(a)
General requirements.
(1) The requirements of
this section constitute national primary drinking water regulations. The
regulations in this section establish monitoring and other requirements for
identifying Stage 2 Disinfection Byproduct compliance monitoring locations for
determining compliance with maximum contaminant levels for total
trihalomethanes (TTHM) and haloacetic acids (five)(HAA5). You must use an
Initial Distribution System Evaluation (IDSE) to determine locations with
representative high TTHM and HAA5 concentrations throughout your distribution
system. IDSEs are used in conjunction with, but separate from, section
11-20-45.1 compliance monitoring, to identify and select Stage 2 Disinfection Byproduct
compliance monitoring locations.
(2)
Applicability. You are subject to these requirements if your
system is a community water system that uses a primary or residual disinfectant
other than ultraviolet light or delivers water that has been treated with a
primary or residual disinfectant other than ultraviolet light; or if your
system is a nontransient noncommunity water system that serves at least 10,000
people and uses a primary or residual disinfectant other than ultraviolet light
or delivers water that has been treated with a primary or residual disinfectant
other than ultraviolet light.
(3)
Schedule. You must comply with the requirements of this section on the schedule
in the following table.
|
If you serve this population
|
You must submit your standard monitoring plan or
system specific study plan1 or 40/30 certificati
on2 to the State by or receive very small system
waiver from the State
|
You must complete your standard monitoring or system
specific study by
|
You must submit your IDSE report to the State
by3
|
|
|
Systems that are not part of a combined distribution
system and systems that serve the largest population in the combined
distribution system
|
|
>=100,000
|
October 1, 2006
|
September 30, 2008
|
January 1, 2009
|
|
50,000-99,999
|
April 1, 2007
|
March 31, 2009
|
July 1, 2009
|
|
10,000-49,999
|
October 1, 2007
|
September 30, 2009
|
January 1, 2010
|
|
<10,000(CWS only)
|
April 1, 2008
|
March 31, 2010
|
July 1, 2010
|
|
|
Other systems that are part of a combined
distribution system
|
|
Wholesale system or consecutive system
|
-at the same time as the system with the earliest
compliance date in the combined distribution system
|
-at the same time as the system with the earliest
compliance date in the combined distribution system
|
-at the same time as the system with the earliest
compliance date in the combined distribution system
|
1If, within 12 months after the
date identified in this column, the State does not approve your plan or notify
you that it has not yet completed its review, you may consider the plan that
you submitted as approved. You must implement that plan and you must complete
standard monitoring or a system specific study no later than the date
identified in the third column.
2You must submit your 40/30
certification under subsection (d) by the date indicated.
3If, within three months after the
date identified in this column (nine months after the date identified in this
column if you must comply on the schedule with a service population of between
10,000 and 49,999), the State does not approve your IDSE report or notify you
that it has not yet completed its review, you may consider the report that you
submitted as approved and you must implement the recommended Stage 2
Disinfection Byproduct monitoring as required.
For the purpose of the schedule in this paragraph, the State
may determine that the combined distribution system does not include certain
consecutive systems based on factors such as receiving water from a wholesale
system only on an emergency basis or receiving only a small percentage and
small volume of water from a wholesale system. The State may also determine
that the combined distribution system does not include certain wholesale
systems based on factors such as delivering water to a consecutive system only
on an emergency basis or delivering only a small percentage and small volume of
water to a consecutive system.
(4)
You must conduct standard monitoring that meets the requirements
in subsection (b), or a system specific study that meets the requirements in
subsection (c), or certify to the State that you meet 40/30 certification
criteria under subsection (d), or qualify for a very small system waiver under
subsection (e).
(A) You must have taken the
full complement of routine TTHM and HAA5 compliance samples required of a
system with your population and source water under section
11-20-45.1 (or you must have taken the full complement of reduced TTHM and HAA5 compliance
samples required of a system with your population and source water under
section
11-20-45.1 if you meet reduced monitoring criteria under section
1-20-45.1)
during the period specified in paragraph (d)(1) to meet the 40/30 certification
criteria in subsection (d). You must have taken TTHM and HAA5 samples under
subsections
11-20-45.1(b)
and (c) to be eligible for the very small system waiver in subsection
(e).
(B) If you have not taken the
required samples, you must conduct standard monitoring that meets the
requirements in subsection (b), or a system specific study that meets the
requirements in subsection (c).
(5) You must use only the analytical methods
specified in subsection
11-20-45.1(b),
or otherwise approved by EPA for monitoring under this section, to demonstrate
compliance with the requirements of this section.
(6) IDSE results will not be used for the
purpose of determining compliance with MCLs in section
11-20-4.1.
(b) Standard
monitoring.
(1) Your standard monitoring plan
must comply with subparagraphs (A) through (D). You must prepare and submit
your standard monitoring plan to the State according to the schedule following
subsection (a)(3).
(A) Your standard
monitoring plan must include a schematic of your distribution system (including
distribution system entry points and their sources, and storage facilities),
with notes indicating locations and dates of all projected standard monitoring,
and all projected section
11-20-45.1 compliance monitoring.
(B) Your
standard monitoring plan must include justification of standard monitoring
location selection and a summary of data you relied on to justify standard
monitoring location selection.
(C)
Your standard monitoring plan must specify the population served and system
type (subpart H or ground water).
(D) You must retain a complete copy of your
standard monitoring plan submitted under this paragraph, including any State
modification of your standard monitoring plan, for as long as you are required
to retain your IDSE report under subparagraph (3)(D).
(2) Standard monitoring requirements.
(A) You must monitor as indicated in the
table in this subparagraph. You must collect dual sample sets at each
monitoring location. One sample in the dual sample set must be analyzed for
TTHM. The other sample in the dual sample set must be analyzed for HAA5. You
must conduct one monitoring period during the peak historical month for TTHM
levels or HAA5 levels or the month of warmest water temperature. You must
review available compliance, study, or operational data to determine the peak
historical month for TTHM or HAA5 levels or warmest water temperature.
|
Source water type
|
Population size category
|
Monitoring periods and sampling frequency
|
Distribution system monitoring
locations1
|
|
Total per monitoring period
|
Near entry points
|
Average residence time
|
High TTHM
|
High HAA5
|
|
|
|
|
|
|
|
|
|
|
Subpart H
|
<500 consecutive systems
|
One (during peak historical month)
2
|
2
|
1
|
|
1
|
|
|
|
<500 non -consecutive systems
|
|
2
|
|
|
1
|
1
|
|
|
500-3,300 consecutive systems
|
Four (every 90 days)
|
2
|
1
|
|
1
|
|
|
|
500-3,300 non -consecutive systems
|
|
2
|
|
|
1
|
1
|
|
|
3,301-9,999
|
|
2
|
|
1
|
2
|
1
|
|
|
10,000 -49,999
|
Six (every 60 days)
|
4
|
|
2
|
3
|
2
|
|
|
50,000 -249,999
|
|
16
|
3
|
4
|
5
|
4
|
|
|
250,000 -999,999
|
|
24
|
4
|
6
|
8
|
6
|
|
|
1,000,000 -4,999,999
|
|
32
|
6
|
8
|
10
|
8
|
|
|
>=5,000,000
|
|
40
|
8
|
10
|
12
|
10
|
|
Ground water
|
<500 consecutive systems
|
One (during peak historical month)
2
|
2
|
1
|
|
1
|
|
|
|
<500 non -consecutive systems
|
|
2
|
|
|
1
|
1
|
|
|
500-9,999
|
Four (every 90 days)
|
2
|
|
|
1
|
1
|
|
|
10,000 -99,999
|
|
6
|
1
|
1
|
2
|
2
|
|
|
100,000 -499,999
|
|
8
|
1
|
1
|
3
|
3
|
|
|
>=500,000
|
|
12
|
2
|
2
|
4
|
4
|
1A dual sample set (i.e. a TTHM
and an HAA5 sample) must be taken at each monitoring location during each
monitoring period.
2The peak historical month is the
month with the highest TTHM or HAA5 levels or the warmest water
temperature
(B) You must
take samples at locations other than the existing section
11-20-45.1 monitoring locations. Monitoring locations must be distributed throughout the
distribution system.
(C) If the
number of entry points to the distribution system is fewer than the specified
number of entry point monitoring locations, excess entry point samples must be
replaced equally at high TTHM and HAA5 locations. If there is an odd extra
location number, you must take a sample at a high TTHM location. If the number
of entry points to the distribution system is more than the specified number of
entry point monitoring locations, you must take samples at entry points to the
distribution system having the highest annual water flows.
(D) Your monitoring under this paragraph may
not be reduced under the provisions of section
11-20-16.
(3) IDSE report. Your IDSE report must
include the elements required in subparagraphs (A) through (D). You must submit
your IDSE report to the State according to the schedule under subsection
(a)(3).
(A) Your IDSE report must include all
TTHM and HAA5 analytical results from section
11-20-45.1 compliance monitoring and all standard monitoring conducted during the period
of the IDSE as individual analytical results and LRAAs presented in a tabular
or spreadsheet format acceptable to the State. If changed from your standard
monitoring plan submitted under this subsection, your report must also include
a schematic of your distribution system, the population served, and system type
(subpart H or ground water).
(B)
Your IDSE report must include an explanation of any deviations from your
approved standard monitoring plan.
(C) You must recommend and justify Stage 2
Disinfection Byproduct compliance monitoring locations and timing based on the
protocol in subsection (f).
(D) You
must retain a complete copy of your IDSE report submitted under this section
for 10 years after the date that you submitted your report. If the State
modifies the Stage 2 Disinfection Byproduct monitoring requirements that you
recommended in your IDSE report or if the State approves alternative monitoring
locations, you must keep a copy of the State's notification on file for 10
years after the date of the State's notification. You must make the IDSE report
and any State notification available for review by the State or the public.
(c) System
specific studies and study plan. Your system specific study plan must be based
on either existing monitoring results as required under paragraph (1) or
modeling as required under paragraph (2). You must prepare and submit your
system specific study plan to the State according to the schedule under
subsection (a)(3).
(1) Existing monitoring
results. You may comply by submitting monitoring results collected before you
are required to begin monitoring under paragraph (a)(3). The monitoring results
and analysis must meet the criteria in subparagraphs (A) and (B).
(A) Minimum requirements. TTHM and HAA5
results must be based on samples collected and analyzed in accordance with
section
11-20-45.1(b).
Samples must be collected no earlier than five years prior to the study plan
submission date. The monitoring locations and frequency must meet the
conditions identified in this subparagraph. Each location must be sampled once
during the peak historical month for TTHM levels or HAA5 levels or the month of
warmest water temperature for every 12 months of data submitted for that
location. Monitoring results must include all section
11-20-45.1 compliance monitoring results plus additional monitoring results as necessary
to meet minimum sample requirements.
|
System type
|
Population size category
|
Number of monitoring locations
|
Number of samples
|
|
TTHM
|
HAA5
|
|
|
|
|
|
|
|
Subpart H
|
<500
|
3
|
3
|
3
|
|
|
500-3,300
|
3
|
9
|
9
|
|
|
3,301-9,999
|
6
|
36
|
36
|
|
|
10,000-49,999
|
12
|
72
|
72
|
|
|
50,000-249,999
|
24
|
144
|
144
|
|
|
250,000-999,999
|
36
|
216
|
216
|
|
|
1,000,000-4,999,999
|
48
|
288
|
288
|
|
|
>=5,000,000
|
60
|
360
|
360
|
|
|
|
|
|
|
|
Ground
|
<500
|
3
|
3
|
3
|
|
water
|
500-9,999
|
3
|
9
|
9
|
|
|
10,000-99,999
|
12
|
48
|
48
|
|
|
100,000-499,999
|
18
|
72
|
72
|
|
|
>=500,000
|
24
|
96
|
96
|
(B)
Reporting monitoring results. You must report the information in this
subparagraph.
(i) You must report previously
collected monitoring results and certify that the reported monitoring results
include all compliance and non-compliance results generated during the time
period beginning with the first reported result and ending with the most recent
section
11-20-45.1 results.
(ii) You must certify
that the samples were representative of the entire distribution system and that
treatment, and distribution system have not changed significantly since the
samples were collected.
(iii) Your
study monitoring plan must include a schematic of your distribution system
(including distribution system entry points and their sources, and storage
facilities), with notes indicating the locations and dates of all completed or
planned system specific study monitoring.
(iv) Your system specific study plan must
specify the population served and system type (subpart H or ground
water).
(v) You must retain a
complete copy of your system specific study plan submitted under paragraph (1),
including any State modification of your system specific study plan, for as
long as you are required to retain your IDSE report under paragraph
(3)(G).
(vi) If you submit
previously collected data that fully meet the number of samples required under
paragraph (1)(A) and the State rejects some of the data, you must either
conduct additional monitoring to replace rejected data on a schedule the State
approves or conduct standard monitoring under subsection
(b).
(2)
Modeling. You may comply through analysis of an extended period simulation
hydraulic model. The extended period simulation hydraulic model and analysis
must meet the criteria in this paragraph.
(A)
Minimum requirements.
(i) The model must
simulate 24 hour variation in demand and show a consistently repeating 24 hour
pattern of residence time.
(iii)
The model must be calibrated, or have calibration plans, for the
current configuration of the distribution system during the period of high TTHM
formation potential. All storage facilities must be evaluated as part of the
calibration process. All required calibration must be completed no later than
12 months after plan submission.
(B)
Reporting modeling. Your system specific study plan must include
the information listed in
40 C.F.R. §
141.602(a)(2)(ii)(A-H).
(C) If you submit a model that does not fully
meet the requirements under this paragraph, you must correct the deficiencies
and respond to State inquiries concerning the model. If you fail to correct
deficiencies or respond to inquiries to the State's satisfaction, you must
conduct standard monitoring under subsection (b).
(3) IDSE report. Your IDSE report must
include the elements required in subparagraphs (A) through (F). You must submit
your IDSE report according to the schedule in paragraph (a)(3).
(A) Your IDSE report must include all TTHM
and HAA5 analytical results from section
11-20-45.1 compliance monitoring and all system specific study monitoring conducted during
the period of the system specific study presented in a tabular or spreadsheet
format acceptable to the State. If changed from your system specific study plan
submitted under this subsection, your IDSE report must also include a schematic
of your distribution system, the population served, and system type (subpart H
or ground water).
(B) If you used
the modeling provision under paragraph (2), you must include final information
for the elements described in paragraph (2)(B), and a 24-hour time series graph
of residence time for each Stage 2 Disinfection Byproduct compliance monitoring
location selected.
(C) You must
recommend and justify Stage 2 Disinfection Byproduct compliance monitoring
locations and timing based on the protocol in subsection (f).
(D) Your IDSE report must include an
explanation of any deviations from your approved system specific study
plan.
(E) Your IDSE report must
include the basis (analytical and modeling results) and justification you used
to select the recommended Stage 2 Disinfection Byproduct monitoring
locations.
(F) You may submit your
IDSE report in lieu of your system specific study plan on the schedule
identified in subsection (a)(3) for submission of the system specific study
plan if you believe that you have the necessary information by the time that
the system specific study plan is due. If you elect this approach, your IDSE
report must also include all information required under this
subsection.
(G) You must retain a
complete copy of your IDSE report submitted under this section for 10 years
after the date that you submitted your IDSE report. If the State modifies the
Stage 2 Disinfection Byproduct monitoring requirements that you recommended in
your IDSE report or if the State approves alternative monitoring locations, you
must keep a copy of the State's notification on file for 10 years after the
date of the State's notification. You must make the IDSE report and any State
notification available for review by the State or the public.
(d) 40/30 certification
(1) Eligibility. You are eligible for 40/30
certification if you had no TTHM or HAA5 monitoring violations under section
11-20-45.1 of this part and no individual sample exceeded 0.040 mg/L for TTHM or 0.030
mg/L for HAA5 during an eight consecutive calendar quarter period beginning no
earlier than the date specified in this paragraph.
|
If your 40/30 certification is due
|
Then your eligibility for 40/30 certification is
based on eight consecutive calendar quarters of Section
11-20-45.1 compliance monitoring results beginning no earlier
than1
|
|
October 1, 2006
|
January 2004
|
|
April 1, 2007
|
January 2004
|
|
October 1, 2007
|
January 2005
|
|
April 1, 2008
|
January 2005
|
1Unless you are on reduced
monitoring under section
11-20-45.1 and were not required to monitor during the specified period. If you did not
monitor during the specified period, you must base your eligibility on
compliance samples taken during the 12 months preceding the specified
period.
(2) 40/30
certification requirements.
(A) You must
certify to your State that every individual compliance sample taken under
section
11-20-45.1 during the periods specified in paragraph (1) were <= 0.040 mg/L for TTHM
and <= 0.030 mg/L for HAA5, and that you have not had any TTHM or HAA5
monitoring violations during the period specified in paragraph (1).
(B) The State may require you to submit
compliance monitoring results, distribution system schematics, and/or
recommended Stage 2 Disinfection Byproduct compliance monitoring locations in
addition to your certification. If you fail to submit the requested
information, the State may require standard monitoring under subsection (b) or
a system specific study under subsection (c).
(C) The State may still require standard
monitoring under subsection (b) or a system specific study under subsection (c)
even if you meet the criteria in paragraph (1).
(D) You must retain a complete copy of your
certification submitted under this section for 10 years after the date that you
submitted your certification. You must make the certification, all data upon
which the certification is based, and any State notification available for
review by the State or the public.
(e) Very small system waivers.
(1) If you serve fewer than 500 people and
you have taken TTHM and HAA5 samples under section
11-20-45.1,
you are not required to comply with this section unless the State notifies you
that you must conduct standard monitoring under subsection (b) or a system
specific study under subsection (c).
(2) If you have not taken TTHM and HAA5
samples under section
11-20-45.1 or if the State notifies you that you must comply with this section, you must
conduct standard monitoring under subsection (b) or a system specific study
under subsection (c).
(f) Stage 2 Disinfection Byproducts
compliance monitoring location recommendations.
(1) Your IDSE report must include your
recommendations and justification for where and during what month(s) TTHM and
HAA5 monitoring under section
11-20-45.3 should be conducted. You must base your recommendations on the criteria in
paragraphs (2) through (5).
(2) You
must select the number of monitoring locations specified in the following
table. You will use these recommended locations as Stage 2 Disinfection
Byproduct routine compliance monitoring locations, unless State requires
different or additional locations. You should distribute locations throughout
the distribution system to the extent possible.
|
Source water type
|
Population size category
|
Monitoring
frequency1
|
Distribution system monitoring
locations1
|
|
Total per monitoring
period2
|
Highest TTHM
|
Highest HAA5
|
Existing section
11-20-45.1 compliance
|
|
|
|
|
|
|
|
|
|
Subpart H
|
<500
|
per year
|
2
|
1
|
1
|
-
|
|
|
500-3,300
|
per quarter
|
2
|
1
|
1
|
-
|
|
|
3,301-9,999
|
per quarter
|
2
|
1
|
1
|
-
|
|
|
10,000 -49,999
|
per quarter
|
4
|
2
|
1
|
1
|
|
|
50,000 -249,999
|
per quarter
|
8
|
3
|
3
|
2
|
|
|
250,000 -999,999
|
per quarter
|
12
|
5
|
4
|
3
|
|
|
1,000,000 -4,999,999
|
per quarter
|
16
|
6
|
6
|
4
|
|
|
>=5,000,000
|
per quarter
|
20
|
8
|
7
|
5
|
|
|
|
|
|
|
|
|
|
Ground
|
<500
|
per year
|
2
|
1
|
1
|
-
|
|
water
|
500-9,999
|
per year
|
2
|
1
|
1
|
-
|
|
|
10,000 -99,999
|
per quarter
|
4
|
2
|
1
|
1
|
|
|
100,000 -499,999
|
per quarter
|
6
|
3
|
2
|
1
|
|
|
>=500,000
|
per quarter
|
8
|
3
|
3
|
2
|
1All systems must monitor during
month of highest DBP concentrations.
2Systems on quarterly monitoring
must take dual sample sets every 90 days at each monitoring location, except
for subpart H systems serving 500-3,300. Ground water systems serving 500-9,999
on annual monitoring must take dual sample sets at each monitoring location.
All other systems on annual monitoring and subpart H systems serving 500-3,300
are required to take individual TTHM and HAA5 samples (instead of a dual sample
set) at the locations with the highest TTHM and HAA5 concentrations,
respectively. For systems serving fewer than 500 people, only one location with
a dual sample set per monitoring period is needed if highest TTHM and HAA5
concentrations occur at the same location, and month.
(3) You must recommend Stage 2 Disinfection
Byproduct compliance monitoring locations based on standard monitoring results,
system specific study results, and section
11-20-45.1 compliance monitoring results. You must follow the protocol in subparagraphs
(A) through (H). If required to monitor at more than eight locations, you must
repeat the protocol as necessary. If you do not have existing section
11-20-45.1 compliance monitoring results or if you do not have enough existing section
11-20-45.1 compliance monitoring results, you must repeat the protocol, skipping the
provisions of subparagraphs (C) and (G) as necessary, until you have identified
the required total number of monitoring locations. Location with the highest
TTHM LRAA not previously selected as a Stage 2 Disinfection Byproduct
monitoring location.
(A) Location with the
highest HAA5 LRAA not previously selected as a Stage 2 Disinfection Byproduct
monitoring location.
(B) Existing
section
11-20-45.1 average residence time compliance monitoring location (maximum residence time
compliance monitoring location for ground water systems) with the highest HAA5
LRAA not previously selected as a Stage 2 Disinfection Byproduct monitoring
location.
(C) Location with the
highest TTHM LRAA not previously selected as a Stage 2 Disinfection Byproduct
monitoring location.
(D) Location
with the highest TTHM LRAA not previously selected as a Stage 2 Disinfection
Byproduct monitoring location.
(E)
Location with the highest HAA5 LRAA not previously selected as a Stage 2
Disinfection Byproduct monitoring location.
(F) Existing section
11-20-45.1 average residence time compliance monitoring location (maximum residence time
compliance monitoring location for ground water systems) with the highest TTHM
LRAA not previously selected as a Stage 2 Disinfection Byproduct monitoring
location.
(G) Location with the
highest HAA5 LRAA not previously selected as a Stage 2 Disinfection Byproduct
monitoring location.
(4)
You may recommend locations other than those specified in paragraph (3) if you
include a rationale for selecting other locations. If the State approves the
alternate locations, you must monitor at these locations to determine
compliance under section
11-20-45.3.
Your recommended schedule must include Stage 2 Disinfection Byproduct
monitoring during the peak historical month for TTHM and HAA5 concentration,
unless the State approves another month. Once you have identified the peak
historical month, and if you are required to conduct routine monitoring at
least quarterly, you must schedule Stage 2 Disinfection Byproduct compliance
monitoring at a regular frequency of every 90 days or fewer.
