The
background
papers
on
the
candidate
national
program
priorities
are
intended
to
initiate
further
discussion.
When
priorities
are
selected
more
detailed
strategies
with
in­
depth
background
information,
numerical
targets,
schedules,
milestones
and
performance
measures
will
be
developed.
______________________________________________________________________________

December,
2003
Page
1
of
2
Proposed
Priority:
Underground
Storage
Tanks/
Resource
Conservation
and
Recovery
Act
Universe
and
Types
of
Facilities
An
underground
storage
tank
system
(
UST)
is
a
tank
and
any
underground
piping
connected
to
the
tank
that
has
at
least
10
percent
of
its
combined
volume
underground.
Federal
UST
regulations
apply
only
to
underground
tanks
and
piping
storing
either
petroleum
or
certain
hazardous
substances.
When
the
UST
program
began,
there
were
approximately
2.1
million
regulated
tanks
in
the
U.
S.
Today
there
are
far
fewer
since
many
substandard
UST
systems
have
been
closed.
From
the
mid
1980'
s
to
1999,
EPA
and
the
states
permanently
closed
approximately
1.3
million
federally
regulated
substandard
UST's.

Geographic
Range
National.

Environmental
Risks
Prior
to
the
mid­
1980s,
most
USTs
were
made
of
bare
steel,
which
is
likely
to
corrode
over
time
and
allow
UST
contents
to
leak
into
the
environment.
Faulty
installation
or
inadequate
operating
and
maintenance
procedures
also
can
cause
USTs
to
release
their
contents
into
the
environment.

The
greatest
potential
hazard
from
a
leaking
UST
is
that
the
petroleum
or
other
hazardous
substance
can
seep
into
the
soil
and
contaminate
groundwater,
the
source
of
drinking
water
for
nearly
half
of
all
Americans.
A
leaking
UST
can
present
other
health
and
environmental
risks,
including
the
potential
for
fire
and
explosion.
EPA
estimates
about
25,000
tanks
hold
hazardous
substances
covered
by
UST
regulations.

Noncompliance
Information
A
common
problem
associated
with
underground
storage
tanks
is
soil
and
groundwater
contamination
by
MTBE
(
methyl
teritary
butyl
ether)
and
other
fuel
oxygenates.
Owners
at
many
small
privately
owned
gas
stations
may
be
unaware
of
UST
regulations
or
may
find
it
prohibitively
expensive
to
resolve
any
problems
that
might
be
present.
Some
tanks
are
owned
by
marketers
who
sell
gasoline
to
the
public
(
such
as
service
stations
and
convenience
stores)
and
others
are
owned
by
nonmarketers
who
use
tanks
solely
for
their
own
needs
(
such
as
fleet
service
operators
and
local
governments.
)
There
is
a
high
rate
of
noncompliance
among
underground
storage
tank
operators,
particularly
among
independent
owners.
In
addition
to
fuel
oxygenates,
UST's
can
also
contain
a
variety
of
other
hazardous
wastes;
there
are
over
800
substances
listed
as
CERCLA
hazardous
substances.

EPA
and
the
states
have
made
significant
progress
over
the
past
15
years
in
developing
and
The
background
papers
on
the
candidate
national
program
priorities
are
intended
to
initiate
further
discussion.
When
priorities
are
selected
more
detailed
strategies
with
in­
depth
background
information,
numerical
targets,
schedules,
milestones
and
performance
measures
will
be
developed.
______________________________________________________________________________

December,
2003
Page
2
of
2
implementing
a
comprehensive
regulatory
UST
program,
which
has
included
the
closure
of
substandard
UST's.
In
addition,
new
releases
have
decreased
from
approximately
26,000
in
1998
to
9000
through
mid­
year
2003.
Even
though
substantial
progress
has
been
made,
considerable
work
­
such
as
improving
the
compliance
rates
of
UST's
­
remains
to
be
accomplished.
Regular
and
frequent
inspections
are
necessary
to
achieve
and
maintain
higher
compliance
rates.
Work
needs
to
continue
to
permanently
close
orphaned
UST's
and
to
remediate
releases
from
those
sites.
