MEMORANDUM
TO:
EPA
Docket
Number
OW­
2003­
0074
FROM:
Cortney
Itle,
ERG
DATE:
August
26,
2004
SUBJECT:
Revised
Industry
Rankings
by
Toxic
Weighted
Pound
Equivalent
(
TWPE)

This
memorandum
presents
revised
results
of
a
screening­
level
review
of
the
pollutant
discharges
reported
by
facilities
in
specific
industry
groupings.
The
pollutant
discharges
were
identified
from
two
data
sources:
1)
EPA's
Permit
Compliance
System
(
PCS)
data
(
located
on
EPA's
mainframe)
and
2)
EPA's
Toxic
Release
Inventory
(
TRI)
data
(
obtained
through
EPA's
Risk
Screening
Environmental
Indicators
model).

EPA
used
year
2000
data
from
PCS,
along
with
the
Effluent
Data
Statistics
(
EDS)
program,
SIC/
Point
Source
Category
(
PSC)
Crosswalk,
Chemical
Abstract
Service
(
CAS)
registry
numbers,
and
EAD's
Toxic
Weighting
Factors
(
TWFs),
to
develop
the
PCSLoads2000
database
tool.
PCSLoads2000
is
a
Microsoft
Access
 
database
that
presents
the
estimated
pollutant
loadings
discharged
by
facilities,
industries,
and
point
source
categories.
The
development
of
this
database
is
discussed
in
more
detail
in
the
report
entitled
Development
of
PCSLoads2000,
dated
December
12,
2003.
The
data
dictionary
for
the
PCSLoads2000
database
is
entitled
PCSLoads2000
Data
Dictionary,
dated
December
12,
2003.

In
TRI,
facilities
report
an
annual
load
(
in
pounds
or
grams)
of
pollutant
released
either
directly
to
a
receiving
stream
or
transferred
to
a
POTW.
For
facilities
discharging
directly
to
a
stream,
the
loads
were
taken
directly
from
the
reported
TRI
data
for
calendar
year
2000.
For
TRI
facilities
that
transfer
their
discharge
to
POTWs,
EPA
first
adjusted
the
pollutant
loads
transferred
to
POTWs
to
account
for
pollutant
removal
that
occurs
at
the
POTW
prior
to
discharge
to
the
POTW's
receiving
stream.
This
adjustment
was
made
using
POTW
removal
efficiencies
from
the
RSEI
model.
These
data
are
compiled
in
the
Microsoft
Access
 
database
entitled
TRIReleases2000.
The
data
dictionary
for
this
database
is
entitled
TRIReleases2000
Data
Dictionary,
dated
December
12,
2003.

To
estimate
the
discharge
of
toxic
weighted
pound
equivalents
(
TWPE)
from
each
of
these
sources,
EPA
weighted
each
pollutant's
discharge
load
with
the
EAD
toxic
weighting
factor
(
TWF).
For
pollutants
that
have
no
TWF
(
e.
g.,
biochemical
oxygen
demand),
the
TWPE
is
zero.

Facilities
are
assigned
to
industry
groupings
based
on
their
SIC
code.
The
industry
1
Point
source
category
discharges
are
regulated
by
Effluent
Limitations
Guidelines
(
ELGs),
found
at
40
CFR
Part
405
to
471.
groupings
may
be
based
on
either
a
point
source
category1,
or
an
SIC
code
grouping;
SIC
codes
not
regulated
under
point
source
categories
were
assigned
to
either
a
2­
or
4­
digit
SIC
code
grouping.

The
TWPEs
for
all
facilities
falling
into
the
same
industry
grouping
were
summed
to
determine
the
total
TWPE
for
an
industry
grouping.
The
industry
grouping
TWPEs
were
ranked
to
determine
the
industry
groupings
with
the
highest
TWPEs.

Throughout
the
screening­
level
review,
EPA
identified
and
corrected
misreported
or
miscalculated
data,
as
documented
in
addenda
to
the
following
reports:

°
Development
of
PCSLoads2000,

°
Evaluation
of
RSEI
Model
Runs;
and
°
TRI
and
PCS
Database
Changes
Memorandum
to
EPA
Docket
Number
OW­
2003­
0074.

This
memorandum
includes
unscaled
pollutant
loads
(
i.
e.,
loads
for
only
those
facilities
that
report
to
these
data
systems)
estimated
for
this
point
source
category
for
the
year
2000
as
of
August
26,
2004.

Two
tables
are
attached
to
this
memo:

°
Table
1
presents
the
2000
TRI
and
PCS
TWPEs
and
rankings
for
point
source
categories
regulated
by
existing
effluent
guidelines;
and
°
Table
2
presents
the
2000
TRI
and
PCS
TWPEs
and
rankings
for
industry
groupings
not
regulated
by
existing
effluent
guidelines.
