California Code of Regulations › Title 22 - Social Security › Division 4 - Environmental Health › Chapter 17 - Surface Water Treatment › Article 9 - Indirect Potable Reuse: Surface Water Augmentation › Section 64668.30 - Swsap Augmented Reservoir Requirements

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a) The SWSAP PWS shall ensure that prior to
				  augmentation of a surface water reservoir by a SWSAP, the surface water
				  reservoir to be used as an augmented reservoir was in operation as an approved
				  surface water supply pursuant to this Chapter for a period of time sufficient
				  to establish a baseline record of the surface water reservoir's raw water
				  quality (including, but not limited to, the monitoring required pursuant to
				  section 60320.326, Chapter 3), and treated
				  drinking water quality. A surface water reservoir shall have been operating as
				  an approved surface water source for at least five years prior to receiving
				  recycled municipal wastewater from a SWSAP, unless approved otherwise in
				  writing by the State Board, but in no case less than two years.
(b) The SWSAP PWS shall ensure that a surface
				  water reservoir used as an augmented reservoir has a minimum theoretical
				  retention time of no less than that which has been approved by the State Board.
				  Monthly, the SWSAP PWS shall calculate and record the theoretical retention
				  time. The theoretical retention time shall be the value (in units of days)
				  resulting from dividing the volume of water in the surface water reservoir at
				  the end of each month, by the total outflow from the surface water reservoir
				  during the corresponding month. The total outflow shall include, but not be
				  limited to, all outflows and withdrawals from the surface water reservoir. An
				  initial approved minimum theoretical retention time may be no less than 180
				  days.
(1) If a month's theoretical retention
				  time is determined to be less than the SWSAP PWS's approved theoretical
				  retention time, the SWSAP PWS shall, by the end of the subsequent month, submit
				  a report to the State Board and Regional Board describing the corrective
				  actions to be taken to ensure future theoretical retention times will be no
				  less than the approved theoretical retention time.
(2) A SWSAP PWS may apply to the State Board,
				  for written approval, for a reduced on-going alternative minimum theoretical
				  retention time of less than 180 days, but no less than 60 days. The SWSAP PWS's
				  application shall include all information requested by the State Board for its
				  consideration of a proposed alternative minimum theoretical retention time,
				  including the following:
(A) Evidence that
				  the SWSAP PWS and SWSAP WRA have reliably and consistently met the requirements
				  of this Article and Article 5.3, Chapter 3, under varying operating
				  conditions;
(B) At the proposed
				  alternative minimum theoretical retention time, the maximum anticipated
				  recycled municipal wastewater flow to the surface water reservoir, the total
				  anticipated outflows from the reservoir, and the total available flows of
				  approved reservoir sources of supply;
(C) The maximum percent, by volume, of
				  recycled municipal wastewater that will be delivered to the surface water
				  reservoir during any 24-hour period, in accordance with subsection (c), at the
				  proposed alternative minimum theoretical retention time;
(D) A description of total proposed treatment
				  and total log10 reduction for enteric virus,
Giardia
cysts, and
Cryptosporidium
oocysts.
				  For proposed alternative minimum theoretical retention times less than 120
				  days, no less than one log10 reduction of such pathogens
				  beyond that otherwise required pursuant to this Article and Article 5.3,
				  Chapter 3, shall be provided;
(E)
				  The ability to adequately respond to potential SWSAP treatment failures in a
				  timely manner, such that there is no interruption of drinking water, meeting
				  all applicable standards, supplied to customers; and
(F) A demonstration that the alternative
				  minimum theoretical retention time provides, based on information provided
				  pursuant to subsection (b)(2), an equivalent or better level of protection of
				  public health than otherwise required pursuant to this Article and Article 5.3,
				  Chapter 3. If required by the State Board, the SWSAP PWS's demonstration shall
				  include a review by an independent scientific advisory panel approved by the
				  State Board.