Section R. 325.10710 - Collection and analysis of samples for inorganic chemicalsRule 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.
(5) The monitoring frequency conducted to determine compliance with the MCLs in R 325.10604c for antimony, arsenic, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium, and thallium shall be as follows: (a) Suppliers of groundwater systems shall take 1 sample at each sampling point during each compliance period. Suppliers of surface water systems, or combined surface water and groundwater systems, shall take 1 sample annually at each sampling point.(b) A supplier may apply to the department for a waiver from the monitoring frequencies specified in subdivision (a) of this subrule. The department may grant a waiver for monitoring cyanide if the department determines the system is not vulnerable due to the lack of any industrial source of cyanide. Waiver provisions are as follows: (i) A supplier shall take at least 1 sample while the waiver is effective.(ii) The term during which a waiver is effective shall not be more than 1 compliance cycle.(iii) A waiver may be granted if a surface water supplier has monitored annually for not less than 3 years or a groundwater supplier has conducted not less than 3 rounds of monitoring. At least 1 sample shall have been taken since January 1, 1990. Both surface and groundwater suppliers shall demonstrate that all previous analytical results were less than the MCL. Supplies that use a new water source are not eligible for a waiver until 3 rounds of monitoring from the new source have been completed.(iv) The department shall consider all of the following factors to determine the appropriate reduced monitoring frequency:(A) Reported concentrations from all previous monitoring.(B) The degree of variation in reported concentrations.(C) Other factors that may affect contaminant concentrations, such as changes in any of the following:(1) Groundwater pumping rates.(2) The system's configuration.(3) The system's operating procedures.(4) Stream flows or characteristics.(v) A waiver shall be in writing and shall set forth the basis for the determination. The determination may be initiated by the department or upon an application by the public water supplier specifying the basis for its request. The department may revise the determination based on new data.(c) Suppliers of systems exceeding the MCLs in R 325.10604c shall monitor quarterly beginning in the next quarter after the violation occurred. The department may decrease the quarterly monitoring requirement to the frequencies specified in subdivisions (a) and (b) of this subrule if it has determined that the system 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 the department's determination.(d) All new supplies or supplies that use a new source of water shall demonstrate compliance with the MCLs before serving water to the public except as otherwise required in this subdivision. The supply shall also comply with the initial sampling frequencies specified by the department to ensure a system can demonstrate compliance with the MCLs. Before January 23, 2006, new nontransient noncommunity water supplies or supplies that use a new source of water that exceed the arsenic MCL of 0.010 mg/l may use the source only if the supply complies with a consent agreement with the department stipulating a plan and schedule satisfactory to the department to meet the MCL.(6) The following monitoring frequency shall be conducted to determine compliance with the MCL in R 325.10604c for asbestos:(a) Suppliers of each community and nontransient, noncommunity water system shall monitor for asbestos during the first 3-year compliance period of each 9-year compliance cycle.(b) If the supplier believes its water is not vulnerable to either asbestos contamination in its source water or asbestos contamination due to corrosion of asbestos-cement pipe, or both, then it may apply to the department for a waiver of the monitoring requirement in subdivision (a) of this subrule. If the department grants the waiver, then the supplier is not required to monitor. A waiver remains in effect until the completion of the 3-year compliance period. The department may grant a waiver based on a consideration of both of the following factors: (i) Potential asbestos contamination of the water source.(ii) The use of asbestos-cement pipe for finished water distribution and the corrosive nature of the water.(c) A supplier of a system vulnerable to asbestos contamination due solely to the corrosion of asbestos-cement pipe shall take 1 sample at a tap served by asbestos-cement pipe and under conditions where asbestos contamination is most likely to occur.(d) A supplier of a system vulnerable to asbestos contamination due solely to source water shall monitor under subrule (4) of this rule.(e) A supplier of a system vulnerable to asbestos contamination due both to its source water supply and corrosion of asbestos-cement pipe shall take 1 sample at a tap served by asbestos-cement pipe and under conditions where asbestos contamination is most likely to occur.(f) A supplier of a system exceeding the MCLs in R 325.10604c shall monitor quarterly beginning in the next quarter after a violation occurred.(g) The quarterly monitoring requirement may be decreased by the department to the frequency specified in subdivision (a) of this subrule if the department determines that the system is reliably and consistently below the MCL. A groundwater supplier shall take a minimum of 2 quarterly samples and a surface water or combined surface water and groundwater supplier shall take not fewer than 4 quarterly samples before this determination.(h) If monitoring data collected after January 1, 1990, are generally consistent with the requirements of this subrule, then that data may be used to satisfy the monitoring requirement for the initial compliance period.(7) The monitoring frequency conducted to determine compliance with the MCLs in R 325.10604c for nitrate shall be as follows:(a) Community water systems and nontransient, noncommunity water systems served by groundwater systems shall be monitored annually. Systems served by surface water shall be monitored quarterly.(b) For community and nontransient, noncommunity water systems, the repeat monitoring frequency for groundwater systems shall be quarterly for at least 1 year following any 1 sample in which the concentration is 50% or more of the MCL. The sampling frequency for groundwater systems may be reduced by the department to annually after 4 consecutive quarterly samples are reliably and consistently less than the MCL.(c) For community and nontransient, noncommunity water systems, the department may allow a surface water supplier to reduce the sampling frequency to annually if all analytical results from 4 consecutive quarters are less than 50% of the MCL. A surface water supplier shall return to quarterly monitoring if any 1 sample is 50% or more of the MCL.(d) Suppliers of transient, noncommunity water systems shall monitor annually.(e) After the initial round of quarterly sampling is completed, suppliers of community and nontransient, noncommunity water systems that are monitored annually shall take subsequent samples during the quarter or quarters which previously resulted in the highest analytical result.(8) The monitoring frequency conducted to determine compliance with the MCLs in R 325.10604c for nitrite shall be as follows: (a) A supplier of a community water system or a noncommunity water system shall take 1 sample at each sampling point during each compliance period.(b) After the initial sample, suppliers of systems where an analytical result for nitrite is less than 50% of the MCL shall monitor at the frequency specified by the department.(c) The repeat monitoring frequency for a system shall be quarterly for at least 1 year following any 1 sample in which the concentration is 50% or more of the MCL. The department may allow a supplier to reduce the sampling frequency to annually after determining the system is reliably and consistently less than the MCL.(d) Suppliers monitoring annually shall take each subsequent sample during the quarter or quarters that previously resulted in the highest analytical result.(9) Confirmation samples are required as follows:(a) Where the results of sampling for any of the following indicate a level that is more than the MCL, the department may require the supply to collect 1 additional sample as soon as possible after the initial sample was taken, but not more than 2 weeks later, at the same sampling point and have it analyzed for the contaminant that was above the MCL: (b) Where nitrate or nitrite sampling results indicate a level that is more than the MCL, the supplier shall take a confirmation sample within 24 hours of the supplier's receipt of notification of the analytical results of the first sample. Suppliers that are unable to comply with the 24-hour sampling requirement shall immediately notify the persons served by the area served by the public water system under part 4 of these rules and shall analyze a confirmation sample within 2 weeks of notification of the analytical results of the first sample.(c) If a confirmation sample required by the department is taken for any contaminant, then the results of the initial and confirmation sample shall be averaged. The resulting average shall be used to determine the system's compliance under R 325.10604c(2). Results of obvious sampling errors may be deleted by the department.(10) The department may require more frequent monitoring than specified in this rule or may require confirmation samples for positive or negative results.(11) Suppliers may apply to the department to conduct more frequent monitoring than the minimum monitoring frequencies specified in this rule.Mich. Admin. Code R. 325.10710
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