Michigan Administrative Code › Department - Environmental Quality › Drinking Water And Municipal Assistance Division › Supplying Water to the Public › Part 6 - STATE DRINKING WATER STANDARDS AND ANALYTICAL › Section R. 325.10610d - Disinfection byproducts; requirements

Current through Vol. 24-12, July 15, 2024
Rule 610d.
(1)
				  This rule and
				  R 325.10719h to
				  R 325.10719n establish monitoring
				  and other requirements for achieving compliance with maximum contaminant levels
				  based on locational running annual averages (LRAA) for total trihalomethanes
				  (TTHM) and haloacetic acids (five) (HAA5), and for achieving compliance with
				  maximum residual disinfectant residuals for chlorine and chloramine for certain
				  consecutive supplies.
(2) Subject
				  to these requirements are community and nontransient noncommunity water
				  supplies that use 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. These public water supplies are
				  considered "water supplies" or "supplies" in this rule and
				  R 325.10719h to
				  R 325.10719n.
(3) The supply shall comply with all of the
				  following provisions:
(a) The supply shall
				  comply with the requirements in this rule and
				  R 325.10719h to R325.10719n when
				  the supply becomes subject to this rule as indicated in subrule (2) of this
				  rule.
(b) The monitoring frequency
				  is specified in
				  R
				  325.10719h(1)(a) and both of the
				  following:
(i) If the supply is required to
				  conduct quarterly monitoring, the supply shall begin monitoring in the first
				  full calendar quarter that the supply becomes subject to this rule, as
				  indicated in subrule (2) of this rule.
(ii) If the supply is required to conduct
				  monitoring at a frequency that is less than quarterly, the supply shall begin
				  monitoring in the calendar month identified in the monitoring plan developed
				  under
				  R 325.10719i not later than 12
				  months after the supply becomes subject to this rule, as indicated in subrule
				  (2) of this rule.
(c) If
				  the supply is required to conduct quarterly monitoring, the supply shall make
				  compliance calculations at the end of the fourth calendar quarter that follows
				  the compliance date and at the end of each subsequent quarter (or earlier if
				  the LRAA calculated based on fewer than 4 quarters of data would cause the MCL
				  to be exceeded regardless of the monitoring results of subsequent quarters). If
				  the supply is required to conduct monitoring at a frequency that is less than
				  quarterly, the supply shall make compliance calculations beginning with the
				  first compliance sample taken after the compliance date.
(d) For the purpose of the schedule in this
				  subrule, the department may determine that the combined distribution system
				  does not include certain consecutive supplies based on factors such as
				  receiving water from a wholesale supply only on an emergency basis or receiving
				  only a small percentage and small volume of water from a wholesale supply. The
				  department may also determine that the combined distribution system does not
				  include certain wholesale supplies based on factors such as delivering water to
				  a consecutive supply only on an emergency basis or delivering only a small
				  percentage and small volume of water to a consecutive supply.