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
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,
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
"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
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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