Document ID: EPA-HQ-OW-2002-0039-0044
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2003-07-09T04:00Z

1EPA
requests
comment
on
how
a
system
would
conduct
a
DOP
of
a
unit
process
while
ensuring
the
other
parts
of
the
treatment
process
were
achieving
their
assumed
Cryptosporidium
treatment.
For
example,
maximizing
removal
in
a
pre­
sedimentation
basin
can
cause
reduced
removal
in
the
subsequent
sedimentation
basin
and
filters.

LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
1
June
2003
12.0
Demonstration
of
Performance
(
DOP):
Microbial
Removal
12.1
Introduction
The
purpose
of
the
"
demonstration
of
performance"
(
DOP)
toolbox
component
is
to
allow
a
system
to
demonstrate
that
a
plant,
or
a
unit
process1
within
a
plant,
should
receive
a
higher
Cryptosporidium
treatment
credit
than
is
presumptively
awarded
under
the
LT2ESWTR.
Presumptive
treatment
credits
are
applicable
to
granular
media
filtration
plant
types
indicated
in
Table
12.1
that
comply
with
the
provisions
of
the
Interim
Enhanced
Surface
Water
Treatment
Rule
(
IESWTR)
and
Long
Term
1
Enhanced
Surface
Water
Treatment
Rule
(
LT1ESWTR)
(
40
CFR
141.720).
These
credits
are
also
applicable
to
unit
processes
in
the
microbial
toolbox
when
they
meet
specified
design
and
operational
criteria,
as
discussed
in
other
chapters
of
this
manual.

Table
12.1
Filtration
Plant
Types
Eligible
for
DOP
Plant
Type
Minimum
Elements
of
Process
Train
Conventional
Coagulation/
Flocculation
Sedimentation
High
Rate
Granular
Media
Filtration
Slow
Sand
Filtration
Slow
Sand
Filtration
Diatomaceous
Earth
Diatomaceous
Earth
Filtration
Softening/
Granular
Media
Filtration
Single­
Stage
Lime
Softening
High
Rate
Granular
Media
Filtration
Direct
Filtration
Coagulation/
Flocculation
High
Rate
Granular
Media
Filtration
Where
a
system
can
demonstrate
that
a
plant,
or
a
unit
process
within
a
plant,
consistently
achieves
a
Cryptosporidium
treatment
efficiency
greater
than
the
presumptive
credit
specified
in
the
LT2ESWTR,
the
State
may
allow
the
system
to
receive
a
higher
Cryptosporidium
treatment
credit
for
compliance
with
the
LT2ESWTR
(
40
CFR
141.727(
c)).
To
demonstrate
the
higher
level
of
Cryptosporidium
treatment,
systems
should
conduct
a
site­
specific
study
using
a
protocol
approved
by
the
State.
This
study
should
account
for
all
expected
operating
conditions
and,
at
the
discretion
of
the
State,
determine
ongoing
monitoring
and/
or
performance
requirements
to
ensure
conditions
under
which
the
DOP
was
awarded
are
maintained
during
routine
operations.
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
2
June
2003
In
general,
the
term
"
treatment"
in
the
LT2ESWTR
refers
to
both
physical
removal
and
inactivation
of
Cryptosporidium.
Treatment
credits
discussed
in
this
chapter
pertain
to
physical
removal
by
the
process
trains
listed
in
Table
12.1
(
or
individual
components
of
these
trains),
presedimentation
bank
filtration,
secondary
filtration,
and
two­
stage
softening.
Treatment
credits
for
physical
removal
by
membranes
and
bag
and
cartridge
filtration
are
addressed
in
the
Membrane
Filtration
Guidance
Manual
and
Chapter
8
of
this
manual,
respectively.
Inactivation
of
Cryptosporidium
by
chlorine
dioxide,
ozone,
and
UV
may
also
be
used
to
provide
additional
treatment
credits,
as
discussed
in
Chapters
10,
11,
and
13
of
this
manual.

This
chapter
provides
guidance
for
implementing
the
DOP
toolbox
option
and
is
organized
as
follows:

12.2
LT2ESWTR
Compliance
Requirements
­
discusses
DOP
treatment
credit
with
respect
to
other
toolbox
options
and
reporting
requirements.

12.3
Toolbox
Selection
Considerations
­
describes
selection
considerations
for
plants
to
consider
before
conducting
a
DOP
study,
the
duration
of
a
DOP
study,
and
an
approach
for
conducting
a
DOP
study.

12.4
DOP
Criteria
Development
­
discusses
key
issues
of
DOP
design
including
process
evaluation
criteria,
selection
of
performance
indicators,
and
full­
scale
versus
pilotscale
testing.

12.5
Demonstration
Protocol
­
discusses
the
minimum
elements
that
should
be
included
in
the
DOP
protocol
­
DOP
test
matrix,
DOP
monitoring
plan,
DOP
implementation,
and
data
analysis
and
reporting.

12.2
LT2ESWTR
Compliance
Requirements
12.2.1
Credits
The
LT2ESWTR
does
not
specify
how
treatment
performance
must
be
demonstrated;
however
the
protocol
used
must
be
approved
by
the
State
(
40
CFR
141.727(
c)).
Determination
of
an
increased
Cryptosporidium
treatment
credit
will
be
made
by
the
State.

The
LT2ESWTR
does
not
allow
systems
to
claim
presumptive
credit
for
the
toolbox
options
listed
below,
if
that
component
is
included
in
the
DOP
credit
(
40
CFR
141.727(
c)(
2)).
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
3
June
2003

Presedimentation

Two­
stage
lime
softening

Bank
filtration

Combined
or
individual
filter
performance

Membrane
filters

Bag
and
cartridge
filters

Second
stage
filtration
For
example,
if
a
plant
receives
a
DOP
credit
for
a
treatment
train,
the
system
may
not
also
receive
credit
for
a
presedimentation
basin
or
achieving
the
lower
finished
water
turbidity
of
the
combined
filter
performance
option.

States
may
award
a
lower
level
of
Cryptosporidium
treatment
credit
towards
compliance
for
the
LT2ESWTR
to
a
system
where,
based
on
site­
specific
information,
a
plant
or
a
unit
process
achieves
a
Cryptosporidium
treatment
efficiency
less
than
a
presumptive
credit
specified
in
the
LT2ESWTR
(
40
CFR
141.727(
c)(
1)).

12.2.2
Reporting
Requirements
The
LT2ESWTR
requires
results
from
the
testing
be
submitted
no
later
than
[
date
72
months
after
promulgation]
for
large
systems
and
[
date
102
months
after
promulgation]
for
small
systems
(
40
CFR
141.730).

The
State
may
require
systems
to
report
operational
data
on
a
monthly
basis
to
verify
that
conditions
under
which
DOP
credit
was
awarded
are
maintained
during
routine
operation
(
40
CFR
141.730).

12.3
Toolbox
Selection
Considerations
The
DOP
toolbox
option
is
intended
for
plants
that
operate
at
a
high
level
of
performance.
A
system
should
review
existing
performance
data
to
verify
that
it
can
meet
high
performance
levels
under
a
range
of
operating
conditions
(
including
filters
out
of
service,
returning
to
service,
and
flow
rate
changes)
before
conducting
a
DOP
study.
EPA
recommends
systems
achieve
less
than
0.1
NTU
in
each
individual
filter
effluent
as
an
indicator
for
considering
whether
the
DOP
option
is
practical.

Before
applying
the
DOP
approach
to
an
individual
unit
process,
facilities
should
carefully
consider
the
potential
advantages
and
disadvantages
of
such
an
approach.
The
microbial
toolbox
allows
for
treatment
credits
for
unit
processes
based
on
specified
design
and/
or
operational
criteria
described
in
other
chapters
of
this
manual.
It
is
possible
that
a
detailed
DOP
program
may
result
in
a
lower
credit
than
already
granted
by
the
LT2ESWTR.
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
4
June
2003
A
DOP
study
should
be
conducted
for
a
minimum
of
one
year.
Systems
should
have
a
contingency
plan
for
achieving
compliance
with
the
LT2ESWTR
if
the
DOP
does
not
provide
the
anticipated
credit.

12.3.1
Overview
of
the
Demonstration
Protocol
This
chapter
presents
one
approach
for
conducting
a
DOP
study.
Other
approaches
or
modifications
to
this
approach
may
be
approved
by
the
State.
Major
elements
of
the
DOP
protocol
include
the
following:

$
Development
of
DOP
evaluation
criteria
and
test
matrix
$
DOP
implementation
$
Data
analysis
and
reporting
Figure
12.1
presents
a
flowchart
relating
these
elements
to
the
overall
microbial
toolbox
framework.
Each
of
these
topics
is
discussed
in
detail
in
this
chapter.
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
5
June
2003
Figure
12.1
Flowchart
for
DOP
Protocol
12.4
DOP
Criteria
Development
Source
water
Cryptosporidium
levels
and
water
quality
characteristics
vary
from
system
to
system.
Accordingly,
DOP
programs
should
be
tailored
to
address
site­
specific
process
issues
associated
with
each
water
treatment
plant
(
WTP).
Major
questions
that
should
be
resolved
during
the
design
of
the
DOP
include
(
but
are
not
limited
to)
the
following:

$
What
are
the
governing
process
evaluation
criteria
and
treatment
objectives?

$
What
microorganism
or
surrogate
parameter(
s)
should
be
used
to
demonstrate
removal
efficiency
of
Cryptosporidium?

$
Should
the
DOP
be
conducted
at
full­
scale
or
pilot­
scale?

Each
of
these
questions
is
addressed
in
the
following
sections.
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
6
June
2003
12.4.1
Process
Evaluation
Criteria
Process
evaluation
encompasses
the
treatment
objectives
of
the
plant,
influent
water
quality,
system
demand,
and
operating
conditions
or
treatment
techniques.
The
DOP
plan
should
address
all
critical
operating
conditions,
whether
conducted
in
full­
scale
or
pilot­
scale.
Influent
water
quality,
flow
rates,
process
configurations,
and
operating
conditions
need
to
be
clearly
defined
during
the
development
of
the
DOP
plan.
Common
process
evaluation
criteria
are
discussed
in
this
section.

12.4.1.1
Treatment
Objectives
The
DOP
toolbox
option
primarily
relates
to
Cryptosporidium
removal
by
physical
methods
such
as
clarification
and
filtration.
However,
WTPs
are
tasked
to
remove
or
control
multiple
contaminants
in
the
source
water
besides
Cryptosporidium.
The
impact
of
operational
strategies
and
treatment
methods
for
other
contaminants
on
the
efficiency
of
Cryptosporidium
removal
should
be
considered
during
the
DOP
criteria
development
stage.
The
system
should
not
change
its
operational
strategy
between
the
DOP
study
conditions
and
routine
operation
after
the
study
has
endedCthe
DOP
credit
is
based
on
the
operational
strategy
used
in
the
study.
For
example,
a
system
that
uses
enhanced
coagulation
throughout
the
study
period
should
also
use
it
during
routine
operation
for
compliance
with
the
LT2ESWTR.

Other
examples
of
treatment
techniques
that
can
affect
Cryptosporidium
removal
and
thus
should
be
considered
in
the
development
stage
include
the
following:

$
Prechlorination
may
be
used
to
enhance
floc
formation
(
and
Cryptosporidium
removal)
in
filtration
trains.
However,
prechlorination
may
also
promote
trihalomethane
(
THM)
and
haloacetic
acid
(
HAA)
formation.
Therefore,
prechlorination
doses
used
during
the
DOP
study
should
be
set
to
balance
floc
and
disinfection
byproduct
formation.
Operational
guidelines
should
be
documented
in
the
DOP
plan.

$
Granular
media
filter
run
times
may
be
extended
to
increase
unit
filter
run
volumes
(
UFRVs)
and
filter
efficiency.
However,
increased
UFRVs
also
increase
the
potential
for
Cryptosporidium
breakthrough.
Maximum
UFRVs
should
be
established
to
minimize
Cryptosporidium
breakthrough.

$
Alternative
coagulation
strategies
may
be
used
to
enhance
Cryptosporidium
removal
in
granular
media
filters
but
may
also
result
in
post­
filtration
flocculation
that
can
cause
deposition
or
scaling
in
water
distribution
systems.
Coagulant
dosing
rates
should
be
set
during
the
DOP
study
to
minimize
downstream
floc
formation.
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
7
June
2003
Additionally,
if
a
treatment
process
or
plant
technique
is
used
intermittently
for
a
seasonal
or
sporadically
occurring
contaminant,
this
treatment
should
also
be
used
as
needed
during
the
DOP
study,
consistent
with
routine
operation.

12.4.1.2
Influent
Water
Quality
Characteristics
Source
water
quality
characteristics
that
may
affect
Cryptosporidium
removal
efficiencies
should
be
identified.
These
will
depend
on
the
treatment
processes
employed
and
may
include
(
but
are
not
limited
to)
turbidity,
pH,
alkalinity
and
temperature.
Critical
(
or
worst­
case)
ranges
for
these
parameters
that
are
anticipated
over
the
plant
design
life
or
permit
period
should
be
clearly
defined.
The
demonstration
study
should
include
tests
run
under
the
worst­
case
source
water
conditions.
In
pilot­
scale
DOP
studies,
raw
source
water
can
be
modified
to
simulate
worst­
case
water
qualities.

12.4.1.3
System
Flow
Rate
The
system
flow
rate
or
range
of
flow
rates
to
be
evaluated
during
the
DOP
should
be
clearly
defined.
Where
possible,
plant
performance
should
be
demonstrated
for
the
critical
flow
condition
that
defines
permitted
plant
capacity
(
e.
g.,
peak
instantaneous
flow
or
peak
daily
flow).
For
full­
scale
studies,
this
may
not
be
feasible
for
facilities
that
operate
significantly
below
permitted
or
maximum
capacity.
For
pilot­
scale
studies,
the
range
of
system
unit
process
flow
rates
should
replicate
the
full­
scale
low,
intermediate,
and
maximum
flow
and
recycles
rates.

12.4.1.4
Plant
Operating
Conditions
WTP
operations
can
vary
significantly
over
the
course
of
the
demonstration
period
due
to
various
factors
including,
but
not
limited
to,
raw
water
quality,
system
flow
rate,
and
maintenance
activities.
The
critical
operating
conditions
that
may
impact
Cryptosporidium
removal
at
the
WTP
should
be
defined.
Issues
to
consider
include
the
following:

$
What
are
the
normal
and
worst­
case
operating
conditions
for
each
unit
process
with
respect
to
Cryptosporidium
removal?

$
How
many
process
trains
or
elements
are
normally
in
service?
How
will
the
plant
perform
when
units
are
out
of
service
for
maintenance
and
repair,
thereby
increasing
unit
process
flow
rates
(
particularly
in
filters)?

$
What
is
the
process
control
strategy
for
chemical
addition?
How
does
this
relate
to
Cryptosporidium
removal?

$
What
is
the
process
control
strategy
for
filter
operations?
How
does
this
relate
to
Cryptosporidium
removal?
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
8
June
2003
$
How
will
the
plant's
recycle,
backwash,
and
filter­
to­
waste
schemes
affect
Cryptosporidium
removal?

In
the
case
of
pilot­
scale
studies,
performance
demonstrations
should
replicate
full­
scale
operating
conditions
in
any
respect
that
may
influence
Cryptosporidium
removal.

12.4.2
Selection
of
Performance
Indicators
Although
the
LT2ESWTR
mandates
treatment
controls
for
Cryptosporidium,
it
is
not
currently
feasible
to
demonstrate
actual
Cryptosporidium
removal
at
full­
scale
facilities.
In
most
cases,
influent
Cryptosporidium
levels
are
not
consistently
high
enough
to
demonstrate
significant
(
such
as
4
log)
removal
across
the
process
train.
Raw
water
spiking
of
Cryptosporidium
is
not
a
feasible
option
at
full­
scale
facilities
due
to
the
potential
health
risk
to
system
users
and
the
number
of
oocysts
required.
Consequently,
alternative
indicators
of
Cryptosporidium
removal
will
be
needed
for
facilities
that
plan
to
conduct
DOP
studies
at
full­
scale.

12.4.2.1
Surrogate
Parameters
for
Cryptosporidium
EPA
has
reviewed
a
number
of
studies
that
suggest
aerobic
bacteria
spores
are
a
suitable
indicator
of
Cryptosporidium
removal
in
conventional
treatment
trains
(
coagulation,
flocculation,
sedimentation
and
filtration).
Some
characteristics
of
aerobic
spores
(
as
summarized
by
Cornwell
et
al.,
2001)
are:

$
Naturally
occurring
(
Nieminski
and
Bellamy
2000,
Jakubowski
et
al.
1996).

$
Do
not
pose
health
risks
(
Jakubowski
et
al.
1996,
Rice
et
al.
1996).

$
Can
be
detected
at
low
concentrations
(<
1
cfu/
100
mL).

$
Are
slightly
smaller
than
Cryptosporidium
oocysts
(
Rice
et
al.,
1996).

$
Spore
removal
by
water
treatment
is
a
conservative
indicator
of
Cryptosporidium
removal
(
Rice
et
al.
1996,
Dugan
et
al.
1999,
Nieminski
and
Bellamy
2000,
Emelko
2001).

$
Reduction
of
indigenous
spores
by
inactivation
is
expected
to
be
negligible
in
comparison
with
removal
of
spores
by
physical
processes
(
Jakubowski
et
al.
1996,
Rice
et
al.
1996).

$
Aerobic
spores
do
not
undergo
re­
growth
during
treatment.
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
9
June
2003
Although
aerobic
spores
appear
to
be
a
suitable
indicator
for
Cryptosporidium
removal
in
filtration
plants,
raw
source
water
spore
concentrations
will
likely
not
be
high
enough
throughout
the
study
period
to
demonstrate
high
log
removal
across
a
full­
scale
treatment
train.

The
State
may
accept
alternative
indicators
for
Cryptosporidium;
however,
they
should
not
be
more
easily
removed
than
Cryptosporidium.
The
surrogate
parameter
should
give
a
direct
view
of
removal
and
should
be
an
element
that
is
not
created
in
the
plant
(
e.
g.,
particle
counts
caused
by
chemical
precipitation).
Furthermore,
the
method
of
measurement
should
be
sensitive
enough
to
detect
temporal
variations
in
the
parameter.
Parameters
such
as
turbidity
or
particle
counts
may
be
used
in
the
DOP
study,
but
are
not
suitable
as
stand­
alone
surrogates.

12.4.2.2
Long­
Term
Performance
Indicators
As
discussed
previously,
plants
that
implement
a
DOP
plan
should
document
long­
term
performance
of
filtration
facilities
for
turbidity
and/
or
particle
count
reduction.
While
turbidity
and
particle
counts
are
not
suitable
as
stand­
alone
indicators
for
full­
scale
Cryptosporidium
removal,
such
data
can
be
used
to
identify
changes
in
the
filtration
performance.

It
is
recommended
that
individual
filter
efficiency
be
monitored
frequently
to
identify
differences
in
individual
filter
performance.
This
will
allow
the
plant
to
assess
temporal
variations
in
filter
effluent
quality
and
will
provide
improved
process
control.

12.4.3
Full­
Scale
Versus
Pilot­
Scale
Testing
In
general,
full­
scale
testing
is
preferred
over
pilot­
scale
testing
since
the
performance
of
existing
process
trains
is
demonstrated
directly.
However,
full­
scale
studies
may
not
be
feasible
for
many
facilities
for
the
following
reasons:

$
Influent
Cryptosporidium
levels
will
not
be
high
enough
to
demonstrate
high
log
removal.
Likewise,
influent
aerobic
spore
concentrations
may
not
be
high
enough
to
demonstrate
significant
log
removal.

$
Full­
scale
spiking
with
aerobic
spores
may
not
be
feasible
due
to
larger
flows.

$
Facilities
may
operate
well
below
design
or
permitted
flow
capacity
for
the
entire
study
period.

$
Demonstration
of
worst­
case
operating
conditions
at
full­
scale
may
be
difficult
to
plan,
especially
with
regard
to
raw
water
quality
and
flow
rates.
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
10
June
2003
The
major
concern
with
the
use
of
pilot­
scale
testing
is
the
uncertainty
associated
with
scale­
up
of
pilot
results
to
predict
the
performance
of
full­
scale
systems.
Other
potential
limitations
of
pilot­
scale
studies
are:

$
Pilot­
scale
data
generally
represent
steady­
state
conditions;
however,
sudden
changes
in
flow
or
water
quality
may
have
a
significant
effect
on
Cryptosporidium
removal;
such
changes
are
difficult
to
capture
in
a
pilot­
scale
plant.

$
Pilot­
scale
plants
generally
have
much
tighter
process
controls
and
higher
levels
of
attention
than
full­
scale
plants;
and
thus,
may
not
be
indicative
of
actual
full­
scale
performance.

$
A
pilot­
scale
plant
cannot
represent
expected
individual
differences
between
multiple
filters
in
a
full­
scale
plant.

$
Particle
loadings
to
the
treatment
process
in
a
pilot­
scale
study
may
be
much
higher
than
actual
full­
scale
loadings,
and
thus,
may
not
represent
actual
operating
conditions.

$
It
may
be
too
difficult
to
construct
a
pilot
plant
that
represents
the
entire
full­
scale
process
train.

Pilot
system
dimensions
and
flow
rates
should
be
sufficiently
large
to
minimize
scale­
up
issues.
Some
recommended
guidelines
for
pilot
filter
sizing
include
the
following
(
USEPA
1991):

$
Unit
filtration
rate
in
the
pilot
system
should
be
identical
to
that
of
the
full­
scale
plant.

$
Pilot
filter
diameter
should
be
greater
than
or
equal
to
100
times
the
media
diameter.

$
Media
diameter
and
depth
should
be
identical
to
that
of
the
full­
scale
system.

Pilot
systems
should
also
incorporate
all
major
process
elements
of
the
full­
scale
process
train,
including
chemical
addition
systems
and
recycle
streams.
Such
systems
must
be
able
to
simulate
flow
rate
and
water
quality
perturbations
(
i.
e.,
temporal
disturbances
to
steady
state
conditions).

12.5
Demonstration
Protocol
Once
the
DOP
criteria
have
been
developed,
the
DOP
protocol
can
be
formulated.
This
section
outlines
the
minimum
elements
that
should
be
included
in
the
DOP
protocol.
Participation
from
the
governing
regulatory
agency
should
be
solicited
during
the
DOP
protocol
development
phase.
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
11
June
2003
12.5.1
DOP
Test
Matrix
The
first
step
in
the
formulation
of
the
specific
DOP
protocol
is
the
development
of
a
matrix
of
test
conditions
to
be
evaluated
during
the
DOP
period.
These
test
conditions
should
be
formulated
to
assess
Cryptosporidium
removal
(
or
other
suitable
parameters)
under
a
range
of
normal
and
worst­
case
scenarios.
The
DOP
matrix
should
clearly
define
specific
test
scenarios
to
be
evaluated,
incorporating
the
following
criteria:

$
Source
water
quality
rangesB
including
minimum/
maximum
limits
for
critical
water
quality
parameters
that
influence
Cryptosporidium
removal
in
the
plant.

$
Influent
flow
ratesB
including
the
maximum
flow
rate
that
defines
plant
capacity.

$
Operating
scenariosB
including
all
operations
that
may
cause
process
upset
in
the
treatment
train
(
e.
g.,
events
that
cause
temporal
changes
in
water
quality,
and
flow
loadings
to
process
units).
These
operations
include,
but
are
not
limited
to:
filter
backwashing,
filter­
to­
waste
practices,
intermittent
recycles,
returning
filters
to
service,
and
routine
maintenance
practices.

Critical
influent
flow
ranges
and
operating
conditions
should
be
identified
during
the
DOP
criteria
development
phase,
as
described
in
section
12.2.
The
demonstration
period
should
be
at
least
one
year,
and
should
encompass
all
critical
operating
conditions.
An
example
test
matrix
format
is
presented
in
Table
12.2.

Table
12.2
Example
DOP
Test
Matrix
Scenario
Condition
(
Normal
or
Worst­
Case)
Influent
Concentration
Range
Flow
Rate
Range
Units
in
Service
Backwash
Conditions
Date
of
Scenario
Test
Surrogate
Turbidity
S1
Normal
Average
Average
Average
4
(
All)
S2
Normal
Average
Average
Average
3
S3
Worst
Case
A
Average
Average
High
3
S4
Worst
Case
B
High
High
Average
3
S5
Worst
Case
C
Low
Low
Average
3
12.5.2
DOP
Monitoring
Plan
The
DOP
involves
sampling
and
analysis
of
Cryptosporidium
indicators
in
the
raw
source
water
and
filtration
train
effluent
over
the
course
of
a
demonstration
period
defined
by
the
DOP
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
12
June
2003
test
matrix.
Once
the
test
matrix
is
established,
the
DOP
monitoring
plan
should
be
formulated
to
define
the
following
protocol
details:

$
Monitoring
locations
°
Test
parameters
(
field
and
laboratory)

$
Monitoring
frequency
$
Quality
assurance/
quality
control
(
QA/
QC)
procedure
for/
during
sampling
A
sample
DOP
monitoring
plan
is
presented
in
Table
12.3.
Chapter
12.0
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
13
June
2003
Table
12.3
Example
DOP
Monitoring
Plan
Monitor
Event
Number
Date
Test
Scenario
ID
(
see
Table
12.2)
Effluent
Sample
LocationsA
Number
of
Samples
per
Location
Filter
1
Filter
2
Filter
3
Filter
4
Crypto/
Aerobic
Spores
Particle
Count
pH
Temp.

1
Week
1
S1
X
X
X
X
2B
1
1
1
2
Week
2
S3
X
X
X
1
1
1
1
3
Week
3
S2
X
X
X
1
1
1
1
 
...
 
...
 
...
 
...
 
...
 

52
Week
52
S4
X
X
X
X
2B
1
1
1
A
­
Influent
sample
location
identical
for
all
test
scenarios
B
­
duplicate
samples
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
14
June
2003
12.5.2.1
Sampling
Location
Paired
samples
should
be
collected
from
the
plant
influent
(
raw
source)
and
the
combined
filter
effluent
for
a
DOP
study
of
an
entire
plant.
The
plant
influent
location
should
be
before
the
pre­
sedimentation
basins
and
off­
stream
storage
facilities
and
follow
any
process
recycles
added
prior
to
the
first
major
unit
process
element
of
the
treatment
train.
For
pilot
studies
involving
microbial
dosing,
the
influent
monitoring
point
should
follow
complete
mixing
of
the
source
water
and
injection
stream.
The
plant
effluent
sample
should
be
comprised
of
composite
samples
from
the
effluent
of
all
operating
filters.
It
is
recommended
that
at
least
five
sample
pairs
(
influent/
effluent)
be
collected
during
each
test
run
to
capture
temporal
changes
in
filter
and
effluent
quality.

12.5.2.2
Monitoring
Parameters
Samples
should
be
analyzed
for
all
parameters
required
to
assess
Cryptosporidium
removal
in
the
treatment
trains,
as
discussed
in
section
12.2.
Parameters
such
as
pH,
alkalinity,
temperature,
and
turbidity
should
be
measured
and
recorded
in
the
field.

12.5.2.3
Monitoring
Frequency
A
monitoring
event
is
defined
as
a
paired
(
concurrent)
sampling
of
plant
influent
and
filter
effluent
samples.
At
a
minimum,
monitoring
should
be
performed
once
per
week
for
52
consecutive
weeks.
More
frequent
monitoring
may
be
required
to
capture
all
critical
operating
scenarios
defined
by
the
DOP
Test
Matrix.
The
DOP
database
should
be
sufficiently
large
to
allow
for
statistical
analysis.

If
a
DOP
credit
is
issued
by
the
State,
the
credit
will
be
conditional
on
continuing
demonstration
of
a
higher
level
of
performance.
The
DOP
Monitoring
Plan
can
be
modified
to
document
continuing
performance
at
a
reduced
sampling
frequency.
However,
sampling
events
should
still
capture
critical
operating
scenarios.

12.5.2.4
Quality
Assurance/
Quality
Control
Quality
assurance/
quality
control
(
QA/
QC)
sampling
should
be
performed
to
allow
assessment
of
data
variability
and
quantification
errors
due
to
sample
collection
procedures
and
analytical
methods.
At
a
minimum,
duplicate
samples
should
be
collected
during
one
monitoring
event
per
month.

12.5.3
DOP
Implementation
The
DOP
should
commence
only
after
the
State
approves
the
DOP
test
matrix
and
monitoring
protocol.
The
DOP
plan
should
be
administered
by
a
qualified
water
treatment
plant
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
15
June
2003
operator
or
water
process
engineer.
Data
review
and
QA/
QC
practices
should
be
conducted
routinely
to
ensure
that
the
objectives
of
the
DOP
program
are
met.
Particular
attention
should
be
given
to
verification
of
the
plant
operating
conditions
(
influent
loadings,
unit
process
loadings,
etc.)
to
confirm
that
all
critical
operating
scenarios
identified
in
the
DOP
test
matrix
are
evaluated
during
the
demonstration
period.

Personnel
responsible
for
implementing
the
DOP
monitoring
plan
should
be
properly
trained
in
sample
collection
techniques,
QA/
QC
procedures
and
operational
data
acquisition.
Specific
procedures
should
be
used
to
collect
and
analyze
samples
as
described
in
the
following
sections:

°
Sample
collection
and
preservation
methods
°
Analytical
methods
°
Microbial
dosing
methods
(
for
pilot
tests)

°
Documentation
procedures
12.5.3.1
Sample
Collection
Methods
Influent
and
effluent
samples
should
be
collected
in
a
manner
that
is
representative
of
the
entire
cross
sectional
flow
at
each
monitoring
point.
If
possible,
monitoring
points
should
be
located
in
straight
sections
of
pipe
or
channel
well
downstream
of
bends.
For
open
channel
flows,
samples
should
be
collected
from
mid­
depth
and
mid­
width
of
the
channel.
For
pipe
flow,
samples
should
be
collected
from
the
tap
directly
into
the
sample
containers.
In
each
case,
the
sampling
method
should
not
reduce
or
prevent
transfer
of
suspended
solids
from
the
process
stream
to
the
sample
container.
Parameters
such
as
pH,
turbidity,
alkalinity
and
temperature
should
be
directly
measured
in
the
field.

All
samples
should
be
grab
samples.
The
individual
effluent
grab
samples
should
not
be
combined
to
make
up
composite
samples.

12.5.3.2
Analytical
Methods
The
analytical
methods
for
monitoring
Cryptosporidium
under
the
LT2ESWTR
are
prescribed
in
the
Public
Water
System
Guidance
Manual
for
Source
Water
Monitoring
under
the
Long­
Term
2
Enhanced
Surface
Water
Treatment
Rule.
Analytical
methods
for
all
other
water
quality
parameters
should
be
performed
in
accordance
with
Standard
Methods
for
the
Examination
of
Water
and
Wastewater,
20th
edition,
or
the
most
recent
edition.
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
16
June
2003
12.5.3.3
Microbial
Dosing
For
pilot
testing
that
involves
spiking
of
Cryptosporidium,
aerobic
spores
or
other
indicators,
microbial
dosing
procedures
should
be
clearly
established.
Guidelines
for
microbial
stock
preparation
and
dosing
are
presented
in
this
section.

A
concentrated
mixture
of
microorganisms
should
be
prepared
and
fed
to
the
raw
source
stream
at
a
known
feed
rate,
based
on
the
microbial
density
in
the
concentrated
stock,
the
flow
rate
of
the
pilot
system,
and
the
desired
microorganism
concentration
in
the
pilot
system.
An
equation
that
describes
this
relationship
is:

Equation
12.1
where:
C
pilot
=
the
microbial
concentration
in
the
pilot
system
C
feed
=
the
microbial
concentration
in
the
concentrated
stock
solution
Q
pilot
=
the
flow
rate
of
the
pilot
system
(
includes
all
process
recycles
present
at
the
influent
feed
point,
if
applicable)
Q
feed
=
the
flow
rate
of
the
concentrated
stock
solution
For
each
trial,
the
test
microorganisms
should
be
completely
mixed
in
a
volume
of
raw
water
sufficient
to
supply
the
pilot
plant
for
the
duration
of
the
experiment.
The
tank
containing
the
suspension
of
test
microorganisms
should
be
continuously
mixed
for
the
duration
of
each
experiment
to
promote
homogeneity
of
the
mixture.
The
concentrated
stock
should
be
delivered
by
a
positive
displacement
pump
(
e.
g.,
peristaltic)
to
the
main
process
flow
at
a
flow
rate
dictated
by
Equation
12.1.
C
pilot
and
C
feed
should
be
selected
to
provide
a
high
enough
influent
microbial
concentration
to
demonstrate
at
least
4
log
removal
in
the
pilot
system.
Based
on
this
approach,
C
pilot
should
be
set
at
least
104
higher
than
the
method
detection
limit
for
the
test
microorganism.
The
microbial
density
in
the
stock
solution
should
be
sampled
at
least
twice,
and
preferably
three
times,
during
a
feeding
interval
to
verify
consistent
densities.

12.5.3.4
Documentation
of
WTP
Operating
Conditions
It
is
important
to
document
WTP
operating
conditions
during
monitoring
events
to
evaluate
the
effect
of
varying
operating
scenarios
on
Cryptosporidium
removal.
Standardized
reporting
forms
should
be
developed
to
provide,
at
a
minimum,
the
following
information:

°
System
flow
rate
(
instantaneous/
flow
chart,
hourly
and
daily
average)

°
Operating
mode
(
process
scheme,
number
of
trains,
number
of
units
in
service)

°
Water
pH,
alkalinity,
turbidity
and
temperature
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
17
June
2003
°
Performance
data
°
Chemical
addition
rates/
doses
°
Mechanical
equipment
in
operation,
with
flow
rates
(
major
pumps,
blowers,
etc.)

°
Recycle
and
backwash
flows/
rates
°
Related
maintenance
activities
occurring
prior
to
or
during
sampling
event.

12.5.4
Data
Analysis
and
Reporting
12.5.4.1
Evaluation
of
Performance
To
receive
DOP
treatment
credits
above
presumptive
credits
in
the
LT2ESWTR,
a
plant
should
demonstrate
consistent
attainment
of
a
specific
log
reduction
of
Cryptosporidium
(
or
suitable
indicators).
To
meet
this
objective,
log
reduction
should
first
be
computed
for
each
monitoring
event
according
to:

Log
Removal
=
­
log
(
C
inf/
C
eff)
Equation
12.2
where:
C
inf
=
influent
Cryptosporidium
or
indicator
concentration
C
eff
=
effluent
Cryptosporidium
or
indicator
concentration
For
effluent
samples
in
which
no
Cryptosporidium,
spores,
or
other
indicators
are
detected,
the
concentration
should
be
set
to
the
method
detection
limit.

The
State
will
determine
the
level
of
DOP
credit
a
facility
receives
based
on
review
of
the
log
removal
data.

For
the
case
of
pilot
testing
and
the
use
of
multiple
indicators
for
Cryptosporidium
removal
calculations
will
be
site
specific.

12.5.4.2
Reporting
for
the
DOP
At
the
conclusion
of
the
DOP
test
period,
a
detailed
report
summarizing
the
major
findings
of
the
DOP
program
must
be
submitted
to
the
governing
regulatory
agency.
At
a
minimum,
the
DOP
report
should
include
the
following
information:
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
18
June
2003
°
Detailed
description
of
full­
scale
WTP,
including
process
flow
schematics
°
Summary
of
treatment
objectives
and
WTP
design
criteria
°
DOP
test
matrix
and
monitoring
plan
°
DOP
data
summary
°
Detailed
pilot
plant
design
data
(
if
applicable)

°
Data
analysis
for
estimate
of
Cryptosporidium
log
reduction
°
Appendices
for
raw
full­
scale/
pilot­
scale
analytical
and
operational
data
°
Monitoring
plan
to
verify
that
on­
going
performance
is
equivalent
to
treatment
credit.
Source
water
indicators
used
in
the
study
should
be
monitored
to
ensure
performance
is
met.

°
Plan
for
addressing
operating
conditions
(
e.
g.,
influent
water
turbidity)
out
of
the
range
tested
in
the
study.
The
DOP
test
matrix
generally
sets
the
range
of
operating
conditions
under
which
the
LT2ESWTR
treatment
credit
is
applicable.
Therefore,
it
is
advisable
to
develop
a
plan
for
addressing
potential
out­
of
compliance
conditions.
For
example,
if
the
influent
source
water
quality
conditions
ranged
from
5
NTU
to
25
NTU
during
the
study,
the
system
may
plan
to
make
operational
adjustments
for
influent
water
with
turbidity
greater
than
25
NTU
and
increase
filter
effluent
monitoring.
Any
such
deviations
would
be
reported
to
the
State.

12.5.4.3
Ongoing
Reporting
As
discussed
previously,
if
a
DOP
credit
is
issued
by
the
State,
the
credit
will
be
conditional
on
continuing
demonstration
of
a
high
level
of
performance.
The
DOP
Monitoring
Plan
should
be
modified
to
document
continuing
performance
at
a
reduced
sampling
frequency,
while
still
capturing
critical
operating
conditions.
States
may
require
systems
receiving
a
DOP
credit
to
report
operational
and
progress
monitoring
data
on
a
routine
basis.
Operational
data
should
verify
that
continuous
process
control
and
optimization
procedures
are
in
place.

The
DOP
credit
is
applicable
to
minimum
and
maximum
raw
source
water
and
finished
water
quality
limits
defined
in
the
DOP
Test
Matrix.
Routine
reporting
should
be
performed
to
verify
that
plants
operate
within
these
limits.
If
an
exception
occurs,
it
should
be
reported
to
the
State
in
a
timely
manner.
Frequent
exceptions
may
prompt
the
State
to
require
the
plant
to
conduct
a
comprehensive
performance
evaluation
(
CPE)
to
identify
causes
and
solutions
for
exceptions.
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
19
June
2003
References
American
Public
Health
Association,
American
Water
Works
Association,
and
Water
Environment
Federation.
1998.
Standard
Methods
for
the
Examination
of
Water
and
Wastewater.
Washington
D.
C.

Cornwell,
D.
A.,
MacPhee,
M.,
Brown,
R.
2001.
Cryptosporidium
Removal
Credit
Assignable
in
the
LT2ESWTR
Toolbox,
Report
to
AWWA
Government
Affairs
Office,
Washington,
D.
C.

Dugan,
N.,
Fox,
K,
Miltner,
R.,
Lytle,
D.,
Williams,
C.,
Parrett,
C.,
Feld,
Owens,
J.
1999.
Control
of
Cryptosporidium
oocysts
by
steady­
state
conventional
treatment.
Proc.
of
1999
AWWA
Annual
Conference
and
Exposition.
Denver,
CO:
AWWA.

Dugan,
N.,
Fox,
K.,
Owens,
J.,
Miltner,
R.
2001.
Controlling
Cryptosporidium
oocysts
through
conventional
treatment.
Journal
AWWA,
93(
12):
64­
76.

Emelko,
M.,
Huck,
P.,
Slawson,
R.
1999.
Design
and
operational
strategies
for
optimizing
Cryptosporidium
removal
by
filters.
Proceedings
of
the
1999
AWWA
Water
Quality
Technology
Conference.
Denver,
CO:
AWWA.

Emelko,
M.
2001.
Removal
of
Cryptosporidium
parvum
by
Granular
Media
Filtration.
Ph.
D.
Dissertation.
University
of
Waterloo,
Waterloo,
Ontario,
Canada.

Jakubowski,
W.,
Boutros,
S.,
Faber,
W.,
Fayer,
R.,
Ghiorse,
W.,
LeChevallier,
M.,
Rose,
J.,
Schaub,
S.,
Singh,
A.,
Stewart,
M.
1996.
Environmental
methods
for
Cryptosporidium.
Journal
AWWA.
88(
9):
107­
121.

Mazounie,
P.,
Bernazeau,
F.
,
Alla,
P.
2000.
Removal
of
Cryptosporidium
by
high
rate
contact
filtration:
The
Performance
of
the
Prospect
Water
Filtration
Plant
During
the
Sydney
Water
Crisis.
Water
Science
and
Technology.
41(
7):
93­
101.

Nieminski,
E.,
Bellamy,
W.
2000.
Application
of
Surrogate
Measures
to
Improve
Treatment
Plant
Performance.
Denver,
CO:
AwwaRF
and
AWWA.

Rice,
E.,
Fox,
K.,
Miltner,
R.,
Lytle,
D.,
Johnson,
C.
1996.
Evaluating
plant
performance
with
endospores.
Journal
AWWA.
88(
9):
122­
130.

USEPA,
1991.
Guidance
Manual
for
Compliance
with
the
Filtration
and
Disinfection
Requirements
for
Public
Water
Systems
Using
Surface
Water
Sources.
Washington,
D.
C.
Chapter
12
­
Demonstration
of
Performance
(
DOP):
Microbial
Removal
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
12­
20
June
2003
Yates,
R.,
Scott,
K.,
Green,
J.,
Bruno,
J.,
De
Leon,
R.
1998.
Using
aerobic
spores
to
evaluate
treatment
plant
performance.
Proceedings
of
the
1998
AWWA
Annual
Conference
and
Exposition.
Denver,
CO:
AWWA.