Memorandum
To:
Phil
Colarusso,
EPA
Region
1
From:
Liz
Strange,
Stratus
Consulting
Inc.

cc:
Tom
Wall,
Debbi
Hart,
and
Lynne
Tudor,
U.
S.
EPA
Date:
6/
26/
02
Subject:
Responses
to
PG&
E
Questions
about
the
§
316(
b)
Phase
II
Brayton
Point
Case
Study.

This
memorandum
provides
responses
to
questions
about
the
§
316(
b)
Phase
II
Brayton
Point
Case
Study
that
were
submitted
to
EPA
Region
1
by
PG&
E
on
6/
24/
02.
Questions
are
presented
in
italics
followed
by
the
corresponding
response.

1.
Entrainment
loss
data
was
collected
at
BPS
from
1972
to
1985
for
all
species
and
1992­
present
for
winter
flounder.
Impingement
data
has
been
collected
since
1972.
Why
did
EPA
choose
to
use
1974­
1983
data
only
in
their
calculation
of
entrainment
and
impingement
losses?

EPA
restricted
the
Brayton
Point
case
study
analysis
for
the
§
316(
b)
Phase
II
rulemaking
to
1974­
1983
because
this
period
represented
consistent
operating
characteristics
and
included
the
most
comprehensive
record
by
the
facility
of
impingement
and
entrainment
rates
for
most
of
the
impacted
species
(
see
Section
F2.2
of
Chapter
F2
of
the
§
316(
b)
Phase
II
Case
Study
Document,
docket
number
4­
0003).

2.
Numerous
studies
have
shown
that
large
numbers
of
organisms
survive
impingement
(
Brayton
Point
Station,
Hudson
River
and
Delaware
River
Plants).
Why
did
EPA
assume
100%
mortality
for
impinged
organisms?

EPA
used
the
impingement
numbers
provided
in
the
Brayton
Point
§
316(
b)
documents
available
to
EPA
(
see
the
Part
F
of
the
§
316(
b)
Phase
II
Case
Study
Document,
docket
number
4­
0003
for
a
complete
list
of
the
data
sources).
If
studies
at
Brayton
Point
indicate
that
these
numbers
should
be
adjusted
in
some
way,
please
provide
this
information
to
EPA.

3.
This
request
is
in
reference
to
a
memorandum
sent
to
Lynne
Tudor
and
Tom
Wall,
U.
S.
EPA
from
Liz
Strange,
Bob
Raucher,
and
Dave
Cacela,
Stratus
Consulting
Inc.,
5/
16/
02,
titled:
Outline
of
§
316(
b)
Case
Study
Evaluation
of
Impingement
and
Entrainment
Data.
Referenced
in
the
Example
section
of
the
memorandum
are
the
`
Input
Data',
`
Evaluation
Method',
and
`
Results'.
We
have
the
`
Input
Data'
file
(
DCN
4­
1305;
brayton.
input.
data.
xls)
used
in
the
Brayton
Point
Station
case
study;
we
do
not
have
the
`
Evaluation
Method',
and
`
Results'
files.
Stratus
Consulting
6/
26/
02
Page
2
We
would
like
to
get
copies
of
all
spreadsheet
and/
or
program
files
associated
with
the
`
Evaluation
methods'
and
`
Results'
portion
of
the
analysis.

The
discussion
of
evaluation
methods
and
results
in
the
5/
16/
02
memo
do
not
refer
to
any
particular
files,
but
rather
to
the
general
evaluation
procedure
(
see
Chapter
A5
of
Part
A
of
the
§
316(
b)
Phase
II
Case
Study
Document,
docket
number
4­
0003).
Computer
programs
used
to
execute
the
calculations
discussed
in
Chapter
A5
of
the
Case
Study
Document
were
not
prepared
for
public
release.

4.
Related
to
request
3.,
we
would
like
to
get
all
files
and/
or
programs
associated
with
the
production
foregone
modeling
calculations
presented
in
Part
A
as
we
are
having
difficulty
recreating
the
results
reported
in
Chapter
F3,
given
the
information
provided
in
the
Part
A
and
Part
F.

The
methods
for
calculating
production
foregone
are
provided
in
Chapter
A5
of
Part
A
of
the
§
316(
b)
Phase
II
Case
Study
Document
(
docket
number
4­
0003).
The
data
used
in
these
calculations
are
provided
in
the
EXCEL
workbook
brayton.
input.
data.
xls
(
docket
number
4­
1305).
Computer
programs
used
to
execute
the
calculations
were
not
prepared
for
public
release.

5.
Specific
questions
on
life
history
parameters:

a.
The
following
species'
life
tables
do
not
have
a
`
juvenile
1'
stage:
butterfish
(
Table
F1­
6),
silver
hake
(
Table
F1­
11),
striped
killifish
(
Table
F1­
12),
white
perch
(
Table
F1­
16).
How
did
EPA
account
for
post­
larval
young­
of­
year
mortality
and
weight
for
these
species
in
the
loss
models
(
i.
e.,
the
equivalent
adult
and
foregone
production
models)?

(
a)
EPA
used
a
value
of
9.06
for
the
total
mortality
rate
(
Z)
for
the
juvenile
stage
of
white
perch.
As
a
result
of
an
inadvertent
clerical
error,
this
information
is
not
in
Table
F1­
16.
The
reported
larval
stage
mortality
rates
for
butterfish,
silver
hake,
and
striped
killifish
were
actually
the
total
mortality
rates
for
the
larval
stage
and
the
juvenile
stage
combined.
EPA
inadvertently
omitted
a
footnote
to
those
tables
that
mentions
this
feature.
Composite
mortality
rates
were
used
for
butterfish
and
silver
hake
because
they
were
deduced
indirectly
using
the
equilibrium
population
(
f
a)
method
(
see
Section
A5­
2.3
of
Chapter
A5
of
Part
A
of
the
§
316(
b)
Phase
II
Case
Study
Document,
docket
number
4­
0003).
Rates
for
striped
killifish
were
deduced
by
reference
to
available
data
for
a
closely
related
species
(
mummichog).

b.
The
windowpane
fishing
rate
of
1.6
(
Table
F1­
17)
equates
to
an
annual
harvest
rate
of
approximately
80%
of
each
age
fully
recruited
to
the
fishery
each
year.
Why
did
EPA
use
this
high
fishing
mortality
rate
for
windowpane
flounder?
Stratus
Consulting
6/
26/
02
Page
3
(
b)
The
value
1.6
for
windowpane
is
the
F
target
for
the
Southern
New
England­
Middle
Atlantic
region
as
reported
by
NOAA
(
http://
www.
nefsc.
nmfs.
gov/
sos/
spsyn/
fldrs/
window/).
This
rate
represents
the
fishing
mortality
rate
that
is
protective
of
the
stock.
As
such,
EPA
considered
this
a
conservative
estimate
of
average
fishing
mortality
for
use
in
yield
calculations.
