Laserfiche WebLink
Ryan Mock 2 5 November 2020 <br /> J.R. Simplot <br /> Anal to Method <br /> Sulfate and Nitrate as Nitrogen EPA 300.0 <br /> Ammonia as Nitrogen EPA 350.1 <br /> Specific Conductance Standard Method 2510B <br /> Title 22 Metals EPA 6010/7470 <br /> Hexavalent Chromium EPA 3060/7199 <br /> Staff reviewed the workplan and below has the following comments. Therefore, no later than <br /> 7 December 2020, please submit an addendum to the workplan that addresses staff's comments. <br /> 1. Both the total concentrations and soluble concentrations must be reported for comparison to <br /> water quality objectives. <br /> 2. Because the Southwest Pond was operated when the Occidental Chemical Company operated at <br /> the site, in addition to the proposed constituents in the workplan, soil samples should be <br /> analyzed for all constituents in Table 2 of Monitoring and Reporting Program R5-2015-0810 for <br /> the former Occidental Chemical Corporation. <br /> 3. Due to the observed shallow groundwater conditions at the site (approximately 10 feet below <br /> ground surface and 5 feet below the base of the ponds) the proposed soil sample depths for <br /> borings B1 through B8 and SW-1 through SW-3 of 0-6 inches below the asphalt liner, 5 feet, 10 <br /> ft, and 15,ft should be modified such that four samples are collected from each boring above the <br /> water table. The Regional Board also suggests that groundwater levels are checked prior to the <br /> investigation to provide data for selecting sampling intervals above the water table. <br /> 4. The proposed single surface soil sample from the agricultural field owned by J.R. Simplot to be <br /> used establish background soils characterization is not adequate because the land continues to <br /> be used for comingled stormwater and wastewater application. Therefore, the Discharger needs <br /> to select a new background location(s) that has not been subject to waste discharge during the <br /> life of this facility as J.R. Simplot or Occidental Chemical Company. Further, the Discharger <br /> needs to propose soil sampling intervals that correlate with the elevations of the southwest pond <br /> sidewalls as well as below the pond bottom. Finally, the Discharger may consider multiple <br /> background locations be sampled and the data pooled, to help account for spatial variability. <br /> 5. Because J.R. Simplot is not permitted to dispose of solids on-site, the accumulated sediments in <br /> the Southwest Pond should be characterized for disposal at a local landfill. <br /> 6. The Discharger should also check with the location that will be receiving any of the pond liner or <br /> potentially contaminated soil for their waste acceptance criteria. That way J.R. Simplot can collect <br /> that information at the same time the other soil sampling is occurring. <br /> If you have any questions regarding this letter, please contact me or Howard Hold by e-mail at <br /> brendan.ken ny(a).waterboards.ca.gov or howard.hold(a_waterboards.ca.gov . <br /> BRENDAN KENNY <br /> Engineering Geologist <br /> Compliance and Enforcement Section <br />