LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
1
7.
Combined
and
Individual
Filter
Performance
7.1
Introduction
Turbidity
is
an
optical
property
that
measures
the
amount
of
light
scattered
by
suspended
particles
in
a
solution.
It
can
detect
a
wide
variety
of
particles
in
water
(
e.
g.
clay,
silt,
mineral
particles,
organic
and
inorganic
matter,
and
microorganisms),
but
cannot
provide
specific
information
on
particle
type,
number,
or
size.
Therefore,
the
U.
S.
Environmental
Protection
Agency
(
EPA)
recognizes
that
turbidity
reduction
is
not
a
direct
indication
of
pathogen
removal,
but
is
an
effective
indicator
of
process
control.

The
Surface
Water
Treatment
Rule
(
SWTR),
Interim
Enhanced
SWTR
(
IESWTR),
and
Long
Term
1
Enhanced
SWTR
(
LT1ESWTR)
all
motivate
public
water
systems
to
achieve
a
certain
level
of
finished
water
quality
by
requiring
them
to
meet
specified
filtered
water
turbidity
limits.
Under
the
IESWTR
and
LT1ESWTR,
combined
filter
effluent
turbidity
in
conventional
and
direct
filtration
plants
must
be
less
than
or
equal
to
0.3
NTU
in
95
percent
of
samples
taken
each
month
and
must
never
exceed
1
NTU.
These
plants
are
also
required
to
conduct
continuous
monitoring
of
turbidity
for
each
individual
filter,
and
provide
an
exceptions
report
to
the
State
or
regulating
agency
when
certain
criteria
for
individual
filter
effluent
turbidity
are
exceeded.

The
LT2ESWTR
awards
additional
Cryptosporidium
treatment
credit
to
certain
plants
that
maintain
finished
water
turbidity
at
levels
significantly
lower
than
currently
required.
This
credit
is
not
available
to
membrane,
bag/
cartridge,
slow
sand,
or
diatomaceous
earth
plants,
due
to
the
lack
of
documented
correlation
between
effluent
turbidity
and
Cryptosporidium
removal
in
these
processes.

This
remainder
of
this
chapter
is
organized
as
follows:

7.2
LT2ESWTR
Compliance
Requirements
­
describes
the
conditions
for
receiving
Cryptosporidium
removal
credit
and
monitoring
requirements
for
maintaining
compliance.

7.3
Reporting
Requirements
­
describes
the
routine
reporting
requirements
that
systems
must
follow
to
receive
credit.

7.4
Process
Control
Techniques
­
discusses
modifications
or
operational
aspects
that
provide
the
tightened
process
control
needed
to
meet
the
turbidity
requirements
for
this
toolbox
option.

7.5
Process
Management
Techniques
­
describes
standard
operating
procedures,
response
plans
for
loss
of
chemical
feed,
adequate
chemical
storage,
and
voluntary
programs
that
encourage
full
process
control
from
administration
to
operation
and
maintenance.
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
2
7.2
LT2ESWTR
Compliance
Requirements
7.2.1
Treatment
Credit
For
systems
using
conventional
or
direct
filtration
treatment
to
obtain
an
additional
0.5
log
Cryptosporidium
removal
credit,
the
LT2ESWTR
requires
the
combined
filter
effluent
(
CFE)
turbidity
measurements
taken
for
any
month
at
each
plant
are
less
than
or
equal
to
0.15
NTU
in
at
least
95
percent
of
the
measurements
(
40
CFR
141.727(
a)).

Alternatively,
the
LT2ESWTR
allows
systems
using
conventional
or
direct
filtration
treatment
to
claim
an
additional
1.0
log
Cryptosporidium
removal
credit
for
any
month
at
each
plant
that
meet
both
of
the
following
individual
filter
effluent
(
IFE)
turbidity
requirements
(
40
CFR
141.727(
b)):

1)
IFE
turbidity
must
be
less
than
0.1
NTU
in
at
least
95
percent
of
the
maximum
daily
values
recorded
at
each
filter
in
each
month,
excluding
the
15
minute
period
following
return
to
service
from
a
filter
backwash
AND
2)
No
individual
filter
may
have
a
measured
turbidity
greater
than
0.3
NTU
in
two
consecutive
measurements
taken
15
minutes
apart.

Systems
may
not
claim
credit
for
combined
filter
performance
AND
individual
filter
performance
in
the
same
month
(
40
CFR
141.727(
a)).

7.2.2
Monitoring
Requirements
For
both
the
CFE
and
IFE
options,
compliance
with
the
LT2ESWTR
is
determined
by
sample
measurements
taken
for
the
IESWTR
and
LT1ESWTR
(
40
CFR
141.727(
a)
and
(
b)).
In
other
words,
the
LT2ESWTR
does
not
require
any
additional
monitoring
from
the
IESWTR
and
LT1ESWTR.

7.2.2.1
Combined
Filter
Effluent
The
monitoring
frequency
and
compliance
calculation
requirements
for
the
CFE
option
are
that
CFE
turbidity
must
be
measured
at
4­
hour
intervals
(
or
more
frequently)
and
95
percent
of
the
measurements
from
each
month
must
be
less
than
or
equal
to
0.15
NTU
(
40
CFR
141.727(
a)).
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
3
[
insert
web
address
for
LT1
Guidance
Manual]
7.2.2.2
Individual
Filter
Effluent
The
monitoring
frequency
and
compliance
calculation
requirements
for
the
IFE
option
are
that
IFE
turbidity
must
be
measured
every
15
minutes
(
excluding
the
15
minute
period
following
return
to
service
from
a
filter
backwash)
and
95
percent
of
the
measurements
from
each
month
must
be
less
than
or
equal
to
0.1
NTU
(
40
CFR
141.727(
b)).

The
LT2ESWTR
specifies
no
individual
filter
may
have
a
measured
turbidity
greater
than
0.3
NTU
in
two
consecutive
measurements
taken
15
minutes
apart
(
40
CFR
141.727(
b)).
If
the
individual
filter
is
not
providing
water
which
contributes
to
the
CFE
(
i.
e.,
it
is
not
operating,
is
filtering
to
waste,
or
its
filtrate
is
being
recycled)
the
system
does
not
need
to
report
the
turbidity
for
that
specific
filter.

7.2.3
Turbidity
Monitors
An
important
aspect
of
awarding
additional
removal
credit
for
lower
finished
water
turbidity
is
the
performance
of
turbidimeters
in
measuring
turbidity
below
0.3
NTU.
The
EPA
believes
that
currently
available
turbidity
monitoring
equipment
is
capable
of
reliably
assessing
turbidity
at
levels
below
0.1
NTU,
provided
instruments
are
well
calibrated
and
maintained.
EPA
strongly
recommends
systems
that
pursue
additional
treatment
credit
for
lower
finished
water
turbidity
to
develop
the
procedures
necessary
to
ensure
accurate
and
reliable
measurement
of
turbidity
at
levels
of
0.1
NTU
and
less,
and
believes
these
procedures
to
be
essential
to
maintain
toolbox
credit.

Turbidimeter
maintenance
should
include
frequent
calibration
by
the
manufacturer's
methods
as
well
as
frequent
verification,
in
order
to
measure
accurately
in
the
low
turbidity
ranges
required
for
this
toolbox
option.
Chapter
3
of
the
LT1ESWTR
Turbidity
Provisions
Guidance
Manual
describes
the
sampling
methods,
operation,
maintenance,
and
calibration
for
turbidimeters
and
discusses
quality
assurance
and
quality
control
measures.
This
section
summarizes
the
information
from
that
chapter,
including
the
approved
methods,
commonly
used
turbidimeters,
calibration
standards,
and
important
factors
of
maintaining
turbidimeters.
Systems
are
encouraged
to
review
Chapter
3
of
the
LT1ESWTR
Turbidity
Provisions
Guidance
Manual
to
ensure
their
operation,
maintenance,
and
calibration
practices
meet
or
exceed
those
recommended
by
EPA.
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
4
7.2.3.1
Methods
Currently,
EPA
has
approved
three
methods
for
the
measure
of
turbidity
(
described
in
40
CFR
141.74).

°
EPA
Method
180.1
°
Standard
Method
2130B
°
Great
Lakes
Instrument
Method
2
These
methods
are
summarized
in
Appendices
C,
D,
and
E
of
the
LT1ESWTR
Turbidity
Provisions
Guidance
Manual.

7.2.3.2
Maintenance
and
Calibration
Maintenance
and
calibration
of
both
benchtop
and
on­
line
turbidimeters
are
fully
described
in
the
LT1ESWTR
Turbidity
Provisions
Guidance
Manual.
It
is
very
important
to
follow
the
manufactures
procedures
for
maintenance
and
calibration
of
turbidimeters,
as
they
vary
between
manufacturers.
Tables
7.1
and
7.2
list
several
maintenance
and
calibration
activities
common
among
manufacturers
for
on­
line
and
bench
top
turbidimeters.
These
activities
should
be
conducted
for
all
turbidimeters
to
ensure
proper
operation
on
a
consistent
basis.
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
5
Table
7.1
Maintenance
and
Calibration
Activities
for
On­
line
Turbidimeters
Activity
Recommended
Frequency
Inspect
for
cleanliness
Weekly
Verify
sample
flow
rate
Weekly
Verify
calibration
with
primary
standard,
secondary
standard
or
by
comparison
with
bench­
top1
For
CFE
credit:
Weekly
on
CFE
turbidimeter
and
monthly
on
all
IFE
turbidimeters
For
IFE
credit:
Weekly
on
both
CFE
and
IFE
turbidimeters
Clean
and
calibrate
with
primary
standard
Quarterly2
Verify
alarm
settings
and
response
to
alarms
Quarterly
Replace
lamp
Annually
1The
sampling
and
comparative
process
of
using
a
bench
top
turbidimeter
is
likely
to
introduce
unacceptable
levels
of
error
into
the
verification
process.
Therefore,
EPA
recommends
using
a
primary
or
secondary
standard
over
the
bench
top
for
calibration.
2Frequency
should
be
increased
if
verification
indicates
greater
than
a
+/­
10
percent
deviation
from
secondary
standard.

Table
7.2
Maintenance
and
Calibration
Activities
for
Bench
Top
Turbidimeters
Activity
Recommended
Frequency
Inspect
for
cleanliness
Daily
Verify
calibration
with
secondary
standard
Weekly
Clean
and
calibrate
Quarterly1
Replace
lamp
Annually
1Frequency
should
be
increased
if
verification
indicates
greater
than
a
+/­
10
percent
deviation
from
secondary
standard.
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
6
In
addition
to
those
activities
listed
in
the
tables,
the
following
documentation
or
record
keeping
items
should
be
developed
and
kept
up
to
date.

$
Log
of
turbidimeter
maintenance
and
calibration
$
QA/
QC
plan
for
accuracy
and
consistency
$
Standard
operating
procedures
7.2.3.3
Quality
Assurance
/
Quality
Control
(
QA/
QC)

Systems
should
develop
a
QA/
QC
plan
for
measuring
turbidity.
This
plan
should
include
written
standard
operating
procedures
(
SOPs)
to
ensure
that
operation,
maintenance,
and
calibration
activities
are
carried
out
in
a
consistent
manner,
and
that
each
activity
is
understood
by
all
that
are
involved.
At
a
minimum,
systems
should
develop
SOPs
for
cleaning
turbidimeters,
creating
Formazin
Standards,
calibrating
turbidimeters,
and
referencing
index
samples.

For
bench
top
turbidimeters,
measurement
errors
can
be
introduced
by
dirt,
scratches,
or
condensation
on
the
glassware,
air
bubbles
in
the
sample,
and
particle
settling.
Operators
should
strictly
follow
manufactures
procedures
for
sampling
and
maintenance.

7.3
Reporting
Requirements
7.3.1
Combined
Filter
Performance
In
order
to
receive
the
0.5
log
removal
credit
for
the
LT2ESWTR,
a
water
system
must
submit
monthly
verification
of
CFE
turbidity
levels
less
than
or
equal
to
0.15
NTU
in
at
least
95
percent
of
the
4­
hour
CFE
measurements
taken
each
month
(
40
CFR
141.730).

7.3.2
Individual
Filter
Performance
For
the
1.0
log
removal
credit
under
the
LT2ESWTR,
a
water
system
must
report
monthly
verification
of
IFE
turbidity
levels
less
than
or
equal
to
0.1
NTU
in
at
least
95
percent
of
all
maximum
daily
IFE
measurements
taken
each
month
for
each
filter
(
excluding
the
15
minute
period
following
startup
after
backwash),
and
monthly
verification
that
there
were
no
IFE
measurements
greater
than
0.3
NTU
in
two
consecutive
readings
15
minutes
apart
for
any
filter
(
40
CFR
141.730).

As
requirements
of
the
IESWTR
and
the
LT1ESWTR,
water
systems
must
report
monthly
that
they
have
conducted
individual
filter
turbidity
monitoring.
Systems
are
required
to
report
actual
IFE
measurements
only
if
they
have
exceeded
one
of
the
IFE
turbidity
triggers.
Systems
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
7
The
IESWTR
guidance
manuals
are
available
on
EPA's
website
at:

www.
epa.
gov/
safewater/
mdbp/
implement.
html.
that
would
apply
successfully
for
the
1.0
log
Cryptosporidium
removal
credit
for
LT2ESWTR
compliance
would
not,
by
definition,
be
systems
that
were
required
to
report
IFE
measurements
under
the
earlier
regulations.
A
system
must,
therefore,
submit
additional
information
about
IFE
turbidity
measurements
in
order
to
receive
the
1.0
log
credit.

7.4
Process
Control
Techniques
To
meet
the
lower
finished
water
turbidity
requirements,
systems
will
need
a
high
level
of
process
control
from
the
source
water
intake
to
the
filters.
The
Guidance
Manual
for
Compliance
with
the
IESWTR:
Turbidity
Provisions
(
EPA
1999)
discusses
many
design
and
operational
aspects
water
systems
should
consider
for
achieving
low
effluent
turbidity.
Chapter
4
of
that
manual
provides
design
and
operational
modifications
systems
can
use
to
optimize
their
process
for
compliance
with
the
LT2ESWTR
toolbox
requirements.
This
chapter
of
the
Toolbox
Guidance
Manual
builds
on
that
information,
by
highlighting
those
modifications
or
operational
aspects
that
provide
the
tightened
process
control
needed
to
meet
the
turbidity
requirements
for
this
toolbox
option.
To
meet
the
lower
finished
water
turbidity
requirements
of
the
CFE
or
IFE
performance
standards,
systems
will
need
consistent
process
performance
and
the
ability
to
maintain
the
high
filtered
water
quality
under
sub­
optimal
conditions
and
changing
water
quality.

Design
and
operational
factors
are
not
the
only
considerations
for
maintaining
the
high
filtered
water
quality
standards;
all
areas
of
a
water
system
must
be
dedicated
towards
the
process
optimization
goal,
including
administration
and
maintenance.
This
toolbox
option
will
require
continuing
effort
and
commitment
from
management
and
operations
staff.
Table
7.3
lists
several
factors
in
the
areas
of
administration,
design,
operation,
and
maintenance
that
may
limit
a
system's
ability
to
continually
meet
the
LT2ESWTR
lower
finished
water
turbidity
requirements.
This
table
demonstrates
the
importance
of
considering
the
capabilities
of
the
entire
water
system.
This
table
was
adapted
from
the
Composite
Correction
Program,
an
EPA
program
for
optimizing
water
treatment
plant
performance
(
discussed
in
section
7.5.4.2).
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
8
Table
7.3
Performance
Limiting
Factors
(
Adapted
from
the
Composite
Correction
Program)

ADMINISTRATION
Plant
Administrators
Policies
Do
existing
policies
or
the
lack
of
policies
discourage
staff
members
from
making
required
operation,
maintenance,
and
management
decision
to
support
plant
performance
and
reliability?

Familiarity
with
Plant
Needs
Do
administrators
lack
first­
hand
knowledge
of
plant
needs?

Supervision
Do
management
styles,
organizational
capabilities,
budgeting
skills,
or
communication
practices
at
any
management
level
adversely
impact
the
plant
to
the
extent
that
performance
is
affected?

Planning
Does
the
lack
of
long
range
planning
for
facility
replacement
or
alternative
source
water
quantity
or
quality
adversely
impact
performance?

Complacency
Does
the
presence
of
consistent,
high
quality
source
water
result
in
complacency
within
the
water
utility?

Reliability
Do
inadequate
facilities
or
equipment,
or
the
depth
of
staff
capability,
present
a
potential
weak
link
within
the
water
utility
to
achieve
and
sustain
optimized
performance?

Source
Water
Protection
Does
the
water
utility
lack
an
active
source
water
protection
program?

Plant
Staff
Number
Does
a
limited
number
of
staff
have
a
detrimental
effect
on
plant
operations
or
maintenance?

Plant
Coverage
Does
the
lack
of
plant
coverage
result
in
inadequate
time
to
complete
necessary
operational
activities?
(
Note:
This
factor
could
have
significant
impact
if
no
alarm/
shutdown
capability
exists
­
see
design
factors).

Personnel
Turnover
Does
high
personnel
turnover
cause
operation
and
maintenance
problems
that
affect
process
performance
or
reliability?

Compensation
Does
a
low
pay
scale
or
benefit
package
discourage
more
highly
qualified
persons
from
applying
for
operator
positions
or
cause
operators
to
leave
after
they
are
trained?

Work
Environment
Does
a
poor
work
environment
create
a
condition
for
"
sloppy
work
habits"
and
lower
operator
morale?

Certification
Does
the
lack
of
certified
personnel
result
in
poor
O&
M
decisions?

Financial
Operating
Ratio
Does
the
utility
have
inadequate
revenues
to
cover
operation,
maintenance,
and
replacement
of
necessary
equipment
(
i.
e.,
operating
ratio
less
than
1.0)?

Coverage
Ratio
Does
the
utility
have
inadequate
net
operating
profit
to
cover
debt
service
requirements
(
i.
e.,
coverage
ratio
less
than
1.25)?

Reserves
Does
the
utility
have
inadequate
reserves
to
cover
unexpected
expenses
or
future
facility
replacement?
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
9
DESIGN
Source
Water
Quality
Microbial
Contamination
Does
the
presence
of
microbial
contamination
sources
in
close
proximity
to
the
water
treatment
plant
intake
impact
the
plant's
ability
to
produce
an
adequate
treatment
barrier?

Unit
Process
Adequacy
Intake
Structure
Does
the
design
of
the
intake
structure
result
in
excessive
clogging
of
screens,
build­
up
of
silt,
or
passage
of
material
that
affects
plant
equipment?

Presedimentation
Basin
Does
the
design
of
an
existing
presedimentation
basin
or
the
lack
of
a
presedimentation
basin
contribute
to
degraded
plant
performance?

Raw
Water
Pumping
Does
the
use
of
constant
speed
pumps
cause
undesirable
hydraulic
loading
on
downstream
unit
processes?

Flow
Measurement
Does
the
lack
of
flow
measurement
devices
or
their
accuracy
limit
plant
control
or
impact
process
control
adjustments?

Chemical
Storage
and
Feed
Facilities
Do
inadequate
chemical
storage
and
feed
facilities
limit
process
needs
in
a
plant?

Flash
Mix
Does
an
inadequate
mixing
result
in
excessive
chemical
use
or
insufficient
coagulation
to
the
extent
that
it
impacts
plant
performance?

Flocculation
Does
a
lack
of
flocculation
time,
inadequate
equipment,
or
lack
of
multiple
flocculation
stages
result
in
poor
floc
formation
and
degrade
plant
performance?

Sedimentation
Does
the
sedimentation
basin
configuration
or
equipment
cause
inadequate
solids
removal
that
negatively
impact
filter
performance?

Filtration
Do
filter
or
filter
media
characteristics
limit
the
filtration
process
performance?

Disinfection
Do
the
disinfection
facilities
have
limitations,
such
as
inadequate
detention
time,
improper
mixing,
feed
rates,
proportional
feeds,
or
baffling,
that
contribute
to
poor
disinfection?

Sludge/
Backwash
Water
Treatment
and
Disposal
Do
inadequate
sludge
or
backwash
water
treatment
facilities
negatively
influence
plant
performance?

Plant
Operability
Process
Flexibility
Does
the
lack
of
flexibility
to
feed
chemicals
at
desired
process
locations
or
the
lack
of
flexibility
to
operate
equipment
or
processes
in
an
optimized
mode
limit
the
plant's
ability
to
achieve
desired
performance
goals?

Process
Controllability
Do
existing
process
controls
or
lack
of
specific
controls
limit
the
adjustment
and
control
of
a
process
over
the
desired
operating
range?

Process
Instrumentation
/
Automation
Does
the
lack
of
process
instrumentation
or
automation
cause
excessive
operator
time
for
process
control
and
monitoring?

Standby
Units
Does
the
lack
of
standby
units
for
key
equipment
cause
degraded
process
performance
during
breakdown
or
during
necessary
preventive
maintenance
activities?

Flow
Proportioning
Does
inadequate
flow
splitting
to
parallel
process
units
cause
individual
unit
overloads
that
degrade
process
performance?
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
10
Alarm
Systems
Does
the
absence
or
inadequacy
of
an
alarm
system
for
critical
equipment
or
processes
cause
degraded
process
performance?

Alternate
Power
Source
Does
the
absence
of
an
alternative
power
source
cause
reliability
problems
leading
to
degraded
plant
performance?

Laboratory
Space
and
Equipment
Does
the
absence
of
an
adequately
equipped
laboratory
limit
plant
performance?

Sample
Taps
Does
the
lack
of
sample
taps
on
process
flow
streams
prevent
needed
information
from
being
obtained
to
optimized
performance?

OPERATION
Testing
Process
Control
Testing
Does
the
absence
or
wrong
type
of
process
control
testing
cause
improper
operational
control
decisions
to
be
made?

Representative
Sampling
Do
monitoring
results
inaccurately
represent
plant
performance
or
are
samples
collected
improperly?

Process
Control
Time
on
the
Job
Does
staff's
short
time
on
the
job
and
associated
unfamiliarity
with
process
control
and
plant
needs
result
in
inadequate
or
improper
control
adjustments?

Water
Treatment
Understanding
Does
the
operator's
lack
of
basic
water
treatment
understanding
contribute
to
improper
operational
decisions
and
poor
plant
performance
or
reliability?

Application
of
Concepts
and
Testing
to
Process
Control
Is
the
staff
deficient
in
the
application
of
their
knowledge
of
water
treatment
and
interpretation
of
process
control
testing
such
that
improper
process
control
adjustments
are
made?

Operational
Resources
Training
Program
Does
inadequate
training
result
in
improper
process
control
decisions
by
plant
staff?

Technical
Guidance
Does
inappropriate
information
received
from
a
technical
resource
(
e.
g.,
design
engineer,
equipment
representative,
regulator,
peer)
cause
improper
decision
or
priorities
to
be
implemented?

Operational
Guidelines/
Procedures
Does
the
lack
of
plant­
specific
operating
guidelines
and
procedures
result
in
inconsistent
operational
decision
that
impact
performance?

MAINTENANCE
Maintenance
Program
Preventive
Does
the
absence
or
lack
of
an
effective
preventive
maintenance
program
cause
unnecessary
equipment
failures
or
excessive
downtime
that
results
in
plant
performance
or
reliability
problems?

Corrective
Does
the
lack
of
corrective
maintenance
procedures
affect
the
completion
of
emergency
equipment
maintenance?

Housekeeping
Does
a
lack
of
good
housekeeping
procedures
detract
from
the
professional
image
of
the
water
treatment
plant?

Maintenance
Resources
Materials
and
Equipment
Does
the
lack
of
necessary
materials
and
tools
delay
the
response
time
to
correct
plant
equipment
problems?
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
11
Skills
or
Contract
Services
Do
plant
maintenance
staff
have
inadequate
skills
to
correct
equipment
problems
or
do
the
maintenance
staff
have
limited
access
to
contact
maintenance
services?

7.4.1
Chemical
Feed
There
are
two
main
considerations
for
the
chemical
application
of
a
coagulation
and
flocculation
treatment
process:

$
Are
the
chemicals
and
their
dose
optimum
for
the
treatment
process?

$
Are
they
properly
mixed
or
dispersed
at
the
right
point
in
the
system?

7.4.1.1
Type
of
Chemical
and
Dose
Optimizing
the
coagulation
and
flocculation
for
the
range
of
water
quality
and
demand
experienced
by
the
plant
is
a
key
factor
in
improving
the
overall
treatment
performance
and
ensuring
process
control.
One
method
commonly
used
to
evaluate
the
type
and
dose
of
coagulant
and
other
chemical
additives
is
the
jar
test
(
AWWA
2000a).

To
provide
the
process
control
necessary
for
producing
consistently
low
filter
water
turbidity,
systems
should
establish
SOPs
for
changing
chemical
additions
when
raw
water
quality
changes
significantly.
The
SOPs
should
list
the
appropriate
chemicals
to
be
added
and
the
dose
according
to
specified
raw
water
conditions.
Jar
tests
or
other
chemical
evaluations
should
be
conducted
with
raw
water
samples
representing
conditions
from
high
water
quality
to
the
worstcase
scenario
and
should
reasonably
represent
the
treatment
process.

7.4.1.2
Mixing
Adding
coagulants
at
the
proper
location
and
providing
the
right
amount
of
mixing
is
critical
to
the
coagulation
and
flocculation
processes.

$
Metal
salts
such
as
alum
and
ferric
chloride
should
be
added
at
the
point
of
highest
mixing.

$
Low
weight
polymers
can
be
added
with
the
metal
salts
or
at
a
second
stage
mixing
process.

$
High
weight
polymers
should
be
added
at
a
point
of
gentle
mixing.

The
coagulation
process
occurs
rapidly;
therefore,
it
is
important
that
the
coagulant
is
welldispersed
and
distributed
across
the
width
of
the
flow
stream
at
the
point
of
addition.
Flash
mixers
are
necessary
for
coagulants
requiring
instantaneous
mixing.
Systems
with
mechanical
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
12
mixers
for
these
types
of
coagulants
should
consider
changing
to
a
design
that
provides
more
uniform
dispersion
as
studies
have
indicated
that
mechanical
mixers
experience
short
circuiting
and
frequent
maintenance
requirements
(
Kawamura
2000).
Kawamura
rated
several
flash
mixer
designs
according
to
(
in
order
of
importance)
effectiveness,
reliability,
minimal
maintenance,
and
cost:

1)
Diffusion
mixing
by
pressured
water
jets
2)
In­
line
static
mixing
3)
In­
line
mechanical
mixing
4)
Hydraulic
mixing
5)
Mechanical
flash
mixing
6)
Diffusion
by
pipe
grid
The
mixing
speed
should
be
adjustable
and
changed
with
flow
and
raw
water
conditions
as
necessary.
Cold
water
is
more
viscous
and
may
require
a
higher
mixing
energy.
Highly
turbid
or
colored
water
may
also
require
more
mixing
power
to
properly
disperse
the
coagulant.
For
flash
mixing,
Kawamura
(
2000)
recommends
G
×
t
values
of
300
to
1600,
where
G
is
the
mixing
energy
(
expressed
in
seconds­
1)
and
t
is
time
(
seconds).

7.4.1.3
Streaming
Current
Detectors
and
Zeta
Potential
Monitors
The
coagulation
process
should
be
monitored
continuously,
with
real
time
output.
Streaming
current
detectors
(
SCDs)
can
provide
on­
line
coagulation
control,
by
measuring
the
net
surface
charge
of
the
particle
and
ionic
species
in
a
sample
of
water.
Through
jar
testing
or
other
coagulant
studies,
the
charge
measurement
is
correlated
to
the
optimal
coagulation
conditions.
The
SCDs
are
typically
located
directly
after
coagulant
addition
to
allow
the
operator
time
to
adjust
the
dose
of
the
coagulant
before
filtration.
This
quick
response
can
prevent
process
upsets
due
to
fluctuations
in
influent
water
quality.

Source
waters
high
in
iron
or
manganese
concentrations
and
the
use
of
treatment
chemicals
with
iron
salts
or
potassium
permanganate
can
extensively
increase
maintenance
requirements
(
AWWA,
2000a).
Additionally,
use
of
powdered
activated
carbon
can
increase
maintenance
requirements.
AWWA
recommends
comparing
the
SCD
measurements
to
jar
tests
and
zeta
potential
monitoring
results
on
a
regular
basis
(
AWWA,
2000a).

Zeta
potential
monitors
also
indicate
particle
surface
charge
and
can
be
used
in
the
same
manner
as
SCDs.
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
13
7.4.2
Flocculation
The
purpose
of
the
flocculation
process
is
to
aggregate
the
particles
into
larger
groups
of
particles
or
"
flocs"
that
will
settle
in
the
subsequent
sedimentation
process.
Through
gentle
and
prolonged
agitation,
the
suspended
particles
collide
with
each
other
and
form
flocs.
The
mixing
must
be
thorough
enough
to
provide
opportunities
for
the
particles
to
collide
but
also
gentle
enough
to
prevent
the
flocculated
particles
from
breaking
apart.
It
is
likely,
however,
that
some
floc
breakup
will
occur.
As
aggregates
grow
in
size,
they
are
more
likely
to
break
up
due
to
the
shearing
forces
in
the
mixing
chamber.
In
this
situation
the
aggregation
and
breakup
can
occur
simultaneously
leading
to
a
steady­
state
distribution
of
floc
sizes.

The
key
factors
of
an
effective
flocculation
process
include:
adequate
mixing,
low
floc
breakup,
and
plug
flow
conditions.
The
following
guidance
can
help
to
achieve
these
conditions:

$
Tapered
mixing
is
most
appropriate
with
variable
G
values
ranging
from
70
sec­
1
to
15
sec­
1.

$
If
flow
is
split
between
two
flocculators,
they
should
be
mixing
at
the
same
speed.
Coagulant
dosages
are
most
likely
optimized
to
one
speed.

$
Basin
inlet
and
outlet
conditions
should
prevent
floc
breakup.

$
Baffling
should
be
adequate
to
provide
plug
flow
conditions.

7.4.3
Sedimentation
The
purpose
of
the
sedimentation
process
is
to
enhance
filtration
by
removing
the
flocculated
particles.
As
with
other
unit
processes,
the
sedimentation
process
must
be
optimized
and
provide
a
consistent
settled
water
quality.
The
key
factors
of
a
good
settling
process
include:

$
Minimization
of
short
circuiting.

$
Sludge
removal
equipment
should
not
resuspend
particles
or
produce
currents
in
the
water.

$
Surface
loading
rate,
or
overflow
rate,
needs
to
provide
enough
settling
time.
If
flocculated
particles
are
not
settling
it
could
be
a
function
of
particle
density
or
the
surface
loading
rate.

$
Continuous
or
frequent
turbidity
monitoring
of
settled
water.
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
14
To
provide
a
consistent
well­
clarified
water
from
the
sedimentation
basin,
the
operating
parameters
of
the
sedimentation
basin
may
need
to
be
adjusted
with
significant
fluctuations
in
raw
water
quality.
For
example,
if
a
runoff
event
causes
a
spike
in
turbidity
the
particles
may
need
more
time
to
settle,
and
by
decreasing
the
flow
through
the
basin
it
is
possible
to
achieve
the
desired
level
of
clarification.
Table
7.4
lists
sedimentation
basin
effluent
turbidity
goals
for
several
State
and
industry
optimization
programs.
Operators
need
knowledge
and
authority
to
modify
the
coagulation
and
flocculation
processes
or
reduce
the
flow
to
the
plant
when
settled
water
quality
goals
are
not
being
met.
For
long­
term
process
control,
tracking
seasonal
raw
water
quality
changes
and
their
impacts
on
the
settling
process
can
provide
valuable
information
for
optimizing
the
overall
sedimentation
process.

Table
7.4
Effluent
Turbidity
Goals
for
the
Sedimentation
Process
Optimization
Program
Sedimentation
Basin
or
Clarifier
Effluent
Turbidity
Goal
California
­
Cryptosporidium
Action
Plan
1
to
2
NTU
Texas
<
2
NTU
Partnership
for
Safe
Water
/
EPA
Composite
Correction
Program
(
CCP)
1
NTU
for
raw
water
conditions
of
<
10
NTU
2
NTU
for
raw
water
conditions
of
>
10
NTU
The
sludge
blanket
level
is
also
an
important
factor
for
optimum
settling
conditions.
A
water
system
should
have
SOPs
for
sludge
draw­
off
that
include
routine
checks
of
the
sludge
pumping
lines.
Sludge
pumping
lines
can
plug,
causing
disruption
of
the
sludge
blanket
and
consequently
disrupting
the
settling
process.

7.4.4
Filtration
Filtration
is
the
last
step
in
the
particle
removal
process.
Although
filter
performance
is
a
function
of
the
coagulation,
flocculation,
and
sedimentation
processes,
proper
filter
operation
is
needed
to
provide
the
high
quality
finished
water
required
for
this
toolbox
option.
The
following
factors
should
be
considered
when
optimizing
or
evaluating
filtration
performance.

7.4.4.1
Flow
Split
Systems
should
evaluate
the
flow
distribution
to
the
filters
to
ensure
there
is
an
even
load
across
all
filters
under
the
range
of
expected
operating
conditions
(
e.
g.,
filter
out
of
service,
backwash).
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
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June
2003
7­
15
7.4.4.2
Filter
Beds
The
filters
should
be
operated
with
a
design
capacity
that
considers
at
least
one
filter
as
a
reserve.
The
reserve
filter
is
put
on­
line
to
maintain
flow
stability
to
the
filters;
if
this
is
not
possible,
flow
to
the
filters
should
be
reduced.
This
will
allow
consistent
flow
when
one
filter
is
backwashed
or
taken
out
of
service
for
maintenance.

Media
loss
or
disturbance
can
lead
to
particles
passing
through
the
filters.
The
filter
should
be
inspected
on
a
regular
basis
to
detect
changes
in
the
media.
Media
should
be
inspected
to
ensure
depths
of
media
are
proper,
the
media
are
evenly
distributed,
and
the
size
distribution
of
the
media
are
still
to
specifications.
Media
samples
can
be
taken
with
a
coring
device
or
by
excavation
for
the
inspection.
If
media
are
lost
or
damaged,
they
should
be
replaced.
Underdrains
should
also
be
examined
regularly
to
be
sure
they
are
not
damaged
and
causing
disturbances
to
the
media
or
allowing
particles
and
media
to
pass
out
of
the
filter.

7.4.4.3
Backwashing
Backwashing
is
an
integral
part
of
the
filtration
process.
Two
important
operating
parameters
for
backwashing
are
the
backwash
flow
rate
and
frequency
of
cycles.
Other
factors
relating
to
backwash
that
affect
filter
effluent
quality
are
hydraulic
surges
and
filter
start­
up
or
"
ripening".

Flow
rate
Systems
should
determine
the
appropriate
flow
that
will
clean
the
filter
and
prevent
mudball
formation,
but
will
not
upset
the
filter
media
and
subject
the
underdrain
to
sudden
momentary
pressure
increases.
Typical
flow
rates
are
15
to
20
gpm/
ft2
which
result
in
15
to
30
percent
bed
expansion.

Frequency
Although
the
filter
effluent
turbidity
is
the
indicator
for
pathogen
control
and
the
determining
factor
for
compliance,
other
operating
parameters
should
be
used
to
determine
when
backwash
is
needed.
Emelko
et
al.
(
2000)
performed
filtration
studies
where
pathogen
breakthrough
occurred
towards
the
end
of
the
filter
cycle
before
an
increase
in
turbidity
was
detected.
Their
studies
emphasize
the
need
to
evaluate
and
optimize
backwashing
cycles
with
respect
to
filter
effluent
water
quality.
Most
systems
use
filtration
time,
headloss,
effluent
turbidity,
or
effluent
particle
counts
to
indicate
when
backwashing
is
needed.
For
improved
process
control,
it
may
be
beneficial
to
use
all
indicators.

Systems
with
multiple
filters
also
should
evaluate
the
hydraulic
surges
resulting
from
backwashing.
The
timing
of
individual
filter
backwash
cycles
should
be
considered
with
respect
to
the
other
filters,
particularly
adjacent
filters.
Consider
the
following
two
examples:
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
16
$
If
a
large
system
with
50
filters
backwashed
10
filters
at
the
same
time,
this
would
cause
a
20
percent
increase
in
flow
to
the
other
filters.
In
this
situation,
the
system
could
backwash
fewer
filters
at
one
time
or
reduce
the
flow
to
the
filters
to
avoid
the
filter
overload.

$
When
one
filter
is
backwashed,
a
hydraulic
surge
can
be
experienced
by
an
adjacent
filter.

Improving
filter
effluent
during
start­
up
It
is
very
important
for
systems
to
conduct
a
full
evaluation
of
their
backwashing
process
and
operational
variations
to
optimize
the
process.
At
the
process
optimization
level,
systems
must
eliminate
turbidity
spikes
in
the
filter
effluent
resulting
from
the
backwashing
processCit
only
takes
a
few
high
turbidity
readings
to
cause
non­
compliance.
The
following
operational
practices
may
provide
improved
filter
effluent
during
start­
up:

$
Ramping
the
backwash
rate
down
in
increments
to
allow
better
media
gradation
$
Resting
a
filter
after
backwash
for
several
minutes
or
up
to
several
hours
before
putting
the
filter
in
service
$
Adding
a
polymer
to
the
backwash
water
$
Slowly
increasing
the
hydraulic
load
on
the
filter
as
it
is
brought
back
on
line
7.4.4.4
Filter
to
Waste
During
the
beginning
of
a
filter
cycle
the
filter
is
"
ripening"
and
the
effluent
turbidity
is
usually
higher.
To
avoid
sending
this
poorer
quality
water
to
the
CFE
stream,
the
filter
effluent
produced
during
the
first
few
minutes
of
a
filter
cycle
can
be
sent
to
waste
(
filter
to
waste)
or
recycled
to
the
head
of
the
plant.
Some
systems
filter
to
waste
or
recycle
until
the
filter
effluent
reaches
the
desired
level
of
turbidity.
Practicing
filter
to
waste
produces
an
overall
higher
quality
water
and
may
be
necessary
to
maintain
a
CFE
or
IFE
below
0.15
NTU.

7.4.4.5
Backwash
Recycle
Plants
that
recycle
the
backwash
water
to
the
head
of
the
plant
should
evaluate
the
impacts
the
backwash
stream
has
on
the
coagulation,
flocculation,
and
sedimentation
processes.
For
example,
the
operator
should
know
how
the
coagulation
and
flocculation
processes
need
adjusting
when
there
is
a
change
in
recycle
flow.
Ideally,
the
impacts
of
the
recycle
flow
on
these
processes
should
be
minimized.
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
17
For
systems
that
recycle,
the
Filter
Backwash
Rule
requires
spent
filter
backwash,
thickener
supernatant,
or
liquids
from
dewatering
processes
to
be
returned
through
all
the
processes
of
a
system's
existing
conventional
or
direct
filtration
treatment
train
(
40
CFR
141.76(
c)).
The
rule
allows
for
alternative
recycle
locations
with
State
approval
(
40
CFR
141.76(
c)).

7.4.4.6
Filter
Assessments
Filter
assessments
can
provide
valuable
information
for
optimizing
the
performance
of
a
filter.
The
IESTWR
and
LT1ESWTR
require
systems
to
conduct
an
individual
filter
selfassessment
if
a
filter
exceeds
specified
effluent
turbidity
criteria.
However,
systems
seeking
Cryptosporidium
treatment
credit
for
lower
finished
water
turbidity
should
also
consider
conducting
filter
assessments
to
evaluate
operating
parameters
and
optimize
filter
performance.
Chapter
5
of
the
IESWTR
Turbidity
Guidance
Manual
describes
how
to
conduct
an
individual
filter
self­
assessment.

7.4.5
Hydraulic
Control
Proper
hydraulic
control
throughout
the
treatment
process
is
essential.
In
the
coagulation
and
sedimentation
processes
it
is
important
to
minimize
short
circuiting
so
the
majority
of
the
water
receives
the
designed
coagulation
and
sedimentation
treatment.
Hydraulic
surges
can
cause
greater
turbulence
that
may
break
up
flocculating
particles
and
resuspend
settling
particles.
In
the
subsequent
filtration
process,
hydraulic
surges
can
cause
particle
breakthrough
anytime
during
the
filtration
cycle.
Systems
should
look
at
historical
water
demand
data
and
other
conditions
that
adversely
affect
the
system's
ability
to
control
filter
performance
(
e.
g.,
backwashing,
changes
in
flow).
With
these
data,
they
should
develop
operating
plans
to
address
the
condition
and
allow
control
of
the
filter
effluent
quality.

7.5
Process
Management
Techniques
7.5.1
Standard
Operating
Procedures
(
SOPs)

Developing
SOPs
for
all
aspects
of
the
operation
and
maintenance
of
a
water
system
is
essential
for
running
a
high
quality
system.
SOPs
provide
the
basis
for
ensuring
that
activities
are
accomplished
in
a
consistent
manner.
They
should
be
kept
as
simple
as
possible
in
order
to
ensure
that
each
operator
is
consistent
in
carrying
out
the
task
at
hand.
The
title
of
the
procedure
should
be
clear,
concise,
and
descriptive
of
the
equipment,
process,
or
activity.
SOPs
should
be
developed
with
input
from
staff,
thus
enabling
them
to
understand
and
implement
procedures
in
compliance
with
applicable
requirements.
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
18
7.5.2
Prevention
and
Response
Plan
for
Loss
of
Chemical
Feed
Loss
of
chemical
feed
is
a
common
cause
of
increased
turbidity
through
the
treatment
processes.
Plants
should
have
equipment
and
SOPs
for
preventing
such
occurrences
or
reacting
to
them
rapidly
if
they
do
occur.
The
following
items
are
necessary
to
prevent
an
upset
in
water
quality
due
to
a
chemical
feed
failure.

$
SOPs
to
verify
doses
with
feed
response
time
(
lag
time)
accounted
for
$
Redundant
feeds
$
Routine
maintenance
of
all
chemical
feed
parts
(
e.
g.,
pump,
feed
line)

$
Inventory
of
spare
parts
available
so
repairs
can
be
made
quickly
$
Pump
or
feed
failure
alarms
$
Process
monitors
detecting
chemical
feed
failure
(
e.
g.,
streaming
current,
zeta
potential,
and
pH
monitors)

7.5.3
Adequate
Chemical
Storage
Sufficient
chemical
storage
is
necessary
to
ensure
continued
operation
of
the
plant
at
proper
dosages,
including
enough
to
run
at
higher
dosages
if
an
unexpected
turbidity
spike
should
occur
in
the
raw
water.
Care
must
also
be
taken,
however,
to
follow
manufacturer's
suggestions
on
the
useful
life
of
the
chemical.
Many
coagulants
will
degrade
over
time
and
will
not
perform
properly
and
may
even
cause
increased
turbidity
if
allowed
to
age
too
long.
Storage
tanks
should
also
be
designed
so
that
there
are
no
dead
spaces
where
chemicals
may
accumulate
with
much
longer
residence
times
than
the
hydraulic
residence
time
of
the
tank.

7.5.4
Voluntary
Programs
EPA,
State
regulatory
agencies,
AWWA,
and
other
drinking
water
organizations
have
established
voluntary
programs
for
systems
to
ensure
the
delivery
of
safe
water
to
their
customers.
These
programs
often
focus
on
optimizing
the
treatment
process
and
identifying
the
limiting
factors
of
performance.
Consequently,
they
are
excellent
aids
for
systems
considering
this
toolbox
option.
This
section
discusses
two
programs,
the
Partnership
for
Safe
Water
and
the
Composite
Correction
Program
(
CCP).
(
The
CCP
is
also
promoted
as
part
of
the
Partnership
for
Safe
Water).
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
19
For
further
information
about
the
Partnership
for
Safe
Water
and
how
to
join,
see
AWWA's
website:
http://
www.
awwa.
org/
partner/
partner1.
htm
7.5.4.1
Partnership
for
Safe
Water
The
Partnership
for
Safe
Water
is
a
voluntary
cooperative
effort
between
EPA,
AWWA,
and
surface
water
systems.
The
goal
of
the
program
is
to
"
provide
a
new
measure
of
safety
to
millions
of
Americans
by
implementing
prevention
programs
where
legislation
or
regulation
does
not
exist.
The
preventive
measures
are
based
around
optimizing
treatment
plant
performance,
and
thus
increasing
protection
against
microbial
contamination
in
America's
drinking
water
supply."
(
http://
www.
awwa.
org/
partner/
partner1.
htm).

Water
systems
that
participate
in
the
program
go
through
four
phases:

Phase
I:
Commitment
B
operators
and
management
indicate
their
willingness
to
complete
the
program
through
phase
III.

Phase
II:
Data
Collection
and
Analysis
B
the
water
system
must
collect
one
year
of
raw,
settled,
and
filter
effluent
turbidity
data
and
submit
to
AWWA
for
analysis.

Phase
III:
Self
Assessment
B
allows
the
system
to
examine
the
capabilities
of
the
existing
plant's
operation
and
administration
and
identify
factors
that
limit
performance.

Phase
IV:
Procedures
and
Applications
Package
B
systems
demonstrate
they
addressed
areas
of
limited
performance
and
produce
high
quality
water
as
measured
by
filter
effluent
turbidity.

Through
the
efforts
of
monitoring,
data
analysis,
and
evaluating
the
capabilities
of
unit
processes,
significant
improvements
in
water
quality
can
be
achieved.
In
the
Partnership's
2001
Annual
report,
AWWA
reported
an
increase
from
20
percent
to
32
percent
of
plants
completing
Phase
II
with
finished
water
turbidity
levels
less
than
0.1
NTU
(
based
on
95th
percentiles).
At
the
beginning
of
Phase
III,
approximately
51
percent
of
plants
reported
95th
percentile
turbidity
less
than
0.1
NTU,
and
after
completing
Phase
III
approximately
70
percent
of
plants
achieved
less
than
0.1
NTU.

7.5.4.2
Composite
Correction
Program
(
CCP)

The
CCP
was
developed
in
1988
to
optimize
surface
water
treatment
plant
performance
with
respect
to
protection
from
microbial
pathogens.
The
program
consists
of
two
parts,
the
comprehensive
performance
evaluation
(
CPE)
and
comprehensive
technical
assistance
(
CTA).
The
CPE
is
a
thorough
review
and
analysis
of
a
facility's
design
capabilities
and
associated
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
20
administrative,
operational,
and
maintenance
practices
as
they
relate
to
achieving
optimum
performance
from
the
facility.
It
can
be
conducted
by
the
system
or
by
a
third
party
over
a
period
of
roughly
3
to
4
days.
The
CTA
builds
on
the
results
of
the
CPE
by
addressing
the
combination
of
factors
that
limit
a
facility's
performance.
If
conducted
by
a
third
party,
it
should
be
implemented
by
a
third
party
who
is
in
a
position
to
pursue
corrective
actions
in
all
areas,
including
politically
sensitive,
administrative,
or
operational
limitations.

EPA
published
a
handbook,
Optimizing
Water
Treatment
Plant
Performance
Using
the
Composite
Correction
Program
(
1998),
that
fully
describes
the
goals,
methods,
and
procedures
of
the
CCP.
To
obtain
a
copy,
call
the
EPA
Safe
Drinking
Water
Hotline
at
1­
800­
426­
4791.
Chapter
7
­
Combined
and
Individual
Filter
Performance
LT2ESWTR
Toolbox
Guidance
Manual
Proposal
Draft
June
2003
7­
21
References
American
Water
Works
Association.
2000a.
Operational
Control
of
Coagulation
and
Filtration
Processes,
2nd
Edition.
American
Water
Works
Association.

American
Water
Works
Association.
2000.
Water
Quality
and
Treatment
5th
Edition.
McGraw
Hill.

Kawamura,
Susumu.
2000.
Integrated
Design
and
Operation
of
Water
Treatment
Facilities.
John
Wiley
&
Sons,
Inc.

USEPA.
1998.
Optimizing
Water
Treatment
Plant
Performance
Using
the
Composite
Correction
Program.
Office
of
Water
and
Office
of
Research
and
Development.
EPA
625/
6­
91/
027.
