Section 445A.522 - Filtration: Efficiencies for removal1. For the purposes of meeting the levels of treatment set forth in NAC 445A.520: (a) Conventional filtration treatment is presumed to be capable of achieving at least 99.9 percent or 3-log removal of Cryptosporidium, 99.7 percent or 2.5 -log removal of Giardialamblia cysts and 99 percent or 2-log removal of viruses if the process is in compliance with the operating criteria set forth in NAC 445A.533 and the standards of performance set forth in NAC 445A.521;(b) Treatment by direct filtration is presumed capable of achieving at least 99.7 percent or 2.5 -log removal of Cryptosporidium, 99 percent or 2-log removal of Giardialamblia cysts and 90 percent or 1-log removal of viruses if the process is in compliance with the criteria and standards set forth in paragraph (a); and(c) Treatment by diatomaceous earth filtration and slow sand filtration is presumed capable of achieving at least 99.9 percent or 3-log removal of Cryptosporidium, 99 percent or 2-log removal of Giardialamblia cysts and 90 percent or 1-log removal of viruses if the process is in compliance with the criteria and standards set forth in paragraph (a).2. The Division or the appropriate district board of health may grant higher efficiencies for removal than those specified in this section if the supplier of water demonstrates by a protocol reviewed and approved by the Division or the appropriate district board of health that: (a) For Giardialamblia cysts and virus, the higher efficiency for removal can be obtained reliably; and(b) For Cryptosporidium, the filtration system can meet the requirements of the treatment performance component of the microbial toolbox pursuant to NAC 445A.5265.Nev. Admin. Code § 445A.522
Added to NAC by Bd. of Health, eff. 11-29-90; A by R088-00, 8-3-2001; A by Environmental Comm'n by R126-05, 10-31-2005; R194-08, 10-27-2009