UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES,
AND
TOXIC
SUBSTANCES
PC
Code:
106901
DP
BARCODE:
D279761
MEMORANDUM
January
3,
2002
SUBJECT:
Asulam:
Revised
Tier
I
Drinking
Water
EECs
for
Use
in
the
Human
Health
Risk
Assessment.

TO:
Jose
Morales
Catherine
Eiden
Health
Effects
Division
(
7509C)

FROM:
Norman
Birchfield
ERB4/
EFED
(
7507C)

THRU:
Dirk
Young
Betsy
Behl,
Chief
ERB4/
EFED
(
7507C)

This
memo
is
a
revision
to
the
previous
Tier
I
estimated
environmental
concentrations
(
EECs)
for
asulam
in
surface
water
and
in
ground
water
for
use
in
the
human
health
risk
assessments
(
memo
from
Dirk
Young
to
T.
Truesdale
January
23,
2001,
DP
Barcode
D272000).
This
revision
is
required
to
1)
Update
surface
water
modeling
using
the
FIRST
reservoir
model
2)
Provide
an
upper
bound
estimate
for
EECs
on
degradates
in
surface
and
ground
water
3)
Estimate
longer
term
ground
water
concentrations
The
EECs
are
summarized
in
Table
1.
EFED
used
FIRST
to
calculate
the
surface
water
EECs
and
used
a
prospective
groundwater
study
to
estimate
the
groundwater
EEC.

For
the
surface
water
assessment,
the
application
rate
for
sugarcane
was
used,
which
represents
the
highest
labeled
rate
for
any
crop.
A
summary
of
the
model
input
parameters
is
given
in
Table
2.
All
parameters
for
asulam
were
taken
according
to
standard
EFED
practice.
Since
no
data
is
available
on
degradates
FIRST
modeling
assumed
immediate
conversion
upon
application
to
very
persistent
and
mobile
degradates.
The
FIRST
output
file
is
located
in
Attachment
1.

For
estimated
groundwater
exposure,
the
highest
observed
concentration
in
the
prospective
groundwater
(
PGW)
study
for
turf
(
MRID
42224701)
was
used.
Three
PGW
studies
(
Florida
turf,
Louisiana
sugarcane,
and
Florida
sugarcane)
were
previously
reviewed
in
a
1994
memo
(
1).
In
the
study
associated
with
asulam
use
on
Florida
turf,
asulam
and
the
sulfanilamide
were
detected
in
shallow
wells
at
a
combined
concentration
of
59
ppb.
The
average
concentration
of
combined
residues
over
the
14
month
sampling
period
was
14.0
ppb.
The
above
values
are
not
corrected
for
incomplete
recovery.
The
average
spike
recoveries
for
asulam
and
the
sulfanilamide
degradate
were
39.4%
and
38.3%,
respectively.
After
correcting
for
recovery
the
values
are
154
ppb
(
peak)
and
37
ppb
(
14
month
average).
The
recommended
EEC
for
groundwater
is
154
ppb
based
on
the
peak
value
(
Table
1).
The
low
spike
recoveries
indicate
problems
with
the
analytical
method.
The
site
and
conditions
monitored
compensates
somewhat
for
the
uncertainty
in
the
analytical
method.
The
monitoring
scenario
is
a
highly
vulnerable
situation
with
sandy
soil
and
shallow
ground
water
(
2.14
m).
Wells
of
this
type
are
not
generally
expected
to
be
used
for
drinking
water
purposes,
although
many
wells
in
Florida
less
than
17
m
deep
are
used
for
drinking
water.

In
a
separate
water
monitoring
study
asulam
was
detected
in
public
drinking
water
sources
from
ground
and
surface
water.
At
the
request
of
EPA,
Rhone­
Poulenc
conducted
a
drinking
water
monitoring
study
in
areas
of
high
asulam
use
in
Florida
and
Louisiana.
The
surface
water
study
was
designed
to
sample
raw
surface
water
in
up
to
15
community
water
systems
in
Florida
and
4
systems
in
Louisiana.
Samples
were
collected
monthly
for
one
year
and
analyzed
for
asulam
and
the
metabolite
sulfanilamide
at
a
detection
limit
of
1
ppb.
In
addition
to
surface
water
collection,
the
study
collected
samples
from
potable
wells
in
Florida
and
Louisiana
that
were
located
within
1,000
feet
of
an
asulam
treated
area.

Seven
of
the
ten
surface
water
community
systems
sampled
contained
traces
(<
1
ppb)
of
asulam
residues
during
May
through
June.
Four
of
the
community
systems
were
located
in
Louisiana
and
three
were
in
Florida.

A
total
of
28
drinking
water
wells
were
sampled
in
Florida.
Because
of
poor
water
quality
in
this
area
of
Florida,
many
of
the
wells
reportedly
use
some
type
of
treatment
system
prior
to
use.
Three
wells
contained
quantifiable
asulam
residues
up
to
1.92
ppb.
[
Note
that
these
asulam
concentration
are
considerably
greater
than
the
SCIGROW
prediction
of
0.95
ppb
(
see
Attachment
2).]
Ten
other
wells
contained
detectable
traces
(<
1
ppb).
Reportedly,
the
depth
of
the
well
and
distance
to
treated
area
did
not
have
any
statistically
significant
effects
on
the
concentrations
observed.
No
residues
were
detected
in
12
wells
sampled
in
the
"
sandier"
areas
of
Hendry
County.
Rhone­
Poulenc
reported
that
there
was
less
intensive
use
of
asulam
in
this
area.
No
residues
were
detected
in
ground
water
samples
in
Louisiana.

2
­­
Table
1.
Tier
I
EECs
for
Drinking
Water
Surface
Water
Surface
Water
Ground
Water
Peak
EEC
Chronic
EEC1
EEC
Asulam
305
µ
g/
L
6.6
µ
g/
L
Asulam
+
380
µ
g/
L
2
272
µ
g/
L
2
154
µ
g/
L3
degradates
1
Based
on
56­
day
average
immediately
following
pesticide
input
to
water
body.
2
Based
on
FIRST
modeling
with
upper
bound
assumptions
on
mobility
and
persistence.
3
From
groundwater
study,
see
reference
1.
This
concentration
is
representative
of
asulam
and
the
sulfnilamide
degradate.

Table
2.
FIRST
environmental
fate
input
parameters
chemical
asulam
asulam
+
degradates
Solubility
4000
mg
L­
1
10,000
mg
L­
1
Hydrolysis
aqueous
photolysis
half
life
(
near
surface)
stable
0.0625
days
stable
stable
aerobic
soil
metabolism
half
life
28
days
(
highest
available
value)
stable
aerobic
aquatic
metabolism
half
life
105
days
(
single
value)
stable
soil
organic
carbon
partitioning
(
Koc)
18
L
kg­
1
(
lowest
available
value)
1
L
kg­
1
crop
sugarcane
sugarcane
application
rate
3.624
lb
a.
i.
acre­
1
*
3.624
lb
a.
i.
acre­
1
*

number
of
applications
1
per
season
1
per
season
application
method
aerial
granular
(
no
drift)
*
highest
labeled
rate;
information
supplied
by
BEAD.

REFERENCES
1.
Memo
to
Linda
Propst,
from
Elizabeth
Behl,
Environmental
Fate
and
Ground
Water
Branch
Review
Action,
Review
of
small­
scale
prospective
groundwater
monitoring
study
results.
Feb
2,
1994.
DPBarcodes:
D162492,
D175842,
D180962,
D181508,
D185103,
D190979,
D190980.

3
ATTACHMENT
1:
FIRST
Files
RUN
No.
1
FOR
asulam
ON
sugarcane
*
INPUT
VALUES
*
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
RATE
(#/
AC)
No.
APPS
&
SOIL
SOLUBIL
APPL
TYPE
%
CROPPED
INCORP
ONE(
MULT)
INTERVAL
Koc
(
PPM
)
(%
DRIFT)
AREA
(
IN)
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
3.624(
3.624)
1
1
18.0
4000.0
AERIAL(
16.0)
87.0
.0
FIELD
AND
RESERVOIR
HALFLIFE
VALUES
(
DAYS)
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
METABOLIC
DAYS
UNTIL
HYDROLYSIS
PHOTOLYSIS
METABOLIC
COMBINED
(
FIELD)
RAIN/
RUNOFF
(
RESERVOIR)
(
RES.­
EFF)
(
RESER.)
(
RESER.)
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
28.00
2
N/
A
.06­
7.75
105.00
7.22
UNTREATED
WATER
CONC
(
MICROGRAMS/
LITER
(
PPB))
Ver
1.0
MAY
16,
2001
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
PEAK
DAY
(
ACUTE)
ANNUAL
AVERAGE
(
CHRONIC)
CONCENTRATION
CONCENTRATION
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
305.275
6.605
RUN
No.
1
FOR
asulam
residues
ON
sugarcane
*
INPUT
VALUES
*
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
RATE
(#/
AC)
No.
APPS
&
SOIL
SOLUBIL
APPL
TYPE
%
CROPPED
INCORP
ONE(
MULT)
INTERVAL
Koc
(
PPM
)
(%
DRIFT)
AREA
(
IN)
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
3.624(
3.624)
1
1
1.010000.0
GRANUL(
.0)
100.0
.0
FIELD
AND
RESERVOIR
HALFLIFE
VALUES
(
DAYS)
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
METABOLIC
DAYS
UNTIL
HYDROLYSIS
PHOTOLYSIS
METABOLIC
COMBINED
(
FIELD)
RAIN/
RUNOFF
(
RESERVOIR)
(
RES.­
EFF)
(
RESER.)
(
RESER.)
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
.00
2
N/
A
.00­.
00
.00
.00
UNTREATED
WATER
CONC
(
MICROGRAMS/
LITER
(
PPB))
Ver
1.0
MAY
16,
2001
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
PEAK
DAY
(
ACUTE)
ANNUAL
AVERAGE
(
CHRONIC)
CONCENTRATION
CONCENTRATION
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
379.819
272.174
4
ATTACHMENT
2:
SCIGROW
File
RUN
No.
1
FOR
asulam
INPUT
VALUES
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
APPL
(#/
AC)
APPL.
URATE
SOIL
SOIL
AEROBIC
RATE
NO.
(#/
AC/
YR)
KOC
METABOLISM
(
DAYS)
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
3.624
1
3.624
63.0
23.0
GROUND­
WATER
SCREENING
CONCENTRATIONS
IN
PPB
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
.950323
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
A=
18.000
B=
68.000
C=
1.255
D=
1.833
RILP=
2.721
F=
­.
581
G=
.262
URATE=
3.624
GWSC=
.950323
5
