Section 179-13-006 - FILTRATIONA public water system that uses a surface water source must provide treatment consisting of both disinfection, as specified in 179 NAC 13-005.02 and filtration treatment which complies with the requirements of 179 NAC 13-006.01 to 13-006.04 by June 29, 1993. A public water system that uses a ground source which is under the direct influence of surface water and does not meet all the criteria in 179 NAC 13-004 for avoiding filtration, must provide treatment consisting of both disinfection, as specified in 179 NAC 13-005.02 and filtration which complies with the requirements of 179 NAC 13-006.01 to 13-006.04 within 18 months of the failure to meet any one of the criteria for avoiding filtration in 179 NAC 13-004. Failure to meet any requirement of 179 NAC 13-006 is a treatment technique violation.
006.01 Conventional Filtration Treatment or Direct Filtration 13-006.01A For systems using conventional filtration or direct filtration, the turbidity level of representative samples of a system's filtered water must be less than or equal to 0.5 NTU in at least 95% of the measurements taken each month, measured as specified in 179 NAC 13-007.01A and 13-007.03A, except that if the Director determines that the system is capable of achieving at least 99.9% removal and/or inactivation of Giardia lamblia cysts at some turbidity level higher than 0.5 NTU in at least 95% of the measurements taken each month, the Director may substitute this higher turbidity limit for that system. However, in no case may the Director approve a turbidity limit that allows more than 1 NTU in more than 5% of the samples taken each month, measured as specified in 179 NAC 13-007.01A and 13-007.03A. 13-006.01B The turbidity level of representative samples of a system's filtered water must at no time exceed 5 NTU, measured as specified in 179 NAC 13-007.01A and 13-007.03A.13-006.01C Beginning January 1, 2002, systems serving at least 10,000 people must meet the turbidity requirements in 179 NAC 17-006.01.13-006.01D Beginning January 14, 2005, systems serving fewer than 10,000 people must meet the turbidity requirements in 179 NAC 19-009.01 through 19-009.04.006.02 Slow Sand Filtration 13-006.02A For systems using slow sand filtration, the turbidity level of representative samples of a system's filtered water must be less than or equal to 1 NTU in at least 95% of the measurements taken each month, measured as specified in 179 NAC 13-007.01A and 13-007.03A, except that if the Director determines there is no significant interference with disinfection at a higher turbidity level, the Director may substitute this higher turbidity limit for that system.13-006.02B The turbidity level of representative samples of a system's filtered water must at no time exceed 5 NTU, measured as specified in 179 NAC 13-007.01A and 13-007.03A.006.03 Diatomaceous Earth Filtration 13-006.03A For systems using diatomaceous earth filtration, the turbidity level of representative samples of a system's filtered water must be less than or equal to 1 NTU in at least 95% of the measurements taken each month, measured as specified in 179 NAC 13-007.01A and 13-007.03A.13-006.03B The turbidity level of representative samples of a system's filtered water must at no time exceed 5 NTU, measured as specified in 179 NAC 13-007.01A to 13-007.03A.006.04 Other Filtration Technologies : A public water system may use a filtration technology not listed in 179 NAC 13-006.01 to 13-006.03 if it demonstrates to the Director using pilot plant studies or other means, that the alternative filtration technology, in combination with disinfection treatment that meets the requirements of 179 NAC 13-005.02, consistently achieves 99.9% removal and/or inactivation of Giardia lamblia cysts and 99.99% removal and/or inactivation of viruses. For a system that makes this demonstration, the requirements of 179 NAC 13-006.02 apply. Beginning January 1, 2002, systems serving at least 10,000 people must meet the requirements for other filtration technologies in 179 NAC 17-005.02. Beginning January 14, 2005, systems serving fewer than 10,000 people must meet the requirements for other filtration technologies in 179 NAC 19-009.01 through 19-009.04.
179 Neb. Admin. Code, ch. 13, § 006
Amended effective 3/22/2016.