Last reviewed on 12-01-2023

Documentation of California's Greenhouse Gas Inventory (2023 Edition - Last updated on 12-1-2023)

♦ Category: Waste

IPCC: 4D1 - Wastewater Treatment and Discharge - Domestic Wastewater Treatment and Discharge
Sector: Industrial : Wastewater Treatment : Domestic Wastewater : Effluent Emissions

♦ Activity: California population -

♦ Greenhouse gas: Nitrous oxide ( N2O )

► Year 2005 —

● Greenhouse gas emission estimate —

Amount: 2,507 tonnes of N2O Emitted (747,220 tonnes CO2 Eq.)
Basis: Calculation
Calculation: ((([California Population] - ([CA population served by biological denitrification] * 0.9)) *[Protein Consumption Rate]*[Fraction of nitrogen in protein]*[Non-consumption protein factor] * [Industrial and commercial codischarge factor]) - [Sewage sludge N not entering aquatic environment]) * [Effluent water emission factor] * [Molecular weight ratio of N2O to N2]
Reference: USEPA (2015). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2013. U.S. Environmental Protection Agency. Chapter 7: Waste. http://www.epa.gov/climatechange/emissions/usinventoryreport.html

● Activity level used in calculations —

Activity: California population = 35,986,000 person
Basis: Data
Reference: CDOF (2022). State of California, Department of Finance, E-6 Population Estimates and Components of Change by County. Sacramento, California. Accessed June 2022. https://dof.ca.gov/forecasting/demographics/estimates/estimates-e6-2010-2021/

● Parameters and Constants used in calculations —

Parameter: CA population served by biological denitrification = 328,784 Person
Reference: CARB (2016). Technical support document on GHG inventory methodologies for the 2000-2014 inventory. See Discussion of emissions from wastewater treatment available at: https://ww3.arb.ca.gov/cc/inventory/pubs/reports/2000_2014/ghg_inventory_00-14_technical_support_document.pdf
Parameter: Effluent water emission factor = 5.000E-03 g / g
Reference: USEPA (2015). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2013. U.S. Environmental Protection Agency. Chapter 7: Waste. http://www.epa.gov/climatechange/emissions/usinventoryreport.html
Parameter: Fraction of nitrogen in protein = 0.16 g / g
Reference: USEPA (2015). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2013. U.S. Environmental Protection Agency. Chapter 7: Waste. http://www.epa.gov/climatechange/emissions/usinventoryreport.html
Parameter: Industrial and commercial codischarge factor = 1.25
Reference: USEPA (2015). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2013. U.S. Environmental Protection Agency. Chapter 7: Waste. http://www.epa.gov/climatechange/emissions/usinventoryreport.html
Parameter: Non-consumption protein factor = 1.4
Reference: USEPA (2015). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2013. U.S. Environmental Protection Agency. Chapter 7: Waste. http://www.epa.gov/climatechange/emissions/usinventoryreport.html
Parameter: Protein consumption rate = 34,700 g / person / year
Reference: USEPA (2015). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2013. U.S. Environmental Protection Agency. Chapter 7: Waste. http://www.epa.gov/climatechange/emissions/usinventoryreport.html
Parameter: Sewage sludge N not entering aquatic environment = 27,575,236,427 g (i.e. 27.58 thousand tonnes)
Reference: CARB (2016). Technical support document on GHG inventory methodologies for the 2000-2014 inventory. See Discussion of emissions from wastewater treatment available at: https://ww3.arb.ca.gov/cc/inventory/pubs/reports/2000_2014/ghg_inventory_00-14_technical_support_document.pdf
Constant: Molecular weight ratio of N2O to N2 = 1.571133815
Reference: IUPAC (2006). Atomic Weights of the Elements 2005 (IUPAC Technical Report). Pure Appl. Chem., Vol. 78, No. 11, pp. 2051–2066, 2006.
Constant: Global warming potential of N2O = 298
Reference: IPCC (2007). Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Solomon S., Qin D., Manning M., Chen Z., Marquis M., Averyt K.B., Tignor M., and Miller H.L. (eds.). http://www.ipcc.ch/publications_and_data/publications_ipcc_fourth_assessment_report_synthesis_report.htm

● Greenhouse gas emitted per unit activity (derived from values listed above) —

Amount: 69.7 g of N2O per person
20,764 g (i.e. 20.76 kg) of CO2eq. per person