Appendix
C
Changes
in
Treatment
Plant
Operation
Significant
Excursions
Identified
Using
the
"
Maximum
Concentration
Approach"
This
page
intentionally
left
blank.
Significant
Excursion
Guidance
Manual
Proposal
Draft
July
2003
C­
1
The
first
part
of
this
appendix
includes
general
system
information
and
a
summary
of
TTHM
and
HAA5
data
that
resulted
in
Elm
City
having
to
perform
a
significant
excursion
evaluation.
This
information
as
part
of
the
documentation
of
a
significant
excursion.
Only
the
Significant
Excursion
Report
is
required
to
be
completed
by
systems
that
experience
a
significant
excursion.

This
appendix
is
provided
as
an
example
of
a
system
in
which
changes
in
treatment
plant
operations
led
to
a
DBP
Significant
Excursion.
Possible
strategies
to
reduce
excursions
are
presented
in
Chapter
4,
but
they
are
not
to
be
included
in
the
identification
and
documentation
process.
Appendices
B,
D,
and
E
provide
similar
examples
for
systems
in
which
changes
in
source
water
quality,
changes
in
distribution
system,
and
multiple
causes
resulted
in
a
significant
excursion.

This
example
assumes
the
state
has
chosen
to
use
100
µ
g/
L
TTHM
and
75
µ
g/
L
HAA5
as
the
trigger
levels
for
determining
that
a
significant
excursion
has
occurred
and
that
a
significant
excursion
evaluation
is
required.

Background
Information
for
this
Example
System
Description:

General
system
characteristics:
Service
area:
Elm
City
plus
surrounding
suburban
areas
Production:
Annual
average
daily
demand
15
MGD
Source
Water
Information:
Hardwood
Lake
(
surface
water)
pH:
from
6.9
to
7.5
Alkalinity:
from
82
to
98
mg/
L
as
CaCO
3
TOC:
from
2.1
to
4.0
mg/
L
as
C
Bromide:
from
0.04
to
0.1
mg/
L
Turbidity:
1
to
100
ntu
Softwood
River
(
surface
water)
pH:
from
6.8
to
7.9
Alkalinity:
from
77
to
94
mg/
L
as
CaCO
3
TOC:
from
1.6
to
9.4
mg/
L
as
C
Bromide:
from
0.03
to
0.1
mg/
L
Turbidity:
2
to
115
ntu
Significant
Excursion
Guidance
Manual
Proposal
Draft
July
2003
C­
2
Treatment
Provided:
Hardwood,
conventional
(
15
MGD
design,
7.5
MGD
average)
Softwood
River,
conventional
with
GAC
(
20
MGD
design,
7.5
MGD
average)
Primary
and
residual
disinfection:
Chlorine/
chlorine
at
both
plants
Summary
of
Stage
2
DBPR
Monitoring
Locations:
Table
C.
1
summarizes
the
Stage
2
DBPR
monitoring
locations
used
by
Elm
City.
Sample
locations
are
marked
in
the
distribution
system
schematic
presented
in
Figure
C.
1.

Table
C.
1
Stage
2
DBPR
Monitoring
Locations
Location
Description
Location
#
1
Hardwood
Plant
­
average
residence
time
Location
#
2
Hardwood
Plant
­
high
TTHM
Location
#
3
Hardwood
Plant
­
high
HAA5
Location
#
4
Hardwood/
Softwood
Mix
Zone
­
high
TTHM
Location
#
5
Hardwood/
Softwood
Mix
Zone
­
high
TTHM
Location
#
6
Hardwood/
Softwood
Mix
Zone
­
high
TTHM
Location
#
7
Softwood
Plant
­
average
residence
time
Location
#
8
Softwood
Plant
­
high
HAA5
Significant
Excursion
Guidance
Manual
Proposal
Draft
July
2003
C­
3
Pineville
MIXING
ZONE
Softwood
River
WTP
Hardwood
WTP
Elevated
Storage
Tank
Ground
storage
tank
Pump
station
2
Oakville
1
3
Elmville
5
Downtown
Appleville
Weeping
Willow
Poplarville
Cedarville
Cypressville
6
7
4
8
Peak
DBP
location
Figure
C.
1
Schematic
of
Elm
City
Distribution
System
and
Stage
2
DBPR
Monitoring
Locations
Significant
Excursion
Guidance
Manual
Proposal
Draft
July
2003
C­
4
DBP
Excursion
Investigation:

During
the
last
sampling
period
which
took
place
in
September
2004,
Elm
City
experienced
unusually
high
TTHM
values
(
relative
to
the
LRAA)
at
five
monitoring
locations
(#
4,
#
5,
#
6,
#
7,
#
8).
Similarly,
unusually
high
HAA5
values
were
detected
at
two
monitoring
locations
(#
7
and
#
8).
DBP
data
from
the
previous
year
and
most
recent
sampling
period
(
five
quarters
total)
are
presented
in
Table
C.
2.

Table
C.
2.
TTHM
and
HAA5
Monitoring
Data
Loc
atio
n
TTHM
(
ug/
L)
HAA5
(
ug/
L)

Quarterly
Pre­
Sept.
2004
Data1
LRAA
Pre­
Sept.
2004
Avg.
Sept.
2004
Data
LRAA
Sept.
2004
Avg.
Quarterly
Pre­
Sept.
2004
Data1
LRAA
Pre­
Sept.
2004
Avg.
Sept.
2004
Data
LRAA
Sept.
2004
Avg.

#
1
54,
67,
58,
75
65
118
74
52,
37,
30,
41
40
84
48
#
2
68,
68,
55,
69
63
145
77
38,
45,
28,
19
33
75
42
#
3
66,
52,
71,
72
64
122
74
41,
46,
45,
39
43
58
47
#
4
50,
55,
51,
61
55
82
60
42,
43,
38,
34
39
54
42
#
5
34,
48,
55,
50
44
68
48
32,
43,
55,
38
42
37
43
#
6
44,
62,
58,
60
49
70
53
45,
33,
41,
40
40
53
42
#
7
40,
41,
37,
46
41
58
46
21,
38,
28,
19
27
29
29
#
8
49,
39,
50,
76
52
78
56
43,
39,
41,
45
42
49
44
1Data
for
sampling
conducted
on
September
2003,
December
2003,
March
2004
and
June
2004.
Data
relevant
to
peak
excursions
are
bold
and
underlined.

Unusually
high
TTHM
samples
were
collected
at
locations
#
1,
#
2,
and
#
3,
and
unusually
high
HAA5
samples
were
collected
at
locations
#
1
and
#
2.
The
results
are
significantly
higher
than
both
the
LRAA
at
those
locations
for
the
previous
12­
month
period
and
the
historic
TTHM
and
HAA5
values
at
those
locations
for
the
years
1999­
2003
(
see
Significant
Excursions
Evaluation
Report).
Significant
excursion
were
identified
when
DBP
levels
exceeded
100
µ
g/
L
TTHM
or
75
µ
g/
L
HAA5.
All
of
the
monitoring
locations
affected
by
high
DBP
are
located
in
the
area
served
by
the
Hardwood
plant.
The
city
staff
has
reason
to
believe
that
a
process
change
occurred
during
treatment
operations
at
the
Hardwood
plant
caused
this
increase
in
DBP
levels.
Significant
Excursion
Guidance
Manual
Proposal
Draft
July
2003
C­
5
Significant
Excursion
Report
date:
October
16th,
2004
Evaluation
Report
Report
prepared
by:
Ronald
Doe,
P.
E.

Page
1
System
name:
Elm
City
1)
When
was
the
significant
excursion
sample(
s)
collected?
What
were
the
TTHM
and
HAA5
concentrations?

Location
No.
#
1
#
2
#
3
#
______

Location
description
Hardwood
Plant
­
average
residence
time
Hardwood
Plant
­
high
TTHM
Hardwood
Plant
­
high
HAA5
Sample
collection
date
Sept.
4th,
2004
Sept.
4th,
2004
Sept.
4th,
2004
Sample
collection
time
1
p.
m.
3
p.
m.
11
a.
m.

TTHM
LRAA
Concentration
(
ug/
L)
74
77
74
TTHM
Concentration
(
ug/
L)
118
145
122
HAA5
LRAA
Concentration
(
ug/
L)
48
42
HAA5
Concentration
(
ug/
L)
84
75
Significant
Excursion
Guidance
Manual
Proposal
Draft
July
2003
C­
6
Note:
Attach
additional
sheets
if
you
observed
more
than
four
significant
excursions
during
this
round
of
sampling.

2)
Where
did
the
excursion(
s)
occur?
Attach
a
schematic
of
your
system,
sketch
your
system
in
the
space
below,
or
have
a
schematic
of
your
system
available
to
review
with
your
state
at
the
time
of
your
next
sanitary
survey.
Indicate
the
location(
s)
of
the
significant
excursion(
s)
on
your
schematic.

Location
#
1
B
Represents
average
residence
time
of
water
leaving
the
Hardwood
Plant.
It
is
located
in
the
Oakville
neighborhood.
There
are
no
storage
facilities
between
the
treatment
plant
and
this
location.

Location
#
2
B
Sample
tap
is
a
hose
bib
at
a
building
located
in
Pineville
in
a
zone
of
the
distribution
system
with
water
age
greater
than
average.
Water
in
this
area
is
from
the
Hardwood
Plant.

Location
#
3
B
This
location
is
located
in
the
Downtown
area.
Water
is
primarily
from
the
Hardwood
Plant.
A
ground
storage
tank
is
near
this
location.

The
location
of
these
sample
locations
is
illustrated
in
Figure
C.
1.

Significant
Excursion
Evaluation
Report
Page
2
Report
date:
October
16th,
2004
Significant
Excursion
Guidance
Manual
Proposal
Draft
July
2003
C­
7
3)
Attach
(
or
provide
in
the
Supplemental
Data
Form)
all
available
water
quality
data
for
the
round
of
sampling
in
which
the
significant
excursion
occurred.
At
a
minimum,
include
all
TTHM
and
HAA5
results
from
the
sampling
period.
You
should
also
consider
including
pH,
temperature,
alkalinity,
TOC,
disinfectant
residual,
and
any
other
data
that
you
think
would
be
useful.

a)
Were
there
any
unusual
circumstances
associated
with
this
round
of
sampling?

Yes
No
X
If
yes,
please
explain.

b)
Were
all
analytical
QA/
QC
measures
met?

Sample
preservation
Yes
X
No
Sample
holding
time
Yes
X
No
Other
If
no,
please
explain.

4)
Attach
(
or
provide
in
the
Supplemental
Data
Form)
historical
TTHM
and
HAA5
data
for
the
location(
s)
at
which
the
significant
excursion(
s)
occurred.
Provide
at
least
three
years
of
data,
if
available.
Significant
Excursion
Guidance
Manual
Proposal
Draft
July
2003
C­
8
Significant
Excursion
Evaluation
Report
Page
3
Report
date:
October
16th,
2004
5)
What
caused
your
excursion(
s)
to
occur?

Sections
A
through
F
starting
on
page
4
can
help
you
determine
the
possible
cause(
s)
of
your
excursion.
Please
note
there
may
be
more
than
one
factor
which
resulted
in
your
excursion.

Section
A:
Source
water
quality
change
Section
B:
Process
upset
at
treatment
plant
Section
C:
Planned
change
or
maintenance
activities
at
plant
Section
D:
Planned
distribution
system
operations
or
maintenance
activities
Section
E:
Unplanned
events
in
distribution
system
6)
List
steps
taken
or
planned
to
reduce
DBP
peak
levels.

Plan
to
calibrate
standby
pumps
for
future
maintenance
of
coagulant
process
feed
pumps.
Considering
improvements
to
coagulant
process
monitoring
(
daily
verification
with
pump
catch,
streaming
current
monitoring).
Significant
Excursion
Guidance
Manual
Proposal
Draft
July
2003
C­
9
Significant
Excursion
Evaluation
Report
Page
4
Report
date:
October
16th,
2004
A.
Source
Water
Quality
Changes
°
Did
any
of
the
events
listed
below
take
place
before
the
DBP
excursion
to
cause
TOC
levels
to
increase?
 
Heavy
rain
fall
 
Flooding
 
Spring
snow­
melt/
runoff
 
Significant
decrease
in
rainfall
or
source
flow
 
Algae
bloom
°
Did
any
of
the
events
listed
below
take
place
before
the
DBP
excursion
to
cause
bromide
levels
to
increase?
 
Significant
decrease
in
rainfall
or
source
flow
 
Brackish
or
seawater
intrusion
°
Did
pH
and/
or
alkalinity
significantly
change?

°
If
two
or
more
supplies
are
used,
was
a
greater
portion
of
water
drawn
from
the
one
with
higher
TOC?

°
Was
raw
water
stored
for
an
unusually
long
period
of
time
resulting
in
a
significant
increase
in
water
temperature?

Conclusions:

Did
source
water
quality
changes
cause
or
contribute
to
your
significant
excursion(
s)?

Yes
No
X
If
yes,
please
explain:

Attach
all
supporting
operational
or
other
data
which
led
you
to
conclude
this
was
the
cause
of
your
excursion(
s)
or
make
sure
this
data
is
available
during
your
sanitary
survey.
Significant
Excursion
Guidance
Manual
Proposal
Draft
July
2003
C­
10
Significant
Excursion
Evaluation
Report
Page
5
Report
date:
October
16th,
2004
B.
Process
Upset
at
Treatment
Plant
°
Was
raw
water
stored
for
an
unusually
long
time,
providing
additional
contact
time
for
DBP
formation
after
prechlorination?

°
Were
there
changes
in
coagulation
practices?

S
Were
there
any
changes
or
malfunctions
of
the
coagulation
process
in
the
days
leading
to
the
excursion?

S
Were
the
coagulant
dose
and
pH
properly
adjusted
for
incoming
source
water
conditions?

°
Were
there
changes
in
chlorination
practices?
 
Were
there
any
changes
in
chlorine
dose
at
any
location
in
the
plant?
 
Were
there
changes
in
plant
flow
that
may
have
resulted
in
longer
than
normal
residence
time
at
any
location
in
the
plant?

S
Did
the
pH
change
at
the
point
of
chlorine
addition?

°
Were
there
changes
in
settling
practices?

S
Was
there
excess
sludge
build­
up
in
the
settling
basin
that
may
have
carried
over
to
the
point
of
disinfectant
addition?

S
Was
there
any
disruption
in
the
sludge
blanket
that
may
have
resulted
in
carryover
to
the
point
of
disinfection?

°
Were
there
changes
in
filtration
practices?

S
Have
filter
run
times
been
changed
to
meet
raw
water
quality
changes?

S
Were
there
any
spikes
in
individual
filter
effluent
turbidity
(
which
may
indicate
particulate
or
colloidal
TOC
breakthrough)
in
the
days
leading
to
the
excursion?

S
Did
chlorinated
water
sit
in
the
filter
for
an
extended
period
of
time?

S
Were
all
filters
run
in
a
filter­
to­
waste
mode
during
initial
filter
ripening?

S
Were
any
filters
operated
beyond
their
normal
filter
run
time?

S
If
GAC
filters
are
used:
Is
it
possible
the
adsorptive
capacity
of
the
GAC
bed
was
reached
before
reactivation
occurred?

S
If
biological
filtration
is
used:
Were
there
any
process
upsets
that
may
have
resulted
in
breakthrough
of
TOC
(
particularly
biodegradable
TOC)?

°
Were
there
changes
in
plant
flow
that
may
have
resulted
in
an
unusually
high
residence
time
in
the
clearwell
on
the
days
prior
to
the
excursion?

S
For
example,
a
temporary
plant
shutdown.

Continued
on
next
page
Significant
Excursion
Guidance
Manual
Proposal
Draft
July
2003
C­
11
Significant
Excursion
Evaluation
Report
Page
6
Report
date:
October
16th,
2004
B.
Process
Upset
at
Treatment
Plant
(
Continued)

Conclusions:

Did
a
process
upset
in
the
treatment
plant
cause
or
contribute
to
your
significant
excursion(
s)?

Yes
X
No
If
yes,
please
explain:

The
combination
of
two
process
changes
at
the
Hardwood
Plant
is
the
most
probable
cause
of
the
DBP
excursion
noted
during
the
September
2004
sampling
event.
Specifically
the
two
events
were:

°
Pre­
oxidation
of
raw
water
with
chlorine
for
taste
and
odor
control
following
an
algae
bloom
in
Hardwood
Lake.
Chlorine
addition
to
the
raw
water
is
not
a
routine
practice.

°
Ferric
chloride
was
underfed
for
two
days
around
the
September
2004
sampling
resulting
in
a
decrease
in
TOC
removal
at
the
Hardwood
Plant.
The
increased
TOC
concentration
passing
through
the
treatment
process
has
probably
lead
to
increased
formation
of
TTHM
and
HAA5.
The
low
ferric
dose
was
the
result
of
poor
calibration
of
the
standby
pumps
that
were
placed
in
service
during
the
maintenance
of
the
feed
pumps
that
are
normally
used.
It
was
noticed
that
pH
of
coagulation
increased
from
the
usual
5.5
to
6.2
range
to
7.1
to
7.3.

Attach
all
supporting
operational
or
other
data
which
led
you
to
conclude
this
was
the
cause
of
your
excursion(
s)
or
make
sure
this
data
is
available
during
your
sanitary
survey.
Significant
Excursion
Guidance
Manual
Proposal
Draft
July
2003
C­
12
Significant
Excursion
Evaluation
Report
Page
7
Report
date:
October
16th,
2004
C.
Planned
Change
or
Maintenance
Activities
for
the
Treatment
Plant
°
Was
there
a
recent
change
(
or
addition)
of
pre­
oxidant?

°
Was
there
any
maintenance
in
the
basin
that
may
have
stirred
sludge
from
the
bottom
of
the
basin
and
caused
it
to
carry
over
to
the
point
of
disinfectant
addition?

°
Did
you
change
the
type
or
manufacturer
of
the
coagulant?

°
Were
there
any
changes
in
disinfection
practices
in
the
days
prior
to
the
excursion?

S
For
example,
a
switch
from
chloramines
to
free
chlorine
for
burnout
period.

S
Discontinuation
of
ozone
which
forms
very
little
TTHM.

°
Was
a
filter(
s)
taken
off­
line
for
an
extended
period
of
time
that
caused
the
other
filters
to
operate
near
maximum
design
capacity
and
creating
the
conditions
for
possible
breakthrough?

°
Were
any
pumps
shut
down
for
maintenance,
leading
to
changes
in
flow
patterns
or
hydraulic
surges?

Conclusions:

Did
a
planned
maintenance
or
operational
activity
in
the
treatment
plant
cause
or
contribute
to
your
significant
excursion(
s)?

Yes
No
X
If
yes,
please
explain:

Attach
all
supporting
operational
or
other
data
which
led
you
to
conclude
this
was
the
cause
of
your
excursion(
s)
or
make
sure
this
data
is
available
during
your
sanitary
survey.
Significant
Excursion
Guidance
Manual
Proposal
Draft
July
2003
C­
13
Significant
Excursion
Evaluation
Report
Page
8
Report
date:
October
16th,
2004
D.
Planned
Distribution
System
Operations
or
Maintenance
Activities
°
Was
a
tank
drained
for
cleaning
or
other
maintenance?

S
Was
the
tank
drained
to
waste
or
to
the
distribution
system?

S
Was
a
larger
volume
than
normal
drained
to
the
distribution
system?

°
If
booster
disinfection
is
used,
was
the
booster
disinfectant
dose
higher
than
the
normal
booster
disinfectant
dose
for
that
season?

°
Were
there
any
system
maintenance
activities
in
the
days
prior
to
DBP
excursion?
Including:
 
Repairing
mains
or
installing
new
mains
 
Closure
of
valves
to
isolate
sections
of
pipes
°
Were
the
pipes
flushed
properly
or
were
the
appropriate
valves
re­
opened
after
work
was
completed?

°
Did
any
pump
or
pipeline
maintenance
occur
that
would
have
changed
the
flow
pattern
in
the
area
the
sample
was
drawn
from?

S
Change
in
flow
can
cause
water
in
stagnant
areas
to
be
drawn
into
another
area.

°
Did
any
pipeline
replacement
occur?

S
Disinfecting
piping
in
contact
with
drinking
water
could
result
in
a
high
concentration
of
chlorine
entering
the
distribution
system
and
thus
increase
DBPs.

Conclusions:

Did
a
planned
distribution
system
maintenance
or
operational
activity
cause
or
contribute
to
your
significant
excursion(
s)?

Yes
No
X
If
yes,
please
explain:

Attach
all
supporting
operational
or
other
data
which
led
you
to
conclude
this
was
the
cause
of
your
excursion(
s)
or
make
sure
this
data
is
available
during
your
sanitary
survey.
Significant
Excursion
Guidance
Manual
Proposal
Draft
July
2003
C­
14
Significant
Excursion
Evaluation
Report
Page
9
Report
date:
October
16th,
2004
E.
Unplanned
Distribution
System
Events
°
Were
there
increases
in
demand
that
caused
older
water
in
storage
tanks
to
be
drawn
into
the
system?

S
Were
there
any
major
fire
events?

S
Did
one
or
more
storage
tank
have
greater
than
average
drawdown
preceding
the
time
of
DBP
peak
excursion?

°
Were
there
decreases
in
demand
that
resulted
in
longer
than
normal
system
residence
times?

S
Were
there
any
large
customers
off­
line?

°
Did
any
main
breaks
occur
causing
changes
in
flow
patterns
in
the
influence
area
of
the
sample
location?

°
If
you
collect
water
temperature
inside
storage
tanks,
was
the
temperature
inside
the
tank
higher
than
normal
for
the
season?

°
Were
any
storage
tanks
hydraulically
locked
out
of
the
system
for
an
extended
period
and
then
used
preceding
the
time
of
DBP
peak
excursion?

°
Did
changes
in
overall
water
demand
cause
a
change
in
water
demand
patterns
in
the
vicinity
of
dead
ends
and/
or
stagnant
zones
in
the
system?

°
Were
there
large
variations
in
localized
system
pressures
that
were
different
from
the
normal
pressure
range
that
could
have
caused
a
change
in
water
demand
patterns
in
the
vicinity
of
dead
ends
and/
or
stagnant
zones
in
the
system?

Conclusions:

Did
an
unplanned
distribution
system
maintenance
or
operational
activity
cause
or
contribute
to
your
significant
excursion(
s)?

Yes
No
X
If
yes,
please
explain:

Attach
all
supporting
operational
or
other
data
which
led
you
to
conclude
this
was
the
cause
of
your
excursion(
s)
or
make
sure
this
data
is
available
during
your
sanitary
survey.
Significant
Excursion
Guidance
Manual
Proposal
Draft
July
2003
C­
15
Significant
Excursion
Evaluation
Report
Page
10
Report
date:
October
16th,
2004
F.
If
you
were
unable
to
identify
the
cause
of
your
significant
excursion(
s)
after
reviewing
Sections
A
through
E,
are
you
able
to
identify
another
potential
cause
of
your
increase
in
DBP
concentrations?
Explain.

Note:
If
you
are
unable
to
determine
the
cause
of
your
excursion
you
may
wish
to
consider:

°
More
frequent
raw
water
temperature
monitoring.
°
More
frequent
raw
water
TOC
monitoring.
°
Increased
disinfectant
residual
monitoring
in
the
distribution
system.
°
Tracer
studies
to
characterize
distribution
system
water
age.
°
Development
of
a
hydraulic
model
to
characterize
the
distribution
system.

Attach
all
supporting
operational
or
other
data
which
led
you
to
conclude
this
was
the
cause
of
your
excursion(
s)
or
make
sure
this
data
is
available
during
your
sanitary
survey.
Significant
Excursion
Guidance
Manual
Proposal
Draft
July
2003
C­
16
Supplemental
Data
Form
for
the
Significant
Excursion
Evaluation
Report
Report
date:
October
16th,
2004
Report
prepared
by:
Ronald
Doe,
P.
E.

System
name:
Elm
City
1)
Water
quality
data
from
significant
excursion
sampling
period.

Location
No.
#
1
#
2
#
3
#
4
#
5
#
6
#
7
#
8
Location
Name
TTHM
(
ug/
L)
118
145
122
82
68
70
58
78
HAA5
(
ug/
L)
84
75
65
58
47
53
30
50
Free
Chlorine
(
mg/
L)
0.6
0.8
0.2
NA
NA
1.1
NA
0.8
Total
Chlorine
(
mg/
L)
0.8
1.2
0.4
NA
NA
1.8
NA
1.2
pH
8.2
8.5
7.9
8.1
7.8
8.3
7.5
8.2
2)
Supplemental
data
from
each
treatment
facility:

Plant
#
1:
Hardwood
Plant
Plant
#
2:
Softwood
Plant
Raw
Water
Temperature:
NA
Raw
Water
Temperature:
NA
Plant
Effluent
Water
Temperature:
20

C
Plant
Effluent
Water
Temperature:
20

C
Raw
Water
TOC:
2.2
mg/
L
(
Avg.

2.0mg/
L)
Raw
Water
TOC:
1.8
mg/
L
(
Avg.

2.0mg/
L)
Other
Data:
Other
Data:
Inf.
turb.
25
ntu
(
Avg.

20
ntu)

3)
Historical
TTHM
and
HAA5
data
at
significant
excursion
sampling
locations.

TTHM
Data
(
ug/
L)
HAA5
Data
(
ug/
L)

Monitoring
#
1
#
2
#
3
#
Monitoring
#
1
#
2
#
#
Location
Location
Date
­
1999
61
78
45
Date
­
1999
32
56
Date
­
2000
55
59
56
Date
­
2000
29
47
Date
­
2001
70
69
41
Date
­
2001
48
23
Date
­
2002
64
81
73
Date
­
2002
36
34
Date
­
2003
66
54
53
Date
­
2003
41
45
Avg.
99­
03
63
68
54
Avg.
99­
03
37
45
Attach
additional
sheets
if
necessary
