LAC 51:XII.1113. Treatment Technique Requirements

A. Each supplier using surface water or GWUDISW shall provide multibarrier treatment that meets the requirements of this Chapter and reliably ensures at least: 1. a total of 99.9 percent (3 Log) reduction of Giardia cysts through treatment processes including filtration and disinfection; 2. a total of 99.99 percent (4 Log) reduction of viruses through treatment processes including filtration and disinfection; 3. a total of 99 percent (2 Log) removal of Cryptosporidium oocysts through treatment processes including filtration; 4. the total reductions to be required by the DHH may be higher and are subject to the source water concentration of Giardia lamblia, viruses, and Cryptosporidium; 5. the residual disinfectant concentration in the water delivered to the distribution system is not less than 0.5 mg/l free chlorine or 0.5 mg/l total chlorine for more than 4 hours in any 24 hour period; and 6. the residual disinfectant concentration is not less than 0.5 mg/l free chlorine or 0.5 mg/l total chlorine in more than 5.0 percent of the samples collected each month from the distribution system for any two consecutive months. B. Suppliers meeting the requirements of §§1115 and 1119 shall be deemed to be in compliance with the minimum reduction and removal requirements specified in §1113.A of this Chapter. C. Section 1117 of this Chapter presents requirements for non-filtering systems. All suppliers which use surface water as a source shall provide filtration. On a case by case basis, systems using GWUDISW may not be required to filter.