NSF 55-2015 Ultraviolet Microbiological Water Treatment Systems.pdf

1、NSF International Standard / American National StandardNSF/ANSI 55 - 2015 Ultraviolet MicrobiologicalWater Treatment Systems NSF International, an independent, not-for-profit, non-governmental organization, is dedicated to being the leading global provider of public health and safety-based risk mana

2、gement solutions while serving the interests of all stakeholders. This Standard is subject to revision. Contact NSF to confirm this revision is current. Users of this Standard may request clarifications and interpretations, or propose revisions by contacting: Chair, Joint Committee on Drinking Water

3、 Treatment Units c/o NSF International 789 North Dixboro Road, P. O. Box 130140 Ann Arbor, Michigan 48113-0140 USA Phone: (734) 769-8010 Telex: 753215 NSF INTL FAX: (734) 769-0109 E-mail: infonsf.org Web: http:/www.nsf.org NSF/ANSI 55 2015 i NSF International Standard/ American National Standard for

4、 Drinking Water Treatment Units Ultraviolet microbiological water treatment systems Standard Developer NSF International NSF International Designated as an ANSI Standard April 26, 2015 American National Standards Institute ii Prepared by The NSF Joint Committee on Drinking Water Treatment Units Reco

5、mmended for Adoption by The NSF Council of Public Health Consultants Adopted by The NSF Board of Directors May 1991 Revised January 2000 Revised January 2002 Addendum, June 2002 Addendum, February 2004 Revised October 2004 Revised October 2007 Revised August 2009 Revised August 2012 Revised December

6、 2013 Revised January 2015 Revised October 2015 Published by NSF International PO Box 130140, Ann Arbor, Michigan 48113-0140, USA For ordering copies or for making inquiries with regard to this Standard, please reference the designation “NSF/ANSI 55 2015.” Copyright 2015 NSF International Previous e

7、ditions 2014, 2013, 2012, 2009, 2007, 2004, 2002, 2000, 1991 Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from NSF International. Printe

8、d in the United States of America. iii Disclaimers1 NSF International (NSF), in performing its functions in accordance with its objectives, does not assume or undertake to discharge any responsibility of the manufacturer or any other party. The opinions and findings of NSF represent its professional

9、 judgment. NSF shall not be responsible to anyone for the use of or reliance upon this Standard by anyone. NSF shall not incur any obligation or liability for damages, including consequential damages, arising out of or in connection with the use, interpretation of, or reliance upon this Standard. NS

10、F Standards provide basic criteria to promote sanitation and protection of the public health. Provisions for mechanical and electrical safety have not been included in this Standard because governmental agencies or other national standards-setting organizations provide safety requirements. Participa

11、tion in NSFs Standards development activities by regulatory agency representatives (federal, local, state) shall not constitute their agencys endorsement of NSF or any of its Standards. Preference is given to the use of performance criteria measurable by examination or testing in NSF Standards devel

12、opment when such performance criteria may reasonably be used in lieu of design, materials, or construction criteria. The illustrations, if provided, are intended to assist in understanding their adjacent standard requirements. However, the illustrations may not include all requirements for a specifi

13、c product or unit, nor do they show the only method of fabricating such arrangements. Such partial drawings shall not be used to justify improper or incomplete design and construction. Unless otherwise referenced, the annexes are not considered an integral part of NSF Standards. The annexes are prov

14、ided as general guidelines to the manufacturer, regulatory agency, user, or certifying organization. 1 The information contained in this Disclaimer is not part of this American National Standard (ANS) and has not been processed in accordance with ANSIs requirements for an ANS. Therefore, this Discla

15、imer may contain material that has not been subjected to public review or a consensus process. In addition, it does not contain requirements necessary for conformance to the Standard. iv This page is intentionally left blank.v Contents 1 General . 1 1.1 Purpose 1 1.2 Scope . 1 1.3 Variance from mini

16、mum requirements . 2 1.4 Alternate materials 2 2 Normative references 2 3 Definitions . 3 4 Materials . 3 4.1 Materials in contact with drinking water . 3 4.2 Materials evaluation 4 4.3 Gas chromatography/mass spectroscopy (GC/MS) analysis 5 5 Structural performance 15 5.1 Structural integrity . 15

17、6 Minimum performance requirements 20 6.1 General . 20 6.2 Performance indication 20 6.3 Elements 21 6.4 Flow control 21 6.5 Waste connections 21 6.6 Product water dispensing outlets . 21 6.7 Hazards 21 6.8 Lamp operation indication . 22 6.9 Lamp replacement 22 6.10 Maintenance . 22 6.11 Temperature

18、 resistance 22 6.12 Corrodible materials 22 6.13 Gaskets, o-rings, shaft seals, and packing materials . 22 6.14 Dissimilar metals. 22 6.15 Insulating fittings . 22 6.16 Plastics . 22 6.17 Welding 22 7 Elective performance claims test methods 23 7.1 General . 23 7.2 Microbiological performance 23 8 I

19、nstructions and information . 32 8.1 Installation, operation, and maintenance instructions . 32 8.2 Data plate . 33 8.3 Replacement components . 34 8.4 Performance data sheet 36 Annex A . A1 Annex B . B1 Annex C . C1 vi This page is intentionally left blank.vii Foreword2 The purpose of this Standard

20、 is to establish minimum requirements for the reduction of microorganisms using ultraviolet radiation (UV). UV water treatment systems covered by this Standard are intended for water that may be either microbiologically safe or microbiologically unsafe. This Standard also specifies the minimum produ

21、ct literature and labeling information that a manufacturer shall supply to authorized representatives and system owners, as well as the minimum service-related obligations that the manufacturer shall extend to system owners. Systems covered by this Standard are in keeping with the Report of Task For

22、ce on Guide Standard and Protocol for Testing Microbiological Water Purifiers, April, 1987.3 It is recognized that the federal, state and local objectives are to provide safe water supplies without user treatment. However, many users are faced with the presence of contaminants of both aesthetic and

23、health concern in their water supplies, and need guidance as to the availability of tested and certified point-of-entry and point-of-use ultraviolet water treatment systems. This Standard will help to meet this need but cannot be expected to address claims beyond those covered in this Standard. Sinc

24、e it was not economically feasible to mount a routine testing program using all of the target microorganisms, e. g., bacteria, viruses, and protozoan cysts, an equivalent “disinfection“ set of tests and requirements was developed for point-of-use and point-of-entry ultraviolet disinfection systems.

25、A virus reduction of 4 log against a poliovirus and rotavirus challenge and a bacteriological reduction of 6 logs against a challenge of a coliform bacteria (Klebsiella terrigena) has been recommended by Schaub and an expert task force (1987).4 The technical and health protection problems (laborator

26、y staff) and the inherent cost of establishing and maintaining a live virus test program preclude its routine application in a multipurpose standards testing laboratory. Consequently, an alternate means of assuring virus efficacy was developed. Survival data for poliovirus and rotavirus (Chang, 1985

27、)5 show that between a 3- and 4-log reduction in both poliovirus and rotavirus may be accomplished by a UV dosage of 30,000 W-sec/cm2 while a greater than 6-log reduction of Escherichia coli may be projected. Additional data (Harris, 1986)6 show a 5-log reduction of poliovirus at 40,000 w-sec/cm2. I

28、n NSF/ANSI 55 2000, a minimum UV dosage of 38,000 W-sec/cm2 at the failsafe setpoint was set as an equivalent 4-log virus reduction requirement. To be consistent with International Standards, the minimum UV dose in NSF/ANSI 55 2002 was changed to 40 mJ/cm2 (40,000 w-sec/cm2) at the alarm set point.

29、Prior to the late 1990s, it was thought that ultraviolet light had limited cysticidal ability, which required information for the user as to the need for a prefilter complying with NSF/ANSI 53: Drinking water treatment units Health effects for cyst reduction. Survival data for Cryptosporidium (Clanc

30、y, 2000)7 and 2 The information contained in this Foreword is not part of this American National Standard (ANS) and has not been processed in accordance with ANSIs requirements for an ANS. Therefore, this Foreword may contain material that has not been subjected to public review or a consensus proce

31、ss. In addition, it does not contain requirements necessary for conformance to the Standard. 3 Guide Standard and Protocol for Testing Microbiological Water Purifiers, Report of Task Force, submitted by Steven A. Schaub to the USEPA, April 1987 4 Ibid. p. 7 5 “UV Inactivation of Pathogenic and Indic

32、ator Microorganisms,” Chang, J.C., Johnson, J. Doald, et al. Journal of Applied Environmental Microbiology, Vol. 49, pp. 13611365, 1985 6 “UV Inactivation of Selected Bacteria and Viruses With Photoreactivation of the Bacteria,” Harris, D. George, Adams, Dean, et al., Water Resources, Vol. 21, pp. 6

33、87692, 1986 7 “Using UV to Inactivate Crypospordium,” Clancy, J. L., et al. Journal of American Water Works, Vol 92, Issue 9, pp. 97-104, 2000 viii Giardia (Craik, 2000)8 show that a minimum 3- to 4-log reduction in both Cryptosporidium and Giardia may be accomplished by a UV dosage of 10 mJ/cm2. Wh

34、ere drinking water is considered to be free of disease causing pathogenic organisms and has a turbidity level within acceptable drinking water standards, ultraviolet treatment may be useful for the supplemental treatment of this drinking water. It would be suitable for the reduction of normally occu

35、rring microbiological flora (non-spore forming heterotrophic bacteria) commonly found in drinking water. Survival data (Chang, 1985)9 show that a greater than 2-log reduction of non-spore forming heterotrophic bacteria may be accomplished by an ultraviolet dosage of 16,000 W-sec/cm2. The yeast organ

36、ism Saccharomyces cerevisiae was chosen as the test challenge to allow for a reasonable influent concentration and an easily measured reduction in the effluent. Most vegetative bacteria, including coliform species, are too susceptible to UV radiation at the dose range of 16,000 W-sec/cm2 to allow fo

37、r measurable testing. This version of the Standard contains the following revisions: Issue 40 This revision added clarification regarding the maximum number of samples exposed in the Materials evaluation under section 4. It is the intent of the Joint Committee to eliminate the use of S. cerevisiae a

38、s a challenge organism for Class B devices from the Standard after September 2017, a period of five years from the adoption of using T1 Coliphage as a challenge organism for Class B devices. This Standard was developed by the NSF Joint Committee on Drinking Water Treatment Units using the consensus

39、process described by the American National Standards Institute. Suggestions for improvement of this Standard are welcome. This Standard is maintained on a Continuous Maintenance schedule and can be opened for comment at any time. Comments should be sent to Chair, Joint Committee on Drinking Water Tr

40、eatment Units at standardsnsf.org or, c/o NSF International, Standards Department, P.O. Box 130140, Ann Arbor, Michigan 48113-0140, USA. 8 “Inactivation of Giardia Muris Cysts Using Medium-Pressure Ultraviolet Radiation in Filtered Drinking water,” Craik, S. A., et al. Water Resources, Vol. 34, No.

41、18, pp 4325-4332, 2000 9 Ibid. p.1362 1 2015 NSF NSF/ANSI 55 2015 NSF/ANSI Standard for Drinking Water Treatment Units Ultraviolet microbiological water treatment units 1 General 1.1 Purpose The purpose of this Standard is to establish minimum requirements for the reduction of microorganisms using u

42、ltraviolet radiation (UV). UV water treatment systems covered by this Standard are intended for water that may be either microbiologically safe or microbiologically unsafe. This Standard also specifies the minimum product literature and labeling information that a manufacturer shall supply to author

43、ized representatives and system owners, as well as the minimum service-related obligations that the manufacturer shall extend to system owners. 1.2 Scope This Standard covers ultraviolet microbiological water treatment systems and components for point-of-use and point-of-entry applications. Systems

44、are intended to be used under the following specific conditions. 1.2.1 Class A systems Class A point-of-entry and point-of-use systems covered by this Standard are designed to inactivate and/or remove microorganisms, including bacteria, viruses, Cryptosporidium oocysts, and Giardia cysts, from conta

45、minated water. Systems covered by this Standard are not intended for the treatment of water that has an obvious contamination or intentional source, such as raw sewage, nor are systems intended to convert wastewater to drinking water. The systems are intended to be installed on visually clear water

46、(not colored, cloudy, or turbid). Class A systems not installed downstream of a device tested for cyst reduction/inactivation in conformance to the appropriate NSF/ANSI standard may claim Cryptosporidium oocysts and Giardia cysts only. Class A systems installed downstream of a device tested for cyst

47、 reduction/inactivation in conformance to the appropriate NSF/ANSI standard may make a general cyst claim when used on untreated surface waters and/or ground water under the direct influence of surface water. NOTE Current data support that Cryptosporidium oocysts and Giardia cysts are inactivated by

48、 ultraviolet treatment. 1.2.2 Class B systems or components Class B point-of-entry and point-of-use systems covered by this Standard are designed for supplemental bactericidal treatment of disinfected public drinking water or other drinking water that has been tested and deemed acceptable for human

49、consumption by the state or local health agency having jurisdiction. The system is designed to reduce normally occurring nonpathogenic nuisance microorganisms only. The Class B system is not intended for the disinfection of microbiologically unsafe water and may not make individual or general cyst claims. Class B systems shall not make microbiological health effects claims. 2015 NSF NSF/ANSI 55 2015 2 1.3 Variance from minimum requirements Variations from the minimum requirements specified in 4, 5, 6, and 7 may be permitted provided that they give the