Chapter 6: Wastewater Treatment and Discharge CHAPTER 6 WASTEWATER TREATMENT AND DISCHARGE 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories 6.1 Volume 5: Waste Authors Deborah Bartram (USA), Michael D. Short (Australia), Yoshitaka Ebie (Japan), Juraj Farkaš (Slovakia), Céline Gueguen (France), Gregory M. Peters (Sweden), Nuria Mariana Zanzottera (Argentina), M. Karthik (India) Contributing Authors Shuhei Masuda (Japan) 6.2 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories Chapter 6: Wastewater Treatment and Discharge Contents 6 Wastewater Treatment and Discharge ....................................................................................................... 6.7 6.1 Introduction ......................................................................................................................................... 6.7 6.1.1 Centralised treatment systems ...................................................................................................... 6.10 6.1.2 Decentralised treatment systems of domestic wastewater (onsite sanitation) ............................... 6.11 6.1.3 Emissions from receiving waters .................................................................................................. 6.12 6.1.4 Changes compared to 1996 Guidelines and Good Practice Guidance ......................................... 6.12 6.1.5 Changes compared to 2006 IPCC Guidelines ............................................................................... 6.12 6.2 Methane emissions from wastewater ................................................................................................. 6.13 6.2.1 Methodological issues .................................................................................................................. 6.13 6.2.2 Domestic wastewater .................................................................................................................... 6.14 6.2.2.1 Choice of method .............................................................................................................. 6.14 6.2.2.2 Choice of emission factors ................................................................................................ 6.18 6.2.2.3 Choice of activity data ....................................................................................................... 6.21 6.2.2.4 Time series consistency ..................................................................................................... 6.29 6.2.2.5 Uncertainties ...................................................................................................................... 6.29 6.2.2.6 QA/QC, Completeness, Reporting and Documentation .................................................... 6.30 6.2.3 Industrial wastewater .................................................................................................................... 6.30 6.2.3.1 Choice of method .............................................................................................................. 6.30 6.2.3.2 Choice of emission factors ................................................................................................ 6.33 6.2.3.3 Choice of activity data ....................................................................................................... 6.35 6.2.3.4 Time series consistency ..................................................................................................... 6.35 6.2.3.5 Uncertainties ...................................................................................................................... 6.35 6.2.3.6 QA/QC, Completeness, Reporting and Documentation .................................................... 6.35 6.3 Nitrous oxide emissions from domestic wastewater .......................................................................... 6.35 6.3.1 Methodological issues .................................................................................................................. 6.35 6.3.1.1 Choice of method .............................................................................................................. 6.36 6.3.1.2 Choice of emission factors ................................................................................................ 6.38 6.3.1.3 Choice of activity data ....................................................................................................... 6.39 6.3.2 Time series consistency ................................................................................................................ 6.43 6.3.3 Uncertainties ................................................................................................................................. 6.43 6.3.4 QA/QC, Completeness, Reporting and Documentation ............................................................... 6.44 6.4 Nitrous oxide emissions from industrial wastewater ......................................................................... 6.44 6.4.1 Methodological issues .................................................................................................................. 6.44 6.4.1.1 Choice of method .............................................................................................................. 6.44 6.4.1.2 Choice of emission factors ................................................................................................ 6.47 6.4.1.3 Choice of activity data ....................................................................................................... 6.47 6.4.2 Time series consistency ................................................................................................................ 6.48 6.4.3 Uncertainties ................................................................................................................................. 6.49 6.4.4 QA/QC, Completeness, Reporting and Documentation ............................................................... 6.49 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories 6.3 Volume 5: Waste Appendix 6A.1 Non-biogenic (fossil) CO2 emissions from wastewater treatment and discharge: Basis for Future Methodological Development ...................................................................................... 6.51 Annex 6A.1 Summary data for pit latrine use, no sanitation facility, and groundwater use by country ..... 6.54 Annex 6A.2 Derivation of the maximum CH4 producing potential (Bo) for domestic wastewater ............. 6.57 Annex 6A.3 Estimation of default methane conversion factors for CH4 in centralised wastewater treatment plants treating domestic wastewater ........................................................................................ 6.58 Annex 6A.4 Calculation of MCF for methane emissions from sewage discharges ..................................... 6.59 Annex 6A.5 Estimation of default emission factors for N2O in domestic wastewater treatment plants ...... 6.61 Annex 6A.6 Estimation of default emission factors for N2O in effluent ..................................................... 6.63 Annex 6A.7 List of countries by region included in Table 6.10a ................................................................ 6.64 References ................................................................................................................................................ 6.65 6.4 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories Chapter 6: Wastewater Treatment and Discharge Equations Equation 6.1 (Updated) CH4 emissions from domestic wastewater for each treatment/discharge pathway or system, j ...................................................................................................................... 6.17 Equation 6.1a (New) Total CH4 emissions from domestic wastewater treatment and discharge .................. 6.17 Equation 6.2 CH4 emission factor for each domestic wastewater treatment/discharge pathway or system ......................................................................................................................... 6.18 Equation 6.3 (Updated) Total organically degradable material in domestic wastewater ................................... 6.21 Equation 6.3a (New) Total organics in domestic wastewater by treatment/discharge pathway or system ... 6.22 Equation 6.3b (New) Organic component removed as sludge from aerobic treatment plants ....................... 6.27 Equation 6.3c (New) Organic component removed as sludge from septic systems ...................................... 6.28 Equation 6.3d (New) Total organics in treated domestic wastewater effluent ............................................. 6.28 Equation 6.4 Total CH4 emissions from industrial wastewater ........................................................ 6.33 Equation 6.5 CH4 emission factor for industrial wastewater ............................................................ 6.33 Equation 6.9 (Updated) N2O emissions from domestic wastewater treatment plants ........................................ 6.37 Equation 6.7 (Updated) N2O emissions from domestic wastewater effluent ..................................................... 6.38 Equation 6.10 (New) Total nitrogen in domestic wastewater by treatment pathway .................................... 6.40 Equation 6.10a (New) Estimation of protein consumed .................................................................................. 6.41 Equation 6.8 (Updated) Total nitrogen in domestic