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. 325.10610c - Control of disinfection byproduct (DBP) precursors; treatment technique

Current through Vol. 24-12, July 15, 2024
Rule 610c.
(1)
				  This rule applies to Subpart H supplies subject to R 325.10610b(1) that use
				  conventional filtration. These public water supplies are considered "water
				  supplies" or "supplies" in this rule. Compliance with this rule is based on all
				  of the following:
(a) Subpart H systems using
				  conventional filtration shall operate with enhanced coagulation or enhanced
				  softening to achieve the TOC percent removal levels specified in subrule (2) of
				  this rule unless the supply meets at least 1 of the alternative compliance
				  criteria listed in subdivision (b) or (c) of this subrule.
(b) Subpart H systems using conventional
				  filtration may use the following alternative compliance criteria to comply with
				  this rule instead of complying with subrule (2) of this rule. Supplies using
				  alternative compliance criteria shall still comply with TOC monitoring
				  requirements in R 325.10719e(4):
(i) The
				  supply's source water TOC level is less than 2.0 mg/l, calculated quarterly as
				  a running annual average.
(ii) The
				  supply's treated water TOC level is less than 2.0 mg/l, calculated quarterly as
				  a running annual average.
(iii) The
				  supply's source water TOC level is less than 4.0 mg/l, calculated quarterly as
				  a running annual average; the source water alkalinity, measured under R
				  325.10605, is more than 60 mg/l as calcium carbonate, calculated quarterly as a
				  running annual average; and either the TTHM and HAA5 running annual averages
				  are not more than 0.040 mg/l and 0.030 mg/l, respectively, or before the
				  effective date for compliance in R 325.10610(2), the supply has made a clear
				  and irrevocable financial commitment to use technologies that will limit the
				  levels of TTHM and HAA5 to not more than 0.040 mg/l and 0.030 mg/l,
				  respectively. Supplies shall submit evidence of a clear and irrevocable
				  financial commitment, in addition to a schedule containing milestones and
				  periodic progress reports for installation and operation of appropriate
				  technologies, to the department for approval not later than the effective date
				  for compliance in R 325.10610(2). These technologies shall be installed and
				  operating not later than June 30, 2005. Failure to install and operate these
				  technologies by the date in the approved schedule is a violation of these
				  rules.
(iv) The TTHM and HAA5
				  running annual averages are not more than 0.040 mg/l and 0.030 mg/l,
				  respectively, and the supply uses only chlorine for primary disinfection and
				  maintenance of a residual in the distribution system.
(v) The supply's source water SUVA, before
				  any treatment and measured monthly, is less than or equal to 2.0 liters per
				  milligram meter (l/mg m), calculated quarterly as a running annual
				  average.
(vi) The supply's finished
				  water SUVA, measured monthly, is less than or equal to 2.0 l/mg m, calculated
				  quarterly as a running annual average.
(c) Water supplies practicing enhanced
				  softening that cannot achieve the TOC removals required by subrule (2)(b) of
				  this rule may use the following alternative compliance criteria instead of
				  complying with subrule (2) of this rule; however, supplies using alternative
				  compliance criteria shall still comply with TOC monitoring requirements in R
				  325.10719e(4)(b):
(i) Softening that results
				  in lowering the treated water alkalinity to less than 60 mg/l as calcium
				  carbonate, measured monthly and calculated quarterly as a running annual
				  average.
(ii) Softening that
				  results in removing not less than 10 mg/l of magnesium hardness as calcium
				  carbonate, measured monthly and calculated quarterly as an annual running
				  average.