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City of South Lake Tahoe
Community-Wide & Government Operations
Greenhouse Gas Emissions Inventories for 2015
FINAL REPORT
Published July 2019
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 2
Prepared by the Sierra Nevada Alliance in Collaboration
with the City of South Lake Tahoe
July 2019
Lead Authors
Meredith Anderson & Sam Ruderman
CivicSpark Climate Fellows at the Sierra Nevada Alliance
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 3
Credits and Acknowledgements
Sierra Nevada Alliance
Meredith Anderson, CivicSpark Climate Fellow
Sam Ruderman, CivicSpark Climate Fellow
Jenny Hatch, Executive Director
City of South Lake Tahoe
Ray Jarvis, Director of Public Works
Ron Corbett, Public Works Operations Manager
Alan Johnson, Facilities Maintenance Manager
Chris Fiore, Communications Manager
Eric Friedlander, GIS Analyst
Tahoe Regional Planning Agency
Devin Middlebrook, Sustainability Program Coordinator
ICLEI USA
Hoi-Fei Mok, Senior Program Officer, Climate Equity
Sierra Business Council
BJ Schmitt, Analyst & Planning Technician
South Lake Tahoe 100% Renewable Committee
Utilities and Special Districts
Liberty Utilities
Southwest Gas
Tahoe Regional Planning Agency
South Tahoe Public Utility District
South Tahoe Refuse
Lake Tahoe Airport
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 4
Table of Contents
Tables & Figures 6
List of Tables 6
List of Figures 7
Executive Summary 8
Community-Wide Inventory Emissions Summary 9
Government Operations Inventory Emissions Summary 11
Conclusions 13
Introduction 15
The City of South Lake Tahoe 15
Local Impacts of Climate Change 16
Emissions Inventorying 16
Purpose 17
Inventory Methodology 18
Overview 18
Greenhouse Effect & Greenhouse Gas Emissions 18
ClearPath & Inventory Protocols 19
Quantifying Emissions 19
Key Inventory Steps 20
Engaging with Project Work Group and Reviewing Baseline Inventory 20
Project Work Group 21
Establishing Geographic Boundary for Inventory 21
Establishing Inventory Year 22
Identifying Emissions Sources 22
Collecting Activity Data 22
Emissions Type & Scope 22
Community-Wide Inventory 24
Technical Approach 24
Grid Electricity 25
Natural Gas 26
Propane 26
Fugitive Emissions (Natural Gas Leakage) 27
Wood 27
On-Road Transportation 28
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 5
Off-Road Transportation 29
Recreational Boats 30
Aircraft 30
Solid Waste 31
Water and Wastewater 32
Community-Wide Emissions Summary 33
Government Operations Inventory 37
Technical Approach 37
Buildings & Facilities 38
Streetlights & Traffic Signals 38
Fugitive Emissions 39
Vehicle Fleet 39
Government-Generated Solid Waste 40
Employee Commute 40
Government Operations Emissions Summary 41
Comparing Emissions 46
Challenges 46
Comparing Inventories 46
Conclusions & Recommendations 48
Emissions Reduction Goals 48
Forecasting Emissions 48
Emissions Reduction Recommendations 49
Community-Wide 49
Government Operations 50
Next Steps 51
References 52
Appendices 55
Appendix A. Population Scaling Factors (Community-Wide) 55
Appendix B. Greenhouse Gas Emissions Summary by Pollutant 55
Appendix C. Detailed Activity Data 56
Appendix D. Emissions Factors & Factor Sets 57
Appendix E. Employee Commute Survey 60
Appendix F. City of South Lake Tahoe Inventory Boundary within the Lake Tahoe Basin 61
Appendix G. South Lake Tahoe 100% Renewable Resolution 62
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 6
Tables & Figures
List of Tables
Table 1. Community-Wide Emissions by Sources & Activities 10
Table 2. Community-Wide Emissions by Sector 11
Table 3. Government Operations Emissions by Sector 12
Table 4. Government Operations Emissions by Sources & Activities 13
Table 5. Local & Statewide Emissions Reduction Targets 14
Table 6. Greenhouse Gases & Global Warming Potentials 20
Table 7. Inventory Project Work Group 21
Table 8. Emissions Sources & Categories by Scope 23
Table 9. Community-Wide Source & Activity Data 24
Table 10. Electricity Consumption 25
Table 11. Natural Gas Combustion 26
Table 12. Residential Propane Combustion 26
Table 13. Natural Gas Leakage 27
Table 14. Residential Wood Combustion 27
Table 15. Vehicle Miles Traveled 28
Table 16. Vehicle Miles Traveled by Fuel Type 28
Table 17. Off-Road Fuel Use 29
Table 18. Recreational Boat Fuel Use 30
Table 19. Lake Tahoe Airport Operations 31
Table 20. Solid Waste Disposal 32
Table 21. Compost 32
Table 22. Energy Use from Wastewater Treatment 33
Table 23. Energy Use from Potable Water Supply 33
Table 24. Community-Wide Emissions by Sources & Activities 35
Table 25. Community-Wide Emissions by Sector 36
Table 26. Government Operations Source & Activity Data by Sector 37
Table 27. Energy Use from Government Buildings & Facilities 38
Table 28. Energy Use from Streetlights & Traffic Signals 38
Table 29. Natural Gas Leakage 39
Table 30. On-Road Vehicle Fleet Breakdown by Vehicle Type 39
Table 31. On-Road Vehicle Miles Traveled & Fuel Use 39
Table 32. Off-Road Fuel Use 40
Table 33. Solid Waste Disposal by Government Building 40
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 7
Table 34. Employee Commute by Vehicle Type 41
Table 35. Employee Commute Vehicle Miles Traveled by Fuel Type 41
Table 36. Government Operations Emissions by Sources & Activities 43
Table 37. Government Operations Emissions by Sector 44
Table 38. Government Operations Emissions by Scope 45
Table 39. Comparison of Source & Activity Data 47
Table 40. Local & Statewide Emissions Reduction Targets 48
List of Figures
Figure 1. Community-Wide Emissions by Sources & Activities 10
Figure 2. Community-Wide Emissions by Sector 11
Figure 3. Government Operations Emissions by Sector 12
Figure 4. Government Operations Emissions by Sources & Activities 13
Figure 5. City of South Lake Tahoe within the Lake Tahoe Basin 15
Figure 6. Greenhouse Effect 18
Figure 7. Strength of Greenhouse Gases 20
Figure 8. City of South Lake Tahoe Jurisdiction 21
Figure 9. City of South Lake Tahoe Census Tracts 25
Figure 10. South Lake Tahoe Road Network 29
Figure 11. Lake Tahoe Airport 31
Figure 12. Community-Wide Emissions Summary 34
Figure 13. Community-Wide Emissions by Sources & Activities 35
Figure 14. Community-Wide Emissions Sector 36
Figure 15. Government Operations Emissions Summary 42
Figure 16. Government Operations Emissions by Sources & Activities 43
Figure 17. Government Operations Emissions by Sector 44
Figure 18. Government Operations Emissions by Scope 45
Figure 19. Community-Wide Emissions Reduction Recommendations 49
Figure 20. Government Operations Emissions Reduction Recommendation 50
Figure 21. Steps to Identify & Reduce Greenhouse Gas Emissions 51
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 8
Executive Summary
In 2017, the City of South Lake Tahoe passed Resolution 2017-26, Establishing
Renewable Energy and Carbon Emissions Reduction Goals. This resolution committed the City
to a number of sustainability goals: 1) to achieve 50% municipal renewable energy by 2025,
100% community renewable electricity by 2032, and 100% community renewable energy by
2050; 2) to reduce community greenhouse gas (GHG) emissions 50% by 2030 and 80% by 2040;
and 3) to publish updated GHG emissions inventories every three years.
This resolution was signed partly in response to national initiatives such as the Climate
Reality Project and Sierra Club’s Ready for 100, but it was largely a local reaction to landmark
California climate legislation, the Global Warming Solutions Act of 2006: emissions limit (SB-
32). Signed in 2016, this bill expanded upon AB-32 and set targets for reducing GHG emissions
across California, a vital step in limiting the effects of climate change. Throughout the state,
jurisdictions have implemented measures to achieve the goals laid out in SB-32. The City of
South Lake Tahoe has been no exception.
In order to achieve the first two goals of the City’s resolution--to increase renewable
energy use and reduce emissions--the third goal is critical. The City must thoroughly understand
its emissions sources in order to effectively take action to reduce emissions; as the saying goes,
you can’t manage what you don’t measure. Greenhouse gas inventorying is a valuable tool as it
identifies the sources, activities, and sectors that are producing these emissions and helps to gain
an understanding of the relative contribution of each. This knowledge is key to developing
effective and efficient climate action policy.
For these reasons, the California Tahoe Conservancy (CTC), in collaboration with
regional partners and stakeholders, published a community-wide GHG emissions inventory for
the Lake Tahoe Basin in 2013. This report analyzed jurisdiction-wide emissions throughout the
Basin for the years 2005 and 2010 and estimated the emissions that each jurisdiction produced.
Building on the CTC inventory, this report presents the updated emissions inventory for the City
of South Lake Tahoe for 2015. The year 2015 was analyzed because this was the most recent
year with comprehensive and available data. In addition, it was consistent with the five-year
intervals established previously in the CTC inventory. However, as stated in the Resolution,
future inventories will be completed every three years. While previous inventories have not
tracked the emissions attributed to government operations, this report includes an analysis of
municipal emissions. The following inventories were conducted to gain a comprehensive
understanding of the GHG emissions attributed to the City of South Lake Tahoe in 2015.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 9
This community-wide inventory was conducted in accordance with the U.S. Community
Protocol in order to establish consistency with future inventories and those of other jurisdictions.
Similarly, the government operations inventory was conducted in accordance with the Local
Government Operations Protocol. Both used the ICLEI USA and Statewide Energy Efficiency
Collaborative inventorying software, ClearPath. Emissions are reported in terms of metric tons of
carbon dioxide equivalent (CO2e). Global Warming Potential (GWP) values from the
Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report were used for the
calculations. To best understand the sources, activities, and sectors producing emissions, the
results are conveyed from a variety of different lenses.
This report aims to help the City develop a better understanding of the emissions it
produces in order to guide its efforts in reducing emissions as quickly and as cost-effectively as
possible. In addition, it should be used as a baseline for future inventories so that the City can
track and monitor its progress. This report outlines the methodologies used to estimate
emissions, summarizes the findings by activities, sources and sectors, and concludes with
recommendations for emissions reduction strategies.
Community-Wide Inventory Emissions Summary
Residents of the City of South Lake Tahoe contribute GHG emissions to the atmosphere
every day; the electricity they use to power buildings, the gasoline they consume for
transportation, and the fuel they burn to heat their homes all contribute directly or indirectly to
the City’s carbon footprint. In 2015, these sources and activities generated a total of 248,225 MT
CO2e. This is roughly the amount of energy used in 30,000 American homes or by 52,700
passenger cars in one year.
Natural gas combustion contributed 74,699 MT CO2e and accounted for 30% of the
City’s emissions, making it the community’s single largest source of GHG emissions. The
second and third largest contributors, each producing approximately 25% of all emissions, were
on-road transportation and grid electricity consumption. They generated 62,472 MT CO2e and
61,133 MT CO2e, respectively. These sources and activities, as well as all of the others that
generate GHG emissions in the City of South Lake Tahoe, are summarized in Table 1 below.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 10
Table 1. Community-Wide Emissions by Sources & Activities
Sources & Activities MT CO2e Percent of Total
Natural Gas 74,699 30.1%
On-Road Transportation 62,472 25.2%
Grid Electricity 61,133 24.6%
Solid Waste 16,944 6.8%
Off-Road Transportation 10,925 4.4%
Recreational Boats 5,999 2.4%
Propane 5,534 2.2%
Water & Wastewater 4,493 1.8%
Aircraft 3,119 1.3%
Natural Gas Leakage 2,441 1.0%
Wood 464.7 0.2%
Total 248,2251
Figure 1. Community-Wide Emissions by Sources & Activities
It is also helpful to analyze emissions results by sector. The residential energy sector and
the transportation and mobile sources sector were the largest producers, both contributing
approximately 33% of all GHGs emitted in the City during 2015. The commercial energy sector
generated over 25% of all emissions, and solid waste contributed nearly 7%. Table 2 summarizes
these emissions results by sector.
1 The difference between total emissions in Table 1 (248,225 MT CO2e) compared to the Table 2 (248,221 MT
CO2e) is due to rounding differences in ClearPath.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 11
Table 2. Community-Wide Emissions by Sector
Sector MT CO2e Percent of Total
Residential Energy 82,704 33.3%
Transportation & Mobile Sources 82,515 33.2%
Commercial Energy 63,123 25.4%
Solid Waste 16,943 6.8%
Fugitive Emissions (Natural Gas Leakage) 2,440 1%
Industrial Energy 458 0.2%
Water & Wastewater 38 0.02%
Total 248,2211
Figure 2. Community-Wide Emissions by Sector
Government Operations Inventory Emissions Summary
The emissions that result from the energy governments use and the actions they take are
estimated in government operations inventories. The fumes that come from police cars, for
example, contribute GHGs to the atmosphere. While these emissions are accounted for within
the community-wide inventory, it is important to isolate and estimate the emissions that result
from municipal operations. Total emissions from government operations in the City of South
Lake Tahoe in 2015 were calculated to be 3,240 MT CO2e, or 1.3% of total community
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 12
emissions. The largest emissions-generating sector was buildings and facilities, which
contributed 2,113 MT CO2e and accounted for 65% of government GHG emissions. The
municipal vehicle fleet was the second largest sector, producing close to 19% of total emissions,
followed by government employee commutes, which contributed 10% of all municipal
operations emissions. Solid waste, fugitive emissions from natural gas leakage, and streetlights
and traffic signals comprised the remaining 6% of emissions. The results of the government
operations emissions inventory by sector, as well as by sources and activities, are summarized in
Tables and Figures 3 and 4 below.
Table 3. Government Operations Emissions by Sector
Sector MT CO2e Percent of Total
Buildings & Facilities 2,113 65.2%
Vehicle Fleet 599 18.5%
Employee Commute 331 10.2%
Solid Waste 93 2.9%
Fugitive Emissions (Natural Gas Leakage) 62 1.9%
Streetlights & Traffic Signals 42 1.3%
Total 3,240
Figure 3. Government Operations Emissions by Sector
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 13
Table 4. Government Operations Emissions by Sources & Activities
Sources & Activities MT CO2e Percent of Total
Natural Gas 1,907 58.9%
On-Road Fleet 497 15.3%
Employee Commute 331 10.2%
Grid Electricity 246 7.6%
Off-Road Fleet 102 3.2%
Solid Waste 93 2.9%
Natural Gas Leakage 62 1.9%
Propane 2 0.1%
Total 3,240
Figure 4. Government Operations Emissions by Sources & Activities
Conclusions
The community of South Lake Tahoe will have to undertake aggressive action and
implement a myriad of mitigation strategies to meet emissions reduction goals. Achieving the
targets set by SB-32 would require limiting total emissions to approximately 148,935 MT CO2e
in 2030 and 49,645 MT CO2e in 2050. The more ambitious goals outlined in the Resolution
would require 2015 emissions to be slashed in half in only 10 years, totaling 124,112 MT CO2e
in 2030. In just 20 years, the City will have to transition to a nearly carbon free community,
producing less than 50,000 MT CO2e annually.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 14
Table 5. Local & Statewide Emissions Reduction Targets
Year SB-32 Targets - Total
Emissions (MT CO2e)
Percent
Reduction
CSLT Targets - Total
Emissions (MT CO2e)
Percent
Reduction
2015 248,225 -- 248,225 --
2030 148,935 40% 124,113 50%
2040 -- -- 49,645 80%
2050 49,645 80% -- --
In the community, emissions resulting from residential energy use--particularly from
natural gas combustion--should be targeted as a priority. On-road transportation is critical to
target as well. With two-thirds of all emissions in the City coming from these two sectors, they
provide a significant opportunity for emissions reductions. Grid electricity consumption in the
commercial sector should also be prioritized in planning. Emissions reduction strategies in the
community based on these targets can be lumped into a handful of categories: energy efficiency
improvements, renewable energy generation, electrification, and land use and transportation
planning.
The majority of government operations emissions were attributed to one source: natural
gas combustion. This makes natural gas a critical focus area in reducing municipal emissions.
The government vehicle fleet will need to be targeted, as will the modes of transportation
employees use to get to work. Building electrification, vehicle fleet electrification and
transportation planning will be the three most efficient areas of government operations to target.
Moving forward, a multitude of emissions reduction strategies will be implemented to
curb emissions in the City of South Lake Tahoe. A variety of strategies across all sectors will be
necessary in order to achieve emissions reduction targets. These will be articulated in the climate
action plan, which will start to be developed in 2019.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 15
Introduction
The City of South Lake Tahoe
The City of South Lake Tahoe, located in California’s El Dorado County on the south
shore of Lake Tahoe, is a community of 21,349 residents (2015). Like most other communities in
the Sierra Nevada mountain range, greenhouse gas (GHG) emissions from the City mainly come
from fuel combustion, electricity consumption, and transportation. The City of South Lake
Tahoe (“the City”) also has a unique situation, given that it is situated in a relatively forested area
and on Lake Tahoe, a highly popular tourist destination. The City has no emissions from
agriculture and very little emissions from industrial energy, but it experiences fairly significant
emissions as a result of recreational boating.
Figure 5. City of South Lake Tahoe within the Lake Tahoe Basin
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 16
Local Impacts of Climate Change
Already, this alpine community has begun to experience the effects of climate change
with low snowpack, more frequent and intense wildfire, heightened tree mortality, unprecedented
periods of drought, and more extreme weather events becoming the norm. In addition to
experiencing the negative impacts that are being felt Sierra-wide, the City and the Lake Tahoe
Basin are facing localized effects as well. Climate change is impacting lake temperature, which
can lead to increased algal growth and a more substantial threat of aquatic invasive species. With
heavier rains and more erosion, lake clarity can worsen, which may eventually hamper the
summer tourism economy. The local winter economy will undoubtedly suffer significantly in the
future due to reduced snowpack and shorter ski seasons.
Emissions Inventorying
In 2013, the California Tahoe Conservancy (CTC) published their Regional Greenhouse
Gas Inventory for the Lake Tahoe Basin. This report, prompted by the 1997 Lake Tahoe
Environmental Improvement Program, documented regional emissions for the years 2005 and
2010. The report provided an initial baseline for future inventories, helped to outline mitigation
strategies, and forecasted future emissions to better assist in developing emissions reduction
targets for jurisdictions within the Lake Tahoe Basin. This initial GHG emissions inventory
ultimately served to help local planning agencies align emissions reduction targets with those set
in progressive California climate legislation. The California Global Warming Solutions Act of
2006: emissions limit (SB-32) and the Sustainable Communities and Climate Protection Act of
2008 (SB-375), for example, imposed emissions reduction goals at both the state and local
levels.
The City built on these goals and took them a step further, taking action in 2017 by
passing Resolution 2017-26, Establishing Renewable Energy and Carbon Emissions Reduction
Goals (“the Resolution”). This committed the City to achieving 50% municipal renewable
energy by 2025, 100% renewable electricity by 2032, and 100% renewable energy by 2050. The
Resolution mandated at least a 50% reduction in total community GHG emissions by 2030 and
an 80% reduction by 2040.
In order to achieve these goals, it is crucial for the City to have a comprehensive
understanding of the emissions it contributes to the atmosphere. Without knowing how many
emissions it produces, it cannot project future emissions or achieve reduction targets.
Greenhouse gas inventorying is pivotal to achieving emissions reduction goals as it identifies the
sources and activities that are producing emissions. It helps to gain an understanding of the
relative contribution of each emissions-generating sector, knowledge which is key to developing
effective and efficient climate action policy. For these reasons, the Resolution’s final mandate
stated that starting in 2018, community-wide inventories must be conducted at least every three
years. Community-wide inventories take stock of all of the GHG emissions generated within a
defined jurisdictional boundary during a specific time period.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 17
Purpose
The comprehensive emissions analyses in this report were produced for the City of South
Lake Tahoe by the CivicSpark Climate Fellows at the Sierra Nevada Alliance. The purpose of
completing the inventories was to help the City gain a better understanding of the emissions it
produces and to set an emissions baseline that can be used as a comparison in the future.
Ultimately, the information in this report will be used in the development of a climate action
plan, which will detail specific strategies, actions and policies to reduce emissions as quickly and
as cost-effectively as possible.
This report describes the methodologies used to estimate emissions in a community-wide
and a government operations GHG emissions inventory for the City in 2015. It summarizes the
findings of both inventories, presents the results from a variety of different lenses, and concludes
with recommendations for emissions reduction strategies.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 18
Inventory Methodology
Overview
Greenhouse Effect & Greenhouse Gas Emissions
The natural process that warms the Earth by trapping radiant heat in the lower
atmosphere is called the greenhouse effect. This is a necessary process that makes the planet
habitable. After absorbing sunlight, the Earth emits infrared radiation in the form of heat. This
heat is then absorbed by GHGs and re-emitted, preventing the heat from escaping out of the
Earth’s atmosphere. Due to the increased burning of fossil fuels and other anthropogenic
activities, there are now elevated levels of GHGs in the atmosphere, which are severely
intensifying the greenhouse effect. These significantly heightened levels of GHGs have caused
the earth to warm at an unprecedented rate, leading to the current climate change crisis.
In order to reduce GHG emissions, it is necessary to track emissions and take stock of
what is being emitted. Greenhouse gas emissions inventorying is an important tool for
monitoring emissions over time and is a necessary component of climate action planning.
Fortunately, a number of resources have been developed to make inventorying a much more
manageable task for communities and local governments.
Figure 6. Greenhouse Effect
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 19
ClearPath & Inventory Protocols
ClearPath is the leading software for completing GHG inventories at the community-
wide and government operations levels. Developed by ICLEI and SEEC, ClearPath includes
several different tools that can be used for completing GHG inventories, forecasting future
emissions, developing climate action plans, and monitoring emissions over time. In addition,
ICLEI and SEEC provide resources for as well as assist local governments with saving energy,
reducing emissions, and developing climate action plans. This online platform is widely used
among local governments, so it was used for these inventories in order to establish consistency
with other jurisdictions.
Inventory protocols have been developed to provide authoritative guidance for
communities and governments to account for emissions accurately and consistently. In
coordination with other partners, ICLEI has published two protocols for completing GHG
inventories. This community-wide inventory was conducted in accordance with the U.S.
Community Protocol (USCP), and similarly, the government operations inventory was conducted
in accordance with the Local Government Operations Protocol (LGOP). Both of these protocols
are integrated into the ClearPath software, which conveniently simplifies the inventorying
process.
Quantifying Emissions
In order to calculate the emissions associated with different sources and activities, it is
necessary to apply emissions factors. Emission factors are values that quantify the amount of a
given pollutant emitted per unit of activity. For this inventory, emissions factors were provided
by a variety of sources (Appendix D).
Greenhouse gas emissions are reported in terms of metric tons of carbon dioxide
equivalent, or CO2e. Carbon dioxide equivalent is used because different GHGs, such as methane
and nitrous oxide, vary in the amount of warming they contribute as compared to CO2 (Table 6).
The carbon dioxide equivalent of each GHG is calculated using its Global Warming Potential
(GWP). This value represents the amount of warming caused by the gas over a period of time,
usually 100 years, as compared to the warming caused by carbon dioxide. Converting emissions
from all gases to CO2e allows for the consideration of GHGs in comparable terms. Using
emissions factors and the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment
Report 100-year GWPs, released in 2014, ClearPath calculates the total emissions from each
emissions-producing activity or source.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 20
Table 6. Greenhouse Gases & Global Warming Potentials
Common Name
Chemical Formula GWP Values (100-Year) - IPCC
Fifth Assessment Report
Carbon Dioxide CO2 1
Methane CH4 28
Nitrous Oxide N2O 265
Figure 7. Strength of Greenhouse Gases
Key Inventory Steps
Engaging with Project Work Group and Reviewing Baseline Inventory
At the beginning of this project, a working group (Table 7) met to discuss the overall
scope of the inventory. With the City’s commitment to the Resolution, this inventory was
identified as a necessary step to begin monitoring the City’s progress toward reducing emissions.
In order to keep the updated community-wide inventory for the City consistent with the previous
regional inventory completed by the CTC, the group reviewed the CTC’s inventory to align
methodologies and determine which emissions sources needed to be included. Greenhouse gas
inventories from other local jurisdictions were also referenced to better understand the emissions
sources unique to Lake Tahoe and the Sierra Nevada region.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 21
Project Work Group
Table 7. Inventory Project Work Group
Meredith Anderson CivicSpark Climate Fellow Sierra Nevada Alliance
Sam Ruderman CivicSpark Climate Fellow Sierra Nevada Alliance
Jenny Hatch Executive Director Sierra Nevada Alliance
Devin Middlebrook Sustainability Program Coordinator Tahoe Regional Planning Agency
Ray Jarvis Director of Public Works City of South Lake Tahoe
Establishing Geographic Boundary for Inventory
The geographic boundary for this inventory is the operational boundary for the City of
South Lake Tahoe. Under the USCP reporting principles, it is recommended that the area over
which the local government has control and responsibility is used as the boundary. It is worth
noting that the City boundary does not conform to its zip code; the 96150 zip code encompasses
a larger area. Some of the original data that was provided for this inventory applied to the entire
96150 zip code, so a population scaling factor was used to estimate consumption in the City
(Appendix A).
Figure 8. City of South Lake Tahoe Jurisdiction
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 22
Establishing Inventory Year
This inventory analyzes emissions from the year 2015 for a number of reasons. First and
foremost, the project work group determined it was likely the most recent year with
comprehensive and available data, as many data sources are slow to be compiled. In addition, the
CTC inventory previously analyzed 2005 and 2010, so keeping up with the five-year intervals
was appealing. However, as stated in the Resolution, future inventories will be completed every
three years.
Identifying Emissions Sources
To determine exactly which emissions sources to include, the data used for the CTC
inventory was cross-referenced with resources provided by ClearPath. Due to the unique nature
of the City, there are certain sources included that are often not considered in more urban areas,
such as recreational boats and other off-road vehicles activity. Conversely, very few emissions in
the jurisdiction come from industrial sources, a source which can be very significant in other
jurisdictions.
Collecting Activity Data
After identifying the emissions sources relevant to the City, data was collected from local
utilities, public agencies, transportation districts, and other primary sources for the 2015. If data
was not available for 2015, proxy data from a similar year to represent 2015 was used. If those
options were not available, secondary data sources were sought out to best estimate emissions.
Activity data and a more comprehensive analysis of each emissions source are documented in the
Technical Approach sections of this report.
Emissions Type & Scope
Emissions in community inventories are commonly categorized into two types: emissions
that are generated by sources, and emissions that are produced from activities. Source emissions
are those which come from natural processes occurring within the inventory boundary. Natural
gas burned in residential homes, for example, contributes to source emissions. Activity emissions
are the result of actions by a community that generate emissions that may be outside of the
inventory boundary (although they may generate emissions within the boundary as well).
Commercial electricity usage is an example of an emissions-producing activity because it
generates GHG emissions outside of the jurisdiction due to the action of the community (using
electricity in the jurisdiction).
Typically, government operations emissions are reported by scope. Scope classifications
are used primarily to categorize emissions and avoid double counting. Scope 1 includes direct
emissions from government-owned or controlled sources emitted within the geographic
inventory boundary. Examples include emissions from vehicle tailpipes and natural gas burning
stoves. Scope 2 consists of indirect emissions that are emitted by sources from outside of the
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 23
inventory boundary. These emissions are a result of activities that take place within the boundary
while originally they are generated outside of the boundary, such as using purchased energy
within the City that was first generated outside of the city limits. Scope 3 includes all other
indirect emissions not included in Scope 2. Solid waste disposal, for example, is an in-boundary
activity that results in emissions that occur outside of the inventory boundary.
Table 8. Emissions Sources & Categories by Scope
Scope Source Category
1
Fuel Combustion & Gas
Leakage
Natural Gas, Propane, and Wood
Fugitive Emissions from Natural Gas
Transportation
On-Road Vehicles (Passenger Cars, Trucks, Buses)
Off-Road Vehicles (Recreational Boats, Aircraft - Local
Flights, Construction Equipment, Lawn & Garden
Equipment, Recreational Vehicles)
Water & Wastewater Wastewater Treatment Processes
2 Grid Electricity Electricity Consumption
3 Solid Waste
Landfilled Solid Waste, Compost, Transportation to and
from Landfill
Aircraft Aircraft - Itinerant Flights
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 24
Community-Wide Inventory
All of the emissions emitted within a defined jurisdictional boundary during a specific
period of time are estimated in community-wide inventories. Burning propane to heat homes and
driving recreational boats are examples of actions that result in community emissions. This
section details the methodologies used to calculate emissions estimates for the City of South
Lake Tahoe community in 2015 and then presents the findings.
Technical Approach
Total emissions in the City of South Lake Tahoe for 2015 were calculated using
ClearPath by applying source- and activity-specific emissions factors to consumption and
activity data. Each of the following sections outline the technical approach and methodologies
used to calculate emissions by sources and activities. Emissions are reported in terms of CO2e.
All community-wide source and activity data is summarized in Table 9.
Table 9. Community-Wide Source & Activity Data
Sources & Activities Quantity Unit
Grid Electricity 152,624,503 kWh
Natural Gas 14,068,819 therms
Propane 89,178 gallons
Fugitive Emissions (Natural Gas Leakage) 93.3 metric tons released
Wood 46,655 MMBtu
On-Road 127,151,951 annual VMT
Off-Road 1,088,164 annual gallons
Recreational Boats 677,193 annual gallons
Aircraft 329,335 annual gallons
Solid Waste 41,092 annual tons
Water & Wastewater 0.14 metric tons N2O released
Water & Wastewater Grid Electricity2 10,090,401 kWh
Water & Wastewater Natural Gas2 23,938 therms
2 The electricity and natural gas used for Water and Wastewater is accounted for in the overall Grid Electricity and
Natural Gas source and activity data. It is included here as a reference only and is marked in ClearPath as an
“information only” item to avoid double counting.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 25
Grid Electricity
Emissions attributed to electricity consumption were calculated using information from
the local electricity utility, Liberty Utilities, who provided data for electricity consumption in the
City of South Lake Tahoe. However, the original data that was provided aggregated all of the
electricity consumed within the 96150 zip code, which includes other unincorporated
jurisdictions, such as Meyers, CA. In order to estimate emissions attributed specifically to the
City, a scaling factor of the population living within City boundaries compared to the entire zip
code was calculated (Appendix A).
Liberty Utilities provided a CO2 emissions factor for the energy they distribute, which is
a figure that accounts for the amount of CO2 that is released as a result of their energy generation.
This figure was for the electricity generated in 2017, and they did not make any data for 2015
available. The 2017 emissions factor was utilized as a proxy for 2015 (Appendix D). EPA eGrid
supplied the emissions factors for CH4 and N2O (Appendix D).
With 21,349 residents living in the City in 2015 and 29,496 living throughout the entire
zip code, the scaling factor was calculated to be 72.38%. After applying the scaling factor to the
original data from Liberty Utilities, residential and commercial electricity consumption for 2015
were estimated to be 64,810,031 kWh and 87,814,472 kWh, respectively, for a total of
152,624,503 kWh. These emissions are categorized as Scope 2.
Figure 9. City of South Lake Tahoe Census Tracts
Table 10. Electricity Consumption
Electricity Consumption Type Total kWh Usage
Residential 64,810,031
Commercial 87,814,472
Total 152,624,503
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 26
Natural Gas
Natural gas fuel combustion emissions were calculated using data from the gas utility and
the natural gas emissions factors supplied by ClearPath. The 2015 data for the City’s natural gas
usage was provided by Southwest Gas. Southwest Gas is the sole provider of natural gas in the
City and categorizes usage as residential, commercial, or industrial. In order to most accurately
represent the amount of natural gas combusted within city limits, the population scaling factor of
72.38% was applied to represent the percentage of the 96150 zip code living within City limits.
After applying the scaling factor, residential natural gas usage in 2015 was 9,195,629
therms, while commercial usage was 4,786,881 therms. Industrial usage was 86,309 therms, so
the total natural gas usage in 2015 was 14,068,819 therms for the City. Emissions from natural
gas combustion are Scope 1 emissions.
Table 11. Natural Gas Combustion
Natural Gas Combustion Type Therms
Residential 9,195,629
Commercial 4,786,881
Industrial 86,309
Total 14,068,819
Propane
Propane consumption data was not available from local providers, so propane emissions
were estimated using a combination of data sources. The Energy Information Agency (EIA)
provided an estimate for California residential propane consumption in 2015. The U.S. Census
Bureau 2011-2015 American Community Survey (ACS) provided an estimate for the number of
households in California that use propane for home heating.
With 231,000,000 gallons of propane consumed across 398,909 households in California
during 2015, the average per-household propane usage was calculated to be 579.1 gallons. The
2011-2015 ACS for the City of South Lake Tahoe estimated that 154 households in the
community used propane. The per-household usage factor was applied to the number of
households using propane, resulting in an estimated 89,178 gallons of propane being consumed
in the community in 2015. Propane combustion contributes to Scope 1 emissions.
Table 12. Residential Propane Combustion
Propane Combustion Quantity Unit
California Households Using Propane 398,909 households
California Propane Usage 231,000,000 gallons
Average Household Propane Use 579.1 gallons/household
City of South Lake Tahoe Households Using Propane 154 households
Estimated Usage 89,178 gallons
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 27
Fugitive Emissions (Natural Gas Leakage)
Fugitive emissions, or natural gas leakages, have become increasingly important in GHG
inventorying. Methane leakage from natural gas occurs throughout the supply chain --
production, processing, distribution, and end-use -- and contribute significantly to emissions due
to the global warming potential of methane, which is 28 times more potent of a GHG than carbon
dioxide. ClearPath supplied default values for leakage rate, gas densities, and natural gas
chemical composition in order to estimate fugitive emissions.
Natural gas consumption in the community was calculated to be 14,068,819 therms in
2015. Emissions were calculated using a leakage rate of 0.3% for the local distribution system,
provided by ClearPath and the EDF User Guide for Natural Gas Leakage Rate Modeling Tool.
These emissions are considered Scope 1.
Table 13. Natural Gas Leakage
Natural Gas Leakage Quantity Unit
Community-Wide Natural Gas Usage 14,068,819 therms
Leakage Rate 0.3 %
Total Natural Gas Released 93.3 MT
Wood
Like propane, local data for wood combustion was not available, so a variety of sources
were used to estimate wood emissions. Estimates for statewide residential wood consumption in
2015 were obtained from the EIA, and the U.S. Census Bureau 2011-2015 ACS provided the
estimated number of households using wood for home heating throughout California. In 2015,
1,611,000 cords of wood were burned across 216,849 households, resulting in a per-household
usage rate of 7.43 cords, or 148.6 MMBtu.3 The 2011-2015 ACS for the City of South Lake
Tahoe estimated that in 2015, 314 households used wood for home heating. Applied to the per-
household usage rate, this results in an estimated 46,655 MMBtu of wood combusted in 2015.
This energy use produces Scope 1 emissions.
Table 14. Residential Wood Combustion
Wood Combustion Quantity Unit
California Households Using Wood 216,849 households
California Wood Usage 1,611,000 cords
Average Household Wood Use 148.6 MMBtu/household
Households Using Wood 314 households
Estimated Usage 46,655 cords
3 The Energy Information Association supplied a conversion factor of 20MMBtu/cord, which was used for this
calculation.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 28
On-Road Transportation
Emissions from on-road transportation were calculated using data from a combination of
sources. The Travel Demand Model from the Tahoe Regional Planning Agency (TRPA)
provided jurisdiction-specific vehicle miles traveled (VMT) data for the Tahoe Metropolitan
Planning Organization (TMPO). The California Air Resources Board’s (CARB) EMFAC2017
model provided aggregated VMT and fuel consumption data for the TMPO as a whole. In
addition, EMFAC2017 estimated regional emissions factors, which were aggregated across
vehicle types and separated by fuel type (Appendix D).
The Travel Demand Model estimated data for the year 2014, and the model is only run
every four years. Due to the fact that this model produces more accurate, City-specific data than
any other source, the working group decided to use the 2014 data from the TRPA as proxy data
for the year 2015. The Travel Demand Model estimated 127,270,390 total annual VMT in the
City across all fuel types. The model does not separate VMT by fuel type.
EMFAC2017 provided fuel consumption estimates in the TMPO during 2015. This
information was used to calculate the percentage of VMT attributed to each fuel. Gasoline and
diesel were shown to be 91.6% and 8.3% of the total VMT, respectively.4 These factors were
then applied to the total VMT estimated from the Travel Demand Model, resulting in
116,571,790 annual VMT for gasoline and 10,580,161 annual VMT for diesel in the City. The
emissions resulting from on-road transportation are Scope 1.
Table 15. Vehicle Miles Traveled
Total VMT Quantity Unit
Daily 348,686 miles/day
Annual 127,270,390 miles/year
Table 16. Vehicle Miles Traveled by Fuel Type
Breakdown by Fuel Type Annual VMT Percent of Total
Gasoline 116,571,790 91.59%
Diesel 10,580,161 8.31%
Electric 118,439 0.9%
4 Electric VMT were not included because it would be considered double counting. The emissions from the
electricity consumed by electric vehicles are already accounted for in grid electricity emissions calculations.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 29
Figure 10. South Lake Tahoe Road Network
Off-Road Transportation
Off-road transportation includes equipment such as construction vehicles, lawn
equipment, and off-road recreational vehicles. California Air Resources Board’s
OFFROAD2017 model was used to obtain fuel consumption data for off-road equipment. Like
the EMFAC2017 model, this software estimates usage for the entire TMPO, so it was necessary
to devise a methodology to determine the off-road emissions attributed only to the City. After
consulting with CARB, it was decided that applying a population scaling factor to the TMPO-
wide data would be an appropriate method. Using Tahoe Open Data, the scaling factor for the
population within the City compared to the entire TMPO was calculated to be 40%.
OFFROAD2017 estimated 480,658 gallons of gasoline and 2,233,763 gallons of diesel
were consumed in the TMPO in 2015. Applying the scaling factor, an estimated 192,687 gallons
and 895,476 gallons of gasoline and diesel were consumed due to off-road transportation sources
in the City, respectively. Like on-road transportation, these emissions are considered Scope 1.
Table 17. Off-Road Fuel Use
Off-Road Fuel Use Gallons
Gasoline 192,687
Diesel 865,477
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 30
Recreational Boats
Data for recreational boating activity in the City was calculated using the TRPA’s 2017
Lake Tahoe Shoreline Plan report. This report used a baseline year of 2004 for fuel consumption
from boating activity in Lake Tahoe. To estimate future emissions, the TRPA assumed an annual
increase in fuel use of 1.5% between 2004 and 2024. Therefore, for 2015, there was an estimated
16.5% increase in the amount of fuel used as compared to 2004. In 2004, a total of 2,642,187
gallons of fuel were used, so the estimated total for 2015 is 3,078,148 gallons for all of Lake
Tahoe.
The Shoreline Plan reported that South Lake Tahoe accounts for 22% of total boat
launches in Lake Tahoe. This was used as a scaling factor when calculating total fuel use for the
City. Boats using gasoline accounted for 99.853% of total fuel use, while boats running on diesel
accounted for 0.00147%. Broken down by fuel type, total gasoline use in 2015 was 676,197
gallons, and total diesel use was 995 gallons. Recreational boating emissions are considered
Scope 1.
Table 18. Recreational Boat Fuel Use
Fuel Type Gallons
Gasoline 676,197
Diesel 995
Aircraft
Aircraft emissions from the Lake Tahoe Airport (TVL), which is owned and operated by
the City of South Lake Tahoe, were calculated using 2016 fuel consumption data and 2015
aircraft operations data. Since 2015 fuel consumption data was unavailable due to a lack of
records before 2016, data from 2016 was used as a proxy instead. Aviation gasoline and Jet A
kerosene consumption data were provided by Lake Tahoe Airport’s fuel provider, Mountain
West Fuel, and flight operations data was provided by the Lake Tahoe Airport Manager. The
emissions factors for each fuel type were supplied by ClearPath.
Local operations are flights that take off from and land in the City of South Lake Tahoe,
while itinerant operations are flights between the City and another jurisdiction. ClearPath takes
this into account when calculating emissions and attributes emissions accordingly. The
breakdown of itinerant and local flight operations was 81% and 19%, respectively. This was
applied to the total number of gallons for each fuel type in order to most accurately estimate
emissions. In 2015, approximately 28,613 gallons of aviation gasoline were used, and 300,722
gallons of Jet A kerosene were used. Flights categorized as local are Scope 1 emissions, while
itinerant flights are considered Scope 3.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 31
Table 19. Lake Tahoe Airport Operations
Lake Tahoe Airport Itinerant Operations Local Operations
Number of Flights 18,960 4,580
Percentage of Total Operations 81% 19%
AV Gasoline (gallons) 23,046 5,567
Jet A (gallons) 242,213 58,509
Figure 11. Lake Tahoe Airport
Solid Waste
Solid waste emissions come from the methane that is generated from the anaerobic
decomposition of landfilled organic waste. Emissions are calculated using total annual tonnage
and a jurisdiction-specific waste characterization. Using 2015 waste, recycling, and compost
tonnage data from South Tahoe Refuse, total emissions were calculated for landfilled solid
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 32
waste. Total emissions from composting wood, South Tahoe Public Utility District (STPUD)
biosolids, and food waste were calculated as well.
Using the City of South Lake Tahoe waste characterization provided by CalRecycle5,
emissions were calculated based on total tonnage of waste landfilled. Whether or not the
receiving landfill--either Carson City or Lockwood--used a methane collection system was an
important factor in estimating emissions. ClearPath supplied emissions factors for the waste
characterization and for transportation to and from landfills. ClearPath also provided emissions
factors associated with the composting of green waste and bio-waste. In addition, emissions
resulting from the transport of waste to and from both the Carson City and Lockwood landfills
were included because the facilities are located outside of the inventory boundary.
Total solid waste generated in the City in 2015 was 32,651 tons. Ninety-five percent of
total solid waste, or 30,895 tons, went to Lockwood Landfill near Reno, and the remaining 5%,
or 1,756 tons, of total solid waste went to Carson City Landfill. Lockwood Landfill has a
methane collection system, which significantly reduces overall emissions, while Carson City
does not have a methane collection system. Wood compost and STPUD biosolid compost were
relatively significant, accounting for 5,037 and 3,352 tons, respectively. Food waste contributed
46 tons. Compost is taken to Full Circle Compost in Nevada.
Both landfills used to process the solid waste that is generated in the City are outside of
the City boundary; therefore, emissions from City-generated solid waste are occurring
completely outside of the Tahoe Basin in Nevada. These are considered Scope 3 emissions.
Table 20. Solid Waste Disposal
Solid Waste Disposal Lockwood Landfill Carson City Landfill
Solid Waste (tons) 30,895 1,756
Distance to Facility (miles) 72 34
Methane Collection Yes No
Table 21. Compost
Compost Type Tons
Wood 5,037
STPUD Biosolids 3,352
Food Waste 46
Water and Wastewater
The South Tahoe Public Utility District is the water provider and the aerobic wastewater
treatment facility operator for the City. The STPUD facilities are powered by electricity from the
grid and from natural gas supplied by Southwest Gas, so the emissions resulting from these
5 The average of the residential and commercial waste characterizations was used to calculate total emissions.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 33
energy sources have already been accounted for in the community-wide grid electricity
consumption and natural gas combustion emissions calculations. Therefore, to avoid double
counting, they are considered “information only” items.
In 2015, STPUD treated 1,110,780 gallons of water, and 6,373,800 kWh of grid
electricity and 9,268 therms of natural gas were used specifically for wastewater treatment.
Energy used for potable water supply accounted for 3,716,601 kWh of grid electricity and
14,670 therms of natural gas combustion, with a total of 1,827,000,000 gallons supplied to
STPUD customers.
Emissions resulting directly from released N2O during the wastewater treatment process
are included in community-wide emissions. Due to uncertainty about the contribution from
industrial and commercial discharges, the default assumption of 1.25 for the “industrial
commercial discharge multiplier” was applied. Total emissions from treatment processes are 38
MT CO2e. These are considered Scope 1 emissions.
Table 22. Energy Use from Wastewater Treatment
Wastewater Treatment Energy Use Quantity Unit
Grid Electricity 6,373,800 kWh
Natural Gas 9,268 therms
Total Volume of Water Treated 1,110,780 gallons
Table 23. Energy Use from Potable Water Supply
Potable Water Supply Energy Use Quantity Unit
Grid Electricity 3,716,601 kWh
Natural Gas 14,670 therms
Total Volume of Water Treated 1,827,000,000 gallons
Community-Wide Emissions Summary
The City of South Lake Tahoe community generated an estimated 248,225 MT CO2e
during 2015. Natural gas combustion contributed 30% of these emissions, making it the largest
emissions source. On-road transportation accounted for 25% of total emissions, and grid
electricity consumption produced another 25%. These three sources and activities were
responsible for nearly 80% of all GHGs emitted in the City in 2015.
Emissions from solid waste were relatively significant, contributing 7% of all emissions,
and off-road transportation, including ATVs, snowmobiles, and construction and lawn
equipment, was responsible for generating 4% of emissions. The other six emissions-generating
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 34
categories -- recreational boats, propane, water and wastewater, aircraft, gas leakage and boats --
together generated about 9% of total emissions.
Analyzing emissions by the sources and activities that produce them is one helpful way to
visualize where GHGs are coming from, but it is also helpful to categorize and evaluate them by
sector. The use of electricity, natural gas, propane and wood made the residential energy sector
one of the largest emissions producers in the City during 2015. Nearly the same amount of
emissions, roughly 82,600 MT CO2e, were emitted by on-road transportation vehicles. Together,
these sectors comprised two-thirds of all community-generated emissions. Commercial energy
consumption was the third largest sector, which contributed 25% of the City’s emissions, and
solid waste was accountable for 7%. Natural gas leakage, energy used for industrial processes,
and water and wastewater contributed the remaining emissions.
Figure 12. Community-Wide Emissions Summary
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 35
Table 24. Community-Wide Emissions by Sources & Activities
Sources & Activities MT CO2e Percent of Total
Natural Gas 74,699 30.1%
On-Road Transportation 62,472 25.2%
Grid Electricity 61,133 24.6%
Solid Waste 16,944 6.8%
Off-Road Transportation 10,925 4.4%
Recreational Boats 5,999 2.4%
Propane 5,534 2.2%
Water & Wastewater 4,493 1.8%
Aircraft 3,119 1.3%
Natural Gas Leakage 2,441 1.0%
Wood 464.7 0.2%
Total 248,2251
Figure 13. Community-Wide Emissions by Sources & Activities
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 36
Table 25. Community-Wide Emissions by Sector
Sector MT CO2e Percent of Total
Residential Energy 82,704 33.3%
Transportation & Mobile Sources 82,515 33.2%
Commercial Energy 63,123 25.4%
Solid Waste 16,943 6.8%
Fugitive Emissions (Natural Gas Leakage) 2,440 1.0%
Industrial Energy 458 0.2%
Water & Wastewater 38 0.02%
Total 248,2211
Figure 14. Community-Wide Emissions by Sector
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 37
Government Operations Inventory
Local governments operate municipal facilities, streetlights and traffic signals, and
vehicle fleets. Government staff drive to and from work and consume goods which eventually
decompose in a landfill. All the energy that governments use and the activities they perform each
day contribute directly or indirectly to the release of GHG emissions. While the emissions
attributed to government operations are accounted for within the community-wide inventory, it is
important to isolate and estimate the emissions that result from municipal operations. Local
governments should be setting an example and acting as leaders to their communities and other
communities across the state by establishing emissions reduction targets and implementing
policies to achieve them. Without an inventory, governments cannot effectively develop and
implement these plans. This section details the methodologies used to calculate emissions
estimates for government operations in the City of South Lake Tahoe in 2015 and then presents
the findings.
Technical Approach
Total emissions attributed to government operations in the City of South Lake Tahoe for
2015 were calculated using ClearPath by applying source- and activity-specific emissions factors
to consumption and activity data. Each of the following sections outline the technical approach
and methodologies used to calculate emissions by sources and activities. Some of the
descriptions of these calculations are abbreviated in the following government operations
sections because the methodologies were outlined in the community-wide technical approach
section of the report. Emissions are reported in terms of CO2e. All government operations source
and activity data is summarized in Table 26.
Table 26. Government Operations Source & Activity Data by Sector
Sector Sources & Activities Quantity Unit
Buildings & Facilities
Grid Electricity 476,182 kWh
Natural Gas 358,568 therms
Propane 325 gallons
Streetlights & Traffic Signals Grid Electricity 98,927 kWh
Fugitive Emissions Natural Gas Leakage 2.8 metric tons released
Vehicle Fleet On-Road Vehicle Fleet 480,324 annual VMT
Off-Road Vehicle Fleet 9,893 annual gallons
Solid Waste Solid Waste 227.3 annual tons
Employee Commute Employee Commute 884,850 annual VMT
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 38
Buildings & Facilities
Grid Electricity
To calculate the emissions from municipal buildings and facilities, electricity
consumption information was obtained from Liberty Utilities. In 2015, the City’s properties
consumed 476,182 kWh of electricity. The CO2 emissions factor provided by Liberty Utilities
and the emissions factors obtained from the EPA eGrid were used to calculate the GHGs emitted
as a result of government electricity usage. These emissions are categorized as Scope 2.
Natural Gas
Data for natural gas combustion at City-owned buildings and facilities was obtained from
the local fuel provider, Southwest Gas. In 2015, the City consumed 358,568 therms of natural
gas at its properties. Emissions were calculated using ClearPath and the associated accepted
emissions factors. These emissions from natural gas combustion are Scope 1.
Propane
The City of South Lake Tahoe provided records of propane purchased from Bi-State
Propane during 2015. There was only one statement available from 2015, so this is what was
used to calculate government operations emissions attributed to propane usage. The City
purchased 325 gallons of propane in 2015. Using the emissions factors supplied by ClearPath,
emissions estimates were calculated. These emissions are Scope 1.
Table 27. Energy Use from Government Buildings & Facilities
Energy Type Quantity Unit
Grid Electricity 476,182 kWh
Natural Gas 358,568 therms
Propane 325 gallons
Streetlights & Traffic Signals
Like government buildings and facilities, emissions from City streetlights and traffic
signals were calculated using data from Liberty Utilities because all local streetlights and traffic
signals are powered by electricity. A combination of emissions factors from Liberty Utilities and
EPA eGrid were again used. Streetlights and traffic signals in the City consumed 98,927 kWh of
electricity in 2015. The emissions produced are considered Scope 2.
Table 28. Energy Use from Streetlights & Traffic Signals
Energy Type Quantity Unit
Grid Electricity 98,927 kWh
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 39
Fugitive Emissions
Natural Gas Leakage
The City government used 358,568 therms of natural gas during 2015. This information
was obtained from Southwest Gas, the City’s gas provider. This consumption figure, along with
the emissions factors supplied by ClearPath, was used to estimate fugitive emissions, or
emissions resulting from natural gas leakage, from municipal operations. These emissions are
considered Scope 1.
Table 29. Natural Gas Leakage
Natural Gas Leakage Quantity Unit
Government Operations Natural Gas Usage 358,568 therms
Leakage Rate 0.3 %
Total Natural Gas Released 2.8 metric tons released
Vehicle Fleet
Vehicle fleet data for 2015 was provided by the City’s Fleet Services Department. This
data set included vehicle types, fuel type, total annual miles traveled, and gallons of fuel or hours
used. Aggregated emissions factors from CARB’s EMFAC2017 model were applied to each
vehicle type and fuel type to calculate emissions. In 2015, on-road gasoline vehicles used 41,795
gallons of fuel and accounted for 475,104 miles traveled, and on-road diesel vehicles used
12,573 gallons of fuel for 5,220 miles traveled. Of all on-road gasoline vehicles, 88% were
categorized as passenger vehicles and 12% were categorized as light trucks, while on-road diesel
vehicles were 57% light trucks and 43% heavy trucks.
All off-road vehicles were categorized as large utility vehicles in ClearPath due to the
City’s large fleet of snow removal and street maintenance equipment. Total fuel use for off-road
gasoline vehicles was 100.7 gallons, while off-road diesel use was 9,793 gallons. Vehicle fleet
emissions are categorized as Scope 1 emissions.
Table 30. On-Road Vehicle Fleet Breakdown by Vehicle Type
On-Road Vehicle Type Gasoline Diesel
Passenger 88% 0%
Light Truck 12% 57%
Heavy Truck 0% 43%
Table 31. On-Road Vehicle Miles Traveled & Fuel Use
On-Road Vehicles Gasoline Diesel Unit
Annual VMT 475,104 5,220 miles
Annual Fuel Use 41,795 12,573 gallons
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 40
Table 32. Off-Road Fuel Use
Off-Road Vehicles Gasoline Diesel Unit
Annual Fuel Use 100.7 9,793 gallons
Government-Generated Solid Waste
In 2015, the City had nine government building locations that each had at least one
dumpster. Considering bin size and an average weight of 250 pounds per cubic yard of solid
waste6, annual tonnage for government-generated solid waste was 227.3 tons. CalRecycle’s
Public Administration waste characterization was used to calculate emissions from government-
generated solid waste. Solid waste emissions are considered Scope 3.
Table 33. Solid Waste Disposal by Government Building
Building Tons
1700 D St 52.4
1052 Tata Ln 13
2101 Lake Tahoe Blvd 26
2951 Lake Tahoe Blvd 13.5
1252 Ski Run Blvd 13.3
1901 Airport Blvd 39.9
3050 Lake Tahoe Blvd 26.4
1352 Johnson Blvd 39.7
1160 Rufus Blvd 3.1
Total 227.3
Employee Commute
In order to compile an employee commute dataset, a survey was distributed by email to
all City employees. This 2018 data was used as a proxy for unavailable 2015 data. The survey
included questions regarding mileage to and from work, how many days per week were spent
driving to work, vehicle type, and fuel type (Appendix E). There were 223 employees in 2015. In
total, there were 102 responses with one invalid response. Using the information gathered from
the 101 survey responses, total vehicle miles traveled per year by fuel and vehicle types were
calculated by multiplying total yearly miles by 2.21 (223 / 101) to account for a lack of survey
response.
6 Average weight per cubic yard estimate was provided by South Tahoe Refuse.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 41
Total vehicle miles traveled are categorized by gasoline and diesel as well as by
passenger vehicle or light duty truck. Emissions attributed to employee commute are categorized
as Scope 3 emissions.
Table 34. Employee Commute by Vehicle Type
Vehicle Type Percentage Gasoline Diesel
Passenger 70% 0%
Light Truck 30% 100%
Heavy Truck 0% 0%
Table 35. Employee Commute Vehicle Miles Traveled by Fuel Type
Fuel Type Annual VMT
Gasoline 769,930
Diesel 78,605
Public Transit 7,585
Electric 28,730
Government Operations Emissions Summary
In 2015, the City of South Lake Tahoe’s government operations generated a total of
3,240 MT CO2e, or 1.3% of total community emissions. The single largest source of emissions
was from natural gas combustion, which produced 1,907 MT CO2e and accounted for nearly
60% of the entire government’s GHG emissions. The municipal on-road vehicle fleet and
employee commutes were the second and third largest contributors, generating 15% and 10% of
total emissions, respectively. Of the remaining municipal emissions, grid electricity consumption
accounted for 8% of the total, and the off-road vehicle fleet, solid waste, and propane usage
combined comprised the remaining 8%.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 42
Figure 15. Government Operations Emissions Summary
Again, it is worth reframing these emissions in terms of emissions by sector. In buildings
and facilities, natural gas combustion generated 1,907 MT CO2e and was the largest emissions
source. Emissions from electricity consumption in buildings and facilities were 204 MT CO2e,
while propane use in buildings and facilities produced 2 MT CO2e. Together, buildings and
facilities’ energy use accounted for 65% of the GHGs emitted by the City’s government, a total
of 2,113 MT CO2e. The second largest producer was the municipal vehicle fleet, which
generated 599 MT CO2e, or 19% of total emissions. Government employee commutes
contributed 10% of total emissions, and solid waste, gas leakage, and streetlights and traffic
signals accounted for the remaining 6% of total emissions.
Looking at government operations emissions by scope also shows which emissions are
occurring inside or outside of the jurisdictional boundary. Scope 1 emissions (direct) accounted
for 2,571 MT CO2e, while 246 MT CO2e were Scope 2 (indirect), and 454 MT CO2e were Scope
3 (indirect). The following tables and charts further illustrate the overall breakdown of
government operations GHG emissions.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 43
Table 36. Government Operations Emissions by Sources & Activities
Sources & Activities MT CO2e Percent of Total
Natural Gas 1,907 58.9%
On-Road Vehicle Fleet 497 15.3%
Employee Commute 331 10.2%
Grid Electricity 246 7.6%
Off-Road Vehicle Fleet 102 3.2%
Solid Waste 93 2.9%
Natural Gas Leakage 62 1.9%
Propane 2 0.1%
Total 3,240
Figure 16. Government Operations Emissions by Sources & Activities
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 44
Table 37. Government Operations Emissions by Sector
Sector MT CO2e Percent of Total
Buildings & Facilities 2,113 65.2%
Vehicle Fleet 599 18.5%
Employee Commute 331 10.2%
Solid Waste 93 2.9%
Fugitive Emissions (Natural Gas Leakage) 62 1.9%
Streetlights & Traffic Signals 42 1.3%
Total 3,240
Figure 17. Government Operations Emissions by Sector
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 45
Table 38. Government Operations Emissions by Scope
Scope MT CO2e
Scope 1 (Direct) 2,571
Scope 2 (Indirect) 246
Scope 3 (Indirect) 454
Figure 18. Government Operations Emissions by Scope
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 46
Comparing Emissions
One of the benefits of conducting a GHG inventory is to be able to track trends and
monitor emissions performance over time. As noted earlier in this report, the CTC performed a
regional inventory in 2013, which analyzed jurisdictions throughout the Lake Tahoe Basin for
the years 2005 and 2010. The City of South Lake Tahoe jurisdiction was included as one of the
inventory boundaries. The CTC report was used as a resource while conducting these updated
inventories for a variety of reasons, such as determining what data should be included and
identifying data sources for the community-wide inventory. Moving forward, both the updated
2015 community-wide and government operations inventories will be used as emissions
baselines when comparing inventories.
Challenges
To estimate carbon pollution accurately and consistently, it is important that emissions
inventories all follow a set of standardized guidelines. Fortunately, the U.S. Community Protocol
provides the authoritative guidance that is needed to achieve these goals. The USCP is currently
the most widely-accepted standard for GHG emissions reporting, and the 2015 City of South
Lake Tahoe community-wide inventory was conducted in accordance with the protocol as much
as possible.
While the 2013 CTC inventory did follow an established and accepted procedure, it did
not use the USCP. At the beginning of this inventory process, whether to use the previously-used
methodologies or the newer protocols was discussed. It was decided that in order to maximize
consistency with future City inventories, along with those of surrounding communities and
others around the state, the USCP would be used. Additionally, as inventorying has become
more common and the scientific understanding has improved, a number of relatively significant
updates have been made to the protocols.
Due to differences between the inventories, namely GWPs and emissions factors, it is
difficult to compare the results of this inventory to those of the CTC inventory. Both GWPs and
emissions factors play a relatively large role in the emissions estimates, and the differences
between the two inventories due to these factors are significant. In addition, the exclusion of
sources and activities such as prescribed burns and livestock, which are not included under the
USCP, contributed to the discrepancy in total emissions between the CTC inventory and this
inventory.
Comparing Inventories
The challenges described above describe why the emissions estimates between the two
inventories are, to an extent, incomparable. However, it may still be helpful to compare activity
data, such as total community electricity consumption in kilowatt-hours or total annual VMT.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 47
Table 39 below compares activity between 2005, 2010 and 2015. The data for 2005 and 2010
was obtained from the CTC inventory. The data from 2015 was obtained for this inventory.
Table 39. Comparison of Source & Activity Data
Sources & Activities 2005 2010 2015 Unit
Grid Electricity 199,755,243 206,735,770 152,624,503 kWh
Natural Gas 20,398,999 21,213,855 14,068,819 therms
Propane 469,533 529,729 89,178 gallons
Fugitive Emissions
(Natural Gas Leakage)
N/A N/A 93.3 metric tons released
Wood 303,139.80 325,796.69 46,655 MMBtu
On-Road 145,346,285 128,749,735 127,151,951 annual VMT
Off-Road N/A N/A 1,088,164 annual gallons
Recreational Boats 2,509,272 1,781,440 677,193 annual gallons
Aircraft 229,279 211,754 329,335 annual gallons
Solid Waste 63,636 72,676 41,092 annual tons
Water & Wastewater N/A N/A 0.14 metric tons N2O released
Water & Wastewater
Grid Electricity
N/A N/A 10,090,401 kWh
Water & Wastewater
Natural Gas
N/A N/A 23,938 therms
Major discrepancies among source and activity data between the two inventories were
likely caused by several different factors. Since the previous inventory accounted for the entire
Tahoe Basin, the scaling factors used to find data for the City of South Lake Tahoe, specifically,
could have played a role in the inconsistencies among electricity and natural gas data. In
addition, different methodologies were used to estimate certain emissions categories, notably
propane usage and wood combustion. A potential explanation for the significant decrease in solid
waste tonnage between 2005 and 2015 could be that waste diversion rates have increased,
meaning more waste is diverted to recycling or compost. Due to differences in methodologies,
and the fact that the 2015 community-wide inventory will be used as a baseline, activity data
trends over time were not analyzed.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 48
Conclusions & Recommendations
Emissions Reduction Goals
Like all California communities, the City of South Lake Tahoe has a responsibility to
reduce its carbon pollution. With the passing of SB-32, jurisdictions across the state were given
emissions reduction targets to strive for. The City is unique in that it took these goals a step
further when they signed their own reduction targets; while SB-32 mandates GHG emissions
reductions of 40% by 2030 and 80% by 2050, the Resolution laid out goals to achieve 50%
reductions by 2030 and 80% reductions by 2040.
In order to meet these goals, the community of South Lake Tahoe will have to undertake
aggressive action and implement a myriad of mitigation strategies. Achieving the targets set by
SB-32 would require limiting total emissions to approximately 148,935 MT CO2e in 2030 and
49,645 MT CO2e in 2050. The more ambitious goals outlined in the Resolution would require
2015 emissions to be slashed in half in only 10 years, totaling 124,112 MT CO2e in 2030. In just
20 years, the City will have to transition to a nearly carbon free community, producing less than
50,000 MT CO2e annually.
Table 40. Local & Statewide Emissions Reduction Targets
Year SB-32 Targets - Total
Emissions (MT CO2e)
Percent
Reduction
CSLT Targets - Total
Emissions (MT CO2e)
Percent
Reduction
2015 248,225 -- 248,225 --
2030 148,935 40% 124,113 50%
2040 -- -- 49,645 80%
2050 49,645 80% -- --
Forecasting Emissions
Forecasting future emissions is an important part of the climate action planning process.
A community or local government can project expected future emissions based on a number of
scenarios. The “Business-As-Usual” scenario, where no action is taken to limit GHGs, is almost
always modeled, and a number of different scenarios based on expected policy measures are
often modeled as well.
Due to time constraints, this inventory does not forecast future emissions. However, the
ClearPath software includes a forecasting tool, which can be applied to any completed inventory
stored on the platform. All of the data and records utilized for the emissions calculations in this
inventory will be saved on the online software and will be accessible for future emissions
forecasting.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 49
Emissions Reduction Recommendations
Moving forward, a multitude of emissions reduction strategies will be implemented to
curb emissions in the City of South Lake Tahoe. A variety of strategies across all sectors will be
necessary in order to achieve emissions reduction targets. These will be articulated in the climate
action plan, which will start to be developed in 2019.
Community-Wide
In the community, emissions resulting from residential energy use--particularly from
natural gas combustion--should be targeted as a priority. On-road transportation is critical to
target as well. With two-thirds of all emissions in the City coming from these two sectors, they
provide a significant opportunity for emissions reductions. Grid electricity consumption in the
commercial sector should also be prioritized in planning.
Emissions reduction strategies in the community based on these targets can be lumped
into a handful of categories: energy efficiency improvements, renewable energy generation,
electrification, and land use and transportation planning. Below are a number of
recommendations that can be taken to mitigate emissions in the City of South Lake Tahoe.
Figure 19. Community-Wide Emissions Reduction Recommendations
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 50
Government Operations
The majority of government operations emissions were attributed to one source: natural
gas combustion. This makes natural gas a critical focus area in reducing municipal emissions.
The government vehicle fleet will need to be targeted, as will the modes of transportation
employees use to get to work.
Building electrification, vehicle fleet electrification and transportation planning will be
the three most efficient areas of government operations to target. Broad strategies for reducing
emissions in these areas are outlined below.
Figure 20. Government Operations Emissions Reduction Recommendations
Taking aggressive action to reduce emissions will be necessary in order to hit the goals
laid out in the Resolution. Achieving these targets will be a challenge, but the benefits go well
beyond compliance. Importantly, many of these initiatives will help community members and the
local government save money through reductions in energy use. Increasing public transit
ridership and alternative transportation participation will reduce traffic congestion, which will
save residents time, improve air quality and ultimately enhance the community’s quality of life.
The co-benefits of many emissions reduction efforts will have noticeable and tangible positive
impacts.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 51
Next Steps
Figure 21. Steps to Identify & Reduce Greenhouse Gas Emissions
This inventory will be an important piece of the emissions reductions planning process.
The emissions estimates from 2015 will be used as a baseline for monitoring and tracking
emissions performance as well as for future emissions forecasting. It will be important to
continue performing updated inventories, which should be completed every three years. The next
inventory should analyze data for 2018. Future inventories should build on this inventory, using
ClearPath for emissions accounting and using the same methodologies. However, updated
techniques and information should be incorporated as the understanding of inventorying and
climate science evolves.
Developing a comprehensive, straightforward plan to implement the recommendations
from this report will be key to reducing emissions, so a climate action plan is a crucial next step
for the City moving forward. With the completion of a robust plan, the City will be able to
follow through on its progressive commitments to climate action, and it will be a part of the
solution, contributing to a more sustainable and healthier world.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 52
References
A.B. 32 (Global Warming Solutions Act), 2005-2006 Session. (California 2006).
“2011-2015 American Community Survey 5-Year Estimates. Selected Housing Characteristics -
California.” U.S. Census Bureau American Fact Finder, (2015).
https://factfinder.census.gov/bkmk/table/1.0/en/ACS/15_5YR/DP04/0400000US06
“2011-2015 American Community Survey 5-Year Estimates. Selected Housing
Characteristics - South Lake Tahoe City, California.” U.S. Census Bureau American Fact
Finder, (2015).
https://factfinder.census.gov/bkmk/table/1.0/en/ACS/15_5YR/DP04/1600000US0673108
“A Regional Greenhouse Gas Inventory for the Lake Tahoe Basin.” California Tahoe
Conservancy, (January 2013). www.tahoe.ca.gov
“A Resolution of the South Lake Tahoe City Council: Establishing Renewable Energy and
Carbon Emissions Reduction Goals for South Lake Tahoe.” City of South Lake Tahoe
Resolution No. 2017-26, (April 2017).
https://slt.granicus.com/MetaViewer.php?view_id=6&clip_id=847&meta_id=83333
“Basic Information of Air Emissions Factors and Quantification.” U.S. Environmental Protection
Agency, (September 2016). https://www.epa.gov/air-emissions-factors-and-
quantification/basic-information-air-emissions-factors-and-quantification
Burt, J. (2018) Personal communication between John Burt, Liberty Utilities, and Sam
Ruderman, Sierra Nevada Alliance.
California Air Resources Board, California Climate Action Registry, ICLEI USA, & The
Climate Registry. (2010). Local Government Operations Protocol: For the Quantification
and Reporting of Greenhouse Gas Emissions Inventories.
“Climate Science.” UC Davis Tahoe Environmental Research Center, (January 2019).
https://tahoe.ucdavis.edu/climate-change
Dettinger, M., Alpert, H., Battles, J., Kusel, J., Safford, H., Fougeres, D.,
Knight, C., Miller, L., & Sawyer, S. (2018). Sierra Nevada Summary Report. California’s
Fourth Climate Change Assessment. Publication number: SUM-CCCA4-2018-004.
http://www.climateassessment.ca.gov/regions/docs/20180827-SierraNevada.pdf
“Greenhouse Gas Equivalencies Calculator.” U.S. Environmental Protection Agency, (2018).
http://www.epa.gov/cleanenergy/energy-resources/calculator.html
Fiore, C. (2019) Personal communication between Chris Fiore, City of South Lake Tahoe, and
Meredith Anderson, Sierra Nevada Alliance.
Frank, T. (2018) Personal communication between Tara Frank, Tahoe Transportation District,
and Sam Ruderman, Sierra Nevada Alliance.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 53
Friedlander, E. (2019) GIS Maps of the City of South Lake Tahoe. Personal communication
between Eric Friedlander, City of South Lake Tahoe, and Meredith Anderson, Sierra
Nevada Alliance.
Gibbs, M. (2018) Personal communication between Mark Gibbs, Airport Manager at Lake Tahoe
Airport, and Meredith Anderson, Sierra Nevada Alliance.
Guttry, M. (2018) Personal communication between Melonie Guttry, South Tahoe Public Utility
District, and Meredith Anderson, Sierra Nevada Alliance.
Haefer, R. (2018) Personal communication between Reid Haefer, Tahoe Regional Planning
Agency, and Sam Ruderman, Sierra Nevada Alliance.
Harwood, P. (2018) Personal communication between Phil Harwood, City of South Lake Tahoe,
and Meredith Anderson, Sierra Nevada Alliance.
ICLEI Local Governments for Sustainability USA. (2013). US Community Protocol for
Accounting and Reporting of GHG Emissions, Version 1.1.
IPCC. (2014). Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II
and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change
[Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland,
151 pp.
“Lake Tahoe Environmental Improvement Program.” Tahoe Regional Planning Agency, (2019).
www.trpa.org/about-trpa/how-we-operate/environmental-improvement-program/
“Lake Tahoe Shoreline Plan Environmental Impact Statement Scoping Summary Report.” Tahoe
Regional Planning Agency, (September 2017). shorelineplan.org/wp-
content/uploads/2017/09/Shoreline-EIS-Scoping-Summary-Report_Sept.2017.pdf
Lear, J. (2018) Personal communication between Jeanne Lear, South Tahoe Refuse, and
Meredith
Anderson, Sierra Nevada Alliance.
Litty, N. (2018) Personal communication between Noreen Litty, Southwest Gas, and Meredith
Anderson, Sierra Nevada Alliance.
Parmer, C. (2019) Personal communication between Cory Parmer, California Air Resources
Board, and Sam Ruderman, Sierra Nevada Alliance.
“Residential Sector Energy Consumption Estimates, 1960-2017, California.” U.S. Energy
Information Association, (2018).
https://www.eia.gov/state/seds/data.php?incfile=/state/seds/sep_use/res/use_res_CA.html
&sid=CA
S.B. 32 (Global Warming Solutions Act of 2006: Emissions Limit), 2016 Session. (California
2016).
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 54
S.B. 375 (Sustainable Communities and Climate Protection Act), 2008 Session. (California
2008).
Schmitt, B.J. (2019) Personal communication between BJ Schmitt, Sierra Business Council, and
Sam Ruderman, Sierra Nevada Alliance.
“The Causes of Climate Change.” NASA: Global Climate Change, 2018.
https://climate.nasa.gov/causes/.
“Understanding Global Warming Potentials.” U.S. Environmental Protection Agency, (2018).
https://www.epa.gov/ghgemissions/understanding-global-warming-potentials.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 55
Appendices
Appendix A. Population Scaling Factors (Community-Wide)
Population Scaling Factor for Grid Electricity and Natural Gas
CSLT Population Compared to 96150 Zip Code
City of South Lake Tahoe Population 21,349
Total 96150 Population 29,496
Percentage of CSLT in 96150 72.38%
Population Scaling Factor for Off-Road Transportation
CSLT Population Compared to Lake Tahoe Basin
City of South Lake Tahoe 21,349
Lake Tahoe Basin 53,255
Percentage of CSLT in Lake Tahoe Basin 40%
Appendix B. Greenhouse Gas Emissions Summary by Pollutant
Community-Wide Emissions by Pollutant
Sources & Activities MT CO2 MT CH4 MT N2O
Natural Gas 74,592.61 7.00 0.14
On-Road Transportation 61,223.30 3.27 4.37
Grid Electricity 65,324.00 2.29 0.28
Solid Waste 639.56 568.27 1.48
Off-Road Transportation 10,834.60 0.52 0.23
Recreational Boats 5,947.16 0.43 0.15
Propane 5,480.90 0.98 0.10
Water & Wastewater 4,445.60 0.13 0.16
Aircraft 3,115.70 0.02 0.01
Natural Gas Leakage 0.93 87.14 0.00
Wood --7 14.74 0.20
TOTAL 227,158.77 684.67 7.10
7 Emissions from wood combustion are considered biogenic CO2 emissions. Biogenic CO2 is not included in GHG
inventories under the USCP because the same CO2 would be emitted when it decomposes naturally.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 56
Government Operations Emissions by Pollutant
Sources & Activities MT CO2 MT CH4 MT N2O
Natural Gas 1,901.10 0.18 0.004
On-Road Fleet 495.33 0.01 0.01
Employee Commute 317.40 0.02 0.03
Grid Electricity 246.15 0.009 0.001
Off-Road Fleet 100.87 0.01 0.003
Solid Waste -- 4.45 --
Natural Gas Leakage 0.24 2.22 --
Propane 1.82 0.0003 0.00003
TOTAL 3,063 6.9 0.05
Appendix C. Detailed Activity Data
See Community-Wide and Government Operations Data Master Sheets.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 57
Appendix D. Emissions Factors & Factor Sets
Emissions Factors by Source and Activity8
Sources & Activities CO2 CH4 N2O Unit
Grid Electricity 943.57859 33.110 4.0410 lbs/MWh
Natural Gas Combustion 53.02 0.005 0.0001 kg/MMBtu
Propane Combustion 61.46 0.010989 0.0010989 kg/MMBtu
Fugitive Emissions (Natural Gas
Leakage)
6.6316E-07 6.1939E-5 -- MT/MMBtu
natural gas used
Wood Combustion -- 11 0.316 0.0042 kg/MMBtu
On-Road Transportation, Gasoline12 441.3974 0.02659 0.02428 g/mile
On-Road Transportation, Diesel12 923.3614 0.01602 0.14514 g/mile
Off-Road Transportation, Gasoline13 0.070268 4.0016E-06 1.7607E-06 MT/MMBtu
Off-Road Transportation, Diesel13 0.073964 4.2017E-06 1.8835E-06 MT/MMBtu
Recreational Boats, Gasoline 0.070268 5.12E-06 1.7607E-06 MT/MMBtu
Recreational Boats, Diesel 0.073964 5.3608E-06 1.8835E-06 MT/MMBtu
Aircraft, Aviation Gasoline 8.31 0.00704 0.00011 kg/gallon
Aircraft, Jet A 9.57 -- 0.00031 kg/gallon
Solid Waste (Methane Collection) -- 0.01489 -- MT CH4/wet ton
Solid Waste (No Methane Collection) -- 0.5957 -- MT CH4/wet ton
Solid Waste, Compost -- 0.000556 0.000204 MT/ton of green
waste
Solid Waste, Compost -- 0.00022 0.000133 MT/ton of bio
waste
Solid Waste, Transport 0.00014 -- -- MT CO2e/wet
short ton mile
Water & Wastewater Treatment
Processes
-- -- 3.2 g/person
8 All emissions factors were provided by ClearPath unless otherwise noted.
9 The grid electricity emissions factor for CO2 was provided by Liberty Utilities for the year 2017, which was used
as a proxy for 2015. 10
The grid electricity emissions factors for CH4 and N2O were provided by the EPA’s Emissions & Generation
Resource Integrated Database (eGRID). The emissions factors used were from the WECC California subregion. 11
Emissions from wood combustion are considered biogenic CO2 emissions. Biogenic CO2 is not included in GHG
inventories under the USCP because the same CO2 would be emitted when it decomposes naturally. 12
Emissions factors for on-road transportation were provided by the CARB’s EMFAC2017. 13
Emissions factors for off-road transportation were provided by the CARB’s OFFROAD2017.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 58
On-Road Transportation Factor Set14
Emissions Factors and Fuel Economy Value Unit
Gas Passenger Vehicle Fuel Economy 23.86 MPG
Gas Passenger Vehicle 0.02659 g CH4/mile
Gas Passenger Vehicle 0.02428 g N2O/mile
Gas Light Truck Fuel Economy 23.86 MPG
Gas Light Truck 0.02659 g CH4/mile
Gas Light Truck 0.02428 g N2O/mile
Gas Heavy Truck Fuel Economy 5.36 MPG
Gas Heavy Truck 0.02659 g CH4/mile
Gas Heavy Truck 0.02428 g N2O/mile
Electric Vehicle Fuel Economy15 103.17 MPGe
Diesel Passenger Vehicle Fuel Economy 23.86 MPG
Diesel Passenger Vehicle 0.01602 g CH4/mile
Diesel Passenger Vehicle 0.1451 g N2O/mile
Diesel Light Truck Fuel Economy 23.86 MPG
Diesel Light Truck 0.01602 g CH4/mile
Diesel Light Truck 0.1451 g N2O/mile
Diesel Heavy Truck Fuel Economy 6.02329 MPG
Diesel Heavy Truck 0.01602 g CH4/mile
Diesel Heavy Truck 0.14514 g N2O/mile
14
Average fuel economies were provided by the EIA unless otherwise noted. 15
MPGe is miles per gallon equivalent. This figure was calculated using U.S. Department of Energy data.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 59
Waste Characterization Factor Set - CalRecycle
Material Type Community-Wide16 Government Operations17
Mixed MSW 0% 0%
Newspaper 2.2% 2.6%
Office Paper 10.75% 27.8%
Corrugated Cardboard 9.1% 4.7%
Magazines/Third Class Mail 4.7% 5.4%
Food Scraps 25.5% 14.6%
Grass 2.63% 1.35%
Leaves 2.63% 1.35%
Branches 0.4% 0%
Dimensional Lumber 13.35% 14.2%
16
The community-wide waste characterization that was used was an average of the residential and commercial
characterizations for the City of South Lake Tahoe. 17
The government operations waste characterization that was used was the public administration characterization
for the City of South Lake Tahoe.
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 60
Appendix E. Employee Commute Survey
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 61
Appendix F. City of South Lake Tahoe Inventory Boundary within the
Lake Tahoe Basin
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 62
Appendix G. South Lake Tahoe 100% Renewable Resolution
City of South Lake Tahoe Greenhouse Gas Inventory, 2015 63