleanup Unit Attachment cc: Ms. Margaret Lagorio, San Joaquin County Public Health Services, Stockton Mr. Jay Jahangire, Port of Stockton, Stockton Mr. Ralph Moran, Arco Products Company, La Palma Ms. Ann Duarte-Wilkinson, Time Oil Company, WA Mr. Kyle Mullins, ST Services, TX Ms. Jill Jefferson, Kinder Morgan Energy Partners, L.P., Orange Mr. Steve McDonald, Luce, Forward, Hamilton, and Scripps, San Diego Mr. Steve Lofholm, IT Group, Sacramento