R 325.10717d Collection and analysis of samples for per- and polyfluoroalkyl substances.

Rule 717d. (1) Suppliers of community and nontransient noncommunity water supplies shall collect samples and cause analyses to be made under this rule for per- and polyfluoroalkyl substances to determine compliance with the state drinking water standards in R 325.10604g. Each supplier shall monitor at the time designated by the department. (2) For transient noncommunity and type III public water supplies, the department may require samples to be collected and analyzed at prescribed frequencies for per- and polyfluoroalkyl substances. (3) A groundwater supplier shall take at least 1 sample at every entry point to the distribution system that is representative of each well after treatment, also known as sampling point. Each sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant. (4) A surface water supplier, or combined surface water and ground water, shall take at least 1 sample at points in the distribution system that are representative of each source or at each entry point to the distribution system after treatment, also known as sampling point. Each sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant. (5) 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 of normal operating conditions when water that is representative of all sources is being used. (6) An existing supplier with one or more samples taken at each sampling point described in subrules (3), (4), or (5) of this rule as part of the State of Michigan’s 2018/2019 Statewide PFAS Survey shall conduct initial sampling as follows: (a) A supplier with one or more sample results greater than 50% of the MCL for a contaminant listed in rule 10604g shall collect samples from each sampling point beginning the first full quarter following the effective date of this rule. (b) A supplier with no detection or a detection less than or equal to 50% of the MCL for a contaminant listed in rule 10604g shall collect at least 1 sample from each sampling point within 6 months of the effective date of this rule. (7) An existing supplier without sampling conducted under subrule (6) of this rule, shall collect samples beginning the first full quarter following the effective date of this rule. (8) A new community or nontransient noncommunity water supply shall collect samples beginning the first full quarter following the initiation of operations. (9) If the results of samples collected under subrules (6), (7), or (8) of this rule are below the reporting limits specified in R 325.12708, the department may allow the water supply to monitor annually. (10) If a contaminant in R 325.10604g is detected above the reporting limit in any sample, then all of the following provisions apply: (a) Each supply shall monitor quarterly at each sampling point that resulted in a detection. The department may decrease the quarterly monitoring requirement specified in this subrule if it has determined that the supply is reliably and consistently below the MCL. A groundwater supplier shall take not fewer than 2 quarterly samples and a surface water supplier shall take not fewer than 4 quarterly samples before this determination. (b) After the department determines that the supply is reliably and consistently below the MCL, the department may allow the supply to monitor annually. (11) A supplier that violates R 325.10604g shall monitor quarterly. If not fewer than 4 quarterly samples show that the supply is in compliance and the department determines the supply is reliably and consistently below the MCL, then the department may allow the supply to monitor annually. (12) The department may require confirmation sampling for positive or negative results. If confirmation sampling is required, then the results must be averaged with the first sampling result and the average must be used for the compliance determination. The department may exclude results of obvious sampling errors from this calculation. (13) The department may increase the required monitoring to detect variations within the system. (14) All new supplies or supplies that use a new source of water shall demonstrate compliance with the MCLs before serving water to the public. The supply shall also comply with the initial sampling frequencies specified by the department.