1、ANSI/AWWA C655-09 (First Edition) American Water Works Association The Authoritative Resource on Safe Water“ AWA Standard Field Dechlorination Effective date: March 1,2010. This first edition approved by AWA Board of Directors June 14, 2009. Approved by American National Standards Institute Jan. 14,
2、2010. 6666 West Quincy Avenue Denver, CO 80235-3098 T 800.926.7337 www.awwa.org Advocacy Communications Conferences Education and Training Science and Technalogy Sections Copyright GI 2010 Arnerlcan Water Works Assoclatlon. All Rlghts Reserved. AWWA Standard This document is an American Water Works
3、Association IAWWAI standard. It is not a specification. AWWA standards describe m nlnwm req.lre!nenls ard 00 Po1 con!a n ai of 1ne eng nerr rg and adm n slralirc nformai on norms y contained n spec,6- cat ons. Tnc A!hA srandaros usla ) conra n opt ans tnat mls: ce eral,atca oy mc “ser of me sranoaro
4、. Lnr each opliona feature is specified by the user, the product or service is not fully defined. AWWA pubiication of a standard does not constitute endorsement of any product or product type, nor does AWWA test, certify, or approve any product. The use of AWWA standards is entirely voluntary. This
5、standard does not supersede or take precedence over or displace any applicable law, regulation, or codes of anv governmental authoritv. AWWA standards are intended to reoresent a consensus of the water suppiv industry that . rne praoLc1 oescrioeo n i yo$ .!e sat sfactor) scn cc. Wnen AVWA re, ses or
6、 i. lnurbcs 111 s stanudrd, an olnc a. nollce of action N be p bcea on lnc hrst Page of tne c ass heo aorert sir$ seci on of o.malAl:llA. Thc ac1 on occomes efec! e on the first day ofthe month following the month of Journal AWWA pubiication of the officiai notice. American National Standard An Amer
7、ican Nationai Standard implies a consensus of those substantially concerned with its scope and provisions. An Ameri- can National Standard is intended as a guide to aid the manufacturer, the consumer, and the eenerai public. The existence of - . an American Nationai Standard does not in any respect
8、preclude anyone, whether that person has approved the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standard. American Nationai Standards are subiect to periodic review, and users are cautioned to obtain the latest editi
9、ons. Producers of oods ride r conform tf n in 3n Arnercan ha:fora Sianuam are erlcdLragc0 lo slate on :hclr onn respos b! 1) n noterr s- n, ane promo: onai mn1er.n 5 or on tags :r laueis tlat lvlc p,oos arc proJ.ce0 n conforrii) .% in yrl C. a, Anltr Cbrl LJlOna Standards CAUTON NOTICE: The American
10、 Nationai Standards institute (ANSI) approval date on the front cover of this standard indicates completion of the ANSl approval process. This American National Standard may be revised or withdrawn at any time. ANSl procedures require that action be taken to reaffirm, revise, or withdraw this standa
11、rd no iater than five years from the date of publication. Purchasers of American National Standards may receive current information an ail standards by calling or writing the American National Standards Institute, 25 West 43rd Street, Fourth Floor, New Yark, NY 10036: (212) 642-4900. Ail rights rese
12、rved. NO part of this pubiication may be reproduced or transmitted in any farm or by any means, electronic or mechanical, including photocopy, recording, or any information or retrieval system, except in the form of brief excerpts or quotations for review purposes, without the written permission of
13、the pubiisher. Copyright O 2010 by American Water Works Association Printed in USA Copyright 0 2010 Amencan Water Works Assoclatlon. Ail Rtghts Reserved. Committee Personnel The Dechlorination Subcommittee for this standard had the following personnel at the time: Robert J. Gordhamer, Chair L. Aguia
14、r, Miami-Dade Water Standards Engineer Liaison, AWWA, Denver, Colo. T. Lambert, Florida Department of Environmental Protection, Orlando, Fla. M.S. Solomon, Winzler and Kelly Consulting Engineers, Santa Rosa, Calif. T.W. Walker, New York State Department of Health, Victor, N.Y. M.L. Wentink, Nebraska
15、 Department of Health and Human Services Division of Public Health, North Platte, Neb. (Am) (Am) (Am) (AWN (Am) (AWWA) (AWWA) (AWWA) * Liaison, nonvoting iii Copyright 2010 Arnencan water Works Assoclation. All Rlghts Reserved. Producer Members R.J. Gordhamer, Measurement Technologies Inc., Redmond,
16、 Wash. W.B. Huebner, Mine Hill, N.J. M.L. Johnsen, Johnsen Corrosion Engineering, Lincoln, Neb. User Mmben T.F. Clark, Monroe County Water Authority, Rochester, N.Y. D.J. artrnan: Greater Cincinnati Water Works, Cincinnati, Ohio L.A. Hensley, GDS Associates Inc., Marietta, Ga. R.C. Lorenz, Westervil
17、le Water Plant, Westerville, Ohio T.W.D. MacDonald, Cambridge Water Department, Cambridge, Mass. P.M. Marchand, Providence Water Supply Board, Providence, R.I. B. ReiUey-Matthews, MWRA, Southborough, Mass. E.D. Schwartz, Plainsboro, N.J. J.L. Stapf, Hernando County Utilities, Brooksville, Fla. (AWWA
18、) (AWWA) (AWWA) (NEWWA) (NEWWA) (AWWA) (AWWA) (AWWA) Liaison, nonvoting iv Copyright GI 201 0 Arnerlcan Water Works Assoclatlon. All Rights ReseNed. Contents All AWWA standards follow the general format indicated snbsequently. Some variations from this format may be found in a partimlar standard. SE
19、C. PAGE SEC. PAGE Foreword 2 References 2 I Introduction vii . . . . . 3 Defintons 2 . 1.A Background VII 4 Requirements 1.B History VIE 4.1 Materials . 3 1.C Acceptance VII . 4.2 Chemical and Nonchemical . . Special Issues VIII Dechlorination 3 . US Regulations viii 4.3 Dechlorination Plan and Cana
20、dian Regulations ix Procedures 10 Determination of Method Used . 4.4 Dechlorination Methods 12 . for Dechlorination x . 111 Use of This Standard x 1II.A Purchaser Options and Alternatives x . 1II.B Modification to Standard xi IV Major Revisions . xi . V Comments xi Standard 1 General 1.1 Scope 1 . 1
21、.2 Purpose 1 1.3 Application 1 5 Verification 5.1 Residual Chlorine Level 13 5.2 Residual Testing 13 . 6 Delivery 14 Tables 1 Chemical Reactions for Dechlorination With . . Free Chlorine 5 2 Dechlorination Chemical Reactions With Chloramines 5 v Copyright 0 2010 Amencan Water Works Assocbatlon. All
22、Rlghts Reserved ?his page intentionally blank. Copyright 0 2010 American Water Works Assoclatlon. All Rlghts ReseNed. Foreword %is foreword is for information only and is not apart ofANSIMWA C655. I. Introduction. I.A. Background. This standard describes procedures, materials, and requirements for t
23、he dechlorination of chlorinated or chloraminated water discharges. It includes current dechlorination regulations, chemical and nonchemical dechlorination, dechlorination plans and procedures, dechlorination methods, and verification. I.B. Histoy. This is the first version of this standard, and it
24、was approved by the AWWA Board of Directors on June 14,2009. I.C. Acceptance. In May 1985, the US Environmental Protection Agency (USEPA) entered into a cooperative agreement with a consortium led by NSF International (NSF) to develop voluntary third-party consensus standards and a certification pro
25、gram for direct and indirect drinking water additives. Other members of the original consortium included the Water Research Foundation and the Conference of State Health and Environmental Managers (COSHEM). The American Water Works Association (AWWA) and the Association of State Drinking Water Admin
26、istrators (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 impose requirements more stringent than those required by the state. To evaluate the health effects of products
27、 and drinking water additives from such products, state and local agencies may use various references, including 1. An advisory program formerly administered by USEPA, Office of Drinking Water, discontinued on April 7, 1990. 2. Specific policies of the state or local agency. 3. Two standards develop
28、ed under the direction of NSF, NSFtIANSI* 60, Drinking Water Treatment Chemicals-Health Effects, and NSFIANSI 61, Drinking Water System Components-Health Effects. *Persons outside of the United States should contact the appropriate authority having jurisdiction. t NSF International, 789 N. Dixhoro R
29、oad, Ann Arbor, MI 48105. f American National Standards Institute, 25 West 43rd Street, Fourth Floor, New York, NY 10036. vii Copyright 2010 American Water Works Assoclatlon. All Rlghts Reserved 4. Other references, including AWWA standards, Food Chemicals Codex, Water Chemicals Codex,* and other st
30、andards considered appropriate by the state or local agency. Various certification organizations may be involved in certifying products in accor- dance with NSFIANSI 60. Individual states or local agencies have authority to accept or accredit certification organizations within their jurisdiction. Ac
31、creditation of certi- fication organizations may vary from jurisdiction to jurisdiction. Annex A, “Toxicology Review and Evaluation Procedures,“ to NSFIANSI 60 does not stipulate a maximum allowable level (MAL) of a contaminant for substances not regulated by a USEPA final maximum contaminant level
32、(MCL). The MALs of an unspecified list of “unregulated contaminants“ are based on toxicity testing guidelines (noncarcinogens) and risk characterization methodology (carcinogens). Use of annex A procedures may not always be identical, depending on the certifier. ANSIIAWWA C655 does not address addit
33、ives requirements. Thus, users of this standard should consult the appropriate state or local agency having jurisdiction in order to 1. Determine additives requirements including applicable standards. 2. Determine the status of certifications by parties offering to certify products for contact with,
34、 or treatment of, drinking water. 3. Determine current information on product certification. 11. Special Issues. ILA. US Regulations. 1. The United States Environmental Protection Agency (USEPA) has estab- lished Water Quality Criteria (WQC) for total residual chlorine (TRC) concentra- tions permiss
35、ible in receiving waters to protect aquatic life and water quality. These concentrations are based on acute and chronic toxicity effects for aquatic life. Under the acute toxicity criterion, the one-hour average chlorine concentration of the stream should not exceed 0.019 mg/L (19 pg/L) more than on
36、ce every three years, on aver- age. Under the chronic toxicity criterion, the four-day average concentrations should not exceed 0.011 mgIL (11 pgIL) more than once every three years, on average. Most states in the United States use 0.019 mgIL (19 pgIL) as the acute criterion and 0.011 mglL (11 pgIL)
37、 as the chronic criterion for TRC for receiving streams. Some states have adopted a toxicity-based criterion for water quality for TRC. The state regu- * Both publications available from National Academy of Sciences, 500 Fifth Street, NW, Washington, DC 20001. viii Copyright 0 2010 Amerlcan Water Wo
38、rks Assoclatlon. All Rlghts Reserved latory agencies require water utilities to abide by the receiving water quality criterion while discharging chlorinated waters. In addition, the regulatory agencies use WQC to develop maximum allowable chlorine concentrations while issuing general or indi- vidual
39、 permits for discharge of chlorinated water into streams. Chlorine discharge limits in water releases into receiving streams and wetlands shall not exceed 0.01 mg/L (or a more stringent limit). 2. In addition to residual chlorine concentrations, some other water quality parameters must be monitored
40、during disposal of chlorinated waters. For example, dechlorination of chloramine residuals may result in the release of ammonia. USEPA has determined the maximum allowable acute and chronic concentrations of ammonia based on the pH, temperature, and the type of aquatic habitat present (warm- vs. col
41、d- water species) in receiving waters. Under the most stringent conditions, (cold-water species, pH of 9, 30C), a one-day average total ammonia concentration must not exceed 0.58 mg/L as NH3 and a four-day average must not exceed 0.08 mg/L as NH3. Most states have adopted the USEPA criteria as the w
42、ater quality standards for ammonia. Water utilities using combined chlorine often maintain a residual chlorine concentration of less than 1.5 mg/L in potable waters, with a chlorine-to-ammonia ratio of 4:l to 5:l by mass. This will result in a total ammonia concentration of approx- imately 0.4 to 0.
43、5 mg/L, which is less than the acute criterion of 0.58 mg/L for total ammonia under the worst-case scenario. A tenfold dilution of chloraminated water in the receiving stream will result in compliance with the chronic ammonia concentra- tion criterion (0.08 mg/L as NH3) under the most stringent cond
44、itions. For the majority of dechlorination operations, ammonia released from chloramines is likely to be within regulatory requirements. However, some states may have regula- tions mote stringent than the USEPA criteria for selected waters. Caution must be exer- cised in releasing dechloraminated wa
45、ter into receiving streams under such conditions. ILB. Canadian Regulations. 1. Canadian Environmental Quality Guidelines (1987) propose a water qual- ity criterion of 0.020 mg/L of total residual chlorine for receiving streams. Many pro- vincial regulatory agencies have adopted this chlorine concen
46、tration as the WQC. However, the criteria for chlorine and chloramine concentrations are currently being reviewed under the 1999 water quality guidelines. Like the United States, each province has set its own discharge regulations to dechlorinate prior to discharge into receiving streams. 2. In gene
47、ral, the water quality criteria for ammonia, dissolved oxygen, and pH in Canada are similar to those in the United States. In Newfoundland, the pH Copyrlghte 2010 Amerlcan Water Works Assoclatlon. All Rkghts Reserved of the released water should be between 5.5 and 9.0. In Saskatchewan, total ammonia
48、 concentrations in the receiving water can be as high as 2.6 mg/L at pH 6.0 and 0C to as low as 0.06 mg1L at pH 9.0 and 30C. Caution must be exercised in complying with ammonia, pH, and dissolved oxygen regulations during dechlorination activities. Chlorine discharge limits in water releases into re
49、ceiving streams and wetlands shall not exceed 0.01 mg1L. 1I.C. Determination of Method Used for Dechlorination. 7he method of dechlorination should be determined by the performance requirements dictated by site-specific conditions. Other issues such as the impact of dechlorination on dissolved oxygen and pH may also be of concern, depending on the quantities involved and the operational characteristics of the dechlorinating equipment. For all practical purposes, nonchemical dechlorination is limited to low chlorine discharges, and it is generally not suitable for flushing a
