SITE INFORMATION AND CORRESPONDENCE_FILE 2

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Weed Oil Fortifiers Add%,lal Information Moore Petroleum Bulk Plant,5491 F Street,Banta,California Page 2 use. Based on this information, Apex believes that weed oil with a concentration of fortifiers of approximately 30% could have been utilized. WEED OIL FORTIFIERS INFORMATION General information has been obtained from EXTOXNET (a cooperative effort on Pesticide Information Profiles from the University of California Davis, Oregon State University,Michigan State University, Cornell University, and the University of Idaho) on DAP (general listing for 2, 4-D), DBP, dinoseb, and PCP, included as Appendix C, the compounds suggested as weed oil fortifiers for analysis. Based on the information obtained from EXTOXNET, the environmental fate of the fortifiers (2, 4-D, dinoseb and PCP) range from low to moderately persistent in the environment. Weed oil fortifiers half lives in soil range from less than 7 to 45 days. In groundwater, half lives range from hours to several weeks with some reported instances of dinoseb (in the some soil conditions) for 10 years. Based on the wide range of half life in groundwater an overall half life of approximately one year will be used. In soil, all compounds have an increased mobility in the presence of organic mater, with dinoseb possessing the ability to remain in the vadose zone for a much longer time frame. Although dinoseb has an overall low persistence in the environment, in groundwater,present in the ammonium and amine slat form (as opposed to the phenolic form), dinoseb may pose a significant risk to groundwater for up to 10 years. PCP in soil is poorly sorbed in neutral and alkaline conditions and may be mobile in many soils. The solubility in water of 2, 4-D, dinoseb, and PCP are reported at 900, 52, and 80 milligrams per liter(mg/L). WEED OIL FATE ANALYSIS On November 9, 2005,total petroleum hydrocarbons as motor oil (TPHmo)were reported in CPT-2 at a maximum of 5,800 micrograms per liter(ttg/L). The following assumptions have been made to determine the likelihood that weed oil fortifiers are currently present in groundwater around CPT-2. Assuming that the concentration of TPHmo represents the total amount of weed oil present in groundwater on November 9, 2005, that weed oil consisted of approximately 30% fortifiers, and an average half life of the fortifiers in non-organic soil of approximately 1 year, concentrations of weed oil fortifier could exist at 400 µg/L. However,Apex notices that weed oil has not been utilized since 1980 and seems unlikely, based on cited half lives that these fortifiers still exist. Even if the analyzed fortifiers are reported below detection limits, the remaining portion of the weed oil (heavier hydrocarbons such as TPHd, TPHk, and TPHmo)may be detected above detection limits, due to the fortifiers decaying over 30 years. Apex proposes to continue with the proposed collection and analysis of a grab water sample near CPT-2 as shown on Figure 3 at 30 (originally proposed) and 42 feet bgs (as suggested by the SJCEHD).