table of contents - Research and Innovative Technology ...

148 � Transportation Statistics Annual Report 1996
years, oceangoing tanker spills accounted for 30
percent of the volume spilled, but only 5 percent
of incidents. Three-quarters of all spills occurred
during transportation; the remainder resulted
from activities at fixed facilities.
The extent of adverse impact from spills
depends on many additional factors aside from
the quantity of oil. These include the characteristics
of the spilled oil and receiving waters, the
environmental sensitivity of the area, and the
weather. Most spills occur in protected environments
such as rivers, harbors, bays, and sounds,
rather than on open seas. Of the approximately
221 million gallons reported spilled over the
past 20 years, less than 15 percent were on the
open ocean. (USDOT Coast Guard in press) The
largest number and volume of spills reported
occurred in internal waters.
� Improper Disposal of Used
Motor Oil
The improper disposal of used motor oil is a
widespread source of groundwater and surface
water contamination. Automobile owners who
change their own motor oil account for a significant
portion of used oil dumping, disposing of up
to 200 million gallons of oil annually; of this, as
much as 120 million gallons may be dumped onto
the ground or into storm drains and another 60
million gallons may be dumped into trash cans.
(Novallo 1993) Annually, this is much more than
the Exxon Valdez spill. (Anderson and Lear 1994)
Although a person may believe that dumping
small amounts of oil is of little consequence, one
quart of oil can taint the taste of 250,000 gallons
of water and can create a 2-acre oil slick on lakes
and streams. (Novallo 1993) Oil also contains
additives that can oxidize during combustion to
form corrosive acids, and used oil is often contaminated
with heavy metals, chlorinated solvents,
and harmful organic substances. EPA did not list
used motor oil as a hazardous waste under the
Resource Conservation and Recovery Act. It has
promulgated, however, used oil handling standards
for generators, transporters, processors, rerefiners,
burners, and marketers. The standards
only apply after used oil is collected and aggregated
by public or private collection services.
(Kreith 1994, 9.166)
According to EPA, only about 10 million gallons
(5 percent) of the used motor oil generated by
do-it-yourself oil changers was recycled in 1988.
More recycling could decrease both the amount of
used oil released into the environment and the
amount of crude oil used for producing motor oil.
Motor oil does not wear out; it merely becomes
contaminated with residuals of fuel combustion
and engine wear. Re-refining removes these contaminants
from the oil and returns it to its original
quality. (Novallo 1993, 109–112)
� Underground Storage Tanks
Groundwater contamination is often caused
by leaks from underground storage tanks, such
as those found at neighborhood gas stations.
Most underground storage tanks are used by the
transportation sector. Of these, about 49 percent
are for retail motor vehicle fuels, 47 percent for
petroleum storage, and 4 percent for chemical
storage. According to EPA, about 1,000 confirmed
releases are reported each week, and 20
percent of the 2 million regulated tanks may be
leaking. (USEPA 1993, 14–15)
To remediate this type of contamination, the
federal government established the Leaking
Underground Storage Tanks program, which
operates under the authority of Subtitle I of the
Hazardous and Solid Waste Amendments Act of
1984 as amended by the Superfund Amendments
and Reauthorization Act of 1986. The
program’s purpose is to achieve rapid and effective
responses to releases from underground
storage tanks containing petroleum and other
hazardous substances.