Document ID: EPA-HQ-OW-2002-0049-0032
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2003-03-19T05:00Z

316B
RULE
TELEPHONE
LOG
Name
of
Caller:
John
Sunda,
SAIC
Date:
July
29,
2002
Company
Name:
Johnson
Screens
Street
Address:

City/
State/
ZIP:
New
Brighton,
MN
55112
Person
Contacted:
Hank
Wells
Title:
Sales
Manager
Telephone
#:
651­
638­
3287
Fax
651­
638­
3177
The
following
questions
had
been
submitted
to
Mr
wells
previously.
Mr
Wells
stated
that
Equipment
Cost
data
is
of
a
sensitive
nature
and
will
require
consultation
with
other
employees
I
explained
that
it
could
be
submitted
in
a
business
confidential
manner
if
necessary.
He
was
going
to
follwup
after
consulting
with
other
employees.

Reponse
to
Questions
obtained
by
phone
from
Hank
Wells,
Johnson
Filter
All
reponse
information
is
presented
in
red
line
italics
QUESTIONS
FOR
PASSIVE
SCREEN
VENDORS
July
29,
2002
The
following
questions
involve
retrofitting
passive
intake
screens
onto
existing
intakes
most
of
which
already
include
traveling
screens..

The
following
questions
cover
the
breadth
of
information
being
sought
but
admittedly
are
somewhat
extensive.
Those
shown
in
non­
bold
print
are
generally
require
brief
or
quality
responses
and
are
intended
to
be
discussed
over
the
phone.
Questions
in
bold
print
may
require
research
and
may
best
be
presented
in
a
follow­
up
context.

He
stated
that
he
would
need
to
consult
with
others
concerning
release
of
cost
information.

General
1.
Are
there
any
specific
types
of
locations,
waterbodies,
or
regions
where
applications
are
limited?
Minimal
depth
of
less
than
2
ft
due
to
clearance
requirements.
Stagnant
water
with
high
debris
load.
Passive
screens
have
been
installed
at
end
of
canals/
channels
but
not
if
debris
is
high
2.
Previous
equipment
supplier
contacts
have
indicated
power
plants
with
large
volume
requirements
have
been
reluctant
to,
or
claim
to
be
unable
to,
use
passive
screens.
What
are
the
issues
or
limitations
regarding
retrofitting
large
volume
systems
with
passive
screens?
Has
the
situation
changed,
and
what
is
the
largest
volume
intake
where
you
have
installed
passive
screens?
Was
not
aware
of
or
had
nothing
to
add
concerning
industry
attitude.
Largest
screen
is
the
T­
96
which
would
typically
use
No
93
wire
(
93
1/
1000
of
an
inch).
They
have
recently
beeen
asked
for
quotes
on
power
plants
with
flows
in
the
300,000
to
400,000
gpm
range.
He
seemed
to
think
that
passive
screens
were
the
selected
technology.

3.
What
portion
of
intake
modification
work
do
you
do?
For
example,
if
retrofitting
traveling
screen
intakes
with
passive
screens,
do
you
provide
only
the
screen
equipment
or
do
you
also:
They
provide
screens
and
backwash
system
only.
Interconnecting
pipe
and
installation
are
provided
by
local
contractors.
Intake
contractors
include:
CH2MHill
Montgomery
Watson
Bechtel
CEM?
He
also
has
trouble
coming
up
with
costs
of
piping
and
structural
requirements
when
trying
to
compare
different
options
for
customers
­
Provide
manifold
pipe
and
fittings
No
­
Provide
steel
plates
or
other
fittings
to
cover
existing
intake
opening
with
t­
screen
pipe
attachment
No
­
Provide
installation
No
4.
What
is
the
recommended
range
or
typical
design
through­
screen
intake
velocity
and/
or
approach
velocity?
Since
the
application
being
considered
here
is
in
response
to
a
requirement
to
reduce
entrainment
and
impingement,
what
is
the
practical
upper
limit
for
ensuring
acceptable
performance?
Generally
in
the
east
it
is
0.5
fps
through­
screen
velocity.
In
the
west
it
is
the
NMFS
requirement
of
0.4
fps
approach
velocity.
When
asked
whether
a
higher
velocity
was
compatible
with
system
operation
he
said
1.0
fps
would
be
acceptable
but
that
as
the
velocity
increases
blockage
and
pressure
drop
across
the
screen
would
be
an
issue.

5.
What
range
of
screen
mesh
opening
sizes
do
you
consider
to
be
"
fine
mesh?"
When
facilities
examine
and/
or
select
finer
mesh
to
reduce
entrainment,
what
is
the
most
common
mesh
size?
Are
there
any
differences
in
the
fine
mesh
sizes
commonly
evaluated
and/
or
selected
for
new
intakes
versus
existing
intake
retrofits?
An
awkward
question.
Generally,
drinking
water
intakes
use
1/
8
inch.
For
reducing
entrainment
of
fish
eggs
1.75
mm
(
NMFS
reqirement).
Anything
less
than
1.0
mm
is
rare.

Shoreline
Intake
Retrofit
6.
When
multiple
rows
of
screens
are
needed
does
it
ever
make
sense
to
stack
the
rows
vertically
along
the
intake
face?
It
is
not
unusual
in
reservoirs
to
stack
intakes
on
a
tower.
They
are
not
always
used
at
the
same
time.
Sometimes
water
quality
and
temperature
will
dictate
from
which
depth
water
is
taken.

7.
An
obvious
solution
would
be
to
place
additional
rows
of
t­
screens
extending
outward
along
the
bottom
but
near
the
shoreline
(
such
as
the
multi­
Tee
system)
.
How
often
is
this
done
and
what
are
the
limitations?
This
is
very
routine.
If
waterway
obstruction
or
debris
is
an
issue,
a
diversion
structure
such
as
a
bypass
canal
may
be
included.

8.
When
does
it
make
more
sense
to
place
the
t­
screens
further
offshore?
Farther
out
costs
more
but
generally
get
better
quality
water.

9.
We
assume
that
moving
the
intakes
from
the
shoreline
to
near
shore
or
offshore
into
public
waterways
will
involve
more
public
and
government
consultation
and
permitting.
Do
you
have
any
knowledge
or
examples
of
how
this
may
affect
costs?
This
is
the
contractors
area.
He
did
note
that
his
understanding
is
that
the
placement
of
new
shoreline
structures
is
the
most
sensitive
issue
with
respect
to
public
participation.

10.
Are
most
near
shore
retrofit
installations
performed
by
divers
or
is
a
coffer
dam
type
structure
used
to
provide
a
dry
working
environment?
What
conditions
affect
the
selected
method
of
installation?
Coffer
dams
are
preferred
except
in
deep
locations.
Certainly
the
screens
can
be
installed
by
divers.

Installing
Passive
Screens
Offshore.

The
following
questions
involve
the
options
of
adding
passive
screens
to
existing
offshore
intakes
and
relocating
shoreline
intakes
offshore.

11.
Do
you
have
any
experience
with
installing
passive
screens
on
submerged
offshore
intakes
that
previously
had
none?
If
so:
­
Please
provide
relevant
information
such
as
facility
name
&
location,
cost
data,
technical
data,
and
general
layout.
If
not
available,
who
should
we
contact
for
such
information?
Gave
no
specific
example
but
said
that
this
was
not
uncommon.
Such
a
project
could
involve
getting
a
diver
to
weld
a
flange
(
or
cut
the
pipe
then
weld
a
flange
onto
the
pipe
end.
The
screen
or
manifold
could
then
be
bolted
onto
the
end.

12.
Excluding
differences
in
equipment
costs,
how
would
installing
passive
screens
compare
to
installing
velocity
caps?
No
difference
see
above.

13.
For
rivers/
lakes
with
boat
traffic,
what
are
the
recommended
clearance
depths
(
depth
of
water
above
the
screen)?
Generally
he
would
select
a
depth
of
twice
the
boats
draft.
5
to
10
ft
would
be
minimum
14.
Do
you
have
any
experience
with
or
knowledge
of
converting
shoreline­
based
intakes
to
submerged
offshore
intakes?
If
so:
­
At
what
facilities
was
this
done?
No
examples
given
­
What
specifically
was
done
and
what
portions
of
the
existing
system
were
retained?
Often
the
existing
structure
is
replaced
by
the
new
intake
or
the
existing
system
is
kept
as
a
option.
Many
of
their
projects
are
drinking
water
system
upgrades
where
the
capacity
is
being
increased.
­
What
are
the
major
cost
components?

15.
For
large
volume
offshore
intakes,
we
assume
an
array
of
t­
screens
may
be
necessary
for
each
pipe.
If
so:
­
What
sort
of
retrofit
construction
would
be
necessary?
See
answer
to
Question
11
­
Could
the
manifold
be
manufactured
onshore
and
installed
by
divers,
or
would
some
sort
of
underwater
manifold
construction
be
necessary?
Could
be
assembled
by
divers
­
Please
describe
construction
components,
example
costs,
and/
or
contacts
for
estimating
costs.

16.
Please
provide
delivered
equipment
costs
for
t­
screens
(
freshwater
and
saltwater)
plus
unit
costs
for
pipe
manifold
components
(
e.
g.,
multi­
Tee
system)
or
totals
if
possible.
See
sizes
below.

­
T­
24
­
T­
36
­
T­
48
­
T­
60
­
T­
72
­
T­
84
­
T­
96
(
or
largest
standard
screen
size)
Are
there
any
savings
for
multiple
unit
orders?
As
mentioned
earlier,
questions
regarding
costs
will
require
consultation
with
others
concerning
release
of
cost
information.
17.
How
do
t­
screen
costs
compare
to
traveling
screens
with
similar
performance
requirements?
When
asked
for
comparison
to
traveling
screens
he
said
that
the
equipment
costs
(
screens
and
backwash
system
only)
should
be
50%
(
or
less)
than
traveling
screens
(
equipment
only).
However,
his
information
concerning
traveling
screen
costs
are
generally
second
hand
and
therefore
he
can
not
be
certain.

18.
What
equipment
materials
do
you
recommend
(
or
are
commonly
selected)
for
freshwater
and
for
corrosive
environments
such
as
brackish
and
saltwater?
­
304
Stainless
Steel
is
standard
for
freshwater
­
316
Stainless
Steel
is
used
in
brackish
water
and
should
increase
cost
by
about
20%
over
304
SS
Z­
Alloy
is
their
high
copper
nickel
alloy
used
to
inhibit
Zebra
Mussels.
This
alloy
is
also
very
good
for
saltwater
corrosion
resistance
and
is
often
used
in
offshore
oil
&
gas
platforms.
This
alloy
adds
about
100%
or
nearly
doubles
the
intake
screen
costs.

19.
What
waterbodies
are
experiencing
problems
with
Zebra
mussels,
and
how
much
extra
are
the
equipment
costs
for
special
alloy
construction
or
comparable
materials?
EPA
has
a
map
that
would
serve
as
a
good
source.
Generally,
everything
east
of
the
Rockies.
See
above
for
relative
price.

20.
Please
provide
equipment
cost
of
this
corrosion
resistant
equipment
or
provide
relative
cost
difference
compared
to
freshwater
unit,
such
as
a
cost
factor
or
percent
increase?
See
Question
16
21.
Please
provide
delivered
and/
or
installed
costs
for
an
air
burst
backwash
system,
including
air
burst
distribution
and
control
equipment,
air
connection
tubing
and
fittings
for
systems
with
flows
from
2,000
gpm
to
500,000
gpm,
or
relative
costs
in
comparison
to
the
tscreen
equipment
costs.
Asked
for
cost
as
a
general
percentage
of
the
screen/
backwash
package.
For
small
systems
it
can
be
85%
(
example
of
small
was
a
single
T­
18).
For
a
large
system
such
as
a
power
plant
it
would
be
around
15%.

22.
Please
provide
information
concerning
passive
screen
installation
costs
for
both
shoreline
and
submerged
offshore
intakes,
particularly
as
compared
to
equipment
costs.

He
stated
that
he
would
need
to
consult
with
others
concerning
release
of
cost
information.
However,
since
they
do
not
perform
installation
I
do
not
expect
any
costs
of
this
sort.