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2017 GHG Emissions Inventory
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<br />Pleasanton Climate Action Plan Update 21
<br />3.3 Water and Wastewater Emissions
<br />Water
<br />Water is primarily supplied to Pleasanton by Zone 7 Water Agency and local groundwater. Zone 7
<br />supplies the City with about 80% of its water, which is mainly treated surface water from the State
<br />Water Project in the Central Valley blended with some local groundwater. The other 20% of
<br />Pleasanton’s water comes from local groundwater, pumped from wells owned and operated by the
<br />City of Pleasanton.46 In 2017, the City began using recycled water as well, from the City of Livermore
<br />and Dublin-San Ramon Services District (DSRSD).
<br />Water supplied to the community contributes emissions through the use of energy to extract, convey,
<br />treat, and deliver water. The amount of energy required for community water usage was calculated
<br />using embodied energy data emission factors based on the processes used, taken from the California
<br />Energy Commission’s 2007 Refining Estimates of Water-Related Energy Use in California report. It was
<br />determined that in 2017, Zone 7 provided water at an average of 4,037 kWh per million gallons, while
<br />City groundwater provides water at an average of 3,979 kWh per million gallons. Recycled water from
<br />the City of Pleasanton and DSRSD provided water at an average rate of 2,320 kWh per million gallons.
<br />This resulted in Zone 7 using 11,810 MWh to provide the City water in 2017, along with an additional
<br />5,883 MWh from the City of Pleasanton, 402 MWh from DSRSD, and 51 MWh from the City of
<br />Livermore.
<br />PG&E is the electricity provider for the City; therefore, PG&E’s energy emissions factor of 210 pounds
<br />CO2e/MWh was applied to the calculated electricity used for water consumption in the city. Energy
<br />consumption related to water use in the city of Pleasanton resulted in the generation of approximately
<br />1,750 MTCO2e in 2017, or 60 percent of total water and wastewater emissions. In 2005, the City used
<br />5,880 million gallons of water. In 2017, Pleasanton used 4,600 million gallons of water, or about 22
<br />percent less overall. Emissions overall decreased by 3,380 MT CO2e, due to this decrease in water
<br />usage as well as the reduction in PG&E’s electricity emission factor.
<br />Wastewater
<br />The wastewater generated by community residents and businesses creates GHG emissions during the
<br />treatment processes, including process, stationary, and fugitive emissions. The sources and magnitude
<br />of emissions depend on the type of wastewater treatment plant and the treatment processes utilized.
<br />Wastewater generated in the City of Pleasanton is collected in local sewer lines which ultimately
<br />discharge into the DSRSD Regional Wastewater Treatment Facility managed by DSRSD. The wastewater
<br />treatment plant treated 1,878 million gallons of sewage from Pleasanton in 2017, according to data
<br />obtained from the City. Emissions were calculated using Community Protocol Methodology WW.2,
<br />WW.8, and WW.12 based on processes used at the treatment facility, as shown in Figure 2. In 2017, a
<br />total of 3.07 MT N2O and 2.29 MT CH4 were emitted from the effluent discharge, process, and
<br />stationary sources at the treatment plant. The wastewater treatment plant also used 3,234,519 kWh of
<br />electricity to treat Pleasanton wastewater in 2017, which resulted in emissions of 310 MT CO2e. As
<br />shown in Table 12, the total process emissions and electricity usage for Pleasanton wastewater
<br />treatment and disposal resulted in emissions of 1,188 MT CO2e per year, or 40 percent of the water
<br />and wastewater emissions.
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<br />46 Pleasanton, City of. 2018 Annual Water Quality Report. Available: <http://www.cityofpleasantonca.gov/pdf/awqr18.pdf>.
<br />Accessed: April 26, 2020.
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