Climate MRV for Africa Phase 2 Development of National GHG Inventory Domestic Wastewater Treatment

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1 Climate MRV for Africa Phase 2 Development of National GHG Inventory Domestic Wastewater Treatment Lead partner Project of the European Commission DG Clima Action EuropeAid/136245/DH/SER/MULTI Amr Osama Abdel-Aziz, Assen Gasharov, Mike Bess and Laura Lahti Team Leader and Key Experts January 2017

2 Agenda Emissions from Wastewater Handling CH4 emissions from domestic wastewater handling N2O estimation from wastewater Needed data for wastewater handling Uncertainties

3 Emissions from Wastewater CH 4 Anaerobic fermentation occurs in wastewater treatment systems, especially anaerobic lagoons Even in aerobic systems, improper management causes methane emissions

4 Changed Compared to 1996 Guidelines No separate equations to estimate emissions from wastewater and from sludge since CH4 generation capacities for sludge and wastewater with dissolved organics are generally the same Guidance has been included to estimate N2O emissions from advanced wastewater treatment plants. Industrial wastewater section has been simplified by accounting for the most significant industrial sources

5 Common Treatment Systems In developing countries: Centralized plants Pit latrines Septic systems Disposed of in unmanaged lagoons Disposed of in waterways

6 Sludge If disposed of in landfills, emissions are accounted under SWDS source category If applied to land, emissions are accounted under LULUCF If sludge is incinerated, emissions are counted under incineration If anaerobically digested, it is accounted for under biological treatment Important to ensure consistency between sludge removal from wastewater treatment and other source categories where emissions are estimated

7 Treatment System and Discharge Pathway

8 CH4 Emissions Fundamental equation

9 CH4 Emissions Where: TOW = P BOD I 365 TOW: Total organics in wastewater in inventory year, kg BOD/ yr P: Country population in inventory year, (person) BOD: Country specific per capita BOD in inventory year, g/person/day 0.001: Conversion from grams BOD to kg BOD I: Correction factor for additional industrial BOD discharged into sewers (for collected the default is 1.25, for uncollected the default is 1.00)

10 CH4 Emissions Estimated BOD₅ VALUES IN DOMESTIC WASTEWATER FOR SELECTED REGION AND COUNTRY Country/Region BOD₅ (g/person/day) Range Reference Africa Doorn and Liles (1999) Canada, Europe, Russia, Oceania Doorn and Liles (1999) Asia, Middle East, Latin America Doorn and Liles (1999) Germany Doorn and Liles (1999) United States Metcalf and Eddy (2003)

11 CH4 Emissions Where: Efј: Emission factor, kg CH₄/ kg BOD J: Each treatment/discharge pathway or system Bₒ: Maximum CH₄ producing capacity, kg CH₄ / kg BOD MCFј: Methane correction factor (fraction)

12 CH4 Emissions Type of treatment and discharge pathway or system Untreated system sea, river and lake discharge DEFAULT MCF VALUES FOR DOMESTIC WASTEWATER Comments MCF Range Rivers with high organics loadings can turn anaerobic stagnant sewer Open and warm flowing sewer (open or closed ) Treated system centeralized aerobic treatment plant Fast moving clean. (Insignificant amounts of CH4 from pump stations, etc.) Must be well managed some CH4 can be emitted from setting basins and other pockets

13 CH4 Emissions Tier 1 DEFAULT MAXIMUM CH4 PRODUCING CAPACITY (Bₒ) FOR DOMESTIC WASTEWATER 0.6 kg CH4/kg BOD 0.25 kg CH4/kg COD

14 Emissions from Domestic Waste Water Tier 1 Methodology SUGGESTED VALUES FOR URBANISATION (U) AND DEGREE OF UTILISATION OF TREATMENT, DISCHARGE PATHWAY OR METHOD (Tіј) FOR EACH INCOME GROUP FOR SELECTED COUNTRIES Urbanistion (U) Degree of utilisation of treatment or discharge pathway or method for each income group (Tіј) Fraction of Population U=rural U= urban high income U= urban low income Country Rural urbanhigh urbanlow Septic Tank Septic Latrine other Sewer None Tank Latrine other Sewer None Septic Latrine other Tank sewer None Africa Nigeria Egypt Kenya South Africa Europe Germany NA NA NA NA NA North America United states NA NA NA NA NA

15 N2O Emissions Two sources of N2O emissions: Indirect emissions from discharge of effluent into waterways, lakes and sea Direct N2O emissions from treatment plants Emissions from treatment plants are low compared to indirect emissions

16 N2O Emissions

17 N2O Emissions

18 N2O Emissions Default EF for N2O emissions from domestic wastewater nitrogen effluent is kg N2O-N/kg N Default value for FNon-Con is 1.1 Default value for FInd-Com is 1.25

19 N2O Emissions From WWTP

20 Default EF For N2O N2O METHODOLOGY DEFAULT DATA Definition Default value Range Emission Factors Efeffulent Emission factor, (kg N2O-N/kg N) EFplants Emission factor, (g N2O/person/year) Activity Data P Number of people in country Country-specific ± 10 % Protein Annaul per capita protein consumption Country-specific ± 10 % FNPR Fraction of nitrogen in protein (kg N/kg protein) Tplant Degree of utilization of large WWT plants Country-specific ± 20 % Fnon-con Factor to adjust for non-consumed protein 1.1 for countries with no garbage disposals, 1.4 for countries with garbage disposals Find-com Factor to allow for co-discharge of industrial nitrogen into sewers. For countries with significant fish processing plants, this factor may be higher. Expert judgment is recommended

21 Sources of Data For Wastewater Handling National statistics Regulatory agencies Wastewater treatment associations Consultation with sanitation experts Industry associations

22 Uncertainties DEFAULT UNCERTAINITY RANGES FOR DOMESTIC WASTEWATER Parameter Uncertainty Range Emission factor Maximum CH₄ producing capacity (Bₒ) ±30% Fraction treated anaerobically (MCF) The MCF is technology dependent. Thus the uncertainty range is also technology dependent. The uncertainty range should be determined by expert judgment, bearing in mind that MCF is a fraction and much be between 0 and 1. Suggested ranges are provided below. Untreated systems and latrines ± 50%. Lagoons, poorly managed treatment plants ±30%. Centralized well managed plant, digester, reactor, ±10% Activity Data Human population (P) ±5% BOD per person ±30% Fraction of population income group (U) Degree of utilization of treatment/ discharge pathway or system for each income group (Tі,ј) Correction factor for additional industrial BOD discharged into sewers (I) Good data on urbanization are available, however, the distinction between urban high income and urban low income may have to be based on expert judgement.±15% Can be as low as ± 3% for countries that have good records and only one or two systems Can be ± 50% for an individual method/pathway. Verify that total Ti,j = 100% For uncollected, the uncertainty is zero %. For collected the uncertainty is ±20%

23 Thank you! Amr Osama Abdel-Aziz, Assen Gasharov, Mike Bess and Laura Lahti