Chloramines in Drinking Water Guideline Technical Document for Public Consultation Consultation period ends January 25, 2019 Chloramines For public consultation Chloramines in Drinking Water Document for Public Consultation Table of Contents Purpose of consultation ................................................................................................................... 1 Part I. Overview and Application................................................................................................ 2 1.0 Proposed guideline .............................................................................................................. 2 2.0 Executive summary ............................................................................................................. 2 2.1 Health effects .......................................................................................................... 2 2.2 Exposure ................................................................................................................. 3 2.3 Analysis and treatment ............................................................................................ 3 2.4 International considerations .................................................................................... 3 3.0 Application of the guideline................................................................................................ 4 3.1 Monitoring .............................................................................................................. 5 Part II. Science and Technical Considerations .......................................................................... 7 4.0 Identity, use and sources in the environment ...................................................................... 7 4.1 Environmental fate .................................................................................................. 9 4.1.1 Impact of chloramines on aquatic life ........................................................ 9 4.2 Terminology ............................................................................................................ 9 4.3 Chemistry in aqueous media ................................................................................. 10 4.4 Application to drinking water treatment ............................................................... 11 4.4.1 Chloramines in water treatment ............................................................... 11 4.4.2 Primary disinfection ................................................................................. 12 4.4.3 Secondary disinfection ............................................................................. 12 4.4.4 Formation of chloraminated disinfection by-products ............................. 12 4.4.5 Taste and odour considerations ................................................................ 13 5.0 Exposure ........................................................................................................................... 15 5.1 Water ..................................................................................................................... 15 5.2 Air ......................................................................................................................... 16 5.3 Swimming pools and hot tubs ............................................................................... 16 5.4 Multiroute exposure through drinking water ........................................................ 17 6.0 Analytical methods ........................................................................................................... 17 6.1 Sampling considerations ....................................................................................... 19 7.0 Treatment technology and distribution system considerations ......................................... 19 7.1 Municipal scale ..................................................................................................... 20 7.1.1 Disinfectant residual and microbial control ............................................. 20 ii Chloramines For public consultation 7.1.2 Considerations when changing disinfection practices to chloramination 21 7.1.3 Presence of ammonia in source water ...................................................... 21 7.2 Distribution system considerations ....................................................................... 21 7.2.1 Residual loss ............................................................................................. 21 7.2.2 Rechlorination and temporary breakpoint chlorination ........................... 22 7.2.3 Opportunistic pathogens ........................................................................... 23 7.2.4 Nitrification .............................................................................................. 24 7.2.5 Lead and copper release ........................................................................... 25 7.2.6 Iron ........................................................................................................... 27 7.2.7 Elastomeric materials ............................................................................... 27 7.3 Residential scale.................................................................................................... 27 7.4 Opportunities for research..................................................................................... 28 8.0 Kinetics and metabolism ................................................................................................... 29 8.1 Absorption............................................................................................................. 29 8.2 Distrib ution ........................................................................................................... 29 8.3 Metabolism ........................................................................................................... 29 8.4 Excretion ............................................................................................................... 30 9.0 Health effects .................................................................................................................... 30 9.1 Effects in humans .................................................................................................. 30 9.1.1 Acute toxicity ........................................................................................... 31 9.1.2 Subchronic and chronic toxicity and carcinogenicity .............................. 31 9.1.3 Developmental and reproductive toxicity ................................................ 34 9.2 Effects on experimental animals ........................................................................... 34 9.2.1 Acute toxicity ........................................................................................... 34 9.2.1.1 Oral ............................................................................................ 35 9.2.1.2 Inhalation ................................................................................... 35 9.2.2 Short-term exposure ................................................................................. 35 9.2.2.1 Monochloramine: decreased body weights and blood effects ... 35 9.2.2.2 Monochloramine: immunotoxic effects ..................................... 37 9.2.2.3 Dichloramine and trichloramine ................................................ 38 9.2.3 Long-term exposure and carcinogenicity ................................................. 38 9.2.4 Genotoxicity ............................................................................................. 39 9.2.4.1 In vitro findings.......................................................................... 40 9.2.4.2 In vivo findings .......................................................................... 40 9.2.5 Reproductive and developmental toxicity ................................................ 40 10.0 Classification and assessment ........................................................................................... 41 10.1 Aesthetic considerations ....................................................................................... 42 10.2 International considerations .................................................................................. 42 11.0 Rationale ........................................................................................................................... 43 12.0 References ......................................................................................................................... 43 Appendix A: List of acronyms ...................................................................................................... 60 iii November 2018 Chloramines in Drinking Water Purpose of consultation The available information on chloramines has been assessed with the intent of updating the current drinking water guideline and guideline technical document. The draft guideline technical document proposes that it is no longer considered necessary to establish a guideline for chloramines in drinking water. However, based on the use of chloramines in the disinfection of drinking water, a guideline technical document is still considered necessary. The document is being made available for a 60-day public consultation period. The purpose of this consultation is to solicit comments on the proposed approach, as well as to determine the availability of additional exposure data. Comments are appreciated, with accompanying rationale, where required.