Casitas MTBE levels decline
by Lenny Roberts

According to a report delivered Wednesday by Casitas Municipal Water District water quality lab supervisor Susan McMahon, the levels of methyl tertiary-butyl ether in Lake Casitas have been negligible since earlier readings showed levels as high as 1.6 parts per billion.
The high reading, which is still well below state-mandated safety levels, was recorded at the treatment plant influent, or incoming flow of water, and 0.6 parts per billion in the effluent, or outgoing flow. According to the state of California, the acceptable limit for secondary MTBE levels, which means there is a noticeable taste or odor to the water, is five parts per billion, while the primary level, indicating possible health effects, is 13 parts per billion. Classifying high levels of MTBE as a possible carcinogen, the Environmental Protection Agency issues a health advisory when the levels reach 20 to 40 parts per billion.
MTBE tends to mix with the water at cooler fall and winter temperatures, when the previous readings were taken, but rises to the top during warm weather, McMahon explained. She said lower levels can be expected in late spring and summer because it evaporates from the surface of the water.
The CMWD board has known for some time that MTBE is present in the lake, and has determined that the source of the problem is the gasoline being used in motorboats. MTBE is an additive that first appeared in 1992 to help oxygenate gasoline, thereby helping reduce pollutants. The highest concentration of MTBE at Lake Casitas is typically recorded at the boat dock.
California Gov. Gray Davis had set Jan. 1, 2003 as the date when MTBE would be taken out of the gasoline in California and replaced with ethanol, but the ruling has been postponed for a year to prevent retail gasoline prices from soaring. It has been estimated that gasoline prices in California could easily double once ethanol has replaced MTBE, and some observers remain uncertain that the use of ethanol in internal combustion engines will be any less harmful to drinking water.
CMWD Director Jim Word said recreational boat owners may be willing to pay the hefty price.
"I'm not sure if the boating public understands it all, and believe that they would not object to paying $3 to $4 a gallon rather than not to be able to use their boats at all," he said. "There has to be another answer than just banning boats."
Although 2-cycle engines have been identified as the main offenders, the CMWD board has indicated that they do not want to make radical changes in the way the lake is used at this point. Possible alternatives until ethanol is in all gasoline would be to prohibit motorboats from the lake, sell MTBE-free gasoline only, wait for the ban on MTBE to become effective, only allow gasoline-powered boats on the lake in the warmer months, or restrict boats to 4-cycle, less-offending engines.
Typically, MTBE levels in the lake are a .6 to .7 parts per billion, and McMahon said that "It doesn't appear that it's accumulating in the lake." Director Bill Hicks wants to educate the boating public at Lake Casitas about the dangers of MTBE, and noted that "The level is still 75 percent below the maximum state level, and I think that's very good.
It has been suggested that boat owners be warned about spilling gasoline into the water, or even using it to power their boats. But of major concern is that many boat owners arrive at the lake with full tanks that could be MTBE-laden even when the ethanol-enhanced fuel becomes more readily available.
CMWD President Jim Coultas said it may be too early to prepare brochures.
"I'd hate to go to the boating public until we have something in place," he said. "Maybe we should ask boaters to go to local 76 stations."
Union Oil Company is already producing MTBE-free gasoline. However, it does not mean that all Unocal 76 stations in the state are selling it.
Coultas also believes that because of its composition, gasoline with the ethanol additive may not be delivered to California via pipelines as gasoline with MTBE is currently, and it's possible that California's gasoline would have to arrive from the Midwest on rail. One solution is that ethanol would be added to the gasoline in local fuel tankers before they are dispatched to gas stations.

© 2002 The Ojai Valley News

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