ANSI AWWA C651-2005 Disinfecting Water Mains《消毒总水管》.pdf

1、The Authoritative Resource on Safe WaterSMANSI/AWWA C651-05(Revision of ANSI/AWWA C651-99)AWWA StandardEffective date: June 1, 2005.First edition approved by AWWA Board of Directors Sept. 30, 1947.This edition approved Jan. 16, 2005.Approved by American National Standards Institute Mar. 9, 2005.Disi

2、nfecting Water MainsAdvocacyCommunicationsConferencesEducation and TrainingH17012 Science and TechnologySections6666 West Quincy AvenueDenver, CO 80235-3098T 800.926.7337www.awwa.orgCopyright American Water Works Association Provided by IHS under license with AWWANot for ResaleNo reproduction or net

3、working permitted without license from IHS-,-,-iiAWWA StandardThis document is an American Water Works Association (AWWA) standard. It is not a specification. AWWA standardsdescribe minimum requirements and do not contain all of the engineering and administrative information normallycontained in spe

4、cifications. The AWWA standards usually contain options that must be evaluated by the user of thestandard. Until each optional feature is specified by the user, the product or service is not fully defined. AWWApublication of a standard does not constitute endorsement of any product or product type,

5、nor does AWWA test, certify,or approve any product. The use of AWWA standards is entirely voluntary. AWWA standards are intended to represent aconsensus of the water supply industry that the product described will provide satisfactory service. When AWWA revisesor withdraws this standard, an official

6、 notice of action will be placed on the first page of the classified advertisingsection of Journal AWWA. The action becomes effective on the first day of the month following the month of JournalAWWA publication of the official notice.American National StandardAn American National Standard implies a

7、consensus of those substantially concerned with its scope and provisions. AnAmerican National Standard is intended as a guide to aid the manufacturer, the consumer, and the general public. Theexistence of an American National Standard does not in any respect preclude anyone, whether that person hasa

8、pproved the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or proceduresnot conforming to the standard. American National Standards are subject to periodic review, and users are cautionedto obtain the latest editions. Producers of goods made in conformity w

9、ith an American National Standard areencouraged to state on their own responsibility in advertising and promotional materials or on tags or labels that thegoods are produced in conformity with particular American National Standards.CAUTION NOTICE: The American National Standards Institute (ANSI) app

10、roval date on the front cover of this standardindicates completion of the ANSI approval process. This American National Standard may be revised or withdrawn atany time. ANSI procedures require that action be taken to reaffirm, revise, or withdraw this standard no later than fiveyears from the date o

11、f publication. Purchasers of American National Standards may receive current information on allstandards by calling or writing the American National Standards Institute, 25 West 43rd Street, Fourth Floor, New York,NY 10036; (212) 642-4900.Science and TechnologyAWWA unites the entire water community

12、by developing and distributing authoritative scientific and technologicalknowledge. Through its members, AWWA develops industry standards for products and processes that advance publichealth and safety. AWWA also provides quality improvement programs for water and wastewater utilities.All rights res

13、erved. No part of this publication may be reproduced or transmitted in any form or by any means, electronicor mechanical, including photocopy, recording, or any information or retrieval system, except in the form of briefexcerpts or quotations for review purposes, without the written permission of t

14、he publisher. Copyright 2005 by American Water Works AssociationPrinted in USACopyright American Water Works Association Provided by IHS under license with AWWANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-iiiCommittee PersonnelThe AWWA Standards Committee on Dis

15、infection of Facilities, which reviewed andapproved this standard, had the following personnel at the time of approval:Marc S. Solomon, ChairGeneral Interest MembersK.C. Choquette, Des Moines, Iowa (AWWA)C.B. Hagar, Carollo Engineers, Phoenix, Ariz. (AWWA)Terrence Lambert, Florida Department of Envi

16、ronmental Protection, Orlando, Fla. (AWWA)T.J. McCandless,*Standards Engineer Liaison, AWWA, Denver, Colo. (AWWA)M.S. Solomon, Winzler mains that have been removed from service forplanned repairs or for maintenance that exposes them to contamination; mains thathave undergone emergency repairs becaus

17、e of physical failure; and mains that, undernormal operation, continue to show the presence of coliform organisms. Thedisinfecting agents discussed in this standard are chlorine solutions that may bederived from liquid chlorine (Cl2), calcium hypochlorite (Ca(OCl)2), or sodiumhypochlorite (NaOCl). C

18、ombinations of free chlorine residual and contact time areprovided.I.B. History. This standard was first approved on Sept. 30, 1947, by theAWWA Board of Directors and published as 7D.2-1948, A Procedure forDisinfecting Water Mains. Revisions were approved by the AWWA Board ofDirectors on Sept. 14, 1

19、948; Mar. 6, 1953; May 27, 1954; June 2, 1968; June 7,1981; and June 20, 1999. All were done under the designation ANSI/AWWA C601,Standard for Disinfecting Water Mains. In 1986, the designation of the standard waschanged to ANSI/AWWA C651, and the subsequent editions were approved by theAWWA Board o

20、f Directors on June 18, 1992, and June 20, 1999. This edition wasapproved on Jan. 16, 2005.I.C. Acceptance. In May 1985, the US Environmental Protection Agency(USEPA) entered into a cooperative agreement with a consortium led by NSFInternational (NSF) to develop voluntary third-party consensus stand

21、ards and acertification program for all direct and indirect drinking water additives. Othermembers of the original consortium included the American Water Works AssociationResearch Foundation (AwwaRF) and the Conference of State Health and Environ-mental Managers (COSHEM). The American Water Works As

22、sociation (AWWA)and the Association of State Drinking Water Administrators (ASDWA) joined later.In the United States, authority to regulate products for use in, or contact with,drinking water rests with individual states.*Local agencies may choose to imposerequirements more stringent than those requ

23、ired by the state. To evaluate the health*Persons outside of the US should contact the appropriate authority having jurisdiction.Copyright American Water Works Association Provided by IHS under license with AWWANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-viiief

24、fects of products and drinking water additives from such products, state and localagencies may use various references, including1. An advisory program formerly administered by USEPA, Office of DrinkingWater, discontinued on April 7, 1990.2. Specific policies of the state or local agency.3. Two stand

25、ards developed under the direction of NSF, NSF*/ANSI60,Drinking Water Treatment ChemicalsHealth Effects, and NSF/ANSI 61, Drink-ing Water System ComponentsHealth Effects.4. Other references, including AWWA standards, Food Chemicals Codex, WaterChemicals Codex,and other standards considered appropria

26、te by the state or localagency.Various certification organizations may be involved in certifying products inaccordance with NSF/ANSI 60. Individual states or local agencies have authority toaccept or accredit certification organizations within their jurisdiction. Accreditationof certification organi

27、zations may vary from jurisdiction to jurisdiction.Annex A, “Toxicology Review and Evaluation Procedures,” to NSF/ANSI 60does not stipulate a maximum allowable level (MAL) of a contaminant for substancesnot regulated by a USEPA final maximum contaminant level (MCL). The MALs ofan unspecified list of

28、 “unregulated contaminants” are based on toxicity testingguidelines (noncarcinogens) and risk characterization methodology (carcinogens).Use of Annex A procedures may not always be identical, depending on the certifier.ANSI/AWWA C651 does not address additives requirements. Thus, users of thisstanda

29、rd should consult the appropriate state or local agency having jurisdiction inorder to1. Determine additives requirements including applicable standards.2. Determine the status of certifications by all parties offering to certify prod-ucts for contact with, or treatment of, drinking water.3. Determi

30、ne current information on product certification.* NSF International, 789 N. Dixboro Rd., Ann Arbor, MI 48105. American National Standards Institute, 25 West 43rd Street, Fourth Floor, New York, NY10036.Both publications available from National Academy of Sciences, 500 Fifth St., N.W.,Washington,DC 2

31、0001.Copyright American Water Works Association Provided by IHS under license with AWWANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ixII. Special Issues.II.A. Information on Application of This Standard. Generally, it is easier todisinfect a new main rather than

32、 one that has had emergency repairs. The unsanitaryconditions created when an existing main bursts or is cut into are likely to be difficultto control. The need to quickly restore water service to the community requires morerapid disinfection procedures than those prescribed for newly constructed ma

33、ins.Crews responsible for the repair of mains should be aware of the potential healthhazards and should be trained to carefully observe prescribed construction practicesand disinfection procedures.Disinfection requires skills not necessarily mastered by competent constructioncrews. Some utilities pr

34、efer to disinfect water mains using specially trained treatmentcrews. However, because the effectiveness of disinfection depends, in large measure,on maintaining clean pipes and avoiding major contamination during construction,there are some advantages to having the construction crew retain the resp

35、onsibilityfor disinfection. Furthermore, certain functions, such as placing tablets, must beperformed by the construction crew. In either case, it is strongly recommended thatpipe crews be aware of the need to maintain clean pipes and avoid contamination. While bacteriological testing in accordance

36、with Sec. 5.1 is used to verify theabsence of coliform organisms and is generally accepted as verification thatdisinfection of the pipeline has been accomplished, following sanitary practices forhandling and installation of pipe, valves, fittings, and accessories, coupled withadequate flushing of th

37、e line before disinfection, is necessary to ensure that thedisinfected pipeline will be ready for connection to the water system. Failure to passthe bacteriological test requires that the flushing or disinfection process be repeated.It must be remembered that the final water quality test is not the

38、primary means forcertifying the sanitary condition of a main. The sanitary handling of materials, thepractices during construction, and the continual inspection of the work are theprimary means for ensuring the sanitary condition of the water main.Three methods of disinfecting newly constructed wate

39、r mains are described inthis standard: the tablet method, the continuous-feed method, and the slug method.The utility should decide which of these methods is most suitable for a givensituation. Factors to consider when choosing a method should include the length anddiameter of the main, type of join

40、ts present, availability of materials, equipmentrequired for disinfection, training of the personnel who will perform the disinfection,and safety concerns. For example, the continuous-feed or slug methods should beCopyright American Water Works Association Provided by IHS under license with AWWANot

41、for ResaleNo reproduction or networking permitted without license from IHS-,-,-xused with gas chlorination only when properly designed and constructed equipmentis available; makeshift equipment is not acceptable when liquid-chlorine cylinders areused.Thorough consideration should be given to the imp

42、act of highly chlorinatedwater flushed into the waste environment. If there is any question that damage maybe caused by chlorinated-waste discharge (to fish life, plant life, physical installations,or other downstream water uses of any type), then an adequate amount of reducingagent should be applie

43、d to water being disposed of in order to thoroughly neutralizethe chlorine residual remaining in the water.The tablet method cannot be used unless the main can be kept clean and dry. Itcannot be used in large-diameter mains if it is necessary for a worker to enter themain to grout joints or perform

44、inspection, because the tablets may release toxicfumes after exposure to moist air. When using the tablet method, the chlorineconcentration is not uniform throughout the main, because the hypochlorite solutionis dense and tends to concentrate at the bottom of the pipe. The use of the tabletmethod pr

45、ecludes preliminary flushing. The tablet method is convenient to use inmains having diameters up to 24 in., and it requires no special equipment.The continuous-feed method is suitable for general application. Preliminaryflushing removes light particulates from the main but not from the pipe-joint sp

46、aces.The chlorine concentration is uniform throughout the main.The slug method is suitable for use in large-diameter mains where the volume ofwater makes the continuous-feed method impractical and difficult to achieve forshort attachments. The slug method results in appreciable savings of chemicals

47、usedto disinfect long, large-diameter mains. Also, this method reduces the volume ofheavily chlorinated water to be flushed to waste.The purpose of all three chlorination methods is to disinfect water lines, resultingin an absence of coliforms as confirmed by laboratory analysis. As noted above, the

48、three methods attempt to provide flexibility in responding to specific situations. Thetablet and continuous-feed methods both have initial chlorine concentrations of25 mg/L and a minimum contact time of 24 hr. Because the tablet method cannotbe flushed and cleaned prior to disinfection, the required

49、 free chlorine residual mustbe detectable after 24 hr. Because the continuous-feed method can be used to flushparticles and prechlorinate with calcium hypochlorite granules, a higher free chlorineresidual of 10 mg/L is required after 24 hr. To meet the needs of situations requiringreduced contact times, the slug feed method allows only a 3-hr contact time, butCopyright American Water Works Association Provided by IHS under license with AWWANot for ResaleNo reproduction or netwo