R 325.10720a
R 325.10720a Filtration and disinfection; reporting and recordkeeping.
Cite as Mich. Admin. Code R 325.10720a
Rule 720a. (1) Suppliers required to monitor under R 325.10720 shall comply with
reporting and recordkeeping requirements specified in R 325.11502 and shall report to the
department the information required in this rule within 10 days after the end of each month
the system serves water to the public, unless otherwise required.
(2) Suppliers shall report turbidity measurements required under R 325.10611b and shall
include all of the following information:
(a) The total number of filtered water turbidity measurements taken during the month.
(b) The number and percentage of filtered water turbidity measurements taken during the
month that are less than or equal to the turbidity limits under R 325.10611b(1)(a)(ii), (b)(ii),
or (c)(ii).
(c) The date and value of any turbidity measurements taken during the month that exceed
the applicable maximum turbidity value in R 325.10611b(1)(a)(i), (b)(i), or (c)(i).
(3) Suppliers shall report that they have conducted individual filter turbidity monitoring
under R 325.10720(2)(c) and (d). Suppliers shall report individual turbidity measurements
only if measurements demonstrate 1 or more of the conditions in subdivisions (a) to (d) of
this subrule. A Supply that uses lime softening may apply to the department for alternative
turbidity exceedance levels for the levels specified in subdivisions (a) to (d) of this subrule
if it can demonstrate that higher turbidity levels in individual filters are due to lime
carryover only and not due to degraded filter performance. Individual filter monitoring
reporting requirements are as follows:
(a) For any individual filter, or combined filter effluent for systems that monitor combined
filter effluent instead of individual filters, that has a measured turbidity level of more than
1.0 ntu in 2 consecutive measurements taken 15 minutes apart, the supplier shall report the
filter number, the turbidity measurement, and the date or dates on which the exceedance
occurred. In addition, the supplier shall report the cause for the exceedance, if known. A
supplier of a system serving 10,000 or more people that cannot identify an obvious reason
for the abnormal filter performance shall produce a filter profile within 7 days of the
exceedance and report that the profile has been produced.
(b) For any individual filter that has a measured turbidity level of more than 0.5 ntu in 2
consecutive measurements taken 15 minutes apart at the end of the first 4 hours of
continuous filter operation after the filter has been backwashed or otherwise taken offline,
the supplier of a system serving 10,000 or more people shall report the filter number, the
turbidity measurement, and the date or dates on which the exceedance occurred. In
addition, the supplier shall either produce a filter profile for the filter within 7 days of the
exceedance and report that the profile has been produced, or report the obvious reason for
the exceedance.
(c) For any individual filter, or combined filter effluent for systems that monitor combined
filter effluent instead of individual filters, that has a measured turbidity level of more than
1.0 ntu in 2 consecutive measurements taken 15 minutes apart at any time in each of 3
consecutive months, the supplier shall report the filter number, the turbidity measurement,
and the date or dates on which the exceedance occurred. In addition, the supplier shall
conduct a self assessment of the filter, unless a comprehensive performance evaluation as
specified in subdivision (d) of this subrule was required. If a self assessment is required,
then the supplier of a system serving 10,000 or more people shall complete it within 14
days after it was triggered and the supplier of a system serving fewer than 10,000 people
shall complete it by the 10th of the following month, or within 14 days if it was triggered
during the last 4 days of the month. A supplier that monitors combined filter effluent
instead of individual filters under R 325.10720(2)(e), shall conduct a self assessment on
both filters. The supplier shall report the date the self assessment was completed. The self
assessment shall consist of at least all of the following components:
(i) Assessment of filter performance.
(ii) Development of a filter profile.
(iii) Identification and prioritization of factors limiting filter performance.
(iv) Assessment of the applicability of corrections.
(v) Preparation of a filter self assessment report.
(d) For any individual filter, or combined filter effluent for systems that monitor combined
filter effluent instead of individual filters, that has a measured turbidity level of more than
2.0 ntu in 2 consecutive measurements taken 15 minutes apart at any time in each of 2
consecutive months, the supplier shall report the filter number, the turbidity measurement,
and the date or dates on which the exceedance occurred. In addition, the supplier shall
arrange for the conduct of a comprehensive performance evaluation by the department or
a third party approved by the department. Either of the following provisions apply:
(i) For a system serving 10,000 or more people, the comprehensive performance
evaluation shall be arranged to be conducted not later than 30 days after the day the filter
exceeded 2.0 ntu in 2 consecutive measurements for the second straight month. The
evaluation shall be completed and submitted to the department not later than 90 days after
the day it was triggered.
(ii) For a system serving fewer than 10,000 people, a new comprehensive performance
evaluation is not required if 1 has been completed by the department, or a third party
approved by the department, within the 12 previous months or if the system and the
department are jointly participating in an ongoing comprehensive technical assistance
project at the system.Suppliers shall report that a comprehensive performance evaluation
is required, if it is required, and the date the filter exceeded 2.0 ntu in 2 consecutive
measurements for the second straight month. The comprehensive performance evaluation
shall be arranged to be conducted not later than 60 days after the day the filter exceeded
2.0 ntu in 2 consecutive measurements for the second straight month. The evaluation shall
be completed and submitted to the department not later than 120 days after the day it was
triggered.
(4) The supplier shall consult with the department as soon as practical, but not later than
24 hours after the exceedance is known, if the turbidity level of representative samples of
filtered water at any time exceeds the levels in R 325.10611b(1)(a)(i), (b)(i), or (c)(i).
(5) A supplier that is required to conduct disinfection profiling and benchmarking shall
report both of the following:
(a) Results of optional monitoring performed that show TTHM and HAA5 levels below
0.064 mg/l and 0.048 mg/l, respectively.
(b) If a supplier is considering a significant change to its disinfection practice, then the
supplier shall report a description of the proposed change in disinfection, the 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.