Current through Register Vol. 48, No. 9, September 27, 2024
(1) General Requirements
(a) The requirements of this regulation
constitute national primary drinking water regulations. These regulations
establish requirements for filtration and disinfection that are in addition to
criteria under which filtration and disinfection are required for systems with
surface water sources or ground water sources under the influence of surface
water. This regulation establishes or extends treatment technique requirements
in lieu of maximum contaminant levels for the following contaminants: Giardia
lamblia, viruses, heterotrophic plate count bacteria, Legionella,
Cryptosporidium and turbidity. The treatment technique requirements consist of
installing and properly operating water treatment processes which reliably
achieve:
(i) At least 99 percent (2 log)
removal of Cryptosporidium between a point where the raw water is not subject
to recontamination by surface water runoff and a point downstream before or at
the first customer for filtered systems, or Cryptosporidium control under the
watershed control plan for unfiltered systems; and
(ii) Compliance with the profiling and
benchmark requirements in paragraphs (4) and (5) of this section.
(b) Who is subject to the
requirements of this section?--You are subject to these requirements if your
system:
(i) Is a public water
system;
(ii) Uses surface water or
GWUDI as a source; and
(iii) Serves
fewer than 10,000 persons.
(c) When must my system comply with these
requirements? You must comply with these requirements in this regulation
beginning January 1, 2005 except where otherwise noted.
(d) What does this regulation require?--There
are seven (7) requirements of this subpart, and you must comply with all
requirements that are applicable to your system. These requirements are:
(i) You must cover any finished water
reservoir that you began to construct on or after March 15, 2002 as described
in paragraph (2) of this section;
(ii) If your system is an unfiltered system,
you must comply with the updated watershed control requirements described in
paragraph (3) of this section;
(iii) If your system is a community or
non-transient non-community water systems you must develop a disinfection
profile as described in paragraph (4) of this section;
(iv) If your system is considering making a
significant change to its disinfection practices, you must develop a
disinfection benchmark and consult with the Department for approval of the
change as described in paragraph (5) of this section;
(v) If your system is a filtered system, you
must comply with the combined filter effluent requirements as described in
paragraph (6) of this section;
(vi)
If your system is a filtered system that uses conventional or direct
filtration, you must comply with the individual filter turbidity requirements
as described in paragraph (7) of this section; and,
(vii) You must comply with the applicable
reporting and recordkeeping requirements as described in paragraph (8) of this
section.
(2)
Finished Water Reservoirs
(a) Is my system
subject to the new finished water reservoir requirements?--All surface water
systems and ground water systems under the direct influence of surface water
which serve fewer than 10,000 people are subject to this requirement.
(b) What is required of new finished water
reservoirs?--If your system begins construction of a finished water reservoir
on or after March 15, 2002 the reservoir must be covered. Finished water
reservoirs for which your system began construction prior to March 15, 2002 are
not subject to this requirement.
(3) Additional Watershed Control Requirements
for Unfiltered Systems
(a) Is my system
subject to the updated watershed control requirements?--If you are a surface
water system or a ground water system under the direct influence of surface
water serving fewer than 10,000 persons which does not provide filtration, you
must continue to comply with all of the filtration avoidance criteria in
Section C, as well as the additional watershed control requirements in
paragraph (3)(b) of this section.
(b) What updated watershed control
requirements must my unfiltered system implement to continue to avoid
filtration?--Your system must take any additional steps necessary to minimize
the potential for contamination by Cryptosporidium oocysts in the source water.
Your system's watershed control program must, for Cryptosporidium:
(i) Identify watershed characteristics and
activities which may have an adverse effect on source water quality;
and
(ii) Monitor the occurrence of
activities which may have an adverse effect on source water quality.
(c) How does the Department
determine whether my system's watershed control requirements are
adequate?--During an onsite inspection conducted under the provisions of
Section C(2)(c), the Department must determine whether your watershed control
program is adequate to limit potential contamination by Cryptosporidium
oocysts. The adequacy of the program must be based on the comprehensiveness of
the watershed review; the effectiveness of your program to monitor and control
detrimental activities occurring in the watershed; and the extent to which your
system has maximized land ownership and/or controlled land use within the
watershed.
(4)
Disinfection Profile
(a) What is a
Disinfection Profile and who must develop one?--A disinfection profile is a
graphical representation of your system's level of Giardia lamblia or virus
inactivation measured during the course of a year. If you are a surface water
system or a ground water system under the direct influence of surface water
which serves fewer than 10,000 persons, your system must develop a disinfection
profile unless the Department determines that your system's profile is
unnecessary. The Department may approve the use of a more representative data
set for disinfection profiling than the data set required under paragraph (4)
(c) through (f) of this section.
(b) What criteria must the Department use to
determine that a profile is unnecessary? The Department may only determine that
a system's profile is unnecessary if a system's TTHM and HAA5 levels are below
0.064 mg/L and 0.048 mg/L, respectively. To determine these levels, TTHM and
HAA5 samples must be collected after January 1, 1998, during the month with the
warmest water temperature, and at the point of maximum residence time in your
distribution system. The Department may approve a more representative TTHM and
HAA5 data set to determine these levels.
(c) How does my system develop a Disinfection
Profile and when must it begin?--A disinfection profile consists of three
steps:
(i) First, your system must collect
data for several parameters from the plant as discussed in paragraph (4)(d) of
this section, over the course of twelve (12) months. If your system serves
between 500 and 9,999 persons you must begin to collect data no later than July
1, 2003. If your system serves fewer than 500 persons you must begin to collect
data no later than January 1, 2004.
(ii) Second, your system must use this data
to calculate weekly log inactivation as discussed in paragraphs (4)(e) and (f)
of this section.
(iii) Third, your
system must use these weekly log inactivations to develop a disinfection
profile as specified in paragraph (4)(g) of this section.
(d) What data must my system collect to
calculate a Disinfection Profile?--Your system must monitor the following
parameters to determine the total log inactivation using the analytical methods
in Section F, once per week on the same calendar day, over twelve (12)
consecutive months:
(i) The temperature of
the disinfected water at each residual disinfectant concentration sampling
point during peak hourly flow;
(ii)
If your system uses chlorine, the pH of the disinfected water at each residual
disinfectant concentration sampling point during peak hourly flow;
(iii) The disinfectant contact time(s) ('T')
during peak hourly flow; and
(iv)
The residual disinfectant concentration(s) ('C') of the water before or at the
first customer and prior to each additional point of disinfection during peak
hourly flow.
(e) How
does my system use this data to calculate an inactivation ratio? Use the tables
in R-61.58.10.F(1)(c)(v) to determine the appropriate
CT99.9 value. Calculate the total inactivation ratio as
follows, and multiply the value by 3.0 to determine log inactivation of Giardia
lamblia:
|
If your system * * *
|
Your system must determine * * *
|
|
(a) Uses only one point of disinfectant
application
|
(1) One inactivation ratio (CTcalc/CT9 9.9) before or
at the first customer during peak hourly flow or
|
|
(2) Successive CTcalc/CT99.9 values, representing
sequential inactivation ratios, between the point of disinfectant application
and a point before or at the first customer during peak hourly flow. Under this
alternative, your system must calculate the total inactivation ratio by
determining (CTcalc/CT99.9) for each sequence and then adding the
(CTcalc/CT99.9) values together to determine
(<<SIGMA>>CTcalc/CT99.9).
|
|
(b) Uses more than one point of disinfectant
application before the first customer
|
The (CTcalc/CT99.9) value of each disinfection
segment immediately prior to the next point of disinfectant application, or for
the final segment, before or at the first customer, during peak hourly flow
using the procedure specified in paragraph (a)(2) of this section.
|
(f)
What if my system uses chloramines, ozone, or chlorine dioxide for primary
disinfection?--If your system uses chloramines, ozone, or chlorine dioxide for
primary disinfection, you must also calculate the logs of inactivation for
viruses and develop an additional disinfection profile for viruses using
methods approved by the Department.
(g) My system has developed an inactivation
ratio; what must we do now?--Each log inactivation serves as a data point in
your disinfection profile. Your system will have obtained fifty-two (52)
measurements (one (1) for every week of the year). This will allow your system
and the Department the opportunity to evaluate how microbial inactivation
varied over the course of the year by looking at all fifty-two (52)
measurements (your Disinfection Profile). Your system must retain the
Disinfection Profile data in graphic form, such as a spreadsheet, which must be
available for review by the Department as part of a sanitary survey. Your
system must use this data to calculate a benchmark if you are considering
changes to disinfection practices.
(5) Disinfection Benchmark
(a) Who has to develop a Disinfection
Benchmark?--If you are a surface water system or a ground water system under
the direct influence of surface water you are required to develop a
disinfection profile under paragraphs (4)(a) through (g) of this section. Your
system must develop a Disinfection Benchmark if you decide to make a
significant change to your disinfection practice. Your system must consult with
the Department for approval before you can implement a significant disinfection
practice change.
(b) What are
significant changes to disinfection practice?--Significant changes to
disinfection practice include:
(i) Changes to
the point of disinfection;
(ii)
Changes to the disinfectant(s) used in the treatment plant;
(iii) Changes to the disinfection process;
or
(iv) Any other modification
identified by the Department.
(c) What must my system do if we are
considering a significant change to disinfection practices?--If your system is
considering a significant change to its disinfection practice, your system must
calculate a disinfection benchmark(s) as described in paragraphs (5)(c) and (d)
of this section, and provide the benchmark(s) to the Department. Your system
may only make a significant disinfection practice change after consulting with
the Department for approval. Your system must submit the following information
to the Department as part of the consultation and approval process:
(i) A description of the proposed
change;
(ii) The disinfection
profile for Giardia lamblia (and, if necessary, viruses) and disinfection
benchmark;
(iii) An analysis of how
the proposed change will affect the current levels of disinfection;
and
(iv) Any additional information
requested by the Department.
(d) How is the Disinfection Benchmark
calculated?--If your system is making a significant change to its disinfection
practice, it must calculate a disinfection benchmark using the procedure
specified in the following table.
|
To calculate a disinfection benchmark your system
must perform the following steps
|
|
Step 1:
|
Using the data your system collected to develop the
Disinfection Profile, determine the average Giardia lamblia inactivation for
each calendar month by dividing the sum of all Giardia lamblia inactivations
for that month by the number of values calculated for that month.
|
|
Step 2:
|
Determine the lowest monthly average value out of the
twelve (12) values. This value becomes the disinfection benchmark.
|
(e)
What if my system uses chloramines, ozone, or chlorine dioxide for primary
disinfection?--If your system uses chloramines, ozone or chlorine dioxide for
primary disinfection your system must calculate the disinfection benchmark from
the data your system collected for viruses to develop the disinfection profile
in addition to the Giardia lamblia disinfection benchmark calculated under
paragraph (5)(d) of this section. This viral benchmark must be calculated in
the same manner used to calculate the Giardia lamblia disinfection benchmark in
paragraph (5)(d) of this section.
(6) Combined Filter Effluent Requirements
(a) Is my system required to meet this
regulation's combined filter effluent turbidity limits?--All surface water
systems and ground water systems under the direct influence of surface water
which serve populations fewer than 10,000, and that utilize filtration other
than slow sand filtration or diatomaceous earth filtration, must meet the
combined filter effluent turbidity requirements of paragraphs (6)(b) through
(d) of this section If your system uses slow sand or diatomaceous earth
filtration you are not required to meet the combined filter effluent turbidity
limits of this regulation, but you must continue to meet the combined filter
effluent turbidity limits in Section E.
(b) What strengthened combined filter
effluent turbidity limits must my system meet?--Your system must meet two
strengthened combined filter effluent turbidity limits.
(i) The first combined filter effluent
turbidity limit is a "95th percentile" turbidity limit that your system must
meet in at least ninety five (95) percent of the turbidity measurements taken
each month. Measurements must continue to be taken as described in Section F(1)
and (3). Monthly reporting must be completed according to paragraph (8) of this
section. The following table describes the required limits for specific
filtration technologies.
|
If your system consists of * * *
|
Your 95th percentile turbidity value is * * *
|
|
(1) Conventional Filtration or Direct Filtration
............
|
0.3 NTU
|
|
(2) All other 'Alternative' Filtration
...................
|
A value determined by the Department (not to exceed 1
NTU) based on the demonstration described in paragraph (6)(c)of this
section.
|
(ii)
The second combined filter effluent turbidity limit is a "maximum" turbidity
limit which your system may at no time exceed during the month. Measurements
must continue to be taken as described in Sections F(1) and C. Monthly
reporting must be completed according to paragraph (8) of this section The
following table describes the required limits for specific filtration
technologies.
|
If your system consists of * * *
|
Your maximum turbidity value is * * *
|
|
(1) Conventional Filtration or Direct
Filtration.............
|
1 NTU
|
|
(2) All other 'Alternative' Filtration
...................
|
A value determined by the Department (not to exceed 5
NTU) based on the demonstration as described in paragraph (6)(c) of this
section.
|
(c) My system consists of "alternative
filtration" and is required to conduct a demonstration what is required of my
system and how does the Department establish my turbidity limits?
(i) If your system consists of alternative
filtration (filtration other than slow sand filtration, diatomaceous earth
filtration, conventional filtration, or direct filtration) you are required to
conduct a demonstration (see tables in paragraph (6)(b) of this section). Your
system must demonstrate to the Department, using pilot plant studies or other
means, that your system's filtration, in combination with disinfection
treatment, consistently achieves:
(A) 99
percent removal of Cryptosporidium oocysts;
(B) 99.9 percent removal and/or inactivation
of Giardia lamblia cysts; and
(C)
99.99 percent removal and/or inactivation of viruses.
(ii) [Reserved]
(d) My system practices lime softening is
there any special provision regarding my combined filter effluent? If your
system practices lime softening, you may acidify representative combined filter
effluent turbidity samples prior to analysis using a protocol approved by the
Department.
(7)
Individual Filter Turbidity Requirements
(a)
Is my system subject to individual filter turbidity requirements? If your
system is a surface water system or a ground water system under the direct
influence of surface water serving fewer than 10,000 people and utilizing
conventional filtration or direct filtration, you must conduct continuous
monitoring of turbidity for each individual filter at your system. The
following requirements apply to continuous turbidity monitoring:
(i) Monitoring must be conducted using an
approved method in Section F(1);
(ii) Calibration of turbidimeters must be
conducted using procedures specified by the manufacturer;
(iii) Results of turbidity monitoring must be
recorded at least every fifteen (15) minutes;
(iv) Monthly reporting must be completed
according to paragraph (8) of this section; and
(v) Records must be maintained according to
paragraph (8)(b) of this section.
(b) What happens if my system's turbidity
monitoring equipment fails? If there is a failure in the continuous turbidity
monitoring equipment, your system must conduct grab sampling every four hours
in lieu of continuous monitoring until the turbidimeter is back on line. Your
system has fourteen (14) days to resume continuous monitoring before a
violation is incurred.
(c) My
system only has two or fewer filters is there any special provision regarding
individual filter turbidity monitoring? Yes, if your system only consists of
two (2) or fewer filters, you may conduct continuous monitoring of combined
filter effluent turbidity in lieu of individual filter effluent turbidity
monitoring. Continuous monitoring must meet the same requirements set forth in
paragraphs (7)(a) through(d) of this section.
(d) What follow up action is my system
required to take based on continuous turbidity monitoring? Follow up action is
required according to the following tables:
|
If * * *
|
Your system must * * *
|
|
(a) The turbidity of an individual filter (or the
turbidity of combined filter effluent (CFE) for systems with 2 filters that
monitor CFE in lieu of individual filters) exceeds 1.0 NTU in two consecutive
recordings 15 minutes apart.
|
Report to the Department by the 10th of the following
month and include the filter number(s), corresponding date(s), turbidity
value(s) which exceeded 1.0 NTU, and the cause (if known) for the
exceedance(s).
|
|
If a system was required to report to the Department
* * *
|
Your system must * * *
|
|
(b) For three months in a row and turbidity exceeded
1.0 NTU in two consecutive recordings 15 minutes apart at the same filter (or
CFE for systems with 2 filters that monitor CFE in lieu of individual
filters).
|
Conduct a self-assessment of the filter(s) within 14
days of the day the filter exceeded 1.0 NTU in two consecutive measurements for
the third straight month unless a CPE as specified in paragraph (c) of this
section was required. Systems with 2 filters that monitor CFE in lieu of
individual filters must conduct a self-assessment on both filters. The
self-assessment must consist of at least the following components: assessment
of filter performance; development of a filter profile; identification and
prioritization of factors limiting filter performance; assessment of the
applicability of corrections; and preparation of a filter self-assessment
report.
|
|
(c) For two months in a row and turbidity exceeded
2.0 NTU in 2 consecutive recordings 15 minutes apart at the same filter (or CFE
for systems with 2 filters that monitor CFE in lieu of individual
filters).
|
Arrange to have a comprehensive performance
evaluation (CPE) conducted by the Department or a third party approved by the
Department not later than 60 days following the day the filter exceeded 2.0 NTU
in two consecutive measurements for the second straight month. If a CPE has
been completed by the Department or a third party approved by the Department
within the 12 prior months or the system and the Department are jointly
participating in an ongoing Comprehensive Technical Assistance (CTA) project at
the system, a new CPE is not required. If conducted, a CPE must be completed
and submitted to the Department no later than 120 days following the day the
filter exceeded 2.0 NTU in two consecutive measurements for the second straight
month.
|
(e) My
system practices lime softening is there any special provision regarding my
individual filter turbidity monitoring? If your system utilizes lime softening,
you may apply to the Department for alternative turbidity exceedance levels for
the levels specified in the table in paragraph (7)(d) of this section. You must
be able to demonstrate to the Department that higher turbidity levels are due
to lime carryover only, and not due to degraded filter performance.
(8) Reporting and Recordkeeping
Requirements
(a) What does this section
require that my system report to the Department? This section requires your
system to report several items to the Department. The following table describes
the items which must be reported and the frequency of reporting. Your system is
required to report the information described in the following table, if it is
subject to the specific requirement shown in the first column.
|
Corresponding requirement
|
Description of information to report
|
Frequency
|
|
(a) Combined Filter Effluent Requirements.
(paragraphs (6)(a) through (d) of this section).
|
(1) The total number of filtered water turbidity
measurements taken during the month.
|
By the 10th of the following month.
|
|
(2) The number and percentage of filtered water
turbidity measurements taken during the month which are less than or equal to
your system's required 95th percentile limit.
|
By the 10th of the following month.
|
|
(3) The date and value of any turbidity measurements
taken during the month which exceed the maximum turbidity value for your
filtration system.
|
By the 10th of the following month
|
|
(b) Individual Turbidity Requirements. (paragraph
(7)(a) through (e) of this section).
|
(1) That your system conducted individual filter
turbidity monitoring during the month.
|
By the 10th of the following month.
|
|
(2) The filter number(s), corresponding date(s), and
the turbidity value(s) which exceeded 1.0 NTU during the month, and cause (if
known) for the exceedance(s), but only if 2 consecutive measurements exceeded
1.0 NTU.
|
By the 10th of the following month.
|
|
(3) If a self-assessment is required, the date that
it was triggered and the date that it was completed. |
By the 10th of the following month (or 14 days after
the self-assessment was triggered only if the self-assessment was triggered
during the last four days of the month) |
|
(4) If a CPE is required, that the CPE is required
and the date that it was triggered.
|
By the 10th of the following month.
|
|
(5) Copy of completed CPE report........
|
Within 120 days after the CPE was triggered.
|
|
(c) Disinfection Profiling..... (paragraphs (4)(a)
through (g) of this section)
|
(1) Results of optional monitoring which show TTHM
levels 0.064 mg/L and HAA5 levels 0.048 mg/L (only if your system wishes to
forgo profiling) or that your system has begun disinfection profiling.
|
(i) For systems serving 500-9,999 by July 1, 2003;
(ii) For systems serving fewer than 500 by January 1, 2004.
|
|
(d) Disinfection Benchmarking (paragraph (5)(a)
through (e) of this section)
|
(1) A description of the proposed change in
disinfection, your system's disinfection profile for Giardia lamblia (and, if
necessary, viruses) and disinfection benchmark, and an analysis of how the
proposed change will affect the current levels of disinfection.
|
Anytime your system is considering a significant
change to its disinfection practice.
|
(b)
What records does this regulation require my system to keep? Your system must
keep several types of records based on the requirements of this regulation, in
addition to recordkeeping requirements under Section G. The following table
describes the necessary records, the length of time these records must be kept,
and for which requirement the records pertain. Your system is required to
maintain records described in this table, if it is subject to the specific
requirement shown in the first column.
|
Corresponding requirement
|
Description of necessary records
|
Duration of time records must be kept
|
|
(a) Individual Filter Turbidity Requirements
(paragraphs (7)(a) through (e) of this section) ........................
|
Results of individual filter monitoring .....
|
At least 3 years.
|
|
(b) Disinfection Profiling (paragraphs (4)(a) through
(g) of this section) ........................
|
Results of Profile (including raw data and analysis)
.........
|
Indefinitely-y.
|
|
(c) Disinfection Benchmarking (paragraphs (5)(a)
through (e) of this section) ........................
|
Benchmark (including raw data and analysis)
....
|
Indefinitely-y.
|
