1
Drinking
Water
Assessment
PronamideTRED.
wpd
UNITED
STATES
ENVIRONMENTAL
PROTECTION
AGENCY
WASHINGTON,
D.
C.
20460
OFFICE
OF
PREVENTION,
PESTICIDES,
AND
TOXIC
SUBSTANCES
PC
Code:
101701
DP
Barcode:
D274842
MEMORANDUM
May
16,
2001
SUBJECT:
Drinking
Water
Assessment
to
Support
TRED
for
Propyzamide
(Pronamide)

FROM:
Lucy
Shanaman,
Chemist
Environmental
Risk
Branch
IV
Environmental
Fate
and
Effects
Division
THROUGH:
Betsy
Behl,
Chief
Environmental
Risk
Branch
IV
Environmental
Fate
and
Effects
Division
R.
David
Jones,
Senior
Agronomist
Environmental
Risk
Branch
IV
Environmental
Fate
and
Effects
Division
TO:
Susan
Lewis,
Branch
Chief
Reregistration
Branch
I
Special
Review
Reregistration
Division
This
memo
presents
the
Tier
I
Drinking
Water
Assessment
for
propyzamide
calculated
using
FIRST
(surface
water)
and
SCIGROW
(groundwater)
for
use
in
the
human
health
risk
assessment.
For
surface
water,
the
acute
(peak)
value
is
390
ppb,
and
the
chronic
(average
annual)
value
is
122
ppb.
The
groundwater
screening
concentration
is
3.0
ppb.
These
concentrations
were
predicted
from
recommended
use
information
for
ornamental
herbaceous
plants,
and
represent
upper­
bound
estimates
of
the
concentrations
that
might
be
found
in
surface
water
and
groundwater
due
to
the
use
of
pronamide/
propyzamine
on
registered
crops.

Should
the
results
of
this
assessment
indicate
a
need
for
further
refinement,
please
contact
us
as
soon
as
possible
so
that
we
may
schedule
a
Tier
II
assessment.
2
Drinking
Water
Assessment
PronamideTRED.
wpd
Background
Information
on
FIRST:

As
indicated
in
the
User's
Manual,
`FIRST'
is
a
first
tier
screening
model
designed
as
a
coarse
screen
to
estimate
the
pesticide
concentrations
found
in
an
`Index
Reservoir'
located
in
Shipman,
Illinois
for
use
in
environmental
risk
assessments
for
drinking
water.
As
such,
it
provides
high­
end
values
on
the
concentrations
due
to
the
use
of
a
pesticide
in
drinking
water
that
might
be
found
derived
from
surface
water.
Pesticide
concentration
values
estimated
using
this
scenario
should
be
exceeded
only
rarely
in
the
source
water
at
the
intake
pipe
of
a
community
water
supply
(CWS)
systems
in
the
United
States.
This
first
level
tier
is
designed
as
a
coarse
screen
and
estimates
concentrations
from
only
a
few
basic
chemical
parameters
and
pesticide
label
application
information.

The
program
considers
reductions
in
dissolved
concentration:
(1)
due
to
the
percentage
of
the
watershed
which
is
cropped,
(2)
due
to
adsorption
of
pesticide
to
field
soil
and
to
reservoir
bottom
sediment,
(3)
due
to
incorporation
of
the
pesticide
at
the
time
of
application,
(4)
due
to
degradation
in
soil
before
washoff
to
the
reservoir,
and
(5)
due
to
degradation
of
the
pesticide
within
the
water
body.
Reservoir
water
concentrations
may
be
increased
due
to
deposition
of
spray
drift
into
the
feeding
stream
or
directly
into
the
reservoir
itself.
The
program
does
not
consider
the
impact
of
water
treatment
processes.
The
`FIRST'
program
is
designed
to
mimic
a
more
complex
simulation
such
as
using
the
linked
PRZM
and
EXAMS
models,
but
requires
less
time
and
effort
to
complete.

If
a
risk
assessment
performed
using
`FIRST'
output
does
not
exceed
the
level
of
concern,
then
one
can
be
reasonably
confident
that
the
acute
risk
will
not
be
exceeded.
However,
because
`FIRST'
can
substantially
overestimate
true
drinking
water
concentrations,
it
will
be
necessary
to
refine
the
`FIRST'
estimates
if
the
level
of
concern
is
exceeded.

Background
Information
on
SCIGROW:

SCIGROW
provides
a
groundwater
screening
exposure
value
to
be
used
in
determining
the
potential
risk
to
human
health
from
drinking
water
contaminated
with
the
pesticide.
Since
the
SCIGROW
concentrations
are
likely
to
be
approached
in
only
a
very
small
percentage
of
drinking
water
sources,
i.
e.,
highly
vulnerable
aquifers,
it
is
not
appropriate
to
use
SCIGROW
concentrations
for
national
or
regional
exposure
estimates.

SCIGROW
estimates
likely
groundwater
concentrations
if
the
pesticide
is
used
at
the
maximum
allowable
rate
in
areas
where
groundwater
is
exceptionally
vulnerable
to
contamination.
In
most
cases,
a
large
majority
of
the
use
area
will
have
groundwater
that
is
less
vulnerable
to
contamination
than
the
areas
used
to
drive
the
SCIGROW
estimate.
3
Drinking
Water
Assessment
PronamideTRED.
wpd
Modeling
Inputs
and
Results
Table
1
and
Table
2
summarize
the
general
input
values
used
in
the
model
runs
for
FIRST
and
SCIGROW,
respectively
for
pronamide
(propyzamide),
applied
four
times
by
low
pressure
ground
spray,
at
a
rate
of
two
pounds
per
acre
to
ornamental
herbaceous
plants.
FIRST
predicted
surface
water
acute
peak
concentration
is
390
ppb.
Chronic
(average
annual)
concentration
is
122
ppb.
SCIGROW
predicted
groundwater
concentration
is
3.0
ppb.
Modeling
results
for
low
pressure
ground
spray
application
to
ornamental
herbaceous
plants
appear
in
Table
3.
FIRST
and
SCIGROW
output
files
appear
at
the
end
of
this
document.

Appendix
I
summarizes
(1)
the
yearly
application
rates
for
individual
crops
as
application
rate
and
number
of
applications
per
year
(pounds/
acre)
for
(2)
specific
methods
of
application,
along
with
the
(3)
FIRST
and
(4)
SCIGROW
output
values
for
all
registered
uses.

Table
1.
Input
Parameters
for
FIRST
Chemical
propyzamide
PC
Code
101701
Water
Solubility
(25
°C)
15
mg/
L
Hydrolysis
Half­
Life
(pH7)
stable
Aerobic
Soil
Metabolism
Half­
Life
1176
days
(n=
1;
use
3
x
reported
half­
life)

Aerobic
Aquatic
Metabolism
Half­
Life
2352
days
(no
reported
value;
use
2
x
aerobic
soil
metabolism
value)

Photolysis
Half­
Life
41
days
Organic
Carbon
Adsorption
Coefficient
(Koc)
504
L/
kg
(slope
of
plot,
adsorption
Kd
versus
%
organic
carbon
Application
Method
low
pressure
ground
spray
Application
Rate
2
lbs.
a.
i./
acre
Application
Frequency
4
per
year
Interval
Between
Applications
21
days
4
Drinking
Water
Assessment
PronamideTRED.
wpd
Table
2.
Input
Parameters
for
SCIGROW
Chemical
propyzamide
PC
Code
101701
Organic
Carbon
Adsorption
Coefficient
(Koc)
701
L/
kg
Aerobic
Soil
Metabolism
Half­
Life
392
days
Application
Rate
2
lbs.
a.
i./
acre
Application
Frequency
4
per
year
Table
3.
Modeling
Results
Based
on
Low
Pressure
Ground
Spray
Application
of
Propyzamide
to
Ornamental
Herbaceous
Plants
Model
Concentration
FIRST
Peak
Day
(Acute)
390
ppb
FIRST
Annual
Average
(Chronic)
122
ppb
SCIGROW
Ground
Water
Value
3.
0
ppb
5
Drinking
Water
Assessment
PronamideTRED.
wpd
RUN
No.
9
FOR
Pronamide
on
ornamental
herbaceous
plants
(8
lb/
Acre,
ground
spray)
INPUT
VALUES
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
RATE
(#/
AC)
No.
APPS
&
SOIL
SOLUBIL
APPL
TYPE
%CROPPED
INCORP
ONE(
MULT)
INTERVAL
Koc
(PPM
)
(%
DRIFT)
AREA
(IN)
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
2.000(
7.854)
4
21
504.0
15.0
GROUND(
6.4)
87.0
.0
FIELD
AND
RESERVOIR
HALFLIFE
VALUES
(DAYS)
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
METABOLIC
DAYS
UNTIL
HYDROLYSIS
PHOTOLYSIS
METABOLIC
COMBINED
(FIELD)
RAIN/
RUNOFF
(RESERVOIR)
(RES.­
EFF)
(RESER.)
(RESER.)
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
1176.00
2
N/
A
41.00­
5084.00
******
1608.06
UNTREATED
WATER
CONC
(MICROGRAMS/
LITER
(PPB))
Ver
1.0
MAY
1,
2001
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
PEAK
DAY
(ACUTE)
ANNUAL
AVERAGE
(CHRONIC)
CONCENTRATION
CONCENTRATION
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
390.164
139.657
(Multiply
by
0.87
to
correct
error
in
program)

RUN
No.
9
FOR
Proamide
on
ornamental
herbaceous
plants
(8
lb/
Acre,
ground
spray)
INPUT
VALUES
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
APPL
(#/
AC)
APPL.
URATE
SOIL
SOIL
AEROBIC
RATE
NO.
(#/
AC/
YR)
KOC
METABOLISM
(DAYS)
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
2.000
4
8.000
701.0
392.0
GROUND­
WATER
SCREENING
CONCENTRATIONS
IN
PPB
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
3.014783
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
A=
387.000
B=
706.000
C=
2.588
D=
2.849
RILP=
2.979
F=
­.
424
G=
.377
URATE=
8.000
GWSC=
3.014783
6
Drinking
Water
Assessment
PronamideTRED.
wpd
APPENDIX
I
Modeling
Results
for
use
on
Registered
Crops
CROP
APPLICATION
RATE
PER
YEAR
(pounds
/
acre)
FREQUENCY
(number
of
uses
/
interval
between
use,
in
days
)
FIRST
DRINKING
WATER
VALUES
(ppb)
SCIGROW
GROUND
WATER
VALUES
(ppb)
APPLICATION
METHOD
Peak
Day
Annual
Average
C
fallow
0.
51
NA
25.96
8.29
0.192192
aircraft
C
endive
C
lettuce
2.04
NA
103.85
33.17
0.768770
aircraft
C
Christmas
tree
3.06
NA
155.78
49.76
1.153154
aircraft
C
artichoke
4.08
2
/
21
206.46
65.95
1.537539
aircraft
C
lettuce
6.12
NA
311.56
99.52
2.306309
aircraft
C
fallow
0.
51
NA
25.33
7.89
0.192192
low
pressure
ground
sprayer
C
ornamental
sod
farm
(turf)
C
peas
(filled)
1.53
NA
76.00
23.66
0.576577
low
pressure
ground
sprayer
C
alfalfa
C
blueberry
C
chicory
C
clover
C
crown
vetch
C
endive
C
grass
for
seed
C
lettuce
C
ornamental
shade
trees
C
ornamental
lawns
and
turf
C
ornamental
woody
shrubs
/
vines
C
rhubarb
C
sainfoin
C
trefoil
2.04
NA
101.33
31.55
0.768770
low
pressure
ground
sprayer
C
blackberry
C
boysenberry
C
Christmas
tree
C
raspberry
(black,
red)
3.06
NA
151.99
47.33
1.153154
low
pressure
ground
sprayer
7
Drinking
Water
Assessment
PronamideTRED.
wpd
C
lettuce
6.12
NA
303.98
94.66
2.306309
low
pressure
ground
sprayer
C
ornamental
herbaceous
plants
8
2
/
4
390.16
121.50
3.014783
low
pressure
ground
sprayer
C
sugar
beet
1.02
NA
50.66
15.77
0.384385
sprayer
C
golf
course
turf
C
recreational
areas
1.5
NA
75.50
23.20
0.565272
sprayer
C
apricot
C
apple
C
artichoke,
C
cherry
C
grapes
C
nectarine
C
peach
C
pear
C
plum
C
prune
4.08
NA
202.65
63.10
1.537539
sprayer
C
alfalfa
C
chicory
C
endive
C
lettuce
2.04
NA
101.33
31.55
0.768770
soil
incorporation
equipment
