Current through Register Vol. 18, September 20, 2024
(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:
(i) date;
(ii) treatment plant name;
(iii) treatment plant on and off time;
(iv) dose; and
(v) flow rate.
(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.
AUTH: 75-6-104, MCA; IMP: 75-6-104,
MCA
