California Code of Regulations › Title 22 - Social Security › Division 4 - Environmental Health › Chapter 3 - Water Recycling Criteria › Article 5.2 - Indirect Potable Reuse: Groundwater Replenishment - Subsurface Application › Section 60320.208 - Pathogenic Microorganism Control

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a) A project sponsor shall design and
				  operate a GRRP such that the recycled municipal wastewater used as recharge
				  water for a GRRP receives treatment that achieves at least 12-log enteric virus
				  reduction, 10-log Giardia cyst reduction, and 10-log Cryptosporidium oocyst
				  reduction. The treatment train shall consist of at least three separate
				  treatment processes. For each pathogen (i.e., virus, Giardia cyst, or
				  Cryptosporidium oocyst), a separate treatment process may be credited with no
				  more than 6-log reduction, with at least three processes each being credited
				  with no less than 1.0-log reduction.
(b) For each month retained underground as
				  demonstrated in subsection (d), the recycled municipal wastewater or recharge
				  water will be credited with 1-log virus reduction.
(c) With the exception of log reduction
				  credited pursuant to subsection (b), a project sponsor shall validate each of
				  the treatment processes used to meet the requirements in subsection (a) for
				  their log reduction by submitting a report for the Department's review and
				  approval, or by using a challenge test approved by the Department, that
				  provides evidence of the treatment process's ability to reliably and
				  consistently achieve the log reduction. The report and/or challenge test shall
				  be prepared by an engineer licensed in California with at least five years of
				  experience, as a licensed engineer, in wastewater treatment and public water
				  supply, including the evaluation of treatment processes for pathogen control.
				  With the exception of retention time underground, a project sponsor shall
				  propose and include in its Operation Optimization Plan prepared pursuant to
				  section 60320.222, on-going monitoring
				  using the pathogenic micro-organism of concern or a microbial, chemical, or
				  physical surrogate parameter(s) that verifies the performance of each treatment
				  process's ability to achieve its credited log reduction.
(d) To demonstrate the retention time
				  underground in subsection (b) a tracer study utilizing an added tracer shall be
				  implemented under hydraulic conditions representative of normal GRRP
				  operations. The retention time shall be the time representing the difference
				  from when the water with the tracer is applied at the GRRP to when either; two
				  percent (2%) of the initially introduced tracer concentration has reached the
				  downgradient monitoring point, or ten percent (10%) of the peak tracer unit
				  value observed at the downgradient monitoring point reached the monitoring
				  point. A project sponsor for a GRRP shall initiate the tracer study prior to
				  the end of the third month of operation. A project sponsor for a GRRP permitted
				  on or before June 18, 2014 that has not already performed such a tracer study
				  shall complete a tracer study demonstrating the retention time underground.
				  With Department approval, an intrinsic tracer may be used in lieu of an added
				  tracer, with no more credit provided than the corresponding virus log reduction
				  in column 2 of Table 60320.208.
(e)
				  For the purpose of siting a GRRP location during project planning and until a
				  GRRP's project sponsor has met the requirements of subsection (d), for each
				  month of retention time estimated using the method in column 1, the recycled
				  municipal wastewater or recharge water shall be credited with no more than the
				  corresponding virus log reduction in column 2 of Table 60320.208.
Table 60320.208
Column
								1
Column
								2
Method used to
								estimate the retention time to the nearest downgradient drinking water
								well
Virus Log Reduction
								Credit per Month
Tracer study utilizing an added
							 tracer.1
1.0 log
Tracer study utilizing an intrinsic
							 tracer.1
0.67 log
Numerical modeling consisting of calibrated finite
							 element or finite difference models using validated and verified computer codes
							 used for simulating groundwater flow.
0.50 log
Analytical modeling using existing
							 academically-accepted equations such as Darcy's Law to estimate groundwater
							 flow conditions based on simplifying aquifer assumptions.
0.25 log
1 The
							 retention time shall be the time representing the difference from when the
							 water with the tracer is applied at the GRRP to when either; two percent (2%)
							 of the initially introduced tracer concentration has reached the downgradient
							 monitoring point, or ten percent (10%) of the peak tracer unit value observed
							 at the downgradient monitoring point reached the monitoring point.
(f)
				  A project sponsor shall obtain Department approval for the protocol(s) to be
				  used to establish the retention times in subsections (d) and (e).
(g) Based on changes in hydrogeological or
				  climatic conditions since the most recent demonstration, the Department may
				  require a GRRP's project sponsor to demonstrate that the underground retention
				  times required in this section are being met.
(h) If a pathogen reduction in subsection (a)
				  is not met based on the on-going monitoring required pursuant to subsection
				  (c), within 24 hours of being aware a project sponsor shall immediately
				  investigate the cause and initiate corrective actions. The project sponsor
				  shall immediately notify the Department and Regional Board if the GRRP fails to
				  meet the pathogen reduction criteria longer than 4 consecutive hours, or more
				  than a total of 8 hours during any 7-day period. Failures of shorter duration
				  shall be reported to the Regional Board by a project sponsor no later than 10
				  days after the month in which the failure occurred.
(i) If the effectiveness of a treatment
				  train's ability to reduce enteric virus is less than 10-logs, or Giardia cyst
				  or Cryptosporidium oocyst reduction is less than 8-logs, a project sponsor
				  shall immediately notify the Department and Regional Board, and discontinue
				  application of recycled municipal wastewater at the GRRP, unless directed
				  otherwise by the Department or Regional Board.
1. New
					 section filed 6-18-2014 as an emergency; operative 6-18-2014. Submitted to OAL
					 for filing and printing only. This adoption is not subject to OAL review and
					 shall remain in effect until revised by the Department of Public Health
					 pursuant to Water Code section
					 13562.5
					 (Register 2014, No. 25).
2. Change without regulatory effect
					 amending subsection (b) filed 7-18-2022 pursuant to section
					 100, title 1, California Code of
					 Regulations (Register 2022, No. 29).
Note: Authority cited: Sections
						13521,
						13540,
						13562 and
						13562.5, Water
						Code; and Sections
						131052
						and
						131200,
						Health and Safety Code. Reference: Sections
						13520,
						13522,
						13522.5,
						13523,
						13523.1,
						13524,
						13540,
						13560,
						13561 and
						13562.5, Water
						Code.