R 325.10719h Disinfection byproducts; routine monitoring.

Rule 719h. (1) A community or nontransient noncommunity water supply that is subject to disinfection byproducts requirements of R 325.10610d shall monitor at the location or locations and dates identified in the monitoring plan in R 325.10719e(5), updated as required by R 325.10719i. These community and noncommunity water supplies are also considered "water supplies" or "supplies" in this rule and R 325.10719i to R 325.10719n. (2) The supply shall monitor at least the number of locations identified in the following table: Source Water Type Population size category Monitoring Frequency 1 Distribution system monitoring locations total per monitoring period 2 Subpart H less than 500 per year 2 Subpart H 500 to 3,300 per quarter 2 Subpart H 3,301 to 9,999 per quarter 2 Subpart H 10,000 to 49,999 per quarter 4 Subpart H 50,000 to 249,999 per quarter 8 Subpart H 250,000 to 999,999 per quarter 12 Subpart H 1,000,000 to 4,999,999 per quarter 16 Subpart H greater than or equal to 5,000,000 per quarter 20 Groundwater less than 500 per year 2 Groundwater 500 to 9,999 per year 2 Groundwater 10,000 to 99,999 per quarter 4 Groundwater 100,000 to 499,999 per quarter 6 Groundwater greater than or equal to 500,000 per quarter 8 1 All supplies shall monitor during month of highest DBP concentrations. 2 Supplies on quarterly monitoring shall take dual sample sets every 90 days at each monitoring location, except for subpart H supplies serving 500 to 3,300. Groundwater supplies serving 500-9,999 on annual monitoring shall take dual sample sets at each monitoring location. All other supplies on annual monitoring and subpart H supplies serving 500 to 3,300 shall take individual TTHM and HAA5 samples (instead of a dual sample set) at the locations with the highest TTHM and HAA5 concentrations, respectively. For supplies serving fewer than 500 people, only 1 location with a dual sample set per monitoring period is needed if the highest TTHM and HAA5 concentrations occur at the same location and month. (3) An undisinfected supply that begins using a disinfectant other than UV light shall consult with the department to identify compliance monitoring locations for TTHM and HAA5 under R 325.10610d and R 325.10719h to R 325.10719n. The supply shall then develop a monitoring plan under R 325.10719i that includes those monitoring locations.