AgdaPkt 2004-10-25 - Laserfiche WebLink

Browse Search

(:ryptospondium (p� 1 of 2) rage 11 of 13 � . � -20 began in 1997. The proposed interim Enhanced Surface Water Treatment Rule (ESWTR) 19 is in its final stages of revision pending comments to the Notice of Data Availability (November 4, 1997). Some significant items noted in the draft ESWTR Preamble (dated ]anuary 26, 1994) are: ■ Differing pathogen densities in different waters accounts for the drive to develop site-specific treatment requirements. ■ In light of current and anticipated research EPA senses that they wiil "soon be in better position to develop a suitable regulation for Cryptosporidium". ■ There appears to be some conferred immunity associated with exposure to Cryptosporidium. A 2-log treatment requirement has been proposed as an option for sources with less than 1 oocyst per 100 liters, though there are other proposals. ■ EPA recognizes that "unfiltered systems would appear to be particularly vulnerable...However, to date, flitered water supplies have been impiicated in all identified waterborne Cryprospo�idium outbreaks...(filtered) surface water may be more vulnerable to Cryprosporidium than unfiltered suppiies with disinfection, depending on the quality of the source water..." Great uncertainty still remains as EPA approaches a regulation. Consequently, they are soliciting input into the structuring of the long-term ESWTR. A major emphasis for unfiltered systems will be on watershed controls. In the 1996 Amendments to the Safe Drinking Water Act, a special section detailed the conditions for a limited alternative to filtration. The text says: "...a State exercising primary enforcement responsibility for public water systems may, on a case-by-case basis, and after notice and opportunity for public comment, establish treatment requirements as an alternative to filtration in the case of systems having uninhabited, undeveloped watersheds in consolidated ownership, and having control over access to, and activities in, those watersheds, if the State determines (and the Administrator concurs) that the quality of the source water and the alternative treatment requirements established by the State ensure greater removal or inactivation efficiencies of pathogenic organisms for which �ational primary drinking water regulations have been promulgated or that are of public health concern than would be achieved by the combination of filtration and chlorine disinfection..." California Department of Health Services (DHS) DHS is concerned over the status of unfiltered supplies in the state. While anticipating that Cryptosporidium will need to be regulated in the near future, DHS will await for EPA's action. In the interim, DHS has issued a Cryptosporidium Action Plan which places heavy emphasis on treatment optimization. http://sfwater.org/printContent.cfin/C_ID/446/ 10/19/2004