Michigan Administrative Code › Department - Environmental Quality › Drinking Water And Municipal Assistance Division › Supplying Water to the Public › Part 7 - SURVEILLANCE, INSPECTION, AND MONITORING › Section R. 325.10710 - Collection and analysis of samples for inorganic chemicals

Current through Vol. 24-12, July 15, 2024
Rule 710.
(1)
				  Suppliers of water of community and noncommunity water systems shall collect
				  water samples and cause analyses to be made for inorganic chemicals to
				  determine compliance with the state drinking water standards in R 325.10604c.
				  Suppliers shall monitor at the time designated by the department during each
				  compliance period.
(2) The
				  department may require samples to be collected and analyzed at a prescribed
				  frequency for inorganic chemicals for type III public water supplies.
(3) Beginning in the initial compliance
				  period, suppliers of community and nontransient, noncommunity water systems
				  shall monitor under this rule to determine compliance with the MCLs for
				  inorganic contaminants in R 325.10604c. Beginning in the initial compliance
				  period, suppliers of transient, noncommunity water systems shall monitor under
				  this rule to determine compliance with the nitrate, nitrite, and total nitrate
				  and nitrite MCLs in R 325.10604c.
(4) Suppliers shall monitor in the following
				  manner:
(a) Suppliers of groundwater systems
				  shall take at least 1 sample at every entry point to the distribution system
				  representative of each well after treatment, also known as sampling point. The
				  supplier shall take each sample at the same sampling point unless conditions
				  make another sampling point more representative of each source or treatment
				  plant.
(b) Suppliers of surface
				  water systems, or combined surface water and groundwater systems, shall take at
				  least 1 sample at every entry point to the distribution system after the
				  application of treatment or in the distribution system at a sampling point that
				  is representative of each source after treatment, also known as sampling point.
				  The supplier shall take each sample at the same sampling point unless
				  conditions make another sampling point more representative of each source or
				  treatment plant.
(c) If a system
				  draws water from more than 1 source and the sources are combined before
				  distribution, then the supplier shall sample at an entry point to the
				  distribution system during periods when water is representative of all sources
				  being used.
(d) The total number of
				  samples that shall be analyzed to meet the requirements of this rule may be
				  reduced by the department when compositing of samples is utilized. Provisions
				  for compositing of samples are as follows:
(i)
				  Composite samples from a maximum of 5 sampling points are allowed.
(ii) Compositing of samples shall be done in
				  the laboratory.
(iii) If the
				  concentration in the composite sample is greater than or equal to 1/5 of the
				  MCL of any inorganic chemical, then a follow-up sample shall be collected
				  within 14 days from each sampling point included in the composite. These
				  samples shall be analyzed for the contaminants that exceeded 1/5 of the MCL in
				  the composite sample.
(iv)
				  Compositing shall only be performed using samples from within a single water
				  system.
(v) If duplicates of the
				  original sample taken from each sampling point used in the composite are
				  available, then the supplier may use these instead of resampling.
The duplicates shall be analyzed and the results reported
					 to the department within 14 days after completing analysis of the composite
					 sample if the holding time of the sample is not exceeded.