AWWA COMMENT PERIOD ON AWWA C655, Field Dechlorination

AWWA COMMENT PERIOD ON AWWA C655, Field Dechlorination

AWWA solicits public comments on all proposed new AWWA Standards, and on all proposed revisions, reaffirmations, or withdrawals of existing AWWA Standards. The referenced standards project is being considered for approval and the publication of this notice begins the 45-day public comment period for AWWA and ANSI. An electronic public review copy of the proposed standard can be obtained for review during the comment period by emailing ETS Support (ETSsupport@awwa.org). Comments must be submitted in writing to the AWWA contact listed below no later than the last day of the comment period specified herein. Such comments shall be specific to the section(s) of the standard under review and include sufficient detail, so as to enable the reader to understand the commenter’s position, concerns and suggested alternative language, if appropriate.

AWWA Comment Period closes on April 7, 2025.

Send comments to:
Amanda Dail, ADail@awwa.org
303.734.3466 phone

The review copy will be edited for publication and may also be revised as appropriate based on any comments received during the public comment period. Therefore, this copy is not suitable for continued utilization and is intended only for comment purposes.

Final publication of the standard may take several months. When it is available, a notice will be published in the official notice section of Journal – American Water Works Association. The standard becomes an effective AWWA standard on the first day of the month following such publication in Journal – American Water Works Association.

SCOPE
This standard describes procedures, materials, and requirements for field dechlorination of chlorinated or chloraminated water discharges such as may occur from pipeline disinfection projects, hydrant flow testing, tank or pipeline draining or flushing, or distribution system maintenance flushing programs, when dechlorination is required.

MAJOR REVISIONS
Major revisions made to the standard in this edition include the following:

1. A requirement for preparing a Disinfection and Dechlorination Plan was added to the Foreword (II.C) and the revised Sec. 4.3; and guidance was added in new Appendix A. Previous Appendix A was renamed Appendix B.
2. A new section II.D was added to the Foreword for Chemical Handling Precautions.
3. The Scope, Purpose, and Application sections were revised to clarify use for field dechlorination only, and the Scope now includes examples of the types of water discharges where this standard may be applicable (Sec. 1.1, Sec. 1.2, and Sec. 1.3).
4. The definitions for chloraminated water, free chlorine, total residual chlorine, loss of control, and low-chloraminated water were removed, and definitions for chloramines, oxygen scavenger, reclaimed water, and total chlorine residual were added. The definitions for highly-chlorinated water and low-chlorinated water were clarified and variations of this terminology were edited throughout the standard for consistency.
5. A new nonchemical dechlorination subsection, 4.2.2.1 Dilution and fast reactions, in receiving water, was added and the remaining subsections renumbered.
6. The following treatment chemicals were removed: sulfur dioxide, sodium sulfite, sodium bisulfite, and sodium metabisulfite (Sec. 4.2.3 and Table A3 (now Table B.1).
7. The field methods for measuring residual chlorine levels in Sec. 5.2 were clarified and corrected as required. Titration is not a suitable method for the field and was replaced with portable chlorine meters (Sec. 5.2.1.3).
8. The chemical reaction tables were deleted from former Appendix A (now Appendix B).
9. Field dechlorination equipment previously covered in Sec. 4.4 were moved to Appendix C.