Document ID: EPA-HQ-OW-2004-0002-0496
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2004-11-30T05:00Z

Cooling
Water
Intake
Structure
(
CWIS)
Information
Data
Required
Rig
Information
Rig
Name
ENSCO
25
ENSCO
26
ENSCO
29
Rig
Type
Transportable
Platform
Rig
(
ENSCO
25
&
ENSCO
29)
Platform
Rig
on
SPAR
Buoy
(
ENSCO
26)
Total
Installed
Power
Generation
Capacity
6250
HP
(
ENSCO
25
&
ENSCO
29)
7200
HP
(
ENSCO
26)

Number
of
Cooling
Water
Intake
Structures
(
CWISs)
2
Brief
description
of
each
CWIS
(
e.
g.,
sea
chest,
simple
pipe)
Raw
Water
Tower
Deep
Well
Pumps
Rough
dimensions
of
each
CWIS
and
indicate
whether
onboard
CWIS
has
an
existing
flange
2ea
raw
water
tower
pumps,
2
/
3
stage
w/
75
hp
motors
pump
rated
1300
gpm
with
10"
suction
at
20'
to
50'
Screen
type
(
e.
g.,
strainer,
wedge
wire)
with
mesh
size
Basket
Strainers,
¼
"
Mesh
on
pump
itself
Total
Design
Specifications
for
Daily
Maximum
Water
Intake
Volume
of
each
CWIS
1,871,940
gals
(
44,570
bbls)

Total
Daily
Water
Intake
Volume
of
each
CWIS
(
Set­
up/
Drilling)
1,871,940
gals
(
44,570
bbls)

Design
Specs
for
Through
Screen
Velocity
of
each
CWIS
(
i.
e.,
Q=
V*
A)
(
Set­
up/
Drilling)
5.50
fps
List
of
Purposes
of
Cooling
Water
Intakes
(
e.
g.,
cool
crude
oil,
produced
water,
power
generators,
drill
pipe
brakes)
Brake
water
cooling
and
5
heat
exchangers
for
main
engines
List
of
Purposes
of
Non­
cooling
Water
Intakes
(
e.
g.,
fire
water,
hotel
loads)
Fire
main,
sanitary,
mud
pits,
shakers
Total
Volume
of
Water
Intake
for
Ballasting,
Duration
of
the
Ballast
intake,
and
the
Through
Screen
Velocity
of
the
Ballast
intake
Not
applicable
Mitigation
Measures
for
reducing
Exotic
Species
Migration
through
Ballast
water
Not
applicable
Mitigation
Measures
for
reducing
Impingement
and
Entrainment
of
Aquatic
Organisms,
as
well
as
Bio­
fouling
Prevention
Measures
Sea
chest
screens,
and
baskets,
cathodic
protection
Is
the
Rig
equipped
with
a
Radiator
Cooling
System
for
the
Main
Engines?
Yes,
heat
exchangers
for
main
engines