Residential well's MTBE levels exceed guidelines
Site among 120 tested in Jacksonville area, where gas station reported
25,000-gallon leak last month
By Timothy B. Wheeler
Sun Reporter
Originally published March 16, 2006
Test results released yesterday show that a residential well in the
Jacksonville area of Baltimore County has been contaminated by
significant levels of a gasoline additive, the first such finding
since testing was ordered in response to a large gasoline leak there.

That well, among 120 tested since a 25,000-gallon leak was reported in
mid-February at the Jacksonville Exxon, shows elevated levels of the
gasoline additive methyl tertiary butyl ether, or MTBE.

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Herbert Meade, administrator of the oil control program at the
Maryland Department of the Environment, said yesterday the well on
Hampshire Glen Court, about a quarter-mile east-northeast of the
service station, is the only residential water source of those tested
to show contamination levels above state guidelines.

Tests found 57 parts per billion MTBE in the residential well in early
March, though the level dropped a week later to 32 parts per billion.

Maryland has set an "action level" of 20 parts per billion for MTBE,
because the gas additive can be tasted or smelled in drinking water
around that threshold. Its human health effects at such levels are
unknown, though it has caused cancer in laboratory rats.

John Larrabee, whose well, according to MDE files, showed elevated
MTBE levels, said that ExxonMobil Corp. had furnished his household
with bottled water and pledged to install a filtration system on the
well to remove the contaminants. He said the well had not shown
evidence of contamination before the leak. He declined to say more,
noting his lawyer's advice.

Meade pointed out that the residential well with elevated MTBE level
is out of line from a string of monitoring wells that have collected
gasoline since the leak. But as a result of the findings on that well
and others, Meade said, the state has ordered ExxonMobil to begin
weekly testing of certain wells on Hampshire Glen Court, Robcaste
Road, Paper Mill Road and Jarrettsville Pike. Officials had originally
ordered tests of residential wells every two weeks.

High levels of MTBE, benzene and other toxic gasoline ingredients have
been found in a well used by a nail salon on Jarrettsville Pike just
south of the Exxon station, according to test results on file with
MDE. The results, showing 4,610 parts per billion MTBE and 15.2 parts
per billion benzene, were made available to The Sun yesterday as the
result of a Public Information Act request.

Previously, contamination had been reported in a well serving a
Bradford Bank branch across the intersection of Jarrettsville Pike and
Paper Mill and Sweet Air roads from the service station. MDE records
show the bank well, no longer in use, contained 773,000 parts per
billion of MTBE and 5,380 parts per billion of benzene. Federal
drinking-water safety standards allow for no more than 5 parts per
billion of benzene, a human carcinogen.

Low levels of MTBE also have been detected in more than three dozen
other residential wells within a half-mile radius of the intersection
of Jarrettsville Pike and Paper Mill and Sweet Air roads. But Meade
said the trace levels of the gas additive found in many of those wells
are too low to be of concern and might stem from previous service
station leaks in the area over the past 25 years.

MTBE, added to gasoline for decades as an octane enhancer and later as
an oxygenate to reduce air pollution, spreads easily through ground
water and can linger there for years.

Meade said gasoline is collecting in several of the 92 monitoring
wells the state ordered ExxonMobil Corp. to drill around the station,
with most of the fuel in wells along a fault running from northeast to
southwest of the station. The state official said those findings, and
the limited residential well contamination so far, give him hope that
the leaked fuel is largely contained in that underground crevice.

ExxonMobil issued a statement yesterday saying it has recovered about
12,000 gallons of gas, either in liquid or vapor form, from the
monitoring wells and the soil.

Glen A. Thomas, president of the Greater Jacksonville Association,
said he was not ready to dismiss trace readings of MTBE in residential
wells, at least not until subsequent tests show no increases in
contaminants.

"We don't know how it's migrating there, and I'm concerned that what
we'll find is with weekly testing, the levels may be going up," Thomas
said. "I absolutely hope and pray that's not the case."