DRAFT
1
August
4,
2006
ENVIRONMENTAL
PROTECTION
AGENCY
40
CFR
Parts
122,
123
and
124
[
EPA­[
HQ
or
R##]­[

[
EPA­
HQ­
OW­
2005­
0523,
FRL
­
XXXX
]

National
Pollutant
Discharge
Elimination
System
Permit
Requirements
for
Peak
Wet
Weather
Discharges
from
Publicly
Owned
Treatment
Works
Treatment
Plants
Serving
Separate
Sanitary
Sewer
Collection
Systems
AGENCY:
Environmental
Protection
Agency
(
EPA)

ACTION:
Notice
of
Policy
SUMMARY:
EPA
is
issuing
a
policy
regarding
National
Pollutant
Discharge
Elimination
System
(
NPDES)
permit
requirements
for
peak
wet
weather
diversions
at
publicly
owned
treatment
works
(
POTW)
treatment
plants
serving
separate
sanitary
sewer
collection
systems.
Regulatory
agencies,
municipal
operators
of
wastewater
facilities,
and
representatives
of
environmental
advocacy
groups
have
expressed
uncertainty
about
the
appropriate
regulatory
interpretation
for
such
situations.
Today's
policy
describes
a
process
for
evaluating
whether
and
under
what
conditions
certain
peak
wet
weather
flow
diversions
should
be
approved
or
denied
in
an
NPDES
permit.
This
process
involves
assessment
and
implementation
of
feasible
alternatives
by
the
POTW
in
conjunction
with
regulatory
authorities
and
the
general
public.
EPA's
intention
is
to
ensure
that
NPDES
permit
requirements
are
developed
and
applied
in
a
manner
that
improves
the
capacity,
management,
operation
and
maintenance
of
POTW
treatment
plants
and
separate
sanitary
sewer
collection
systems
and
protects
human
health
and
the
environment.

DATES:
The
policy
is
effective
immediately.

ADDRESSES:
EPA
has
established
a
docket
for
this
action
under
Docket
ID
No.
EPA­
HQ­
OW­
2005­
0523.
All
documents
in
the
docket
are
listed
on
the
www.
regulations.
gov
web
site.
Publicly
available
docket
materials
are
available
either
electronically
through
www.
regulations.
gov
or
in
hard
copy
at
the
Water
Docket,
EPA
Docket
Center,
EPA/
DC,
EPA
West,
Room
B102,
1301
Constitution
Ave.,
NW,
Washington,
D.
C.
The
Public
Reading
Room
is
open
from
8:
30
a.
m.
to
4:
30
p.
m.,
Monday
through
Friday,
excluding
legal
holidays.
The
telephone
number
for
the
Public
Reading
Room
is
(
202)
566­
1744,
and
the
telephone
number
for
the
Water
Docket
is
(
202)
566­
2426).

FOR
FURTHER
INFORMATION
CONTACT:
For
questions
about
this
policy,
contact
Kevin
Weiss
(
e­
mail
at
weiss.
kevin@
epa.
gov
or
phone
at
(
202)
564­
0742)
at
Water
Permits
DRAFT
2
August
4,
2006
Division,
Office
of
Wastewater
Management,
U.
S.
Environmental
Protection
Agency
(
Mailcode
4203M),
1200
Pennsylvania
Ave.,
NW,
Washington,
D.
C.
20460.

SUPPLEMENTARY
INFORMATION:

I.
General
Information
Acronyms
Used
CSO
Combined
sewer
overflow
EPA
Environmental
Protection
Agency
I/
I
infiltration
and
inflow
NPDES
National
Pollutant
Discharge
Elimination
System
POTW
Publicly
owned
treatment
works
SSO
Sanitary
sewer
overflow
(
this
does
not
include
CSOs)

II.
BACKGROUND
Many
stakeholders
have
requested
that
EPA
clarify
the
NPDES
requirements
for
discharges
from
POTW
treatment
plants
serving
separate
sanitary
sewers
where
peak
wet
weather
flow
is
routed
around
secondary
treatment
units
and
then
blended
with
the
effluent
from
the
secondary
units
prior
to
discharge
and
where
the
final
discharge
meets
permit
effluent
limitations
based
on
the
secondary
treatment
regulations
and
any
more
stringent
limitations
necessary
to
attain
water
quality
standards.
On
November
7,
2003,
EPA
requested
public
comment
on
a
proposed
policy
addressing
this
issue.
See
68
FR
63042
(
November
7,
2003).
Under
that
proposed
interpretation,
a
wet
weather
diversion
around
secondary
treatment
units
that
was
blended
with
the
wastewaters
from
the
secondary
units
prior
to
discharge
would
not
have
been
considered
a
bypass
if
the
six
criteria
specified
in
the
November
7,
2003
proposed
policy
were
met.

EPA
received
significant
public
comment
on
the
proposed
policy,
including
over
98,000
comments
opposing
that
proposed
policy
due
to
concerns
about
human
health
risks.
On
May
19,
2005,
EPA
indicated
that
after
consideration
of
the
comments,
it
did
not
intend
to
finalize
the
2003
proposal.
On
July
26,
2005,
Congress
enacted
the
Fiscal
Year
2006
Department
of
the
Interior
and
Related
Agencies
Appropriations
Act
(
P.
L.
109­
54).
Section
203
of
the
Appropriations
Act
provides
that
none
of
the
funds
made
available
in
the
Act
could
be
used
to
finalize,
issue,
implement
or
enforce
the
November
7,
2003
proposed
blending
policy.

In
October
2005,
the
Natural
Resources
Defense
Council
(
NRDC)
and
the
National
Association
of
Clean
Water
Agencies
(
NACWA)
provided
EPA
with
their
joint
proposal
recommending
further
action
that
the
Agency
should
take
regarding
the
blending
issue.
The
approach
recommend
by
NRDC/
NACWA
included
an
interpretation
of
the
bypass
regulation
that
is
significantly
different
from
the
November
7,
2003
proposal,
in
that
it
would
clarify
that
the
bypass
provision
would
apply,
in
all
instances,
to
wet
weather
diversions
at
POTW
treatment
DRAFT
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August
4,
2006
plants
serving
separate
sanitary
sewers.
It
also
included
an
interpretation
that
certain
peak
flow
wet
weather
diversions
could
be
approved
as
anticipated
bypasses.
On
December
22,
2005,
EPA
requested
public
comments
on
a
new
draft
policy
that
reflected
the
approach
recommended
by
the
NRDC
and
NACWA.
See
70
FR
76013
(
December
22,
2005).

III.
Summary
of
Comments
and
Changes
from
the
Draft
Policy
The
December
2005
draft
policy
had
two
major
objectives.
The
first
objective
was
to
provide
EPA's
interpretation
of
how
the
bypass
provision
applies
to
wet
weather
diversions
at
POTW
treatment
plants
serving
sanitary
sewers.
The
second
objective
was
to
outline
a
process
for,
in
very
limited
circumstances,
NPDES
authorities
to
consider
the
appropriateness
of
approving
anticipated
bypasses
in
NPDES
permits
for
discharges
from
POTW
treatment
plants
serving
sanitary
sewers.

EPA
received
156
comments
on
the
December
22,
2005,
draft
policy.
EPA
has
prepared
a
response
to
comment
document
as
part
of
its
consideration
of
these
comments.
A
brief
summary
of
major
comments
and
EPA's
response
are
provided
below.

A.
Interpretation
of
the
Bypass
Provision
Most
commenters
on
the
December
22,
2005
draft
policy
supported
the
interpretation
of
the
bypass
provision
in
the
draft
policy
along
with
the
general
approach
of
the
draft
policy,
indicating
that
they
thought
the
general
framework
of
the
approach
was
workable.
Many
of
the
commenters
supporting
the
draft
policy
indicated
that
they
believed
the
approach
would
reduce
the
health
and
environmental
risks
of
wet
weather
discharges.

Some
commenters
opposed
the
approach
because
they
believed
that
it
was
inappropriate
to
approve
anticipated
bypasses
in
a
permit
because
it
would
allow
insufficiently
treated
sewage
to
be
discharged.
Some
of
these
commenters
indicated
that
they
believed
that
approval
of
bypasses
in
permits
would
`
legitimize'
bypasses.
EPA
disagrees
with
these
comments.

The
policy
strongly
discourages
reliance
on
peak
wet
weather
diversions
around
secondary
treatment
units
as
a
long­
term
wet
weather
management
approach
at
a
POTW
treatment
plant
serving
sanitary
sewer
conveyance
systems.
Under
the
policy,
permits
would
need
to
require
that
all
discharges
from
POTW
treatment
plants
serving
sanitary
sewer
conveyance
systems
meet
effluent
limitations,
including
limits
based
on
secondary
treatment
and
any
more
stringent
limitations
necessary
to
meet
water
quality
standards
under
all
permitted
flow
conditions.
Under
the
policy,
NPDES
agencies
would
evaluate
whether
the
discharges
that
occur
during
bypasses
provided
under
the
NPDES
permit
need
more
stringent
water
quality­
based
effluent
limitations,
and
if
so,
what
those
limits
would
be.
The
policy
promotes
the
highest
possible
treatment
to
the
most
peak
wet
weather
flow
and
seeks
to
minimize
diversions
from
secondary
treatment
to
the
maximum
extent
feasible.
The
policy
recognizes
that
some
POTW
treatment
plants
may,
under
some
wet
weather
conditions,
need
to
divert
a
portion
of
the
incoming
peak
flows
around
their
DRAFT
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August
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2006
secondary
treatment
units
to
prevent
temporary
loss
of
function
of
those
treatment
units.
Currently,
NPDES
permits
for
facilities
experiencing
diversions
may
not
be
requiring
adequate
public
notice,
monitoring
of
discharges
during
bypass,
evaluation
of
alternatives
or
conditions
under
which
a
diversion
may
be
allowed,
and
implementation
of
practices
to
reduce
reliance
on
peak
wet
weather
diversions.

The
peak
flows
policy
is
intended
to
use
the
NPDES
permit
process
to
employ
a
more
comprehensive
regulatory
framework
to
minimize
wet
weather
diversions
to
the
extent
feasible.
The
permitting
process
described
in
the
policy
has
several
key
components,
including
ensuring
the
public
is
informed
and
has
an
opportunity
to
provide
input;
providing
a
format
for
identifying
feasible
alternatives
to
peak
wet
weather
flow
diversions;
and
clarifying
the
use
of
permits
to
ensure
feasible
alternatives
are
implemented.
The
policy
clarifies
that
for
a
facility
with
a
permit
developed
under
today's
policy
in
anticipation
of
bypasses,
there
would
be
a
presumption
applicable
at
the
time
of
permit
renewal
against
the
continued
use
of
diversions
to
manage
peak
wet
weather
flows.

Other
commenters
were
concerned
that
the
`
no
feasible
alternative'
criterion
of
the
bypass
provision
would
be
an
inappropriate
standard
for
blended
discharges
that
meet
permit
limitations
because
it
would
be
overly
stringent
and/
or
unworkably
subjective.
Some
of
these
commenters
indicated
that
they
thought
that
the
lack
of
objective
standards
would
result
in
conflicts
between
States
and
EPA
and
in
national
inconsistency.

EPA
disagrees,
and
today's
policy
retains
the
proposed
interpretation
that
the
bypass
regulation
applies
to
all
peak
flow
diversions
at
POTW
treatment
plants
serving
separate
sanitary
sewers.
The
policy
goes
on
to
provide
an
approach
to
address
anticipated
diversions
at
POTW
treatment
plants
serving
separate
sanitary
sewers
where
blended
discharges
meet
permit
limitations
based
on
secondary
treatment
and
any
more
stringent
limitations
necessary
to
meet
water
quality
standards.
Application
of
the
bypass
regulation,
which
has
been
in
existence
since
1979
1984
,
to
a
POTW
plant
that
meets
limits
based
on
secondary
treatment
is
not
overly
stringent.

EPA
also
disagrees
with
the
comment
that
the
criteria
in
the
bypass
provisions
are
overly
subjective.
Today's
policy
provides
a
framework
for
determining
whether
peak
wet
weather
flow
diversions
should
be
approved
or
denied
in
an
NPDES
permit.
Approval
of
peak
wet
weather
flows
as
anticipated
bypasses
under
the
policy
is
available
only
to
permittees
that
demonstrate
through
a
comprehensive
analysis
to
the
NPDES
authority
that
the
requirements
of
the
bypass
rule
are
met.
This
approach
provides
a
relatively
uniform
national
framework
that
also
takes
into
account
facility
specific
information.
To
implement
this
approach,
EPA
intends
to
work
with
NPDES
permit
authorities
and
others
to
identify
issues
where
additional
technical
guidance
would
be
appropriate.
EPA
will
also
review
all
NPDES
permits
seeking
to
apply
this
policy
to
peak
wet
weather
flow
diversions
to
ensure
consistent
implementation.
for
consistency.

B.
Existing
Permits
DRAFT
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August
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2006
Some
commenters
requested
that
EPA
clarify
how
today's
policy
would
apply
to
existing
NPDES
permits.
Some
of
these
commenters
noted
that
in
the
past,
some
permits
for
discharges
from
POTWs
that
blended
peak
wet
weather
flows
did
not
have
language
in
the
permit
that
specifically
approved
the
wet
weather
diversion
or
blending
of
flows,
although
they
may
have
believed
the
NPDES
authority
was
aware
of
the
practice
at
the
facility
because
the
permittee
described
the
practice
at
the
facility
in
the
permit
application
or
because
the
NPDES
authority
had
other
information.
Some
of
these
commenters
indicated
that
they
believed
that
the
policy
should
not
place
any
community
in
immediate
non­
compliance
merely
because
blending
is
not
specifically
addressed
in
the
permit.

Substantive
response
to
this
comment
necessarily
would
require
evaluation
of
the
language
of
a
specific
permit
and
the
facts
and
circumstances
at
the
particular
facility.
All
NPDES
permits
are
required
to
include
the
standard
permit
conditions
published
at
40
CFR
122.41
(
or
more
stringent
or
analogous
requirements
of
authorized
State
programs),
including
the
bypass
provision.
Thus,
wet
weather
bypasses
or
diversions
at
facilities
with
permits
that
do
not
specifically
approve
bypasses
at
the
facility
are
prohibited
and
the
NPDES
authority
may
enforce
such
conditions
unless
the
criteria
of
40
CFR
122.41(
m)(
4)
were
met.
Where
the
permittee
demonstrates
that
the
criteria
at
40
CFR
122.41(
m)(
4)
have
been
met,
EPA
will
not
bring
an
enforcement
action
for
the
bypass.
Where
the
status
of
wet
weather
bypasses
or
diversions
at
a
facility
is
not
clear
under
an
existing
permit,
the
POTW
should
seek
clarification
from
the
NPDES
authority
on
the
legal
status
of
such
diversions
(
including
the
extent
to
which
they
may
be
within
the
scope
of
the
authorization
of
section
402(
k)
of
the
CWA)
covered
by
EPA's
April
11,
1995
policy
on
the
scope
of
permit
authroization
(
permit­
as­
a­
shield))
and
the
appropriate
next
steps
to
expeditiously
implement
this
policy.

C.
Requests
for
Clarifications
The
December
22,
2005,
draft
policy
would
not
have
applied
to
a
variety
of
situations,
including
discharges
or
overflows
prior
to
the
headworks
of
the
POTW
treatment
plant;
dry
weather
diversions;
diversions
around
primary
or
tertiary
treatment
units;
or
diverted
flow
that
is
not
recombined
with
flow
from
the
secondary
treatment
units
prior
to
discharge.
Some
commenters
requested
that
EPA
clarify
whether
the
bypass
provision
applied
to
diversions
around
advanced
treatment
or
tertiary
treatment
units.
Some
of
these
commenters
noted
that
some
types
of
advanced
treatment
or
tertiary
treatment
units
are
biological
treatment
units,
and
urged
that
the
bypass
provision
should
not
apply
to
treatment
units
that
are
operated
in
manner
to
meet
water
quality­
based
effluent
limitations.

In
response,
EPA
reiterates
that
today's
policy
focuses
on
peak
wet
weather
diversions
at
POTW
treatment
plants
serving
separate
sanitary
sewer
conveyance
systems.
Today's
policy
identifies
a
number
of
situations
where
the
policy
does
not
apply
and
approvals
of
anticipated
bypasses
would
not
be
appropriate.
The
policy
does
not
apply
to
discharges
or
overflows
prior
to
the
headworks
of
a
POTW
treatment
plant;
or
to
dry
weather
diversions;
or
to
diversions
around
primary
or
diversions
that
are
not
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August
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2006
recombined
with
flow
from
the
secondary
treatment
units
prior
to
discharge;
or
to
treatment
plants
(
municipal
or
industrial)
other
than
those
serving
separate
sanitary
sewer
collection
systems;
and
does
not
address
diversions
around
tertiary
treatment
units
that
are
separate
from
secondary
treatment
units.
EPA
encourages
the
use
and
permitting
of
technologies
that
are
more
advanced
than
or
supplementary
to
secondary
treatment
where
they
produce
a
higher
quality
effluent.
The
policy
indicates
that
the
NPDES
authority
should
take
into
consideration
situations
where
a
POTW
treatment
plant
is
using,
or
plans
to
use,
technology
that
is
more
effective
in
baseline
pollutant
removal
than
is
required
to
meet
secondary
treatment­
based
permit
limits.

Some
commenters
noted
that
in
the
discussion
of
approved
anticipated
bypasses
in
the
December
22,
2005
draft
policy,
EPA
only
identified
the
`
no
feasible
alternative'
criterion
of
the
bypass
and
inappropriately
excluded
the
other
criteria
that
must
be
considered.
EPA
agrees
with
the
commenter
because
the
regulation
is
clear
about
its
three
criteria.
The
bypass
provision
at
40
CFR
122.41(
m)(
4)(
ii)
provides
that
the
Director
of
the
NPDES
program
may
approve
an
anticipated
bypass,
after
considering
its
adverse
effects,
if
the
Director
determines
that
it
will
meet
the
three
conditions
listed
in
the
regulation,
specifically
that
1)
bypass
was
unavoidable
to
prevent
loss
of
life,
personal
injury,
or
severe
property
damage;
2)
there
were
no
feasible
alternatives
to
the
bypass;
and
3)
the
permittee
submitted
the
required
notices.
The
policy
has
been
corrected
to
clarify
that
each
of
the
three
criteria
in
the
bypass
provision,
plus
the
consideration
of
adverse
effects,
would
need
to
be
implemented
as
contemplated
under
the
policy.

Today's
policy
provides
a
clarification
on
a
matter
that
was
not
addressed
in
the
December
2005
draft
policy
upon
which
EPA
invited
public
comment.
The
December
2005
draft
proposed
an
interpretation
of
the
term
"
no
feasible
alternatives"
in
40
CFR
122.41(
m)(
4)(
i)(
B)
as
it
would
apply
to
the
treatment
of
certain
peak
flow
wet
weather
discharges
as
anticipated
bypasses
under
40
CFR
122.41(
m)(
4)(
ii).
Specifically,
the
interpretation
addressed
that
flow
that
is
anticipated
to
exceed
the
peak
flow
capacity
of
the
secondary
treatment
unit(
s),
and
to
meet
the
other
bypass
criteria,
even
after
implementation
of
the
feasible
technologies
and
approaches
identified
via
the
process
outlined
in
the
policy.
For
that
flow,
as
in
the
draft
policy,
today's
policy
provides
that
a
permitting
authority
could
determine
that
the
conditions
of
122.41(
m)(
4)(
ii),
including
the
need
to
show
that
no
feasible
alternatives
were
available,
had
been
satisfied.
The
policy
provides
that,
for
those
flows,
the
bypass
provision
allows
for
explicit
approval
as
an
anticipated
bypass
in
the
permit.

Based
on
a
sentence
in
the
December
2005
draft
policy,
a
commenter
asked
for
clarification
on
how
EPA
intended
to
treat
those
peak
flow
diversions
that
occurred
while
the
permittee
was
implementing
the
feasible
technologies
and
approaches
in
accordance
with
the
permit.
The
draft
policy
included
a
sentence
that
read,
"
In
NPDES
permits
with
such
implementation
schedules,
the
approval
of
any
anticipated
bypass
would
be
contingent
upon
the
permittee's
performance
of
the
implementation
schedule."
The
commenter
sought
clarification
on
the
status
of
anticipated
bypasses
that
occur
during
and
prior
to
completion
of
the
implementation
schedule,
particularly
for
those
flows
that
would
not
need
to
occur
after
DRAFT
7
August
4,
2006
implementation
of
the
feasible
alternatives
required
in
the
permit.
Today's
policy
provides
that
clarification.

The
diversions
to
which
the
comment
refers
would
not
fall
within
the
Agency's
interpretation
of
section
122.41(
m)(
4)
that
supports
permit­
based
approval
of
anticipated
bypass.
Such
diversions
that
occur
where
feasible
alternatives
exist
would
not
meet
the
requirement
of
122.41(
m)(
4)(
i)(
B)
that
"
there
were
no
feasible
alternatives
to
the
bypass."
Therefore,
they
would
not
be
approvable
in
a
permit
as
anticipated
bypasses
under
122.41(
m)(
4)(
ii).
Under
today's
policy,
however,
where
a
record
is
created
that
contains
a
comprehensive
evaluation
of
feasible
alternatives
(
i.
e.,
using
the
process
outlined
in
the
policy),
and
the
permitting
authority,
imposes
permit
conditions
requiring
such
alternatives
to
be
implemented
as
expeditiously
as
is
feasible,
EPA
believes
the
permitting
process
provides
an
appropriate
framework
for,
as
a
matter
of
sound
public
policy,
requiring
implementation
of
those
alternatives
and
moving
the
facility
forward
towards
improved
environmental
and
system
performance.
Accordingly,
EPA
will
treat
as
a
low
enforcement
priority
those
bypasses
that
occur
while
the
POTW
is
adhering
to
the
implementation
schedule
for
feasible
alternatives
and
any
other
permit
conditions
designed
to
implement
the
bypass
rule.
While
a
POTW
is
adhering
to
the
implementation
schedule
for
feasible
alternatives
and
any
other
permit
conditions
designed
to
implement
the
bypass
rule,
EPA
recognizes
that
the
permittee's
actions
will
be
consistent
with
this
policy
and
its
objectives
and
will
therefore
act
accordingly.

D.
Other
Issues
A
number
of
commenters,
including
several
State
NPDES
authorities,
raised
concerns
about
the
potential
burdens
of
the
utility
analysis
on
small
municipalities.
Some
of
these
commenters
suggested
that
EPA
should
simplify
the
utility
analysis
discussed
in
the
policy
for
small
municipalities.
In
response,
EPA
believes
that
there
is
sufficient
flexibility
in
the
outline
for
the
utility
analysis
in
the
policy
to
allow
the
permittee
to
tailor
its
utility
analysis
to
the
size
and
complexity
of
its
sewage
collection
and
treatment
system.

IV.
Policy
Many
municipalities
currently
experience
situations
in
which
high
peak
influent
flows
during
significant
wet
weather
events
exceed
the
treatment
capacity
of
existing
secondary
treatment
units.
In
these
situations,
wet
weather
flows
are
sometimes
diverted
around
secondary
treatment
units.
The
diverted
flows
are
then
either
discharged
directly
to
receiving
waters
or
recombined
with
the
flows
from
the
secondary
treatment
units
prior
to
discharge.
EPA
interprets
existing
regulations,
specifically,
the
"
bypass"
regulation
at
40
CFR
122.41(
m),
to
apply
in
both
circumstances
and
is
restating
this
interpretation.
Today's
policy
focuses
on
the
second
circumstance,
specifically,
peak
flow
wet
weather
diversions
that
are
recombined
prior
to
discharge.
Today's
policy
provides
an
interpretation
of
the
bypass
provision
under
which
diversions
that
would
remain
after
full
implementation
of
all
feasible
alternatives
and
meet
other
requirements
of
the
bypass
rule
can
be
approved
in
a
NPDES
permit.
DRAFT
8
August
4,
2006
Today's
policy
applies
only
to
peak
wet
weather
diversions
around
secondary
treatment
units
that
occur
at
publicly
owned
treatment
works
(
POTW)
treatment
plants
that
serve
separate
sanitary
sewer
systems.
(
EPA
previously
explained
the
processes
by
which
wet
weather
diversions
can
be
approved
in
NPDES
permits
for
POTW
treatment
plants
serving
combined
sewer
systems
in
the
1994
CSO
Policy,
59
Fed
Reg.
18,693­
18,694
(
April
19,
1994).)
Nothing
in
this
policy
addresses
the
requirements
for
POTW
treatment
plants
serving
combined
sewer
systems.
Neither
today's
policy
nor
the
CSO
Policy
addresses
the
appropriateness
of
approval
of
anticipated
bypass
outside
of
the
municipal
peak
wet
weather
flow
context.

In
recent
years
there
has
been
confusion
regarding
the
regulatory
status
of
peak
wet
weather
flow
diversions
around
secondary
treatment
units
at
POTW
treatment
plants
serving
separate
sanitary
sewer
conveyance
systems.
In
some
cases,
such
diversions
have
been
considered
a
bypass
and
held
to
the
criteria
of
the
NPDES
bypass
regulation
at
40
C.
F.
R.
122.41(
m).
In
other
cases,
structures
for
the
diversion
of
peak
wet
weather
flows
around
secondary
treatment
units
at
POTW
treatment
plants
have
been
constructed,
and
in
even
fewer
cases
the
diversions
have
been
reflected
in
permits,
without
consideration
of
the
bypass
regulation
criteria.
While
EPA
recognizes
that
peak
wet
weather
flow
diversions
around
secondary
treatment
units
at
POTW
treatment
plants
serving
separate
sanitary
sewer
conveyance
systems
may
be
necessary
in
some
circumstances
to
prevent
temporary
loss
of
function
of
secondary
treatment
units,
the
Agency
and
stakeholders
have
been
concerned
for
some
time
that
peak
wet
weather
flow
diversions
could
have
adverse
environmental
or
public
health
impacts
because
of
the
higher
expected
pollutant
load
of
diverted
flows.

Accordingly,
EPA
strongly
discourages
reliance
on
peak
wet
weather
flow
diversions
around
secondary
treatment
units
as
a
long­
term
wet
weather
management
approach
at
a
POTW
treatment
plant
serving
separate
sanitary
sewer
conveyance
systems.
Such
diversions
should
be
minimized
to
the
maximum
extent
feasible
taking
into
account
the
factors
discussed
in
this
policy.
EPA
anticipates
that,
over
time,
the
need
to
undertake
peak
wet
weather
flow
diversions
at
POTW
treatment
plants
serving
separate
sanitary
sewer
conveyance
systems
can
be
eliminated
from
most
systems
in
a
variety
of
ways,
such
as
by
enhancing
storage
and
treatment
capacity
and
reducing
sources
of
peak
wet
weather
flow
volume.
EPA
expects
that
aggressive
efforts
by
POTW
treatment
plants
operators
in
consultation
with
NPDES
authorities
can:
lead
to
dramatic
reductions
in
the
volume
and
duration
of
peak
wet
weather
flows;
in
most
cases
completely
phase
out
diversions;
and
improve
the
treatment
and
quality
of
peak
wet
weather
flow
discharges.
EPA
also
believes
that
the
involvement
of
the
general
public
will
improve
the
assessment
of
various
options
to
minimize
peak
wet
weather
flow
diversions.

Today's
policy
applies
only
to
NPDES
permits
issued
after
the
date
of
the
policy.
In
addition,
the
policy
is
limited
in
scope;
it
only
applies
(
1)
to
peak
flow
wet
weather
diversions,
(
2)
from
POTW
plants,
(
3)
that
serve
separate
sewer
collection
systems,
and
(
4)
that
recombine
the
diverted
peak
flows
prior
to
discharge.
The
policy
describes
the
circumstances
under
which
anticipated
bypasses
at
these
plants
could
be
either
approved
or
treated
as
approved
denied
as
a
DRAFT
9
August
4,
2006
result
of
the
NPDES
permitting
process.
The
policy
identifies
the
content
of
an
appropriate
utility
analysis
that
POTWs
should
submit
with
their
permit
applications
to
facilitate
development
of
appropriate
permit
conditions.
The
policy
outlines
the
decision
process
involved
in
reviewing
a
utility
analysis
and
determining
whether
approval
of
peak
wet
weather
flow
diversions
is
appropriate..

EPA's
NPDES
regulations
prohibit
bypass
 
defined
as
the
intentional
diversion
of
waste
streams
from
any
portion
of
the
treatment
facility
 
except
in
very
limited
circumstances.
Section
122.41(
m)(
4)(
i)
prohibits
bypass,
and
EPA
or
the
NPDES
authority
may
take
enforcement
action
against
a
permittee
for
bypass,
unless:

(
A)
The
bypass
was
unavoidable
to
prevent
loss
of
life,
personal
injury,
or
severe
property
damage;

(
B)
There
were
no
feasible
alternatives
to
the
bypass,
such
as
the
use
of
auxiliary
treatment
facilities,
retention
of
untreated
wastes,
or
maintenance
during
normal
periods
of
equipment
downtime;
and
(
C)
The
permittee
submitted
required
notices.

Under
section
122.41(
m)(
4)(
ii),
the
Director
may
approve
an
anticipated
bypass,
after
considering
its
adverse
effects,
if
the
Director
determines
that
the
bypass
will
meet
the
criteria
listed
in
subsection
(
m)(
4)(
i).
Today's
policy
describes
the
circumstances
under
which
anticipated
bypasses
that
reflect
the
full
implementation
of
feasible
alternatives
would
be
approved
for
the
purposes
of
section
122.41(
m)(
4)(
ii)
in
the
limited
context
of
this
policy.

Today's
policy
does
not
change
EPA's
interpretation
of
the
bypass
regulation
as
applied
in
United
States
v.
City
of
Toledo,
Ohio,
63
F.
Supp.
2d
834
(
N.
D.
Ohio
1999).
Thus,
POTW
treatment
plants
that
fail
to
move
forward
to
meet
their
obligations
under
this
policy
remain
subject
to
the
full
scope
of
enforcement
remedies
for
any
violations.
Furthermore,
nothing
in
today's
policy
provides
a
basis
to
reopen
existing
enforcement
remedies
(
e.
g.,
orders,
decrees,
or
agreements)
that
address
measures
to
reduce
and/
or
eliminate
peak
flow
wet
weather
diversions.
The
utility
analysis
described
below,
however,
should
be
useful
to
facilitate
resolution
of
any
pending
matters
that
address
such
peak
flow
diversions.

Policy
Applicable
to
Peak
Flow
Wet
Weather
Diversions
at
POTWs
Serving
Separate
Sanitary
Sewer
Systems
This
policy
explains
how
the
NPDES
authority
should
determine
whether
anticipated
peak
wet
weather
flow
diversions,
at
POTW
treatment
plants
serving
separate
sanitary
sewer
collection
systems,
which
are
recombined
with
flow
from
the
secondary
treatment
units
prior
to
discharge,
should
be
approved
or
denied
under
40
CFR
122.41(
m)(
4)(
ii).
Under
today's
policy,
if
the
NPDES
authority
determines,
based
on
a
utility
analysis
described
in
today's
policy
and
DRAFT
10
August
4,
2006
any
other
available
information,
that
the
criteria
of
section
122.41(
m)(
4)(
i)
will
be
met
and,
if
the
permit
includes
any
more
stringent
limits
necessary
to
meet
water
quality
standards
(
including
when
an
anticipated
bypasses
occurs
(
i.
e.,
in
order
to
take
into
account
its
adverse
effects)),
then
the
NPDES
authority
may
provide
for
approval
of
anticipated
bypass
of
peak
wet
weather
flow
diversions
around
secondary
treatment
units
through
the
NPDES
permitting
process
as
described
below.

This
policy:

o
Explains
how
EPA
intends
to
apply
the
bypass
regulation,
specifically,
40
CFR
122.41(
m)(
4),
to
peak
wet
weather
flow
diversions
around
secondary
treatment
units
at
POTW
treatment
plants
serving
separate
sanitary
sewer
systems
where
the
diverted
flow
is
recombined
with
flow
from
the
secondary
treatment
units
prior
to
discharge;
o
Describes
a
utility
analysis
and
relevant
steps
of
the
permit
review
process;
o
Identifies
a
framework
within
the
permit
process
through
which
the
criteria
of
the
bypass
rule
can
be
evaluated
for
determining
whether
anticipated
peak
flow
wet
weather
flow
diversions
at
such
POTW
treatment
plants
serving
separate
sanitary
sewer
systems
should
to
which
this
policy
applies
could
be
approved
as
anticipated
bypasses;
o
Promotes
use
of
measures
to
provide
the
highest
possible
treatment
to
the
greatest
possible
peak
wet
weather
flow;
and
o
Promotes
reporting
and
public
notification
of
peak
wet
weather
diversion
events.

The
policy
is
limited
in
scope.
The
policy:

o
Does
not
apply
to
discharges
or
overflows
prior
to
the
headworks
of
a
POTW
treatment
plant;
or
to
dry
weather
diversions;
or
to
diversions
around
primary
or
diversions
that
are
not
recombined
with
flow
from
the
secondary
treatment
units
prior
to
discharge;
or
to
treatment
plants
(
municipal
or
industrial)
other
than
those
serving
separate
sanitary
sewer
collection
systems;
and
o
Does
not
address
diversions
around
tertiary
treatment
units
that
are
separate
from
secondary
treatment
units.

A
combination
of
approaches
can
be
used
to
achieve
the
goals
of
this
policy.
These
approaches
include:

o
ensuring
full
utilization
of
available
secondary
treatment
capacity;
o
reducing
infiltration
and
inflow
(
I/
I);
o
maximizing
the
use
of
the
collection
system
for
storage;
o
providing
off­
line
storage;
and
o
enhancing
secondary
treatment
capacity.

In
cases
where
these
approaches,
alone
or
in
combination,
are
not
sufficient
to
enable
a
POTW
treatment
plant
to
process
its
peak
wet
weather
flows
through
its
secondary
treatment
DRAFT
11
August
4,
2006
units,
a
POTW
treatment
plant
operator
may
have
no
feasible
alternative
to
peak
wet
weather
flow
diversions
around
secondary
treatment
units.
This
policy
sets
forth
a
process
for
determining
whether
or
not
such
feasible
alternatives
to
peak
wet
weather
flow
diversions
exist.
If
the
NPDES
authority
determines
that
there
are
no
feasible
alternatives
to
peak
wet
weather
flow
diversions
around
secondary
treatment
units
at
the
treatment
plant
using
the
analysis
set
forth
in
this
policy,
and
the
other
conditions
of
the
bypass
regulation
are
met,
including
a
showing
that
"
the
bypass
was
unavoidable
to
prevent
loss
of
life,
personal
injury,
or
severe
property
damage"
(
i.
e.,
wash
out),
then
the
NPDES
authority
may
approve
peak
wet
weather
flow
diversions
around
secondary
treatment
units
at
a
POTW
treatment
plant
serving
separate
sanitary
sewer
conveyance
systems
as
an
anticipated
bypass
in
accordance
with
40
CFR
122.41(
m).
The
only
flow
that
can
be
approved
as
an
anticipated
bypass
around
secondary
treatment
units
is
flow
that
is
anticipated
to
exceed
the
peak
flow
capacity
of
the
secondary
treatment
unit(
s)
and
that
would
cause
severe
property
damage,
i.
e.,
wash
out
of
that
unit,
even
after
implementation
of
the
feasible
technologies
and
approaches
identified
via
the
process
outlined
in
this
policy.
The
use
of
diversions
around
secondary
treatment
units
at
POTW
treatment
plants
serving
separate
sanitary
sewer
conveyance
systems
to
manage
peak
wet
weather
flows
is
not
necessary
in
many
cases
and
cannot
be
approved
at
flow
levels
below
for
diversions
as
to
which
if
feasible
alternatives
are
identified
for
those
diversions
through
the
analysis
described
herein
or
if
the
other
elements
of
the
bypass
regulation
are
not
met.

If
feasible
alternatives
to
avoid
all
anticipated
bypasses
are
available
during
the
permit
term,
such
that
there
will
be
no
need
for
diversions
by
or
before
the
end
of
the
permit
term,
then
approval
in
the
permit
under
section
122.41(
m)(
4)(
ii)
would
not
be
appropriate,
rather
the
permit
would
only
address
the
requirements
to
implement
the
alternatives,
including
a
schedule,
as
discussed
below.

Where
the
NPDES
authority
identifies
feasible
alternatives
to
the
diversion,
the
permit
is
to
include,
based
on
40
CFR
122.43(
a),
an
implementation
schedule
with
specific
dates
for
implementing,
as
quickly
as
feasible,
the
technologies,
upgrades
and
approaches
identified
and
estimates
of
the
associated
flow
volumes.
This
implementation
schedule
would
be
considered
a
permit
condition
as
opposed
to
a
schedule
of
compliance
under
40
CFR
122.47.

Review
of
available
feasible
alternatives
may
result
in
a
POTW
identifying
technologies,
upgrades,
or
approaches
that
reduce
peak
wet
weather
flow
diversions.
As
these
technologies,
practices,
or
improvements
are
implemented,
diversions
will
typically
occur
at
flow
levels
lower
than
diversions
that
would
no
longer
occur
after
full
implementation
of
alternatives.
These
diversions
are
not
approved
as
anticipated
bypasses
at
the
time
of
permit
issuance.
However,
the
permitting
authority's
identification
of
an
implementation
schedule
in
the
permit
documents
the
available
feasible
alternatives
to
reduce
peak
wet
weather
flow
diversions.
Accordingly,
EPA
will
treat
as
a
low
enforcement
priority
those
bypasses
that
occur
while
While
the
POTW
is
adhering
to
the
implementation
schedule
for
feasible
alternatives
and
any
other
permit
conditions
designed
to
implement
the
bypass
rule,
EPA
recognizes
that
the
permittee's
actions
will
be
consistent
with
this
policy
and
its
objectives
and
will
therefore
act
accordingly.
DRAFT
12
August
4,
2006
In
the
POTW
NPDES
permits
with
such
implementation
schedules
developed
pursuant
to
today's
policy,
the
approval
of
any
anticipated
bypass
would
be
contingent
upon
the
permittee's
performance
of
the
interim
milestones
in
the
implementation
schedule.
It
is
therefore
important
that
the
permitting
authority
assure
that
the
implementation
schedule
in
the
permit
specifically
identifies
the
feasible
technologies,
upgrades,
and
approaches
(
i.
e.,
measures
and
controls
to
be
implemented
(
and
associated
flow
volumes))
to
reduce
peak
flows
as
quickly
as
is
feasible
and
that
the
schedule
requires
implementation
of
those
alternatives
as
quickly
as
is
feasible.
The
regulations
at
40
CFR
122.43(
a)
provide
for
development
and
inclusion
of
such
conditions
in
the
permit.

A
thoughtful
public
planning
process
at
the
local
level
is
important
to
development
and
implementation
of
feasible
alternatives
that
minimize
or
eliminate
overflows
in
the
collection
system,
minimize
I/
I
into
the
collection
system,
maximize
treatment
of
all
flows,
and
improve
wet
weather
flow
management.
EPA
recommends
that
POTW
treatment
plants
operators
work
with
their
NPDES
authorities
and
local
communities
to
proactively
minimize
peak
wet
weather
influent
flow
volume
and
improve
effluent
quality,
reduce
the
frequency
and
volume
of
diversion
events,
and
improve
the
structural
integrity
and
capacity
of
collection
systems
and
the
reliability
of
POTW
treatment
plants.

On
permit
renewal,
the
presumption
by
the
NPDES
authority
would
be
against
the
utility's
continued
use
of
diversions
to
manage
peak
wet
weather
flows.
This
presumption
could
be
overcome
by
the
POTW
treatment
plant
operator
demonstrating
to
the
satisfaction
of
the
NPDES
authority
that
there
are
no
feasible
alternatives
to
continued
diversions
and
that
the
other
criteria
of
the
bypass
rule
are
met.
Such
a
demonstration
should
include
updating
and
submitting
or
resubmitting
the
utility
analysis
described
in
this
policy,
ensuring
that
the
submission
identifies
any
changes
at
the
facility,
progress
made
in
performance
of
the
implementation
schedule
and
in
peak
wet
weather
flow
reduction
and
treatment,
and
any
other
information
available
relevant
to
the
need
for
diversions
and
the
implications
of
re­
approving
their
use.
Timely
permit
renewals
for
facilities
that
employ
peak
wet
weather
diversions
around
secondary
treatment
units
at
the
POTW
treatment
plant
should
be
a
priority.
Because
of
the
importance
of
regular
analysis
of
the
ongoing
need
to
utilize
diversions
at
a
particular
facility,
NPDES
permits
for
facilities
that
employ
or
seek
to
employ
peak
wet
weather
diversions
around
secondary
treatment
units
at
their
treatment
plant
should
be
timely
renewed
rather
than
administratively
continued.

The
determination
of
what
constitutes
a
"
peak
wet
weather
event,"
during
which
the
use
of
a
peak
wet
weather
diversion
could
be
approved
as
an
anticipated
bypass
under
today's
policy,
will
be
a
site­
specific
determination.
NPDES
authorities
should
not
approve
as
anticipated
bypasses
diversions
at
POTW
treatment
plants
serving
separate
sanitary
sewer
conveyance
systems
during
routine
rain
events.
Approved
anticipated
bypasses
should
be
limited
to
those
diversions
that
are
necessary
due
to
extreme
precipitation
events,
which
would
be
determined
on
a
community­
specific
basis.
EPA
also
cannot
reasonably
estimate
or
endorse
an
`
acceptable'
DRAFT
13
August
4,
2006
number
of
anticipated
bypasses
(
e.
g.,
fixed
number
per
fixed
time
period).
Such
a
one­
size­
fitsall
approach
would
not
recognize
the
site­
specific
nature
of
peak
wet
weather
diversions
and
could
lead
to
excessive
use
of
diversions
in
some
communities.
Rather,
it
is
EPA's
intention
through
this
policy
to
provide
a
framework
according
to
which
POTW
treatment
plants
operators,
NPDES
authorities,
and
the
general
public
can
evaluate
what
constitutes
a
peak
wet
weather
event
for
a
POTW
treatment
plant
for
which,
in
the
specified
context
described
in
this
policy,
the
requirements
of
the
bypass
rule
are
met
and
remaining
peak
wet
weather
diversions
could
be
approved
as
anticipated
bypasses.
Among
the
factors
that
should
influence
that
evaluation
are
the
history
of
past
diversions
at
a
particular
facility
(
and
the
causes
for
the
diversions),
facility­
specific
opportunities
for
eliminating
or
reducing
diversions,
and
future
considerations,
such
as
emerging
technical
innovations.

In
order
to
minimize
potential
adverse
effects
of
diversions
around
secondary
treatment
even
for
peak
wet
weather
diversions
at
a
POTW
treatment
plant
subject
to
this
policy,
additional
technologies
(
e.
g.,
providing
supplemental
biological
or
physical/
chemical
treatment)
and
approaches
should
be
used
to
maximize
treatment
of
diverted
flows
where
feasible.
EPA
does
not
support
NPDES
authorities'
approval
of
peak
wet
weather
diversions
around
secondary
treatment
units
at
POTW
treatment
plants
when
the
peak
flows
are
largely
due
to
poor
collection
system
maintenance
or
the
inadequate
investment
in
or
upgrades
to
treatment
capacity.

Under
this
policy,
NPDES
authorities
and
POTW
treatment
plants
operators
should
ensure
that
all
flows
that
will
be
diverted
from
the
secondary
treatment
units
in
peak
wet
weather
events
receive
a
minimum
of
primary
treatment
and
any
supplemental
treatment
or
technology
that
is
determined
to
be
feasible.
All
discharges
from
POTW
treatment
plants
serving
separate
sanitary
sewer
conveyance
systems
must
meet
effluent
limitations,
including
the
85
percent
removal
requirement
(
unless
the
discharge
from
the
POTW
treatment
plant
meets
the
requirements
of
40
CFR
133.103(
d)
(
less
concentrated
influent
wastewater
for
separate
sanitary
sewers))
and
other
secondary
treatment
requirements
and
any
more
stringent
limitations
necessary
to
meet
water
quality
standards,
including
all
applicable
state
anti­
degradation
policies.
Failure
to
meet
effluent
limitations
is
a
permit
violation.
Failure
to
comply
with
the
schedule
for
implementing
feasible
alternatives
as
specified
in
the
POTW's
NPDES
permit
is
also
a
permit
violation.
NPDES
authorities
should
ensure
that
discharges
from
the
facility,
including
discharges
when
diverting,
do
not
cause,
have
the
reasonable
potential
to
cause,
or
contribute
to
non­
attainment
of
any
water
quality
standards,
and
if
so,
must
include
more
stringent
water
quality­
based
effluent
limitations
in
the
permit.

EPA
recognizes
that
some
POTW
treatment
plants
may
be
implementing
technologies
that
are
more
advanced
than
or
supplementary
to
secondary
treatment.
The
Agency
encourages
the
use
and
permitting
of
such
technologies
(
e.
g.,
membrane,
tertiary)
where
they
produce
a
higher
quality
effluent.
In
the
case
where
a
POTW
treatment
plant
is
using,
or
plans
to
use,
technology
that
is
more
effective
in
baseline
pollutant
removal
than
is
required
to
meet
secondary
treatment­
based
permit
limits,
the
NPDES
authority
should
take
that
improved
baseline
performance
into
consideration
when
determining
whether
peak
flow
diversions
at
a
DRAFT
14
August
4,
2006
POTW
treatment
plant
are
approved
and
under
what
conditions.

No
Feasible
Alternatives
Analysis
Process
A
permitting
authority's
determination,
under
this
policy,
as
to
whether
or
not
there
are
feasible
alternatives
to
peak
wet
weather
diversions
at
a
POTW
treatment
plant
serving
a
separate
sanitary
sewer
collection
system
should
be
made
using
the
following
inputs
and
criteria,
which
are
derived
from
40
CFR
122.41(
m)(
4)(
i)(
A)­(
C)
and
40
CFR
122.21(
j).
At
the
time
of
application
for
an
NPDES
permit
(
new,
modification,
or
renewal):

1.
POTW
treatment
plants
operators
seeking
approval
of
peak
wet
weather
diversions
at
a
treatment
plant
as
an
anticipated
bypass
should
submit
a
comprehensive
analysis
(
utility
analysis)
to
the
NPDES
authority
that:
a.
documents
current
treatment
plant
design
capacity
for
all
treatment
units,
the
maximum
flow
that
can
be
processed
through
those
units,
and
the
feasibility
of
increasing
such
treatment
capacity
and
related
costs;
b.
estimates
the
frequency,
duration,
and
volume
of
current
wet
weather
diversions,
and
evaluates
alternatives
to
reduce
the
frequency,
duration,
and
volume
of
such
occurrences
and
related
costs;
c.
estimates
future
peak
wet
weather
flows
based
upon
information
such
as
predicted
climatic
conditions,
anticipated
dry
weather
flows,
projected
treatment
plant
and
collection
system
changes
(
e.
g.,
upgrades,
extensions,
deterioration),
and
evaluates
options
for
reducing
diversions
based
on
these
variables;
d.
assesses
existing
storage
within
the
collection
system
or
on­
site
and
options
for
enhanced
utilization
or
expansion
(
taking
into
account
physical
and
technological
considerations)
of
storage
to
reduce
the
frequency,
duration,
and
volume
of
peak
wet
weather
diversions,
and
the
related
costs;
e.
assesses
other
ways
to
reduce
peak
wet
weather
flow
volumes,
such
as
limiting
collection
system
extensions
and
slug
loadings
from
indirect
dischargers,
or
water
conservation
or
green
infrastructure
techniques;
f.
evaluates
technologies
,
such
as
supplemental
biological
treatment,
physical/
chemical
treatment,
(
e.
g.,
ballasted
flocculation,
deep
bed
filtration,
or
membrane
technology)
that
are
or
could
be
used
to
provide
additional
treatment
to
peak
wet
weather
flows
or
peak
wet
weather
diversions
at
the
POTW
treatment
plant
and
the
costs
of
implementing
those
technologies;
g.
evaluates
the
extent
to
which
the
permittee
is
maximizing
its
ability
to
reduce
I/
I
throughout
the
entire
collection
system
(
i.
e.,
not
only
the
portions
operated
by
the
utility,
but
also
portions
operated
by
any
municipal
satellite
community),
including
the
use
of
existing
legal
authorities,
potential
improvements
in
the
timing
or
quality
of
such
efforts,
and
options
for
obtaining
or
expanding
legal
authorities
to
reduce
I/
I
from
satellite
collection
systems;
h.
evaluates
peak
flow
reductions
obtainable
through
implementation
of
existing
capacity,
management,
operations,
and
maintenance
(
C­
MOM)
programs
and
potential
DRAFT
15
August
4,
2006
improvements
in
the
timing
or
enhancement
of
those
programs
and
the
related
costs;
or,
if
no
such
program
exists,
reductions
obtainable
through
the
development
and
implementation
of
a
C­
MOM
program
and
the
related
costs;
i.
assesses
the
community's
ability
to
fund
the
peak
wet
weather
flow
improvements
discussed
in
the
utility
analysis,
taking
into
consideration:
current
sewer
rates,
planned
rate
increases,
other
potential
sources
of
federal,
state,
or
local
funds,
and
the
costs,
schedules,
anticipated
financial
impacts
to
the
community
of
other
planned
water
and
wastewater
expenditures
and
other
relevant
factors,
impacting
the
utility's
rate
base,
using
as
a
guide
EPA's
CSO
Guidance
for
Financial
Capability
Assessment
and
Schedule
Development,
EPA
832­
B­
97­
004;
j.
proposes
a
protocol
for
monitoring
the
total
volume
diverted,
and
the
duration
of
each
peak
wet
weather
diversion
event,
and
a
protocol
monitoring
of
the
recombined
flow
at
least
once
daily
during
diversions
for
all
parameters
for
which
the
POTW
treatment
plant
has
daily
effluent
limitations
or
other
requirements
(
e.
g.,
monitoring
only
requirements)
and
representative
monitoring
for
other
monitoring
requirements
of
the
permit;
and
k.
projects
the
POTW
treatment
plant
effluent
improvements
and
other
improvements
in
collection
system
and
treatment
plant
performance
that
could
be
expected
should
the
technologies,
practices,
and/
or
other
measures
discussed
in
the
utility
analysis
be
implemented.

2.
For
any
POTW
treatment
plant
operator
seeking
approval
through
the
NPDES
permitting
process
for
an
anticipated
bypass
under
this
policy,
the
NPDES
authority
should:

a.
make
the
utility
analysis
publicly
available
with
other
draft
permit
information
for
public
review
and
comment;
b.
review
and
evaluate
the
utility
analysis
and
require
measures
to
be
undertaken
to
provide
the
highest
possible
treatment
to
the
greatest
possible
peak
wet
weather
flow,
taking
into
account
the
full
range
of
economic,
environmental,
public
health,
and
engineering
considerations;
c.
based
on
review
of
a
utility
analysis
and
other
relevant
information,
approve
or
deny
the
peak
wet
weather
diversions
based
on
the
determination
of
whether:
there
are
feasible
alternatives
to
those
diversions
using
the
analysis
set
forth
in
this
policy;
the
other
provisions
of
the
bypass
regulation
are
met;
and
effluent
limitations
will
be
met
at
all
times
under
all
flow
conditions;
d.
develop
and
incorporate
conditions
in
the
permit,
including
an
implementation
schedule,
that
require
the
POTW
to
implement
the
identified
feasible
technologies
and
approaches
to
reduce
peak
flows
as
quickly
as
the
analysis
indicates
is
feasible;
e.
include
a
permit
provision
requiring
any
POTW
treatment
plant
operator
that
has
an
anticipated
bypass
to
provide
prior
notice
upon
knowledge
of
the
need
for
a
peak
wet
weather
diversion
event
to
the
NPDES
authority
consistent
with
40
CFR
122.41(
m)(
3);
f.
include
a
permit
provision
requiring
the
operator
of
any
POTW
treatment
plant
that
has
an
anticipated
bypass
to
monitor
the
recombined
flow
at
least
once
daily
during
diversions
for
all
parameters
for
which
the
POTW
treatment
plant
has
daily
effluent
DRAFT
16
August
4,
2006
limitations
or
other
requirements
(
e.
g.,
monitoring
only
requirements),
the
total
volume
diverted,
and
the
duration
of
the
peak
wet
weather
diversion
event.
For
parameters
for
which
the
permit
establishes
non­
daily
effluent
limitations,
include
in
the
permit
monitoring
requirements
sufficient
to
yield
data
representative
of
the
final
blended
discharge,
in
order
to
ensure
compliance
with
applicable
effluent
limitations.
See
40
CFR
122.48(
b).
Where
the
permit
establishes
non­
daily
effluent
limitations
or
monitoring
requirements
for
TSS,
in
order
to
be
representative,
the
permit
should
require
that
TSS
be
measured
during
diversions;
g.
describe
in
the
permit
Fact
Sheet
prepared
under
40
CFR
124.8(
b)
how
the
permitting
authority
determined
what
constitutes
the
peak
wet
weather
event,
the
reasons
for
allowing
any
peak
wet
weather
diversions,
and
all
requirements
or
conditions
applicable
to
peak
wet
weather
diversions;
h.
ensure
that
permit
load
limitations
account
for
the
anticipated
flow
into
secondary
treatment
units
during
both
wet
and
dry
weather
conditions;
i.
include
permit
provisions
for
public
notification
(
e.
g.,
via
utility
website)
of
the
peak
wet
weather
diversion
event
within
24
hours
of
the
inception
of
each
event;
follow
up
public
notification
of
the
duration
and
volume
of
the
event
within
48
hours
of
its
cessation;
and
for
making
readily
available
public
access
to
for
public
review
of
the
POTW
treatment
plant's
operator's
peak
wet
weather
flow
diversion
practices
and
records
(
i.
e.,
monitoring
data,
duration
and
volume
information)
upon
request;
j.
include
permit
provisions
requiring
the
control
authority
with
an
approved
pretreatment
program
to
review,
and
revise
if
necessary,
local
pretreatment
limits
for
indirect
dischargers
to
take
into
account
peak
wet
weather
diversion
events
(
e.
g.,
significant
industrial
users
with
batch
discharging);
k.
if
the
discharge
will
be
to
sensitive
receiving
waters
(
i.
e.,
waters
used
for
recreation;
waters
used
as
drinking
water
sources;
waters
containing
shellfish
beds;
waters
formally
designated
by
state
or
federal
authorities
as
requiring
special
consideration
or
protection;
waters
with
threatened
or
endangered
species),
ensure
that
the
impact
of
any
peak
wet
weather
diversion
events
on
these
waters
is
minimized
and
additional
caution
exercised
as
permit
limitations
and
other
conditions
(
e.
g.,
disinfection,
notice
to
downstream
water
suppliers)
are
set;
and
l.
rigorously
review
every
POTW
permit
renewal
request
that
anticipates
continued
peak
wet
weather
diversions
to
ensure
that
a
comprehensive
utility
analysis
consistent
with
section
1
above
is
re­
submitted
and
re­
evaluated
and
that
peak
wet
weather
diversions
are
approved
only
when
consistent
with
this
policy.

3.
EPA
will:

a.
use
this
policy
in
making
NPDES
permitting
decisions
for
all
POTW
treatment
plants
serving
separate
sanitary
sewer
conveyance
systems
in
non­
authorized
states;
b.
review
permits
in
NPDES
authorized
states
within
the
timelines
specified
in
40
CFR
123.44
for
POTW
treatment
plant
operators
for
which
the
NPDES
authorized
state
has
prepared
a
draft
permit
anticipating
peak
flow
diversions
pursuant
to
this
policy,
to
DRAFT
17
August
4,
2006
ensure
that
such
permits
are
consistent
with
the
regulatory
applications
in
this
policy;
c.
ensure
that
enforcement
actions
are
taken,
where
appropriate,
against
POTW
treatment
plants
operators
that
fail
to
move
forward
expeditiously
to
meet
their
legal
obligations
as
determined
consistent
with
this
policy;
and
d.
ensure
that
links
and
contact
information
for
monitoring
data
concerning
peak
wet
weather
diversions
at
POTW
treatment
plants
is
available
to
the
public
on
EPA's
website;
and
e.
create
technical
resources
to
assist
POTWs,
NPDES
authorities,
and
citizens
in
implementing
this
policy.
DRAFT
18
August
4,
2006
EPA
will
work
to
ensure
municipalities
and
NPDES
authorities
implement
this
policy
as
soon
as
possible.
This
will
protect
human
health
and
the
environment
by
ensuring
that
municipal
permittees
employ
all
feasible
alternatives
when
addressing
wet
weather
diversions
at
POTWs
served
by
sanitary
sewer
collection
systems.

Dated:

Stephen
L.
Johnson
Administrator
