DCN
300­
012
SUBJ:
Ammonia
Limits
FROM:
Shari
Barash,
Technical
Coordinator
TO:
MPP
Project
Record
DATE:
February
24,
2004
DCN
300­
011
explains
EPA's
rationale
in
selecting
data
from
Episode
307a
to
calculate
the
Poultry
Subcategory
BOD
5
and
TSS
pollutant
limitations.
For
ammonia,
however,
EPA
found
that
Episode
307a
is
most
likely
not
representative
of
poultry
facilities
in
general
because
its
effluent
ammonia
concentration
is
less
than
the
median
ammonia
effluent
concentration
of
all
the
Option
2.5
poultry
facility
discharges
in
EPA's
database.
Therefore,
EPA
looked
to
other
model
facilities
to
select
a
representative
poultry
facility
to
form
the
basis
of
the
ammonia
limitation.

Similar
to
the
manner
in
which
EPA
selected
Episode
307a
to
calculate
the
conventional
pollutant
limitations,
EPA
first
determined
the
median
ammonia
effluent
concentrations
of
all
the
poultry
facilities
in
its
database
that
utilize
the
Option
2.5
technologies.
In
order
to
respond
to
comments,
EPA
eliminated
all
Option
2.5
facilities
with
a
filter
or
chemical
phosphorus
removal.
The
Option
2
and
Option
2.5
technologies
are
the
same
except
that
Option
2.5
also
includes
partial
denitrification.
For
this
evaluation,
EPA
used
only
the
data
from
facilities
using
Option
2.5
because
EPA
does
not
want
to
interfere
with
denitrification
(
which
is
required
to
achieve
BAT
limits
for
total
nitrogen)
and
the
data
indicate
that
effluent
discharges
of
ammonia
tend
to
be
higher
from
facilities
that
employ
partial
denitrification.
EPA
is
particularly
concerned
about
this
effect
with
ammonia
because
of
the
issue
of
seasonal
variability
(
see
below)
and
because
the
data
show
that
the
median
ammonia
concentration
from
2.5
facilities
(
1.05)
is
65%
higher
than
the
median
concentration
from
2.0
facilities
(
0.63).
This
effect
is
more
pronounced
than
for
BOD
or
TSS,
for
which
EPA
based
the
limits
on
data
from
both
2.0
and
2.5
facilities.
Table
1
provides
information
on
the
facilities
and
ammonia
effluent
discharges
used
to
calculate
the
median
ammonia
effluent
concentration.
Based
on
comments
That
EPA
should
use
all
of
the
data
available
to
it,
EPA
used
its
full
effluent
database
for
Option
2.5
facilities
(
i.
e.,
including
data
from
facilities
that
only
provided
data
reported
as
summarized
monthly
averages
)
to
select
a
model
facility
for
use
in
developing
the
ammonia
(
as
nitrogen)
LTAs
for
the
final
rule.
This
ensures
that
facilities
operating
the
selected
technology
would
be
able
to
achieve
the
limitations
and
standards
of
the
final
rule
(
including
the
BAT
limitations
for
total
nitrogen.)
Table
1:
Mean
Ammonia
Effluent
Concentration
Data
from
Treatment
with
Option
2
or
Option
2.5
Technologiesa
Facility
Numberb
Treatment
Option
Mean
Ammonia
Effluent
Concentrationamg/
L
11
2.5
2.2
22
2
0.36
26
2.5
1.4
27
2
2.2
32
2.5
0.69
39
2
0.60
42
2
0.38
45
2.5
0.17
133
2
2.0
291
2
0.89
300
2.5
2.5
307a
2
.303
307e
2.5
0.36
309
2
0.66
aFor
facilities
in
EPA's
model
facility
database,
these
values
reflect
the
final
values
after
data
exclusions
as
detailed
in
Section
14
of
the
final
Technical
Development
Document.
bEPA
also
has
data
for
EPA
sampling
Episode
6448.
EPA
did
not
include
Episode
6448
in
this
table
because
its
ammonia
effluent
concentration
is
already
accounted
for
by
Episode
307e.
This
is
because
the
data
for
Episode
307e
encompass
the
time
period
of
sampling
Episode
6448.

Using
the
information
in
Table
1,
EPA
determined
that
the
median
ammonia
effluent
concentration
for
all
poultry
facilities
in
EPA's
database
employing
the
Option
2.5
technologies
is
1.05
mg/
L.
However,
for
purposes
of
calculating
the
long­
term
average
(
LTA)
and
variability
factors
(
VFs)
for
use
in
developing
limitations
and
standards
for
the
final
rule,
EPA
is
limited
to
using
only
those
episodes
with
individual
data
points
(
i.
e.
unsummarized
daily/
weekly
monitoring
or
EPA's
3­
5
day
sampling
episodes.)
The
median
value
calculated
for
ammonia
did
not
correspond
to
an
existing
facility,
therefore,
EPA
selected
the
facility
whose
data
was
most
representative
of
the
median
data
but
that
also
provided
individual
data.
Table
2
below
presents
the
Episode
data
that
could
be
used
to
develop
limitations
and
standards
for
the
final
rule.
For
ammonia,
the
facility
with
an
LTA
closest
to
1.05
mg/
L
for
ammonia
is
Episode
26,
so
EPA
used
this
data
to
develop
the
LTAs
and
Vfs
for
the
final
limitations
and
standards.

Episode
Number
Option
LTA
1­
Day
VF
4­
Day
VF
11
2.5
1.93
7.69
3.08
26
2.5
1.1
5.37
2.55
32
2.5
.69
2.46
1.66
45
2.5
.153
4.57
2.33
291
2
0.82
7.68
3.08
307a
2.
.303
5.02
2.40
307e
2.5
.36
5.83
2.0
309
2
0.56
7.49
3.16
6448
2.5
1.28
1.69
1.21
Using
the
methodology
described
in
Chapter
14,
the
ammonia
daily
maximum
limit
based
on
Episode
26
would
be
5.9
mg/
L
and
the
monthly
average
would
be
2.81
mg/
L.

However,
EPA
received
comments
about
the
seasonal
variability
of
ammonia.
In
order
to
address
these
comments,
EPA
summarized
all
of
the
information
for
poultry
facilities
with
ammonia
limits
in
its
database
(
DCN
300,043).
For
each
facility
that
had
tiered
limits
based
on
the
time
of
the
year,
EPA
compared
the
highest
value
to
the
lowest
value.
Tables
3
shows
this
comparison.

Table
3:
Comparison
of
Winter
and
Summer
Ammonia
Permit
Limitations
Episode
Number
Ammonia
Daily
Maximum
Limit,
mg/
L
Ammonia
Monthly
Average
Limit,
mg/
L
Winter
High
Summer
Low
Winter
High
Summer
Low
20
14
8
9
5
26
39
29
26
19
27
30
7.5
20
5
291
4
2.4
2.7
1.6
297
12
8
8
5
307
2.7
1.3
1.7
0.7
Episode
Number
Ammonia
Daily
Maximum
Limit,
mg/
L
Ammonia
Monthly
Average
Limit,
mg/
L
Winter
High
Summer
Low
Winter
High
Summer
Low
310
11
7.5
5.5
5
314
18
5
12
3
339
3.9
2.9
1.2
0.9
For
each
facility
and
each
type
of
limit,
EPA
calculated
the
ratio
between
the
winter
high
permit
limit
and
mean
of
the
winter
and
summer
permit
limit.
EPA
found
that
the
average
of
these
ratios
was
1.30
for
the
daily
maximum
permit
limits
and
the
monthly
average
permit
limits.

Therefore,
in
order
to
account
for
seasonal
variability,
EPA
calculated
the
final
ammonia
limits
by
multiplying
the
daily
maximum
and
monthly
average
limitations
determined
from
Episode
26
by
the
average
of
the
ratio
determined
above.
The
ammonia
daily
maximum
and
monthly
average
limitations
are
8
mg/
L
(
5.9*
1.3)
and
4
mg/
L
(
2.8*
1.3),
respectively.
These
limit
numbers
have
all
been
rounded
up
to
the
nearest
integer.
This
ensures
that
these
limits
can
be
achieved
in
all
seasons
of
the
year.
EPA
could
also
have
tried
to
promulgate
seasonal
limitations,
but
chose
not
to
do
this
because
the
amount
of
seasonal
variability
will
vary
substantially
from
one
region
of
the
country
to
another.
Instead
EPA
chose
to
establish
limits
that
it
believes
facilities
in
all
parts
of
the
country
can
achieve
in
all
seasons.

Because
EPA
did
not
identify
well­
operated
Option
2.5
BAT
facilities
in
the
meat
subcategories,
EPA
transferred
these
limits
to
those
meat
subcategories
that
do
not
already
have
limits
for
ammonia
(
as
nitrogen).
