­
1­
Design
Flow
gpm
304
SS
316
SS
CuNi
304
SS
316
SS
CuNi
304
SS
316
SS
CuNi
304
SS
316
SS
CuNi
Freshwater
Saltwater
Zebra
Mussels
Freshwater
Saltwater
Zebra
Mussels
Freshwater
Saltwater
Zebra
Mussels
Freshwater
Saltwater
Zebra
Mussels
2,500
$
99,693
$
101,526
$
103,042
$
127,159
$
132,487
$
130,508
$
159,856
$
169,346
$
163,206
$
225,251
$
243,064
$
228,601
5,700
$
119,651
$
124,624
$
131,831
$
160,600
$
173,563
$
172,780
$
209,349
$
231,824
$
221,529
$
306,847
$
348,346
$
319,027
10,000
$
153,804
$
159,690
$
176,185
$
202,743
$
216,620
$
225,124
$
261,004
$
284,393
$
283,385
$
377,526
$
419,939
$
399,907
15,800
$
192,786
$
202,967
$
225,520
$
269,691
$
293,355
$
302,425
$
361,244
$
400,959
$
393,978
$
544,350
$
616,168
$
577,084
22,700
$
243,404
$
262,395
$
297,757
$
350,272
$
396,229
$
404,625
$
477,495
$
555,555
$
531,848
$
731,941
$
874,207
$
786,294
31,000
$
291,077
$
313,773
$
364,766
$
436,896
$
490,553
$
510,585
$
610,490
$
701,006
$
684,179
$
957,678
$
1,121,912
$
1,031,367
40,750
$
350,065
$
379,015
$
445,982
$
530,840
$
597,743
$
626,758
$
746,049
$
858,134
$
841,967
$
1,176,467
$
1,378,916
$
1,272,385
81,500
$
556,250
$
614,150
$
748,085
$
917,801
$
1,051,607
$
1,109,636
$
1,348,219
$
1,572,389
$
1,540,054
$
2,209,055
$
2,613,953
$
2,400,890
122,250
$
786,489
$
873,340
$
1,074,242
$
1,328,816
$
1,529,525
$
1,616,568
$
1,974,443
$
2,310,698
$
2,262,195
$
3,265,697
$
3,873,044
$
3,553,449
163,000
$
1,009,571
$
1,125,372
$
1,393,241
$
1,732,673
$
2,000,285
$
2,116,343
$
2,593,509
$
3,041,849
$
2,977,179
$
4,315,181
$
5,124,977
$
4,698,851
Total
Costs
20
Meters
Offshore
Total
Costs
125
Meters
Offshore
Total
Costs
250
Meters
Offshore
Total
Costs
500
Meters
Offshore
316b
Phase
II
Cost
Module
1.2
Add
Submerged
Fine
Mesh
Passive
Screens
to
Existing
Offshore
Intakes
Please
note
that
much
of
the
supporting
documentation
has
been
previously
described
in
Section
1.1.

Capital
Costs
Adding
passive
screens
to
an
existing
submerged
offshore
intake
requires
many
of
the
same
construction
steps
and
components
described
in
section
1.1
above,
excluding
those
related
to
the
main
trunk
of
the
manifold
pipe
and
connecting
wall.
Similar
construction
components
include:
modifying
the
submerged
inlet
to
connect
the
new
screens,
installing
T­
screens,
and
installing
the
airburst
backwash
air
supply
equipment
and
the
blowpipes.
Nearly
all
of
these
components
will
require
similar
equipment,
construction
steps
and
costs
as
described
in
Section
1.1
for
the
specific
components.
One
possible
difference
is
that
the
existing
submerged
piping
distance
may
not
match
one
of
the
four
lengths
for
which
costs
were
estimated.
This
is
a
somewhat
important
consideration
because
the
costs
of
the
blowpipes
are
dependent
on
length.
However,
this
difference
only
affects
this
component
of
cost.
The
cost
scenario
distance
chosen
is
the
one
that
closely
matches
or
exceeds
the
existing
offshore
distance.
Table
1­
11
presents
the
combined
costs
of
the
installed
T­
screens,
airburst
air
supply
system,
and
air
supply
pipes.
The
costs
in
Table
1­
11
include
direct
and
indirect
costs,
as
described
in
Section
1.1.
Figures
1­
6,
1­
7,
and
1­
8
present
plots
of
Table
1­
11
data,
including
the
second­
order,
best­
fit
equations
are
used
to
estimate
technology
costs
for
specific
facilities.

TABLE
1­
11
CAPITAL
COST
OF
INSTALLING
PASSIVE
T­
SCREENS
AT
AN
EXISTING
SUBMERGED
OFFSHORE
INTAKE
O&
M
Costs
O&
M
costs
are
assumed
to
be
nearly
the
same
as
for
relocating
the
intake
offshore
with
passive
screens.
EPA
assumes
there
are
some
offsetting
costs
associated
with
the
fact
that
the
existing
intake
should
already
have
periodic
inspection/
cleaning
by
divers.
The
portion
of
the
costs
representing
a
single
annual
inspect
has
therefore
been
deducted.
Table
1­
12
presents
the
annual
O&
M
costs
for
low
debris
and
high
debris
locations.
Figure
1­
9
presents
the
plotted
O&
M
data
along
with
the
second­
order,
best
fit
equations.
­
2­
Design
Flow
Annual
Power
Costs
Annual
Power
Costs
Annual
Labor
Cost
Annual
Labor
Cost
Dive
Team
Costs
Dive
Team
Costs
Total
O&
M
Costs
Total
O&
M
Costs
gpm
Low
Debris
High
Debris
Low
Debris
High
Debris
Low
Debris
High
Debris
Low
Debris
High
Debris
2,500
$
24
$
145
$
9,982
$
22,314
$
0
$
5,260
$
10,007
$
27,719
5,700
$
61
$
363
$
9,982
$
22,314
$
0
$
5,260
$
10,043
$
27,937
10,000
$
121
$
726
$
9,982
$
22,314
$
0
$
5,260
$
10,103
$
28,300
15,800
$
145
$
871
$
11,891
$
24,222
$
0
$
7,250
$
12,036
$
32,343
22,700
$
182
$
1,089
$
11,891
$
24,222
$
0
$
7,250
$
12,072
$
32,561
31,000
$
242
$
1,452
$
11,891
$
24,222
$
0
$
7,250
$
12,133
$
32,924
40,750
$
303
$
1,815
$
11,891
$
24,222
$
0
$
7,250
$
12,193
$
33,287
81,500
$
605
$
3,631
$
13,799
$
26,130
$
0
$
9,240
$
14,404
$
39,001
122,250
$
908
$
5,446
$
13,799
$
26,130
$
0
$
9,240
$
14,707
$
40,816
TABLE
1­
12
NET
INTAKE
O&
M
COSTS
FOR
PASSIVE
T­
SCREENS
INSTALLED
AT
EXISTING
SUBMERGED
OFFSHORE
INTAKES
Construction
Downtime
Unlike
the
cost
for
relocating
the
intake
from
shore­
based
to
submerged
offshore,
the
only
construction
activities
that
would
require
shutting
down
the
intake
is
to
modify
the
inlet
and
install
the
T­
screens.
Installing
the
air
supply
system
and
the
major
portion
of
the
air
blowpipes
can
be
performed
while
the
intake
is
operating.
Downtimes
are
assumed
to
be
similar
to
those
for
adding
velocity
caps,
which
were
reported
to
range
from
two
to
seven
days.
An
additional
one
to
two
days
maybe
needed
to
connect
the
blowpipes
to
the
T­
screens.
The
total
estimated
intake
downtime
of
three
to
nine
days
can
easily
be
scheduled
to
coincide
with
the
routine
maintenance
period
for
power
plants
(
approximately
four
weeks).

Application
Separate
capital
costs
have
been
developed
for
freshwater,
freshwater
with
Zebra
mussels,
and
saltwater
environments.
In
selecting
the
materials
of
construction,
the
same
methodology
described
in
Section
1.1
is
used.
BECAUSE
the
retrofit
is
an
addition
to
an
existing
intake,
selecting
the
distance
offshore
involves
matching
the
existing
distance
to
the
nearest
or
next
highest
distance
costed.

Similarly,
the
O&
M
costs
are
applied
using
the
same
method
as
described
in
Section
1.1.
­
3­
Figure
1­
6
Capital
Costs
for
Passive
Screen
Existing
Offshore
in
Freshwater
at
Selected
Offshore
Distances
y
=
3E­
06x
2
+
25.095x
+
154574
R
2
=
0.9999
y
=
­
4E­
07x
2
+
15.21x
+
123289
R
2
=
0.9999
y
=
­
2E­
06x
2
+
10.267x
+
107646
R
2
=
0.9997
y
=
­
3E­
06x
2
+
6.1145x
+
94506
R
2
=
0.999
$
0
$
1,000,000
$
2,000,000
$
3,000,000
$
4,000,000
$
5,000,000
0
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
180,000
Design
Intake
Flow
(
gpm)

Total
Capital
Costs
20
Meter
125
Meter
250
Meter
500
Meter
­
4­
Figure
1­
7
Capital
Costs
for
Passive
Screen
at
Existing
Offshore
in
Saltwater
at
Selected
Offshore
Distances
y
=
3E­
06x
2
+
30.025x
+
161224
R
2
=
0.9998
y
=
­
5E­
07x2
+
17.945x
+
126572
R
2
=
0.9998
y
=
­
2E­
06x
2
+
11.905x
+
109246
R
2
=
0.9997
y
=
­
3E­
06x
2
+
6.8309x
+
94692
R
2
=
0.9991
$
0
$
1,000,000
$
2,000,000
$
3,000,000
$
4,000,000
$
5,000,000
$
6,000,000
0
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
180,000
Design
Intake
Flow
(
gpm)

Total
Capital
Costs
20
Meter
125
Meter
250
Meter
500
Meter
­
5­
Figure
1­
8
Capital
Costs
for
Passive
Screen
Existing
Offshore
in
Freshwater
with
Zebra
Mussels
at
Selected
Offshore
Distances
y
=
2E­
06x
2
+
27.504x
+
152489
R
2
=
0.9999
y
=
­
7E­
07x
2
+
17.618x
+
121204
R
2
=
0.9999
y
=
­
2E­
06x
2
+
12.675x
+
105561
R
2
=
0.9998
y
=
­
4E­
06x
2
+
8.5232x
+
92421
R
2
=
0.9994
$
0
$
1,000,000
$
2,000,000
$
3,000,000
$
4,000,000
$
5,000,000
0
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
180,000
Design
Intake
Flow
(
gpm)

Total
Capital
Costs
20
Meter
125
Meter
250
Meter
500
Meter
­
6­
Figure
1­
9
Total
O&
M
Cost
for
Passive
Screen
Existing
Offshore
with
Airburst
Backwash
y
=
­
3E­
07x
2
+
0.0845x
+
11155
R
2
=
0.9376
y
=
­
4E­
07x
2
+
0.1741x
+
30519
R
2
=
0.9651
$
0
$
10,000
$
20,000
$
30,000
$
40,000
$
50,000
$
60,000
0
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
180,000
Design
Intake
Flow
Annual
O&

M
Costs
Low
Debris
High
Debris
­
7­
