
Page
1
of
33
Memorandum
From:
Carey
A.
Johnston
USEPA/
OW/
OST
ph:
(
202)
260
7186
johnston.
carey@
epa.
gov
To:
Alan
Spackman,
International
Association
of
Drilling
Contractors
(
IADC)
Kent
Satterlee,
Offshore
Operators
Committee
(
OOC)
Roger
Claff,
American
Petroleum
Institute
(
API)
Susan
Gregersen,
USDOE/
OFE
Robert
LaBelle,
USDOI/
MMS/
Environmental
Division
Date:
March
21,
2001
Re:
EPA
Data
Needs
to
Help
EPA
Assess
section
316(
b)
Comments
related
to
MODUs
Background
Section
316(
b)
of
the
Clean
Water
Act
(
CWA)
directs
EPA
to
assure
that
the
location,
design,
construction,
and
capacity
of
cooling
water
intake
structures
reflect
the
best
technology
available
for
minimizing
adverse
environmental
impact.
EPA
issued
a
proposal
on
August
10,
2000,
which
would
apply
to
new
facilities
that
use
large
amounts
of
cooling
water.
EPA
received
numerous
comments
on
the
proposal
including
comments
related
to
mobile
offshore
drilling
units
(
MODUs).
This
memorandum
identifies
EPA
data
collection
needs
to
assess
and
answer
316(
b)
MODU
comments.
Attachment
A
to
this
memorandum
describes
the
major
issues
raised
by
commentors
related
to
MODUs
and
Attachment
B
contains
the
parsed
set
of
316(
b)
MODU
comments.

EPA
Data
Needs
EPA
would
like
to
review
additional
reference
information
on
MODU
CWI
structures.
EPA
would
like
to
review
peer
reviewed
data
(
e.
g.,
journal
articles),
operator/
drilling
contractor
field
data,
and/
or
MODU
design
schematics
to
support
the
assertions
made
by
commentors.
Specifically,
EPA
would
like
to
see
additional
reference
data
for
the
following
subject
areas:


MODU
CWI
rates,
velocities,
and
duration
in
both
coastal
and
offshore
waters
for
various
rig
types
(
e.
g.,
drill
ships,
semi­
submersibles,
jack­
ups,
submersibles,
and
drill
barges);


Velocity
requirements
and
other
preventative
measures
(
e.
g.,
type
and
amount
of
chemical
treatment,
backwashing)
for
marine
growth
inhibition;


Potential
typical
costs
and
issues
related
to
retrofitting
sea
chests
(
e.
g.,
hull
design
implications,
load
paths,
fatigue,
risks
to
divers);
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33

MODU
scheduling
impacts
due
to
316(
b)
requirements
for
new
sources;
and

Whether
ZD
technologies
are
not
cost
effective
or
will
not
operate
on
MODUs.

EPA
would
also
like
to
work
with
MMS
to
identify
any
current
MMS
regulations
or
requirements
(
e.
g.,
Notices
to
Lessees
and
Operators)
or
Executive
Orders
governing
MODU
CWI
structures.
Please
let
me
know
if
you
have
any
questions
or
comments
regarding
EPA's
data
needs
related
to
this
rulemaking.

cc:
Tim
Connor,
USEPA/
OW/
OST
Marvin
Rubin,
USEPA/
OW/
OST
Tom
Wall,
USEPA/
OW/
OST
Mary
Ellen
Levine,
USEPA/
OGC
Attachments:

Attachment
A
­
MODU
316(
b)
Comment
Summaries
Attachment
B
­
MODU
316(
b)
Parsed
Comments
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of
33
Attachment
A
­
MODU
316(
b)
Comment
Summaries
MODU
316(
b)
Commentors
The
following
people
and
organizations
submitted
MODU
related
comments
on
the
316(
b)
rule
for
new
sources.

Name
Organization
Alan
Spackman
International
Association
of
Drilling
Contractors
(
IADC)

Jim
Gormanson
Noble
Drilling
Servides,
Inc.

Kent
Satterlee
Offshore
Operators
Committee
(
OOC)

Roger
Claff
American
Petroleum
Institute
(
API)

Roger
S.
Kripowicz
U.
S.
Department
of
Energy
(
DOE)

Charles
A.
Bedell
Murphy
Exploration
&
Production
Co.

Brian
M.
Harney
ExxonMobil
Refining
&
Supply
MODU
316(
b)
Comments
All
of
the
commentors
were
critical
of
the
316(
b)
proposal
for
new
sources.
Most
of
the
commentors
requested
that
MODU's
be
categorically
excluded
from
the
316(
b)
rule
for
new
sources.
Other
commentors
suggested
alternative
methods
to
control
MODU
CWI
structures:

S
Allow
the
NPDES
permitting
authority
to
set
appropriate
controls
(
IADC);

S
Set
the
applicability
criteria
at
greater
than
25
MGD
for
MODU
CWI
structures
or
set
the
BTA
for
open
ocean
environments
at
a
maximum
of
5
feet/
second
(
OOC);

S
Set
the
CWI
threshold
to
30
MGD
(
API).

The
following
is
a
brief
description
of
each
major
MODU
316(
b)
comment
area.
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of
33
1.
MODU's
Listed
as
Potentially
Regulated
but
Not
Considered
in
Proposal's
Engineering
and
Economic
Analyses
Commentors
Raising
this
Issue:
IADC,
OOC,
API,
DOE,
Murphy,
ExxonMobil
General
Comment:
Commentors
claim
that
the
proposed
rule
did
not
consider
offshore
oil
and
gas
facilities
in
its
cost/
benefit
analysis.
Several
commentors
claim
that
the
impacts
could
be
large
including
loss
of
production.

Specific
Comments:
OOC
stated
that
many
MODU
CWI
structures
are
designed
as
"
sea
chests"
in
the
hull
of
the
vessel
which
means
that
any
retrofits
would
be
very
costly
and
complex.
API
states
that
these
retrofits
are
not
cost­
effective.
IADC
also
stated
that
the
seafood
processing
industry
might
also
be
affected
by
this
proposed
rule.

2.
MODU
Retrofits
are
Potentially
Dangerous
Commentor
Raising
this
Issue:
IADC,
OOC,
Noble
General
Comment:
Commentors
state
that
retrofits
of
existing
MODUs
would
be
inadvisable
due
to
worker
safety
and
marine
engineering
structure
concerns.

Specific
Comments:
OOC
stated
that
the
depth
of
intake
structures
range
from
20
to
280
feet
below
water.
OOC's
states
that
retrofits
to
reduce
intake
velocity
would
require
costly
underwater
installations
with
its
associated
risk
to
diving
personnel.
IADC
states
that
typical
marine
engineering
practice
is
to
maintain
relatively
high
flow
rates
through
the
seachests
and
piping
in
order
to
reduce
both
seachest
and
piping
size.
Noble
stated
that
MODU
retrofits
would
create
problems
with
hull
design,
load
paths,
and
fatigue.

3.
Lack
of
Demonstrated
MODU
CWI
Impacts
Commentors
Raising
this
Issue:
IADC,
OOC,
API
General
Comment:
Commentors
claim
that
there
are
no
indications
fo
mortality
or
injury
to
aquatic
organisms
due
to
MODU
CWI
structures.

Specific
Comments:
IADC
references
the
Technical
Development
Document
for
the
Uniform
National
Discharge
Standards
as
the
basis
for
its
assertion
of
no
impacts.
OOC
submitted
a
video
tape
of
three
different
MODU
CWI
structures
to
support
its
position
of
no
observable
adverse
environmental
impacts.
API
states
that
many
of
the
underlying
assumptions
EPA
used
to
justify
the
proposed
rule
are
not
applicable
to
offshore
operations
(
i.
e.,
MODUs
operate
in
open
ocean
waters
and
not
in
marine
nurseries).
API
further
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33
stated
that
there
are
no
environmental
studies
of
impingement
and
entrainment
in
areas
similar
to
areas
where
MODUs
operate.

4.
Marine
Bio­
Fouling
of
MODU
CWI
Structures
Commentors
Raising
this
Issue:
IADC,
Noble,
OOC,
API,
DOE,
Murphy
General
Comment:
Commentors
claim
that
reducing
the
flow
rate
in
MODU
CWI
structures
(
e.
g.,
sea
chests)
and
piping
would
produce
an
ideal
environment
to
encourage
growth
of
marine
organisms.
The
commentors
claim
that
the
marine
growth
would
need
to
be
controlled
by
chemical
treatment
and/
or
periodic
manual
cleaning
by
divers.

Specific
Comments:
OOC
stated
that
intake
structures
are
not
easily
cleaned.
API
states
that
MODUs
must
use
intake
velocities
of
2
­
5
ft/
s
to
prevent
marine
biofouling.

5.
Existing
MODU's
May
Fall
Under
CWI
New
Source
Restrictions
Commentors
Raising
this
Issue:
IADC,
Noble,
OOC,
API,
Murphy
General
Comment:
Commentors
claim
that
EPA
did
not
consider
the
impact
to
existing
MODUs
which
could
be
considered
new
sources
when
drilling
new
source
developments
wells.

Specific
Comment:
IADC
stated
that
the
316(
b)
rule
for
new
sources
would
"
greatly
diminish,
if
not
entirely
eliminate
for
some
period
of
time,
the
availability
of
MODUs
to
drill
develop
wells
from
the
OCS
locations
that
[
are]
increasingly
becoming
the
mainstay
of
the
nation's
domestic
oil
and
gas
supply."
OOC
stated
that
the
new
requirements
could
cause
costly
scheduling
delays.
[
Note:
rig
rental
rates
can
average
$
50,000
to
$
250,000
per
day].

6.
MODU's
Not
Capable
of
Achieving
Zero
Discharge
Commentors
Raising
this
Issue:
API
General
Comment:
Commentor
claims
that
EPA's
technology
alternative
that
would
require
zero
cooling
water
intake
is
technically
infeasible
and
has
not
been
shown
to
be
necessary
to
minimize
adverse
environmental
impacts.

Specific
Comment:
API
is
unaware
of
any
ZD
technologies
for
MODUs.
API
notes
that
the
warmer
weather
of
the
GOM
may
also
limit
or
eliminate
ZD
technologies
investigated
for
other
industries.
DOE
also
states
that
MODUs
are
extremely
space
limited
and
in
most
cases
could
not
accommodate
Page
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significant
physical
changes.
Page
7
of
33
Attachment
B
­
MODU
316(
b)
Parsed
Comments
See
attached
document.
