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. 325.10604f - Treatment techniques for lead and copper

Current through Vol. 24-12, July 15, 2024
Rule 604f.
(1)
				  Treatment techniques for lead and copper are as follows:
(a) This rule,
				  R 325.10410, and
				  R 325.10710a to
				  R 325.10710d are the requirements
				  for lead and copper and apply to community and nontransient noncommunity water
				  supplies. These public water supplies are considered "water supplies" or
				  "supplies" in this rule,
				  R 325.10410, and
				  R 325.10710a to
				  R 325.10710d.
(b) These rules establish a treatment
				  technique that includes requirements for corrosion control treatment, source
				  water treatment, lead service line replacement, and public education. These
				  requirements are triggered, in some cases, by lead and copper action levels
				  measured in samples that are collected at consumers' taps.
(c) Through December 31, 2024, the lead
				  action level is exceeded if the ninetieth percentile lead level is more than
				  0.015 milligrams per liter (mg/l) in tap water samples collected during a
				  monitoring period conducted under
				  R 325.10710a. Beginning January 1,
				  2025, the lead action level is exceeded if the ninetieth percentile lead level
				  is more than 0.012 mg/l in tap water samples collected during a monitoring
				  period conducted under
				  R 325.10710a. The copper action
				  level is exceeded if the ninetieth percentile copper level is more than 1.3
				  mg/l in tap water samples collected during a monitoring period conducted under
				  R 325.10710a. The ninetieth
				  percentile lead and copper levels shall be computed as follows:
(i) The highest lead result or the highest
				  copper result from each sampling site taken during a monitoring period shall be
				  placed in ascending order from the sample with the lowest concentration to the
				  sample with the highest concentration. Each sampling result shall be assigned a
				  number, ascending by single integers beginning with the number 1 for the sample
				  with the lowest contaminant level. The number assigned to the sample with the
				  highest contaminant level shall be equal to the total number of samples
				  taken.
(ii) The number of samples
				  taken during the monitoring period shall be multiplied by 0.9.
(iii) The contaminant concentration in the
				  numbered sample yielded by the calculation in paragraph (ii) of this
				  subdivision is the ninetieth percentile contaminant level.
(iv) If a total of 5 samples are collected
				  per monitoring period, the ninetieth percentile is computed by taking the
				  average of the highest and second highest concentrations.
(v) For a water supply that has been allowed
				  by the department to collect fewer than 5 samples under
				  R 325.10710a(3),
				  the sample result with the highest concentration is considered the 90th
				  percentile value.
(d) A
				  supply shall install and operate optimal corrosion control treatment on the
				  system under subrules (2) and (3) of this rule. A supply that is in compliance
				  with the applicable corrosion control treatment requirements specified by the
				  department under subrules (2) and (3) of this rule is in compliance with the
				  treatment requirement.
(e) A supply
				  exceeding the lead or copper action level shall implement all applicable source
				  water treatment requirements specified by the department under subrule (4) of
				  this rule.
(f) A supply exceeding
				  the lead action level after implementation of applicable corrosion control and
				  source water treatment requirements shall complete the lead service line
				  replacement requirements contained in subrule (5) of this rule. All other
				  supplies shall complete the lead service line replacement requirements
				  contained in subrule (6) of this rule.
(g) Under
				  R 325.10410, all water supplies
				  shall provide a consumer notice of lead and copper tap water monitoring results
				  to persons served at the sites (taps) that are tested. A supply exceeding the
				  lead action level shall implement the public education requirements specified
				  in
				  R 325.10410.
(h) Tap water monitoring for lead and copper,
				  monitoring for water quality parameters, source water monitoring for lead and
				  copper, and analyses of the monitoring results under this subrule shall be
				  completed under
				  R 325.10605,
				  R 325.10710a,
				  R 325.10710b, and
				  R 325.10710c.
(i) A supply shall report, to the department,
				  the information required by the treatment provisions of this subrule and
				  R 325.10710d.
(j) A supply shall maintain records under
				  R
				  325.11506(1)(e).
(k) Failure to comply with the applicable
				  requirements of this rule,
				  R 325.10410,
				  R 325.10710a,
				  R 325.10710b,
				  R 325.10710c,
				  R 325.10605,
				  R 325.10710d, and
				  R
				  325.11506(1)(e) constitutes a
				  violation of these rules for lead or copper, as applicable.
(l) When notified of a new source or
				  long-term change in treatment as required under
				  R
				  325.10710d(a)(iii), the department
				  may require the supply to conduct a new or updated corrosion control study as
				  described in R 325.10604f(3)(c), additional monitoring, or other action the
				  department considers appropriate to ensure the supply maintains optimal
				  corrosion control.
(m) The
				  department may require the supply to conduct a new or updated corrosion control
				  study as described in R 325.10604f(3)(c).