California Code of Regulations › Title 22 - Social Security › Division 4 - Environmental Health › Chapter 17 - Surface Water Treatment › Article 3 - Monitoring Requirements › Section 64655 - Filtration Monitoring

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a)
				  To determine compliance with the performance standards specified in section
				  64653 and the operating criteria
				  in section
				  64660, a supplier shall conduct
				  turbidity monitoring in accordance with table 64655. Monitoring shall be
				  conducted when the treatment plant is in operation and pursuant to the
				  operations plan required by section
				  64661.
Table 64655
Filtered Water Turbidity Monitoring
If a supplier
							 uses...
Turbidity monitoring shall be
							 conducted of...
And the turbidity level
							 shall be recorded...
(1) Conventional or direct filtration
(A)
							 Each individual filter, continuously; and
At least once every 15
							 minutes
treatment and serves 10,000 or more
							 persons
(B) The combined filter effluent(b),
							 continuously
At least once every 15 minutes
(2) Conventional or direct filtration
(A)
							 Each individual filter, continuously(c);
							 and
At least once every 15 minutes
treatment and serves fewer than 10,000
							 persons(a)
(B) The combined filter
							 effluent(b), by grab sample at least once every four
							 hours(d)
At least once every four hours
(3) Diatomaceous earth or slow sand
							 filtration(a)
The combined filter
							 effluent(b), by grab sample at least once every four
							 hours(d)
At least once every four hours
_______________________________________________________
(a) A supplier
							 using slow sand filtration, or serving 500 or fewer persons, that is in
							 compliance with the performance standards specified in section
							 64653 may reduce turbidity
							 monitoring of the combined filter effluent to one grab sample per day. The
							 result shall be recorded daily.
(b)
							 Representative sample prior to clearwell storage.
(c) If there
							 are two or fewer filters, a supplier may conduct continuous monitoring of the
							 combined filter effluent in lieu of continuous monitoring of each individual
							 filter. The results shall be recorded at least once every 15 minutes.
(d) Continuous
							 turbidity measurements may be substituted for grab sample monitoring provided
							 the supplier validates the accuracy of the measurements on a weekly basis.
(b)
				  A supplier shall calibrate turbidimeters used for continuous turbidity
				  monitoring according to the procedure specified by the manufacturer.
(c) If there is an interruption in continuous
				  turbidity monitoring due to equipment failure or maintenance, a supplier that
				  uses conventional or direct filtration treatment shall conduct grab sample
				  monitoring once every four hours in lieu of continuous monitoring until the
				  continuous turbidimeter is back on-line. From the time of equipment failure or
				  maintenance interruption, continuous monitoring shall be reinitiated:
(1) For a supplier serving 10,000 or more
				  persons, within 48 hours for the combined filter effluent and within five
				  working days for the individual filter effluent; or
(2) For a supplier serving fewer than 10,000
				  persons, within 14 working days for the individual filter
				  effluent.