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z 4# CALIFORNIA REGIWATER QUALITY CONTROL BOAR* CENTRAL VALLEY*ION 2 3443 Routier Road, Suite A � Sacramento, CA 95827-3098 Phone (916) 255-3000 FAX (916) 255-3015 18 July 1997 Revised 30 August 19972 To Whom It May Concern Cal/EPA Pete Wilson, Goverwr ANALYSIS REQUIRED FOR OXYGENATE COMPOUNDS USED IN CALIFORNIA GASOLINE - EPA METHOD 8260 (8240-B and 8020) At a June 1997 meeting at the Department of Health Services in Berkeley, the statewide analytical methods committee for establishing analytical TPH and additive standards, was informed that oxygenate compounds, which may constitute a threat to groundwater, other than MTBE, have been and are being added to gasoline. The list includes, in order of analytical identification: 1. Methanol 2. Ethanol 3. Tertiary Butyl Alcohol (TBA) 4. MTBE 5. Di -isopropyl ether (DIPE) 6. Ethyl Tertiary Butyl Ether (ETBE) 7. Tertiary Amyl Methyl Ether (TAME) The first three are alcohols and the latter four are ether compounds. Ethanol has been used for several years in California. MTBE, as you know, has been used as an octane enhancer additive since the late 1970s and is now used at a higher percentage as an oxygenate in gasoline. Now we have learned that, TAME has been added to California fuels, since 1995. DIPE has been used on the East Coast, but recently has been found in Southern California ground water (May 1997) and San Joaquin County (August 1997). TBA has been found in ground water at a gasoline service station site in San Joaquin County (1100 ppb, August 1997). To date, we have no information regarding the use of ETBE in California. The introduction of these additives present analytical problems for laboratories because the multiple analytes can co -elute from the column. For instance, TAME may co -elute with benzene in the EPA -8020 analytical method commonly used today. Therefore, we believe that Mass Spectrometry (MS) is the most definitive procedure to determine oxygenate compounds. MS will likely increase the cost of sample analysis; but, until another comprehensive analytical method is developed that can distinguish between the compounds, we believe that EPA Method 8260 is the most reliable, readily available procedure for laboratories. Completion of proposed studies on analytical procedures for oxygenate compounds by the Lawrence Livermore National Laboratory, under contract to the State Water Resources Control Board, should provide additional guidance by early 1998. Recycled Paper our mission is to preserve and enhance the quality of California's water resources, and ensure their proper allocation and efficient use for the benefit of present and future generations.