Nebraska Administrative Code
Topic - HEALTH AND HUMAN SERVICES SYSTEM
Title 179 - PUBLIC WATER SYSTEMS
Chapter 19 - LONG TERM 1 (LT 1) ENHANCED SURFACE WATER TREATMENT (for Systems Serving Fewer Than 10,000 People)
Section 179-19-008 - DISINFECTION BENCHMARK
Current through September 17, 2024
008.01 Who Must Develop a Disinfection Benchmark
Systems that use surface water or ground water under the direct influence of surface water that are required to develop a disinfection profile under 179 NAC 19-007.01 through 19-007.07 must develop a disinfection benchmark if they decide to make a significant change to their disinfection practice. These systems must consult with the Director for approval before implementing a significant disinfection practice change.
008.02 Significant changes to disinfection practices include:
008.03 If a system is considering a significant change to its disinfection practice, the system must calculate a disinfection benchmark(s) as described in 179 NAC 19-008.04 and 19-008.05 and provide the benchmark(s) to the Director. Systems may only make a significant disinfection practice change after consulting with the Director for approval. Systems must submit the following information to the Director as part of the consultation and approval process:
008.04 Calculating the disinfection benchmark
Systems making a significant change to their disinfection practice must calculate a disinfection benchmark using the procedure specified in the following table.
To Calculate a Disinfection Benchmark Your System Must Perform the Following Steps
Step 1: Using the data your system collected to develop the disinfection profile, determine the average Giardia lamblia inactivation for each calendar month by dividing the sum of all Giardia lamblia inactivations for that month by the number of values calculated for that month.
Step 2: Determine the lowest monthly average value out of the twelve values. This value becomes the disinfection benchmark.
008.05 Systems That Use Chloramines, Ozone, or Chlorine Dioxide for Primary Disinfection
These systems must calculate the disinfection benchmark from the data the system collected for viruses to develop the disinfection profile in addition to the Giardia lamblia disinfection benchmark calculated under 179 NAC 19-008.04. This viral benchmark must be calculated in the same manner used to calculate the Giardia lamblia disinfection benchmark in 179 NAC 19-008.04.