1. A. All surface water or GWUDISW utilized by a supplier shall be treated using one of the following filtration technologies unless an alternative process has been approved by the DHH.

   1. 1. Conventional Filtration Treatment
   2. 2. Direct Filtration Treatment
   3. 3. Slow Sand Filtration
   4. 4. Diatomaceous Earth Filtration

2. B. Conventional filtration treatment shall be deemed to be capable of achieving at least 99.7 percent (2.5 Log) removal of Giardia cysts, 99 percent (2 Log) removal of Cryptosporidium oocysts, and 99 percent (2 Log) removal of viruses when in compliance with operation criteria (Subchapter D of this Chapter) and performance standards (§§1115 and 1119 of this Subchapter). Direct filtration treatment and diatomaceous earth filtration shall be deemed to be capable of achieving at least 99 percent (2 Log) removal of Giardia cysts, 99 percent (2 Log) removal of Cryptosporidium oocysts, and 90 percent (1 Log) removal of viruses when in compliance with operation criteria (Subchapter D of this Chapter) and performance standards (§§1115 and 1119 of this Subchapter). Slow sand filtration shall be deemed to be capable of achieving at least
   99 percent (2 Log) removal of Giardia cysts, 99 percent (2 Log) removal of Cryptosporidium oocysts, and 99 percent (2 Log) removal of viruses when in compliance with operation criteria and performance standards.

   1. 1. Expected minimum removal credits for public water systems are listed in Table 2 of this Chapter along with the corresponding remaining minimum disinfection log inactivation required.

      Table 2
      Treatment Methods
      Filtration Method	Expected Minimum Log Removals	Remaining Minimum Disinfection Log Inactivation Required
      	Giardia	Crypto	Virus	Giardia	Crypto	Virus
      Conventional	2.5	2.0	2.0	0.5	-0-	2.0
      Direct	2.0	2.0	1.0	1.0	-0-	3.0
      Slow Sand	2.0	2.0	2.0	1.0	-0-	2.0
      Diatomaceous Earth	2.0	2.0	1.0	1.0	-0-	3.0

   2. 2. The remaining minimum disinfection log inactivation shall not be less than what is required pursuant to Table 2.

3. C. Conventional Filtration Treatment or Direct Filtration Treatment shall comply with the following performance standards for each treatment plant.

   1. 1. The turbidity level of the filtered water shall be equal to or less than 0.3 NTU in at least 95 percent of the measurements taken each month.
   2. 2. Filtered water turbidity shall not exceed 1 NTU at any time.

4. D. Slow Sand Filtration shall comply with the following performance standards for each treatment plant.

   1. 1. The turbidity level of the filtered water shall be less than or equal to 1 NTU in at least 95 percent of the measurements taken each month.
   2. 2. The turbidity level of the filtered water shall at no time exceed 5 NTU.

5. E. Diatomaceous earth filtration shall comply with the following performance standards for each treatment plant.

   1. 1. The filtered water turbidity shall be less than or equal to 1 NTU in at least 95 percent of the measurements each month.
6. F. An alternative to the filtration technologies specified in §1115.A of this Chapter may be used provided the supplier demonstrates to the DHH that the alternative technology: provides a minimum of 99 percent Giardia cyst removal, a 99 percent virus removal, and a 99 percent
   (2 Log) Cryptosporidium oocyst removal, and meets the turbidity performance standards established in §1115.C of this Chapter. Such alternative filtration technology, in combination with disinfection treatment, shall be shown to consistently achieve a total of no less than 99.9 percent
   (3 Log) removal and/or inactivation of Giardia lamblia cysts and 99.99 percent (4 Log) removal and/or inactivation of viruses. The demonstration shall be based on the results from a prior equivalency demonstration or a testing of a full scale installation that is treating a water with similar characteristics and is exposed to similar hazards as the water proposed for treatment. A pilot plant test of the water to be treated may also be used for this demonstration if conducted with the approval of the DHH. The demonstration shall be presented in an engineering report prepared by a qualified engineer. Additional reporting for the first full year of operation of a new alternative filtration treatment process approved by the DHH, may be required at DHH discretion. The report shall include results of all water quality tests performed and shall evaluate compliance with established performance standards under actual operating conditions. It shall also include an assessment of problems experienced, corrective actions needed, and a schedule for providing needed improvements.

Authority Note

AUTHORITY NOTE: Promulgated in accordance with R.S. 40:4(A)(8) and 40:5(2)(3)(5)(6)(17)(20).

Historical Note

HISTORICAL NOTE: Promulgated by the Department of Health and Hospitals, Office of Public Health, LR 28:1340 (June 2002), amended LR 28:2519 (December 2002), LR 30:1196 (June 2004), LR 35:1241 (July 2009).