Document ID: EPA-HQ-OW-2004-0002-0530
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
Rowan
Midland
Rig
Type
Semisubmersible
Total
Installed
Power
Generation
Capacity
6,625HP
Number
of
Cooling
Water
Intake
Structures
(
CWISs)
4
Brief
description
of
each
CWIS
(
e.
g.,
sea
chest,
simple
pipe)
Seachests
Rough
dimensions
of
each
CWIS
and
indicate
whether
onboard
CWIS
has
an
existing
flange
(
2)
14"
dia.
&
(
2)
16"
dia.
pipes
with
30.5"
x32.5"
screens
Screen
type
(
e.
g.,
strainer,
wedge
wire)
with
mesh
size
Not
reported
Total
Design
Specifications
for
Daily
Maximum
Water
Intake
Volume
of
each
CWIS
3,600,000
gals
(
85,714
bbls)

Total
Daily
Water
Intake
Volume
of
each
CWIS
(
Set­
up/
Drilling)
Not
reported
Design
Specs
for
Through
Screen
Velocity
of
each
CWIS
(
i.
e.,
Q=
V*
A)
(
Set­
up/
Drilling)
1.05
ft.
per
second
List
of
Purposes
of
Cooling
Water
Intakes
(
e.
g.,
cool
crude
oil,
produced
water,
power
generators,
drill
pipe
brakes)
Brake
water
cooling,
engine
oil
cooling,
electric
motor
cooling
List
of
Purposes
of
Non­
cooling
Water
Intakes
(
e.
g.,
fire
water,
hotel
loads)
Fire
main,
ballast,
sanitary,
pits,
drill
water,
hotel
loads,
distiller
input,
wasdown
Total
Volume
of
Water
Intake
for
Ballasting,
Duration
of
the
Ballast
intake,
and
the
Through
Screen
Velocity
of
the
Ballast
intake
1,796,718
gal
(
42,779
bbls)
Duration
­
6­
12
hours
Velocity
­
4.08
­
5.21
fps
Mitigation
Measures
for
reducing
Exotic
Species
Migration
through
Ballast
water
Operates
only
in
Gulf
of
Mexico
Mitigation
Measures
for
reducing
Impingement
and
Entrainment
of
Aquatic
Organisms,
as
well
as
Bio­
fouling
Prevention
Measures
Seachests
covered
by
gratings.

Is
the
Rig
equipped
with
a
Radiator
Cooling
System
for
the
Main
Engines?
No