Document ID: EPA-HQ-OW-2002-0049-0178
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:
September
10,
2002
&
October
23,
2002
Company
Name:
Brackett
Green
Street
Address:

City/
State/
ZIP:
Houston,
TX
Person
Contacted:
Trent
Gathright
Title:
Sales
Manager
Telephone
#:
281­
480­
7955
Talked
to
(
receptionist)
forwarded
to
Trent
Called
to
inquire
about
O&
M
cost
for
traveling
screens.

September
10,
2002
Screen
Motor
Requirements:
Motor
size
is
based
on
expected
water
differential
at
screen
startup.
Screens
are
generally
balanced
,
the
weight
of
water
in
the
buckets
rising
above
water
is
offset
by
air
in
trapped
in
the
buckets
on
the
downward
moving
side.
The
differential
exerts
pressure
on
the
screen
and
it
produces
differences
in
the
buoyancy
of
the
two
screen
sides.
General
are:
For
5
ft
screen
about
2
Hp
but
could
be
higher
For
10
ft
screen
5
to
7.5
Hp
For
14
ft
screens
7.5
Hp+
He
will
provide
some
additional
data
and
guidance
with
the
cost
spreadsheets.

Spray
Water
Requirements
He
was
not
sure
about
quantity
but
reminded
me
that
fish
troughs
need
a
minimum
flow.
Can
estimate
using
2
"
deep,
22"
wide
trough
and
1.5
fps
velocity.
Pressure
needed
is
just
above
ambient.
80
PSI
is
average
pressure
for
trash
spray,
fish
spray
is
around
10
psi.
I
asked
if
they
use
different
sources
or
use
regulators.
He
said
they
often
use
regulators
for
low
pressure
source.

Labor
Generally
about
200
manhours
per
year
per
screen.
For
different
sizes,
scale
such
that
shallownarrow
is
100
hours
and
wide
deep
is
300
hours.
Materials
Suggested
assuming
15%
of
equipment
purchase
cost
is
replaced
every
5
yrs.
Typical
is
$
12,000
to
$
15,000
every
5
yrs
which
is
roughly
15%.

October
23,
2002
Called
back
to
get
more
O&
M
costs
detail
on
contrasting
O&
M
costs
for
coarse
mesh
versus
fine
mesh
and
capital
costs
for
different
types
of
screen
panels.

For
time
of
operation
of
the
screen
traveling
screens,
Those
with
fish
handling
&
fine
mesh
will
be
operated
continuously
but
at
a
slow
rate
of
speed
(
e.
g.,
5
fpm),
Those
with
coarse
mesh
will
operate
about
4­
6
hours/
day
with
spray
pumps
on
and
off
the
same
time
period.
The
screen
travel
rate
will
be
15
to
30
fpm.
While
the
time
of
operation
is
4­
5
times
for
fish
handling
screens,
the
slower
speed
tempers
some
of
this
added
werar
and
tear
such
that
the
amount
of
wear
is
only
about
double.

For
parts
replacement
the
15%
every
five
years
applies
to
coarse
mesh.
He
estimates
that
this
figure
changes
to
15%
every
2.5
years
for
fine
mesh.

For
Labor
estimates
the
200
hour
average
applied
to
coarse
mesh
this
figure
should
be
double
for
fine
mesh
with
fish
handling.

Concerning
changing
from
coarsew
mesh
to
fine
mesh
you
don't
necessarily
need
to
change
the
screen
panels.
Overlays
equal
in
costs
to
about
8%
to
10%
of
the
scen
costs
can
be
used
in
this
case
the
labor
requirement
will
be
less
taking
30
min
for
dual
flow
screens
and
about
1
hour
for
through
flow.
The
difference
is
that
with
dual
flow
the
overlays
always
have
water
flow
towards
the
supporting
screen
while
through
flow
have
water
flow
reversed
on
the
backside
requiring
stronger
connections
to
the
existing
panels.
He
agreed
that
if
the
baskets
are
being
replaced
that
a
30%
(
he
estimated
25%)
capital
cost
figure
is
reasonable.

Concerning
various
mesh
types,
the
difference
between
fine
mesh
and
smooth
top
mesh
(
1/
8
by
½
inch)
would
only
change
total
screen
unit
costs
by
about
2%.
Fine
mesh
dopes
not
change
through
screen
velocity
by
much
he
gave
an
example
where
it
changed
from
68%
to
64%.

The
idea
is
that
fine
mesh
is
weaker
is
not
true
in
that
while
the
wire
diameter
is
smaller,
the
number
of
wires
per
inch
increases
and
mostly
compensates
for
it.
What
is
sometimes
a
problem
with
fine
mesh
is
that
corrossion
of
the
screen
can
be
\
more
problematic.
In
corrosive
environments
he
often
recommends
using
nylon
mesh.
There
is
little
difference
in
the
costs
for
nylon
versus
metal
mesh.

Note
that
smooth
top
screen
was
designed
to
reduce
fish
descaling
that
occurred
as
a
result
of
the
rough
surface
of
coarser
mesh.
This
is
not
a
problem
with
fine
mesh
screen.

Concerning