1. (a) Each OTNWS must be equipped with a continuous process verification monitoring system that can verify, at all times, the proper operation of each treatment process' ability to achieve its credited log reduction consistent with its validation conditions. Each pathogen control treatment train must meet its designated critical limits provided in subsections (c) through (i).
2. (b) Alternatives to pathogen control treatment trains, authorized pursuant to section 60634, must perform continuous process verification monitoring utilizing either a pathogenic microorganism of concern or a microbial, chemical, or physical surrogate parameter(s) consistent with each treatment process' validation conditions and the treatment train's approved validation study.

3. (c) Pathogen control treatment Train A, listed in Table 60632-1, must meet the following critical limits:

   1. (1) The turbidity of MBR system effluent must not exceed any of the following:

      1. (A) 0.2 NTU for more than 5 percent of the time within a 24-hour period; and
      2. (B) 0.5 NTU at any time.
   2. (2) The UV disinfection process following the MBR system must provide a minimum UV dose of 160 millijoules per square centimeter through the UV disinfection process at all times. Influent to the UV disinfection process must be at or below the maximum flow rate certified for the system and have UV transmittance greater than or equal to 65 percent;

   3. (3) The chlorine disinfection process following the UV disinfection process must meet the following requirements:

      1. (A) A CT value of not less than 12 mg-min/L at all times, based on maximum flow;
      2. (B) A flow rate through the chlorine contact chamber that does not exceed 1 gpm/100 gallons of reactor volume. Alternative limits on flow rate, baffling factor, and T10 may be proposed through a tracer study conducted in accordance with a protocol that has been reviewed and approved by the local jurisdiction;
      3. (C) A free chlorine residual of at least 1.2 mg/L to be maintained at all times, measured at or downstream of the point at which T10 is achieved;
      4. (D) An influent turbidity entering the chlorine contact chamber not to exceed 0.5 NTU at any time;
      5. (E) An influent ammonia concentration entering the chlorine contact chamber not to exceed 0.5 mg/L at any time;
      6. (F) An influent pH not to exceed 8.0 at any time; and
      7. (G) An influent temperature of at least 15°C (59°F) at all times.

4. (d) Pathogen control treatment Train B, listed in Table 60632-1, must meet the following critical limits:

   1. (1) The turbidity of MBR system effluent must not exceed any of the following:

      1. (A) 0.2 NTU for more than 5 percent of the time within a 24-hour period; and
      2. (B) 0.5 NTU at any time.
   2. (2) The UV disinfection process following the MBR system must provide a minimum UV dose of 120 millijoules per square centimeter through the UV disinfection process at all times. Influent to the UV disinfection process must be at or below the maximum flow rate certified for the system and have UV transmittance greater than or equal to 65 percent;

   3. (3) The chlorine disinfection process following the UV disinfection process must meet the following requirements:

      1. (A) A CT value of not less than 16 mg-min/L, based on maximum flow;
      2. (B) A flow rate through the chlorine contact chamber that does not exceed 1 gpm/100 gallons of reactor volume. A project proponent may propose an alternative baffling factor and T10 through a tracer study conducted in accordance with a protocol that has been reviewed and approved by the local jurisdiction;
      3. (C) A free chlorine residual of at least 1.6 mg/L to be maintained at all times, measured at or downstream of the point at which T10 is achieved;
      4. (D) An influent turbidity entering the chlorine contact chamber not to exceed 0.5 NTU at any time;
      5. (E) An influent ammonia concentration entering the chlorine contact chamber not to exceed 0.5 mg/L at any time;
      6. (F) An influent pH not to exceed 8.0 at any time; and
      7. (G) An influent temperature of at least 10°C (50°F) at all times.

5. (e) Pathogen control treatment Train C, listed in Table 60632-1, must meet the following critical limits:

   1. (1) The turbidity of MBR system effluent must not exceed any of the following:

      1. (A) 0.2 NTU for more than 5 percent of the time within a 24-hour period; and
      2. (B) 0.5 NTU at any time.
   2. (2) The UV disinfection process following the MBR system must provide a minimum UV dose of 160 millijoules per square centimeter through the UV disinfection process at all times. Influent to the UV disinfection process must be at or below the maximum flow rate certified for the system and have UV transmittance greater than or equal to 65 percent;

   3. (3) A chlorine disinfection process following the UV disinfection process must meet the following requirements:

      1. (A) A CT value of not less than 7 mg-min/L at all times, based on maximum flow;
      2. (B) A flow rate through the chlorine contact chamber must not exceed 1 gpm/100 gallons of reactor volume. A project proponent may propose an alternative limit on flow rate, baffling factor, and T10 through a tracer study conducted in accordance with a protocol that has been reviewed and approved by the local jurisdiction;
      3. (C) A free chlorine residual of at least 0.70 mg/L must be maintained at all times, measured at or downstream of the point at which T10 is achieved;
      4. (D) An influent turbidity entering the chlorine contact chamber must not exceed 0.5 NTU at any time;
      5. (E) An influent ammonia concentration entering the chlorine contact chamber must not exceed 0.5 mg/L at any time;
      6. (F) An influent pH not to exceed 8.0 at any time; and
      7. (G) An influent temperature at least 15°C (59°F) at all times.

6. (f) Pathogen control treatment Train D, listed in Table 60632-1, must meet the following critical limits:

   1. (1) The turbidity of MBR system effluent does not exceed any of the following:

      1. (A) 0.2 NTU for more than 5 percent of the time within a 24-hour period; and
      2. (B) 0.5 NTU at any time.
   2. (2) The UV disinfection process following the MBR system must provide a minimum UV dose of 240 millijoules per square centimeter through the UV disinfection process at all times. Influent to the UV disinfection process must be at or below the maximum flow rate certified for the system and have UV transmittance greater than or equal to 65 percent.

7. (g) Pathogen control treatment Train E, listed in Table 60632-1, must meet the following critical limits:

   1. (1) The turbidity of membrane filtration system effluent does not exceed any of the following:

      1. (A) 0.2 NTU for more than 5 percent of the time within a 24-hour period; and
      2. (B) 0.5 NTU at any time.
   2. (2) The UV disinfection process following the MBR system must provide a minimum UV dose of 160 millijoules per square centimeter through the UV disinfection process at all times. Influent to the UV disinfection process must be at or below the maximum flow rate certified for the system and have UV transmittance greater than or equal to 65 percent.

   3. (3) A chlorine disinfection process following the UV disinfection process must meet the following requirements:

      1. (A) A CT value of not less than 10.0 mg-min/L at all times, based on maximum flow;
      2. (B) A flow rate through the chlorine contact chamber not to exceed 1 gpm/100 gallons of reactor volume. A project proponent may propose an alternative limit on flow rate, baffling factor, and T10 through a tracer study conducted in accordance with a protocol that has been reviewed and approved by the local jurisdiction;
      3. (C) A free chlorine residual of at least 1.0 mg/L to be maintained at all times, measured at or downstream of the point at which T10 is achieved;
      4. (D) An influent turbidity entering the chlorine contact chamber not to exceed 0.5 NTU at any time;
      5. (E) An influent ammonia concentration entering the chlorine contact chamber not to exceed 0.5 mg/L at any time;
      6. (F) An influent pH not to exceed 8.0 at any time; and
      7. (G) An influent temperature of at least 15°C (59°F) at all times.

8. (h) Pathogen control treatment Train F, listed in Table 60632-1, must meet the following critical limits:

   1. (1) The UV disinfection process must provide a minimum UV dose of 40 millijoules per square centimeter through the UV disinfection process at all times. Influent to the UV disinfection process must be at or below the maximum flow rate certified for the system and have UV transmittance greater than or equal to 65 percent.

9. (i) Any treatment train that includes an MBR process treating either onsite wastewater or graywater sources, and has not been operational or receiving onsite wastewater or graywater influent for at least 96 hours, must meet the following critical limits until the treatment train reaches normal operating condition:

   1. (1) The turbidity of MBR system effluent does not exceed any of the following:

      1. (A) 0.2 NTU for more than 5 percent of the time within a 24-hour period; and
      2. (B) 0.5 NTU at any time.
   2. (2) The MBR process effluent must have UV transmittance greater than or equal to 65 percent; and
   3. (3) The MBR process effluent ammonia concentration must not exceed 0.50 mg/L at any time.

Note: Authority cited: Sections 13558 and 13558.1, Water Code; and Section 116271, Health and Safety Code. Reference: Sections 13520, 13522 and 13558, Water Code.

History

1. New section filed 4-22-2026; operative 4-22-2026 pursuant to Water Code section 13558(f) (Register 2026, No. 17).