4/
7/
04
1
FIFRA
SAP
April
1
­
2,
2004
4/
7/
04
2
Overview
°
Context

Objectives
of
Level
II
RRA

Architecture
of
Aquatic
Level
II
RRA
Pilot
model
(
Version
1.0)

°
Proposed
exposure
model
changes
Version
2.0
°
Implementation
and
Next
Steps
(
Version
2.1,
etc.)
4/
7/
04
3
General
Assessment
Endpoint
°
Survival,
growth,
and/
or
reproduction
of
aquatic
organisms
for
assessment
of
populations
that
are
located
adjacent
to
the
edge
of
a
treated
field
4/
7/
04
4
Objectives
°
Provide
estimates
of
likelihood
and
magnitude
of
effect
using
data
available
for
a
Level
I
risk
assessment
°
Identify
regional/
cropping
patterns
or
effects­
refinement
(
Level
III),
mitigation
4/
7/
04
5
Ecological
Exposure
Modeling
Scenario
­
Version
1.0
°
Small
but
permanent
water
body
°
Location
edge
of
a
treated
field
°
All
runoff
from
treated
field
is
routed
to
the
water
body
°
Fixed
volume
standing
water

Assumption:
runoff
+
precipitation
=

evaporation

Calendar
month
averages
for
meteorologically­
dependent
properties
4/
7/
04
6
Ecological
Exposure
Modeling
Scenario
­
Version
1.0
°
Small
but
permanent
water
body
°
Location
edge
of
a
treated
field
°
All
runoff
from
treated
field
is
routed
to
the
water
body
°
Fixed
volume
standing
water

Assumption:
runoff
+
precipitation
=

evaporation

Calendar
month
averages
for
meteorologically­
dependent
properties
4/
7/
04
7
Ecological
Exposure
Modeling
Scenario
­
Version
2.0
°
Small
but
permanent
water
body
°
Location
edge
of
a
treated
field
°
All
runoff
from
treated
field
is
routed
to
the
water
body
°
Varying
volume
standing
water

Water
source

runoff
+
precipitation

Daily
volume
variation

runoff
+

precipitation
­
evaporation
­
overflow

Daily
averages
for
meteorologicallydependent
properties
4/
7/
04
8
Aquatic
Version
1.0
Model
Components
­
Acute
EXPOSURE
°
Model
 
PRZM/
EXAMS
°
Mixed
Empirical
Distribution
Function
(
annual
instantaneous
peaks)
TOXICITY
°
Species
Sensitivity
Distribution
(
5th,
50th,
95th
generic
species)

°
Concentration­
response
Curve
(
Probit)

RISK
Two
Dimension
Monte­
Carlo
Analysis
4/
7/
04
9
Aquatic
Version
2.0
Model
Components
­
Acute
EXPOSURE
°
Model
 
PRZM/
VVWM
°
Mixed
Empirical
Distribution
Function
(
annual
instantaneous
peaks)
TOXICITY
°
Species
Sensitivity
Distribution
(
5th,
50th,
95th
generic
species)

°
Concentration­
response
Curve
(
Probit)

RISK
Two
Dimension
Monte­
Carlo
Analysis
4/
7/
04
10
"
Standard"
Surface
Water
Body
and
Field
Size
Dimensions
Treated
Field
Drainage
Area
(
DA)
­
10
ha
Surface
Area
1
ha
Depth
2
meters
Relationship
based
on
DA/
VC
1.5
acres/
acre­
ft
(
5
m2/
m3)

Volume
Capacity
(
VC)

20,000
m3
4/
7/
04
11
Proposed
Exposure
Model
Modifications
°
Varying
volume
surface
water
model
body
to
replace
fixed
volume
°
Incorporate
daily
variations
in
meteorologically­
dependent
properties
°
Adopt
crop
scenario­
specific
drainage
area
and
water
body
sizes
