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30 August 1997 <br /> oxygenate Analysis 2 . <br /> TheP roblem of identifying which oxgenates are present is further compounded because the oil <br /> refineries ship gasoline around the state and then trade gasoline between geographic areas. ' <br /> For instance, if gasoline is needed in the San Francisco Bay area by BogCo Oil,BogCo-will <br /> obtain some gasoline from,say,Generic Oil in the Bay area and,in exchange,Generic will <br /> receive some BogCo gasoline in Southern California. The result is that'we do not know what <br /> oxygenate compound is in the gasoline at a particular gas station. TAME may be used by <br /> Generic,but, because of this swapping,TAME,rather than MTBE,will end up in the ground <br /> water at a BogCo site. <br /> Research recently completed by DuPont-Dow (htq:,://www.dupont-dow.com/products/vitm/lkprev.hrml) <br /> show that oxygenates may be incompatible with some elastomer seals used on underground <br /> tank piping. One test, using several concentrations of MTBE,were short term(168 hours) and <br /> showed swelling could occur with some elastomers at currenseasoline e levels.over a <br /> Presumably, this will be true, to some extent, for all ether oxynate additives, <br /> a <br /> longer time, conceivably cause the failure of the seals;thereby,releasing the oxygenated <br /> gasoline into the environment. We are particularly concerned that older tank seals or material <br /> used to upgrade tanks may not be compatible with the oxygenates and may fail due to the <br /> high concentrations of oxygenates in the alternative fuel sources. <br /> On 14 August 1997, a workshop was conducted at the Sacramento office of this Regional <br /> Board, attended by representatives of Regional and State Boards,Local Implementing <br /> Agencies, analytical Laboratories and the petroleum industry. The objective was to provide <br /> guidance to the regulated community on how and where to analyze for the oxygenated <br /> compounds in gasoline until definitive protocol can be established in several months. The goal <br /> was to allow closure of underground tank sites with assurances that the interim methodology <br /> f can detect and quantify oxygenates. <br /> The workshop attendees concurred that the methyl and ethyl alcohols`can't be detected by <br /> EPA Method 8260 with certainty and that detection limits for methyl and ethyl alcohols are <br /> about two orders of magnitude higher than TBA and the ethers. Also with the exception of <br /> one oil company and special, alternative fuel vehicles (including the State of California <br />` automobiles), ethanol and methanol are used infrequently in California, and can be isolated by <br /> station and the more accurate analytical methods used. Therefore, at this time,unless ethanol <br /> or methanol are specifically requested,we are requiring soil and water analysis ordy for TBA <br /> and the ether compounds by EPA Method 8260 in order to determinewhich oxygenated <br /> compound is present- <br /> Presence <br /> resentPresence or absence of the oxygenate must be reported. However,because free product or <br /> high petroleum concentrations raise the detection limits of the oxygenates,the oxygenates <br /> cannot be detected with certainty. Therefore, at this time,we do not recommend sampling <br /> where product is present on groundwater. ,. <br /> 4 <br /> rt l- <br />