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 : Centralized Aerobic

♦ Activity: California population -

♦ Greenhouse gas: Methane ( CH4 )

► Year 2017 —

● Greenhouse gas emission estimate —

Amount: 0 tonne of CH4 Emitted (0 tonne CO2 Eq.)
Basis: Calculation
Calculation: [California Population] * [Per Capita biological organic demand (BOD5)] * [Average number of days per year] * [Proportion centrally treated] * [Proportion aerobic] * ([Proportion aerobic without primary treatment] + ([Proportion aerobic with primary treatment] * (1 - [Proportion of BOD removed in primary treatment]))) * [Proportion of operations not well managed] * [Maximum methane production capacity] * [Methane correction for aerobic not well managed]
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 = 39,329,000 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: Maximum methane production capacity = 0.6 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: Methane correction for aerobic not well managed = 0.3
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: Per capita biological organic demand (BOD5) = 90 g / person / day
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: Proportion aerobic = 0.968
Reference: DATA NOT AVAILABLE - Values were extrapolated from years for which data were available.
Parameter: Proportion aerobic with primary treatment = 0.736
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: Proportion aerobic without primary treatment = 0.251
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: Proportion centrally treated = 0.9
Reference: CWTRC, (2003). Status Report: Onsite Wastewater Treatment Systems in California. Jointly presented by: California Wastewater Training & Research Center, California State University Chico and USEPA Region 9 Ground Water Office. August 2003. http://www.csuchico.edu/cwtrc/Pages/InfoandReoprtspage.htm
Parameter: Proportion of BOD removed in primary treatment = 0.325
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: Proportion of operations not well managed = 0
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
Constant: Average number of days per year = 365.2425 day
Reference: USNO (2004). U.S. Naval Observatory, Astronomical Applications Department, Leap Years. Accessed online at: http://www.usno.navy.mil/USNO/astronomical-applications/astronomical-information-center/leap-years
Constant: Methane density = 662 g / m3
Reference: USEPA (2013). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2011. U.S. Environmental Protection Agency. Annex 3.11: Methodology for Estimating CH4 and N2O Emissions from Manure Management. https://www.epa.gov/sites/production/files/2015-12/documents/us-ghg-inventory-2013-annexes.pdf
Constant: Global warming potential of CH4 = 25
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: 0 g of CH4 per person
0 g of CO2eq. per person