Document ID: EPA-HQ-OW-2002-0049-0015
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2003-03-19T05:00Z

­
1­
316b
Phase
II
O&
M
Compliance
Cost
Estimation
­
Fixed
&
Variable
O&
M
Plus
Construction
Downtime
5.0
Determining
Fixed
Versus
Variable
O&
M
Costs
When
developing
the
annual
O&
M
cost
estimates,
the
underlying
assumption
was
that
facilities
were
operating
nearly
continuously
with
the
only
downtime
being
periodic
routine
maintenance.
This
routine
maintenance
was
assumed
to
be
approximately
four
weeks
per
year.
The
economic
model
however,
considers
variations
in
capacity
utilization.
Lower
capacity
utilization
factors
result
in
additional
generating
unit
shutdown
that
may
result
in
reduced
O&
M
costs.
However,
it
is
not
valid
to
assume
that
intake
technology
O&
M
costs
drop
to
zero
during
these
additional
shutdown
periods.
Even
when
the
generating
unit
is
shut
down,
there
are
some
O&
M
costs
incurred.
To
account
for
this,
total
annual
O&
M
costs
were
divided
into
fixed
and
variable
components.
Fixed
O&
M
costs
include
items
that
occur
even
when
the
unit
is
periodically
shut
down,
and
thus
are
assumed
to
occur
year
round.
Variable
O&
M
costs
apply
to
items
that
are
allocable
based
on
estimated
intake
operating
time.
The
general
assumption
behind
the
fixed
and
variable
determination
is
that
shutdown
periods
are
relatively
short
(
on
the
order
of
several
hours
to
several
weeks).

5.1
Overall
Approach
The
annual
O&
M
cost
estimates
used
in
the
cost
models
is
the
net
O&
M
cost,
which
is
the
difference
between
the
estimated
baseline
and
compliance
O&
M
costs.
Therefore,
the
fixed/
variable
proportions
for
each
facility
may
vary
depending
on
the
mix
of
baseline
and
compliance
technologies.
In
order
to
account
for
this
complexity,
EPA
calculated
the
fixed
and
variable
O&
M
costs
separately
for
both
the
baseline
technology
and
each
compliance
technology
and
then
calculated
the
total
net
fixed
and
variable
components
for
each
facility/
intake.

In
order
to
simplify
the
methodology
(
i.
e.,
avoid
developing
a
whole
new
set
of
O&
M
cost
equations),
a
single
fixed
O&
M
component
cost
factor
was
estimated
for
each
technology
application
represented
by
a
single
O&
M
cost
equation.
To
calculate
fixed
O&
M
factors,
EPA
first
calculated
fixed
O&
M
cost
factors
for
the
range
of
data
input
values,
using
the
assumptions
described
below,
to
develop
the
cost
equation
.
For
baseline
technologies,
EPA
selected
the
lowest
value
in
the
range
of
fixed
component
factors
for
each
technology
application.
The
lowest
value
was
chosen
for
baseline
technologies
to
yield
a
high­
side
net
compliance
costs
for
intermittently
operating
facilities.
Similarly,
for
compliance
technologies,
EPA
selected
the
highest
value
in
the
range
of
fixed
component
factors
for
each
technology
application,
again,
to
provide
a
high­
side
estimate.

For
each
O&
M
cost
equation,
a
single
value
(
expressed
either
as
a
percentage
or
decimal
value)
representing
the
fixed
component
of
O&
M
costs,
is
applied
to
each
baseline
and
compliance
technology
O&
M
cost
estimate
for
each
facility.
The
variable
O&
M
component
is
the
difference
between
total
O&
M
costs
and
the
fixed
O&
M
cost
component.
The
fixed
and
variable
cost
components
were
then
separately
combined
to
derive
the
overall
net
fixed
and
overall
net
variable
O&
M
costs
for
each
facility/
intake.
­
2­
.

5.2
Estimating
the
Fixed/
Variable
O&
M
Cost
Mix
Depending
on
the
technology,
the
O&
M
cost
estimates
may
generally
include
components
for
labor,
power,
and
materials.
The
cost
breakdown
assumes
facility
downtime
will
be
relatively
short
(
hours
to
weeks).
Thus,
EPA
assumes
any
periodic
maintenance
tasks,
e.
g.,
changing
screens,
changing
nets,
or
inspection/
cleaning
by
divers)
are
performed
regardless
of
plant
operation,
and
therefore
are
considered
fixed
costs.
Fixed
costs
associated
with
episodic
cost
components
are
allocated
according
to
whether
they
would
still
occur
even
if
the
downtime
coincided
with
the
activity.
For
example,
annual
labor
estimates
for
passive
screens
includes
increased
labor
for
several
weeks
during
high
debris
episodes.
This
increased
labor
is
considered
a
100%
variable
component
because
it
would
not
be
performed
if
the
system
were
not
operating
during
this
period.
A
discussion
of
the
assumptions
and
rationale
for
each
general
component
is
described
below.

Power
Requirements
In
most
cases,
power
costs
are
largely
a
variable
cost.
If
there
is
a
fixed
power
cost
component,
it
will
generally
consists
of
low
frequency,
intermittent
operations
necessary
to
maintain
equipment
in
working
condition.
For
example,
a
1%
fixed
factor
for
this
component
would
equal
roughly
1.0
hours
of
operation
every
four
days
for
systems
that
normally
operated
continuously.
Such
a
duration
and
frequency
is
considered
as
reasonable
for
most
applications.
For
systems
already
operating
intermittently,
a
factor
that
results
in
the
equivalent
of
one
hour
of
operation
or
one
backwash
every
four
days
was
used.

Labor
Requirements
Labor
costs
generally
have
one
or
more
of
the
following
components:

°
Routine
monitoring
and
maintenance
°
Episodes
requiring
higher
monitoring
and
maintenance
(
high
debris
episodes)
°
Equipment
deployment
and
removal
°
Periodic
inspection/
cleaning
by
divers.

Routine
Monitoring
and
Maintenance
This
component
includes
monitoring/
adjustment
of
the
equipment
operation,
maintaining
equipment
(
repairs
&
preventive
O&
M),
and
cleaning.
Of
these
the
monitoring/
adjustment
and
cleaning
components
will
drop
significantly
when
the
intakes
are
not
operating.
A
range
of
30%
to
50%
will
be
considered
for
the
fixed
component.

Episodes
requiring
higher
monitoring
and
maintenance
­
3­
This
component
is
generally
associated
with
equipment
that
is
operating
and
will
be
assumed
to
be
100%
variable.
­
4­
Equipment
deployment
and
removal
This
activity
is
generally
seasonal
in
nature
and
assumed
performed
regardless
of
operation
(
i.
e.,
100%
fixed).

Equipment
Replacement
The
component
includes
two
factors:
parts
replacement
due
to
wear
and
tear
(
and
varies
with
operation)
and
parts
replacement
due
to
corrosion
(
and
occurs
regardless
of
operation).
A
range
of
50%
to
70%
of
these
costs
will
be
considered
the
fixed
component.

Technology­
Specific
Input
Factors
Traveling
Screens
To
determine
the
range
of
calculated
total
O&
M
fixed
factors,
fixed
O&
M
cost
factors
(
Table
5­
1)
were
applied
to
individual
O&
M
cost
components
for
the
various
screen
width
values
that
were
used
to
generate
the
O&
M
cost
curves.
As
described
earlier,
the
lowest
value
of
this
range
was
selected
for
the
baseline
O&
M
fixed
cost
factor
and
the
highest
of
this
range
was
selected
as
the
compliance
O&
M
fixed
cost
factor.
Table
5­
1
O&
M
Cost
Component
Fixed
Factor
Routine
Labor
Parts
Replacement
Equipment
Power
Equipment
Deployment
All
Traveling
Screens
Without
Fish
Handling
0.5
0.7
0.05
1.0
All
Traveling
Screens
With
Fish
Handling
0.3
0.5
0.01
1.0
Passive
Screens
The
fixed
O&
M
component
was
based
on
the
following:

°
Seasonal
high
debris
period
monitoring
labor
set
equal
to
0
hours
°
Routine
labor
set
at
50%
of
full
time
operation
°
Back
washes
are
performed
once
every
four
days
°
Dive
team
costs
for
high
debris
were
set
at
50%
of
full
time
operation
°
Dive
team
cost
for
new
screens
at
existing
offshore
were
set
equal
to
0
assuming
no
net
additional
diver
costs
over
what
was
necessary
for
existing
submerged
intake
without
screens.
­
5­
Velocity
Caps
Because
the
O&
M
cost
for
velocity
caps
was
based
on
annual
inspection
and
cleaning
by
divers,
the
entire
velocity
cap
O&
M
cost
is
assumed
to
be
fixed
(
100%).

Fish
Barrier
Nets
Fish
barrier
net
O&
M
costs
are
based
on
deployment
and
removal
of
the
nets
plus
periodic
replacement
of
net
materials.
As
described
above,
EPA
assumes
seasonal
deployment
and
removal
is
a
100%
fixed
O&
M
cost.
EPA
has
assumed
that
the
need
for
net
maintenance
and
replacement
is
a
due
to
its
presence
in
the
waterbody
and
should
not
vary
with
the
intake
operation.
Therefore,
entire
fish
barrier
net
O&
M
cost
is
assumed
to
be
fixed
(
100%).

Recirculating
Wet
Cooling
Towers
Because
the
cooling
tower
O&
M
costs
were
derived
using
cost
factors
that
estimate
total
O&
M
costs
that
are
based
on
capital
costs,
a
detailed
analysis
is
not
possible.
However,
using
the
pumping
and
fan
energy
requirements
described
in
the
Proposed
Rule
Development
Document,
EPA
was
able
to
estimate
that
the
O&
M
energy
component
was
under
50%
of
the
total
O&
M
cost.
This
energy
requirement
reduction,
coupled
with
reductions
in
labor
and
parts
replacement
requirements,
should
result
in
a
fixed
cost
factor
of
approximately
50%.

5.3
O&
M
Fixed
Cost
Factors
Table
5­
2
and
5­
3
present
the
fixed
O&
M
cost
factors
for
baseline
technologies
and
compliance
technologies,
respectively,
derived
using
the
above
assumptions.
­
6­
Technology
Description
Application
Water
Type
Fixed
Factor
Traveling
Screen
With
Fish
Handling
10
Ft
Screen
Wells
Freshwater
0.28
Traveling
Screen
With
Fish
Handling
25
Ft
Screen
Wells
Freshwater
0.30
Traveling
Screen
With
Fish
Handling
50
Ft
Screen
Wells
Freshwater
0.32
Traveling
Screen
With
Fish
Handling
75
Ft
Screen
Wells
Freshwater
0.33
Traveling
Screen
With
Fish
Handling
10
Ft
Screen
Wells
Saltwater
0.31
Traveling
Screen
With
Fish
Handling
25
Ft
Screen
Wells
Saltwater
0.34
Traveling
Screen
With
Fish
Handling
50
Ft
Screen
Wells
Saltwater
0.36
Traveling
Screen
With
Fish
Handling
75
Ft
Screen
Wells
Saltwater
0.38
Traveling
Screen
Without
Fish
Handling
10
Ft
Screen
Wells
Freshwater
0.45
Traveling
Screen
Without
Fish
Handling
25
Ft
Screen
Wells
Freshwater
0.47
Traveling
Screen
Without
Fish
Handling
50
Ft
Screen
Wells
Freshwater
0.48
Traveling
Screen
Without
Fish
Handling
75
Ft
Screen
Wells
Freshwater
0.49
Traveling
Screen
Without
Fish
Handling
10
Ft
Screen
Wells
Saltwater
0.49
Traveling
Screen
Without
Fish
Handling
25
Ft
Screen
Wells
Saltwater
0.51
Traveling
Screen
Without
Fish
Handling
50
Ft
Screen
Wells
Saltwater
0.53
Traveling
Screen
Without
Fish
Handling
75
Ft
Screen
Wells
Saltwater
0.53
Table
5­
2
Baseline
Technology
Fixed
O&
M
Cost
Factors
­
7­
Technology
Description
Application
Water
Type
Fixed
Factor
Add
Fish
Barrier
Net
Using
Anchors
and
Bouys
All
Freshwater
1.0
Add
Fish
Barrier
Net
Using
Pilings
for
Support
10
Ft
Net
Depth
Saltwater
1.0
Add
Fish
Barrier
Net
Using
Pilings
for
Support
20
Ft
Net
Depth
Saltwater
1.0
Add
Passive
T­
screens
to
Existing
Offshore
Intake
High
Debris
All
0.21
Add
Passive
T­
screens
to
Existing
Offshore
Intake
Low
Debris
All
0.27
Relocate
Intake
Offshore
with
Passive
T­
screens
High
Debris
All
0.46
Relocate
Intake
Offshore
with
Passive
T­
screens
Low
Debris
All
0.56
Traveling
Screen
With
Fish
Handling
and
Fine
Mesh
10
Ft
Screen
Wells
Freshwater
0.38
Traveling
Screen
With
Fish
Handling
and
Fine
Mesh
25
Ft
Screen
Wells
Freshwater
0.35
Traveling
Screen
With
Fish
Handling
and
Fine
Mesh
50
Ft
Screen
Wells
Freshwater
0.37
Traveling
Screen
With
Fish
Handling
and
Fine
Mesh
75
Ft
Screen
Wells
Freshwater
0.39
Traveling
Screen
With
Fish
Handling
and
Fine
Mesh
10
Ft
Screen
Wells
Saltwater
0.41
Traveling
Screen
With
Fish
Handling
and
Fine
Mesh
25
Ft
Screen
Wells
Saltwater
0.38
Traveling
Screen
With
Fish
Handling
and
Fine
Mesh
50
Ft
Screen
Wells
Saltwater
0.40
Traveling
Screen
With
Fish
Handling
and
Fine
Mesh
75
Ft
Screen
Wells
Saltwater
0.41
Traveling
Screen
With
Fish
Handling
10
Ft
Screen
Wells
Freshwater
0.40
Traveling
Screen
With
Fish
Handling
25
Ft
Screen
Wells
Freshwater
0.42
Traveling
Screen
With
Fish
Handling
50
Ft
Screen
Wells
Freshwater
0.42
Traveling
Screen
With
Fish
Handling
75
Ft
Screen
Wells
Freshwater
0.42
Traveling
Screen
With
Fish
Handling
10
Ft
Screen
Wells
Saltwater
0.42
Traveling
Screen
With
Fish
Handling
25
Ft
Screen
Wells
Saltwater
0.43
Traveling
Screen
With
Fish
Handling
50
Ft
Screen
Wells
Saltwater
0.44
Traveling
Screen
With
Fish
Handling
75
Ft
Screen
Wells
Saltwater
0.44
Traveling
Screen
Dual­
Flow
10
Ft
Screen
Wells
Freshwater
0.40
Traveling
Screen
Dual­
Flow
25
Ft
Screen
Wells
Freshwater
0.40
Traveling
Screen
Dual­
Flow
50
Ft
Screen
Wells
Freshwater
0.40
Traveling
Screen
Dual­
Flow
75
Ft
Screen
Wells
Freshwater
0.40
Traveling
Screen
Dual­
Flow
10
Ft
Screen
Wells
Saltwater
0.44
Traveling
Screen
Dual­
Flow
25
Ft
Screen
Wells
Saltwater
0.44
Traveling
Screen
Dual­
Flow
50
Ft
Screen
Wells
Saltwater
0.44
Traveling
Screen
Dual­
Flow
75
Ft
Screen
Wells
Saltwater
0.44
Velocity
Cap
All
All
1.0
Cooling
Towers
All
All
0.5
Table
5­
3
Compliance
Technology
Fixed
O&
M
Cost
Factors