Community-Wide & Government Operations Greenhouse Gas ...€¦ · City of South Lake Tahoe Greenhouse Gas Inventory, 2015 8 Executive Summary In 2017, the City of South Lake Tahoe

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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


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


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


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


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


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


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.


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.


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.


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%


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


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


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


Table 4. Government Operations Emissions by Sources & Activities



On-Road Fleet 497 15.3%


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.


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.


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


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.


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.


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


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.


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.


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


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


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


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.


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


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


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.


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.


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


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.


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


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.


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


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



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


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


Table 24. Community-Wide Emissions by Sources & Activities



On-Road Transportation 62,472 25.2%

Grid Electricity 61,133 24.6%


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


Table 25. Community-Wide Emissions by Sector


Residential Energy 82,704 33.3%

Transportation & Mobile Sources 82,515 33.2%

Commercial Energy 63,123 25.4%


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


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


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


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



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



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


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.


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%.


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.


Table 36. Government Operations Emissions by Sources & Activities



On-Road Vehicle Fleet 497 15.3%


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


Table 37. Government Operations Emissions by Sector


Buildings & Facilities 2,113 65.2%

Vehicle Fleet 599 18.5%


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


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


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.


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.


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.


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


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.


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.


References

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Climate Registry. (2010). Local Government Operations Protocol: For the Quantification

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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.

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and Meredith Anderson, Sierra Nevada Alliance.

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Accounting and Reporting of GHG Emissions, Version 1.1.

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[Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland,

151 pp.

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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.

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Anderson, Sierra Nevada Alliance.

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Board, and Sam Ruderman, Sierra Nevada Alliance.

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Information Association, (2018).

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&sid=CA

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2016).

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https://climate.nasa.gov/causes/

https://www.epa.gov/ghgemissions/understanding-global-warming-potentials


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.


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.


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.


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.


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.


Appendix E. Employee Commute Survey


Appendix F. City of South Lake Tahoe Inventory Boundary within the

Lake Tahoe Basin


Appendix G. South Lake Tahoe 100% Renewable Resolution


Documents

Community-Wide & Government Operations Greenhouse Gas ...€¦ · City of South Lake Tahoe Greenhouse Gas Inventory, 2015 8 Executive Summary In 2017, the City of South Lake Tahoe