Rule 17.38.228 - ULTRAVIOLET TREATMENT FOR GROUNDWATER SOURCES(1) Systems that use ultraviolet (UV) treatment for any groundwater source must meet the requirements of this rule All UV treatment must be reviewed and approved by the department under the requirements of ARM 17.38.101. All systems that are designed and approved to provide 4-log virus inactivation must treat all water to be served to achieve 4-log virus inactivation.(2) For systems using UV treatment that does not provide 4-log virus inactivation: (a) a sample tap must be installed that allows for sampling of raw water from each source individually;(b) one raw water total coliform sample must be collected by the system from each source that is subject to the UV treatment at the same frequency as the distribution system total coliform samples. Raw water samples under this rule are in addition to routine total coliform monitoring; and(c) raw water sample results are subject to ARM 17.38.211, 17.38.215, and 17.38.234.(3) Systems with UV treatment that provide 4-log virus inactivation must monitor to ensure the UV treatment is functioning. (a) Monitoring must be done at the point of disinfectant application.(b) The dose and flow rate must be monitored and recorded continuously.(c) For each day the treatment system is operating and serving water, the following must be recorded for each UV reactor: (ii) treatment plant name;(iii) treatment plant on and off time;(4) Systems with UV treatment that provide 4-log virus inactivation must report on department-approved forms and formats that include the following information: (a) Public water system name; public water system identification number; month and year; treatment plant name; treatment plant status (on and off);(b) For each day the treatment system was operational and serving water, it must include the date, minimum daily dose, and highest flow rate;(c) If the UV treatment system consists of multiple UV reactors, the monitoring and reporting shall be for each reactor separately;(d) The operational status of all UV lamps; and(e) The calibration of ultraviolet transmittance (UVT) instruments, calibration of the UV sensors, and recalibration of reference sensors in accordance with a protocol the department approves.(f) Water that does not meet the specifications of this rule is not allowed. All of the water served must be treated by UV treatment to the minimum UV dose as approved by the department.Mont. Admin. r. 17.38.228
NEW, 2024 MAR p. 2144, Eff. 9/7/2024AUTH: 75-6-104, MCA; IMP: 75-6-104, MCA