GREAT BASIN UNIFIED AIR POLLUTION CONTROL DISTRICT 

AIR QUALITY MAINTENANCE PLAN AND PM10 REDESIGNATION REQUEST FOR 

THE TOWN OF MAMMOTH LAKES AND REVISIONS TO DISTRICT 

RULE 431 – PARTICULATE EMISSIONS 

ADOPTED MAY 5, 2014 

ENCLOSURE 4 

Adopted Air Quality Maintenance Plan and PM10 Redesignation Request for the Town of Mammoth 

Lakes and Revisions to District Rule 431 – Particulate Emissions 

Mammoth Lakes AQMP 

2014 Update

AIR QUALITY

MAINTENANCE PLAN AND

REDESIGNATION REQUEST

for the		

Town of Mammoth Lakes

May 5, 2014
Mammoth Lakes AQMP 

2014		

AIR	QUALITY	

	MAINTENANCE	PLAN	AND	

REDESIGNATION	REQUEST	

for	the		

Town	of	Mammoth	Lakes	

Prepared	for	the		

PM‐10	State	Implementation	Plan	

By	

The	Town	of	Mammoth	Lakes	and		

The	Great	Basin	Unified	Air	Pollution	Control	District	

Authors	

William	Taylor,	Duane	Ono,	and	Jen	Daugherty	

Contributors	

Phil	Kiddoo	and	Megan	Rybacki	
Mammoth Lakes AQMP 

iii 

Mammoth Lakes Air Quality Maintenance Plan and 

Redesignation Request 

2014 

Executive Summary ................................................................................................... v 

Chapter 1 Introduction ................................................................................................ 1 

Chapter 2 1990 AQMP Summary ............................................................................... 6 

Chapter 3 Federal and State Air Quality Standards for Particulate Matter ............... 11 

Chapter 4 Air Quality Data ........................................................................................ 13 

Chapter 5 Emissions Inventory ................................................................................. 17 

Chapter 6 Receptor Modeling ................................................................................... 23 

Chapter 7 Control Measures .................................................................................... 28 

Chapter 8 Maintenance Demonstration .................................................................... 36 

Chapter 9 Contingency Plan and Maintenance Measures ........................................ 43 

Chapter 10 Transportation Conformity ....................................................................... 46 

Chapter 11 General Conformity .................................................................................. 48 

Chapter 12 Redesignation Request............................................................................ 49 

Chapter 13 References .............................................................................................. 50 

List of Figures 

Figure ES-1 Design Day Projection for High Residential Wood Combustion Day.......... xi 

Figure ES-2 Design Day Projection for High Road Dust Day ........................................ xii 

Figure 1-1 Mono County, CA boundary and Mammoth Lakes Vicinity ........................ 3 

Figure 1-2 Mammoth Lakes Planning Area ................................................................. 4 

Figure 4-1 Mammoth Lakes PM-10 Quarterly Peaks and Averages (1990-2013)......15 

Figure 4-2 Mammoth Lakes PM-10 Winter Season Peaks and 

 Averages (1990-2013) ............................................................................. 16 

Table 7-2 Vehicle Miles Traveled (VMT) Comparison .............................................. 35 

Figure 8-1 Design Day Projection for High Residential Wood Combustion & Road 

 Dust Days ................................................................................................ 40 

Figure 8-2 Design Day Projection for High Residential Wood Combustion Day ....... 41 

Figure 8-3 Design Day Projection for High Road Dust Day ....................................... 42 

List of Tables 

Table ES-1 Summary of Peak 24 hour PM-10 Emissions (kg/day) 2012 ..................... vii 

Table ES-2 Peak 24-hour PM-10 Emissions (kg/day) ................................................... ix 

Table ES-3 Forecasted PM-10 Design Day Concentrations for High Residential 

 Wood Combustion Day .............................................................................. xi 

Table ES-4 Forecasted PM-10 Design Day Concentrations for High Road Dust Day . xii 

Table 2-1 Summary of PM-10 Air Quality Standard Violations for the Town 

 of Mammoth Lakes 1990-2012 ................................................................ 10 

Table 3-1 National Ambient Air Quality Standard for Particulates ............................ 11 

Table 3-2 California Ambient Air Quality Standard for Particulates .......................... 12 
Mammoth Lakes AQMP 

iv 

Table 4-1 PM-2.5 Monitoring Results ....................................................................... 14 

Table 5-1 Residential Wood Burning Device Count ................................................. 18 

Table 5-2 Amount of Wood Burned Annually in Homes with Wood 

 Combustion Devices ................................................................................ 18 

Table 5-3 Annual PM-10 Estimates for Residential Wood Combustion ................... 19 

Table 5-4 Peak 24-Hour Emission Estimates for Residential Wood Combustion .... 20 

Table 5-5 24-Hour Road Dust Emissions ................................................................. 21 

Table 5-6 Permitted Particulate Matter Sources Within the Mammoth Lakes 

AQMP .......................................................................................22 

Table 5-7 Summary of Peak 24-Hour PM-10 Emissions (kg/day) 2012 ................... 22 

Table 6-1 Dates with only PM-10 Filters .................................................................. 24 

Table 6-2 Dates with PM-10 and PM-2.5 Filters ...................................................... 24 

Table 6-3 CMB Attribution Results and Performance Statistics ............................... 26 

Table 6-4 CMB Percent Contributions by Road Dust and Residential 

Wood Combustion 1987-88 and 2003-2011 Data Sets ........................... 26 

Table 7-1 Change in Peak 24-Hour Emissions 1990-2012 ...................................... 33 

Table 8-1. Peak Roadway Emissions Per Day 2012-2030 ....................................... 36 

Table 8-2. Peak Residential Wood Combustion Emissions Per Day 2012-2030 ...... 37 

Table 8-3. Peak Winter 24-hour PM-10 Emissions for Planning Area ...................... 37 

Table 8-4. Four Highest Monitored PM-10 Concentrations at Gateway Center, 

 Mammoth Lakes, CA (2010-1012) ........................................................... 38 

Table 8-5 Future PM-10 Concentrations for RWC and Road Dust Days ................. 40 

Table 8-6 Forecasted PM-10 Concentrations by Source for High Road Dust Day .. 41 

Table 8-7 Forecasted PM-10 Concentrations by Source for High Residential 

 Wood Combustion Day ............................................................................ 42 

Appendices 

Appendix A Glossary 

Appendix B Residential Wood Burning Survey 2013 Summary 

Appendix C Town of Mammoth Lakes Municipal Code Chapter 8.30 (Revised) 

Appendix D VMT Estimates for Days of Air Quality Monitoring – 2003 to 2011 

 (LSC, 2013) 

Appendix E Mammoth Lakes Vehicle Miles Traveled Analysis (LSC, 2012) 

Appendix F Mammoth Lakes Vehicle Miles Traveled Analysis – Comparison with 1990 

 Study (LSC, 2012) 

Appendix G Chemical Analysis of PM10 and PM2.5 Filters from Mammoth Lakes 

 (DRI, 2013)
Mammoth Lakes AQMP 

v 

EXECUTIVE SUMMARY 

Introduction 

This document is a revision to the 1990 Air Quality Management Plan (AQMP) for the 

Town of Mammoth Lakes. It includes 1) a request to redesignate the area from 

nonattainment for the National Ambient Air Quality Standard for PM10 (NAAQS) to 

attainment based on monitoring data and a modeling analysis, and 2) a maintenance plan 

that contains requirements to ensure the federal PM10 standard will not be violated in the 

future. 

Background 

From 1985 to 1990, monitoring in Mammoth Lakes by the Great Basin Unified Air Pollution 

Control District (GBUAPCD) recorded 10 violations of the federal 24-hour PM10 standard. 

Since monitoring was on a once every six day cycle, extrapolation of the data predicted 

11.2 expected violations of the NAAQS per year. 

In response to the violations of the NAAQS, and determination by the EPA that the Town 

of Mammoth Lakes was non-attainment for the federal PM-10 standard, the Town of 

Mammoth Lakes (Town) and the GBUAPCD formed an ad hoc air quality committee. The 

committee investigated potential control strategies to be included in new particulate 

emissions regulations for the Town. Multiple potential control strategies were evaluated 

resulting in a recommendation to the Town of Mammoth Lakes Town Council. On 

November 30, 1990, the Town Council adopted the recommended measures. 

Implementation of the adopted measures resulted in an immediate decline in PM-10 

levels in the planning area, and since 1994, despite continued community growth, there 

have been no further exceedences of the NAAQS. 

This Air Quality Maintenance Plan and Redesignation Request is an update to the 1990 

Air Quality Management Plan for the Town of Mammoth Lakes. This plan reviews the 

background of the 1990 plan, the measures implemented as a result of that plan and their 

effectiveness, and changes to clean air regulations since the adoption of the 1990 plan. 

This plan then recommends maintenance measures and requests that the Town of 

Mammoth Lakes be redesignated as attainment for the federal PM-10 standard. 

PM Standards 

PM-10 stands for particulate matter less than 10 microns in diameter. The National 

Ambient Air Quality Standard (NAAQS, or federal standard) for PM-10 was set July 1, 

1987 at 150 micrograms per cubic meter (μg/m3) for the 24 hour standard. Levels for the 

PM-10 standard were selected to protect the health of people who may be sensitive to 

exposure to airborne particulate matter (OAQPS 2005). 

The state 24-hour average PM-10 standard is set at 50 μg/m3. Violations of the state 

standard have also declined significantly since the adoption of the AQMP. The number of 

monitored state standard violations was as high as 56 days in 1993. Over the last four 
Mammoth Lakes AQMP 

vi 

years (2009-12) the number of state standard violations has ranged from four to 31 per 

year. 

Area Description and Population 

The Town of Mammoth Lakes is located on the eastern slopes of the Sierra Nevada 

mountains at an elevation of 7,861 feet (2,396 m). The Town was incorporated in 1984 

and has grown from a permanent population of 4,785 in 1990 to 8,234 in 2010. Included 

in the Town boundaries is Mammoth Mountain ski area which attracts about 1.2 to 1.5 

million skiers each winter. During major winter weekends there are about 35,000 people 

in Mammoth Lakes. It is anticipated this figure will grow to about 45,000 to 52,000 people 

by 2025 (Town of Mammoth Lakes, 2007a). 

Need for a Plan Update 

In the 23 years since the adoption of the 1990 AQMP, the conditions affecting PM-10 in 

Mammoth Lakes have changed significantly. This AQMP update addresses improved air 

quality in Mammoth Lakes; a revised General Plan for the Town of Mammoth Lakes; 

updated traffic modeling for the Town; an updated chemical mass balance study; 

revisions to the GBUAPCD Rules; and a request to have Mammoth Lakes redesignated 

as attainment for the federal PM-10 standard. 

1990 AQMP Summary 

In 1987, the Town and the Great Basin Unified Air Pollution Control District (APCD) began 

developing a plan to reduce air pollution from fireplaces, woodstoves and dust caused by 

vehicles traveling on roads treated with volcanic cinders. 

The AQMP relied on controlling wood smoke by replacing old wood stoves and fireplaces 

with cleaner wood burning appliances and curtailing wood burning on days that could 

violate the air quality standard. The Town reduced road dust emissions by using vacuum 

street sweepers to remove volcanic cinders soon after the roads dried and through 

promotion of increased transit usage. After adoption of the AQMP, monitored air pollution 

levels dropped significantly in Mammoth Lakes. 

PM-10 and Data Summary 

Based on airborne pollutant and meteorological monitoring conducted at the Gateway 

Center (also known as the Rite Aid/Do-It Yourself shopping center) in Mammoth Lakes, 

the Mammoth Lakes Planning Area has not exceeded the federal 24-hour NAAQS since 

1994. In 1990 when the AQMP was adopted, three exceedences were recorded. Since 

then, only two exceedances of the 24-hour NAAQS were recorded – one in 1991 and one 

in 1994. 
Mammoth Lakes AQMP 

vii 

Emissions Inventory 

The emissions inventory section describes the PM-10 emission estimates for residential 

wood combustion (RWC), resuspended road dust, cinders, mobile source tailpipe 

emissions and point sources. The methodology and data used to determine emissions is 

discussed for each source type. Because Mammoth Lakes exceeds the state 24-hour 

PM-10 standard, the emissions inventory is estimated for a peak 24-hour period. 

Woodburning and resuspended road dust comprise almost all the PM-10 emissions 

during the winter. Motor vehicle exhaust, tire wear industrial sources contribute only 

approximately 1.4% of the area wide inventory. Estimates for the annual and 24-hour 

PM-10 emissions are calculated for wood burning and road dust. The annual residential 

wood combustion emissions estimates, which are based on survey data, provide good 

information to improve the estimates for the peak 24-hour period. The PM-10 emission 

estimate for resuspended road dust is based on the AP-42 methodology for estimating 

reentrained road dust emissions from paved roads (EPA, 2013). 

The current total PM-10 emissions on a peak winter day in the Town of Mammoth Lakes 

are 3,385 kg/day in the Town of Mammoth Lakes and 4,324 in the entire nonattainment 

area boundary, see Table ES-1. A distinction is made for the in-Town emissions inventory 

that was used for Chemical Mass Balance receptor model and the maintenance 

demonstration, as opposed to the inventory for the larger nonattainment area. The 

inventory for the larger nonattainment area included emissions from road dust, motor 

vehicles and industrial sources from areas east of the Town that did not contribute to high 

PM-10 levels monitored in the Town. It is also important to refer to the In-Town emissions 

inventory when making any comparisons to the analysis in the 1990 Air Quality 

Management Plan for the Town of Mammoth Lakes, which was based on In-Town 

emissions. 

Table ES-1 Summary of 24-hour PM-10 Emissions (kg/day) 2012 

Source 

In Town of 

Mammoth Lakes 

Nonattainment 

Area Total 

Residential Wood Combustion 850 850 

Resuspended Road Dust & Cinders 2,522 3,455 

Tailpipe, Tire and Brake Wear 9 11 

Industrial Sources 4 8 

Total 3,385 4,324 

Chemical Mass Balance Results 

The Desert Research Institute of Reno, Nevada (DRI) conducted a chemical mass 

balance (CMB) study for Mammoth Lakes in 2013. Chemical source profiles, or 

fingerprints, were taken from the 1990 AQMP. The sources profiled were: 
Mammoth Lakes AQMP 

viii 

 Mammoth Lakes road cinder storage 

 Mammoth Lakes paved road dust 

 idling diesel ski tour buses in Mammoth Lakes 

 fireplace burning a typical Mammoth Lakes wood mix 

 a Fisher woodstove with typical Mammoth Lakes wood mix 

CMB model version 8 (USEPA) was used to estimate source contributions to PM-10 and 

PM-2.5 for days with chemically speciated data. For the winter 1987-1988 study (Ono et 

al, 1990), on average, fireplaces contributed 75% of the PM-10 and road dust 25%. Table 

6-4 compares the results of the 1987-88 study to this study. Three of the days in the 

1987-88 study showed wood smoke contributing >95% of the PM-10; the current study 

shows no high PM-10 days with greater than 75% of the PM-10 contributed from wood 

smoke (DRI, 2013). The CMB study found that since the adoption of the 1990 AQMP, 

peak PM-10 impacts from wood smoke and road dust have both dropped by about 33%. 

(DRI, 2013). 

Control Measures 

In December of 1990, the Town of Mammoth Lakes adopted the Air Quality Management 

Plan (AQMP) for the Town of Mammoth Lakes. The 1990 AQMP relied on controlling 

wood smoke by replacing old wood stoves and fireplaces with cleaner wood burning 

appliances and curtailing wood burning on days that could violate the air quality standard. 

The Town reduced road dust emissions by using vacuum street sweepers to remove 

volcanic cinders applied for traction control during icy conditions soon after the roads 

dried and by limiting future VMT growth. Control measures were adopted by the Town of 

Mammoth Lakes as Municipal Code Chapter 8.30, Particulate Emissions Regulations. 

Major controls in the Chapter 8.30 regulations were: 

 Replacement or removal of existing uncertified residential wood combustion 

appliances at the time of sale of a property; 

 Limit the maximum number of residential wood combustion appliances in new 

construction to one certified appliance plus one pellet fueled appliance; 

 Institute voluntary and mandatory wood burning curtailment days; 

 Implement a public education program; 

 Implement a vacuum street sweeping program; and 

 Limit peak VMTs to 106,600. 

With the implementation of the control measures from the 1990 AQMP, PM-10 levels in 

Mammoth Lakes declined significantly. The 1990 AQMP estimated 4,259 kg/day of PM10 for the peak 24-hour period and forecast 8,036 kg/day for the peak 24 hour total PM10 emissions in the Town by 2005 absent any controls (Ono et al. 1990). The updated 

emissions estimate shows 3,385 kg/day PM-10 in 2012, which is a 20% reduction in 

emissions since 1990 when the AQMP was adopted. This reduction was achieved 

despite a 72% population increase from 4,785 in 1990 to 8,234 in 2010. Table ES-2 

shows the peak 24-hour PM-10 emissions inventory for Mammoth Lakes in 1990 when 

the AQMP was adopted, the current inventory in 2012, and the projected emissions 
Mammoth Lakes AQMP 

ix 

inventory in 2030 after the town has reached its buildout population and visitor numbers. 

The emissions inventory projections for 2030 are based on current control measures for 

residential wood combustion and on a change to the peak daily traffic volume limit derived 

from the modeling analysis that was performed for this plan update. 

Table ES-2 Peak In-Town 24-hour PM-10 Emissions (kg/day) 

Source Category 1990 2012 2030 

Residential Wood Combustion 1,839 850 802 

Road Dust and Cinders 2,390 2,522 3,143 

Tailpipe, Tire & Brake Wear 23 9 11 

Industrial Sources 1 4 4 

Total 4,253 3,385 3,960 

Amendments to Control Measures 

Most of the changes to the implementing regulations of the Town of Mammoth Lakes MC 

8.30 revise outdated sections or make non-substantive technical edits. The three 

meaningful amendments are: 

 Section 8.30.040 B. This section is modified to clarify that no new wood burning 

appliances may be installed in multi-family developments. Prohibition of new wood 

burning appliances in multi-family projects has been the policy of the Town. The 

proposed revision formalizes that practice and implements General Plan Policy 

R.10.3. 

 Section 8.30.080, Mandatory Curtailment. This section has been modified to 

include all wood burning appliances, except pellet stoves, in the no-burn day 

program. Currently, EPA certified stoves are exempted under Town regulations, 

but are required to participate under the District regulations. 

 Section 8.30.100 B. This section sets a limit for vehicle miles traveled (VMT) within 

the town. The current limit is one hundred six thousand six hundred (106,600) 

VMT on any given day. Proposed development projects and other Town approved 

activities which affect vehicle trips are evaluated against this limit. A revised traffic 

model for the community incorporates additional roadway segments and revises 

VMT projections based on updated traffic counts and current modeling 

technologies. It shows an estimated VMT at General Plan buildout of one hundred 

seventy nine thousand seven hundred eight (179,708) for the revised model 

roadway segments. The air quality modeling shows that this overall level of traffic 

will not cause an exceedence of the NAAQS and is suggested as the VMT limit for 

the AQMP. 
Mammoth Lakes AQMP 

x 

Maintenance Demonstration 

The AQMP evaluates the effects of increased population and visitors on PM-10 emissions 

and forecasts the resulting change in the ambient PM-10 design concentration. Receptor 

modeling results were used with the revised emissions inventory (Table ES-2) that 

reflected changes in permanent and visitor populations and the adopted control measures 

to forecast changes in ambient PM-10 concentrations. 

The 2007 Town of Mammoth Lakes General Plan evaluated population in terms of People 

at One Time (PAOT). PAOT is the number of people in town on a peak winter Saturday 

and includes both residents and visitors. PAOT is expected to grow from 34,265 in 2007 

to 52,000 in 2025. 2025 was considered the build out year by the General Plan. The 

buildout number from the General Plan has been used as the year 2030 projected 

population in both the RWC and VMT analyses. This provides supporting information for 

an analysis to demonstrate that the PM-10 standard can be maintained in Mammoth 

Lakes for at least a 10-year period. This 10-year maintenance demonstration is required 

under the Clean Air Act (CAA) to allow the area to be redesignated from nonattainment 

to attainment for PM-10. 

Proportional Rollback Analysis for Control Measure Evaluation 

The effect of PM-10 emissions increases or decreases on the ambient PM-10 

concentration can be determined by using a linear rollback method of calculation. This 

method is based on the assumption that the ambient concentration due to a given source 

is proportional to the emissions from that source. The effect on the design day PM-10 

concentration was used to evaluate the overall effect on future ambient PM-10 levels. The 

design day concentration, which is the statistical fourth highest daily PM-10 concentration 

over a three-year period, was used for PM-10 forecasts because it is the value used by 

the EPA to determine compliance with the federal PM-10 standard. Based on PM-10 

data collected over the last three years (2010-12), the fourth high PM-10 concentration, 

and therefore the PM-10 design day concentration, is 99 μg/m3. 

As was described in the 1990 AQMP, Mammoth Lakes’ air pollution episodes are 

characterized by two different scenarios. One with high wood smoke contributions and 

one with high road dust contributions. The proportional roll-back analysis tested both 

cases. Using the peak wood smoke and peak road dust and cinders days, Tables ES-3 

and ES-4 show the expected PM-10 emissions and concentrations due to growth with 

continued implementation of existing controls. These results show that with current 

control measures, growth could result in a 1% to 6% increase in the design day ambient 

PM-10 concentrations over the next 15 years. Since buildout conditions under the 

General Plan are expected to be sustained beyond 2030, PM-10 projections for 2050 are 

the same as for 2030. These PM-10 forecasts are also shown graphically in Figures ES1 and ES-2. 

 
Mammoth Lakes AQMP 

xi 

Table ES-3. Forecasted PM-10 Design Day Concentrations for High Residential 

Wood Combustion Day 

Source Category 1990 2012 2030 2050 

Background 5 μg/m3 5 μg/m3 5 μg/m3 5 μg/m3

Road Dust 5 μg/m3 23 μg/m3 29 μg/m3 29 μg/m3

Residential Wood 

Combustion 195 μg/m3 71 μg/m3 66 μg/m3 66 μg/m3

Vehicles* 5 μg/m3 negligible negligible negligible 

Industrial Sources negligible negligible negligible negligible 

Total 210 μg/m3 99 μg/m3 100 μg/m3 100 μg/m3

0

50

100

150

200

250

1990 2012 2030 2050

μg/m3

Figure ES-1 Design Day Projection for

High Residential Wood Combustion Day 

Vehicles

Residential Wood Combustion

Road Dust

Background and Industrial
Mammoth Lakes AQMP 

xii 

Table ES-4. Forecasted PM-10 Design Day Concentrations 

for High Road Dust Day 

Source Category 1990 2012 2030 2050 

Background 5 μg/m3 5 μg/m3 5 μg/m3 5 μg/m3

Road Dust 93 μg/m3 37 μg/m3 46 μg/m3 46 μg/m3

Residential Wood Combustion 112 μg/m3 57μg/m3 54 μg/m3 54 μg/m3

Vehicles* negligible negligible negligible negligible 

Industrial Sources negligible negligible negligible negligible 

Total 210 μg/m3 99 μg/m3 105 μg/m3 105 μg/m3

 

 * Vehicle tailpipe and brake wear emission amount to less than 0.3 μg/m3 except for the 1990 RWC case. 

0

50

100

150

200

250

1990 2012 2030 2050

μg/m3

Figure ES-2 Design Day Projection for

High Road Dust Day

Vehicles

Residential Wood Combustion

Road Dust

Background and Industrial
Mammoth Lakes AQMP 

xiii 

Contingency Plan and Maintenance Measures 

The analysis in this Plan shows that the adopted control measures for the Town of 

Mammoth Lakes are sufficient to maintain compliance with the NAAQS for PM-10 with a 

substantial buffer in the event that the measures do not fully achieve the same level of 

PM-10 reduction going forward that has been achieved to date. The Plan indicates a 

future PM-10 level of 105 μg/m3 on a high road dust day (Table ES-4). This is 45 μg/m3

(30%) lower than the NAAQS of 150 μg/m3. 

The success of the existing control measures demonstrates that PM-10 levels have been 

reduced and will be reduced to a sufficient degree that contingency measures are not 

required. Nonetheless, additional measures have been incorporated into the AQMP to 

assist in further reductions of PM-10 levels with the goal of improved compliance with the 

California Ambient Air Quality Standard for PM-10. These measures include amending 

the Town of Mammoth Lakes Particulate Emissions Regulations to match GBUAPCD 

Rule 431, requiring all wood burning fireplaces and stoves, whether certified or not, to 

comply with no-burn days. 

The District will continue to maintain monitoring network integrity and, with the Town, will 

continue to monitor PM-10 in order to (1) verify the attainment status of the area as 

required by the US EPA (CAA Sec 175A, Calcagni, 1992) and (2) to implement the no 

burn day program, which relies on daily PM-10 monitoring. Although the intention is to 

continue monitoring indefinitely in order to implement the no burn day program, the Town 

and the District will commit to continue ambient PM-10 monitoring for at least 20 years 

following the redesignation of the area to attainment in order to comply with CAA Sec 

175A(b). 

The US EPA requires areas to track the progress of maintenance plans. (Calcagni, 1992) 

This would include updating the emissions inventory, assessing air quality trends and reevaluating modeling assumptions. The Town and the District will commit to submitting 

progress reports every third year starting in 2017 to track the progress of the maintenance 

plan. Progress reports will include an update on PM-10 air quality, a revised peak daily 

emission inventory for all sources in the planning area, a reassessment of the modeled 

air quality trend using the modeling assumptions in Section 8.3, and additional information 

that may be relevant to the air quality program in the Town. 

Section 175A of the Clean Air Act requires that maintenance plans include contingency 

provisions to assure that any air quality violation of the NAAQS that occurs after the 

redesignation of the area as attainment is promptly corrected. As per guidance provided 

by the US EPA, (Calcagni, 1992) the maintenance plan should identify the measures to 

be adopted and a schedule and procedures for action. This plan takes a two-tiered 

approach to address contingency measures; 1) to adopt additional measures with this 

plan to strengthen existing rules and to prevent NAAQS violations, and 2) to commit to 

adopt additional measures if the standard is violated in the future. 

 

If a monitored violation of the federal PM-10 standard occurs in the Town of Mammoth 

Lakes or the surrounding nonattainment area, the Town and the District will investigate 
Mammoth Lakes AQMP 

xiv 

the cause of the violation(s). Violation days would exclude days that are considered to 

be exceptional events, such as high PM-10 due to smoke from wildfires as provided for 

under the EPA’s Exceptional Event Rule. (72 FR 13560) 

Within 18 months of the violation, the Town and District will adopt additional control 

measures needed to meet the PM-10 NAAQS. Depending on the cause of the violation 

these control measures may include the following: 

 Reducing the no burn day trigger threshold from a target of 130 to 100 μg/m3, if 

residential wood smoke is found to be a significant contributor. 

 Implementing measures to reduce the use of volcanic cinders or to improve street 

clean up procedures on roadways during the winter, if road dust is found to be a 

significant contributor. 

Redesignation Request 

States may ask U.S. EPA to redesignate an area “attainment” if: 

 the area has monitored attainment of the air quality standard; 

 the area has a fully approved State Implementation Plan; 

 U.S. EPA has determined that the improvement in air quality is due to permanent 

and enforceable reductions in emissions; 

 the state has submitted, and U.S. EPA has approved, a maintenance plan for the 

area; and, 

 the area has met all other applicable federal CAA requirements. 

As described in Chapter 8, the Town of Mammoth Lakes last exceeded the federal PM10 24-hour standard in 1993. Attainment of the PM-10 standard is a direct result of the 

implementation of control measures by the Town as described in the 1990 Air Quality 

Management Plan. 

The daily ambient PM-10 monitoring data collected by the Great Basin Unified Air 

Pollution Control District in Mammoth Lakes demonstrates that no more than 1.0 

statistical exceedances of the NAAQS have occurred over the last three years as is 

required to demonstrate attainment of the federal standard. In fact, the data show that 

there have been no exceedances of the federal PM-10 standard during the last 19 years. 

Applying a proportional roll back analysis to the PM-10 present and future emissions this 

document demonstrates that no more than 1.0 exceedances per year would be expected 

through the next 20 year planning period and beyond. With continued implementation of 

the control measures, attainment will be maintained. 

The District finds that the Mammoth Lakes PM-10 Planning Area has attained the federal 

PM-10 standard and requests the California Air Resources Board recommend to the US 

Environmental Protection Agency that the area be redesignated from nonattainment to 

attainment with the federal PM-10 standard. 
Mammoth Lakes AQMP 

1 

1. Introduction 

1.1 BACKGROUND 

Twenty five years ago, the normally clean air in Mammoth Lakes was often polluted during 

the winter by wood smoke and dust. Smoke from wood stoves and fireplaces and dust 

from volcanic cinders used on roadways for traction control contributed to high particulate 

matter levels that caused violations of air quality standards. Air pollution obscured 

visibility in what should be an idyllic mountain setting, and it posed a health hazard to the 

public, especially to those that might be sensitive to particulate matter air pollution, such 

as children, the elderly, and people with existing heart or lung problems. Poor air quality 

was usually associated with calm winter days when there was little wind to blow the 

pollution away. Due to these conditions, federal air quality standards for particulate matter 

were violated on about 11 days each year, and the US Environmental Protection Agency 

(EPA) required an air pollution control plan for the Town of Mammoth Lakes. 

In 1987, the EPA identified the Mammoth Lakes area as having a high probability of 

violating the federal PM-10 standard (52 FR 29384). This designation was based on 

measurements of PM-10 that exceeded the standard. As a result of this Group I 

classification, a PM-10 State Implementation Plan (SIP) for the Mammoth Lakes area was 

required under the Federal Clean Air Act. The 1990 Air Quality Management Plan 

(AQMP) for the Town of Mammoth Lakes was developed to satisfy this requirement for a 

PM-10 SIP. 

Implementation of the measures included in the 1990 AQMP, resulted in the PM-10 levels 

in Mammoth Lakes dropping significantly. The result has been no exceedences of the 

federal standard since 1994. 

This Air Quality Maintenance Plan is an update to the 1990 Air Quality Management Plan 

for the Town of Mammoth Lakes. This plan reviews the background of the 1990 plan, the 

measures implemented as a result of that plan and their effectiveness, and changes to 

clean air regulations since the adoption of the Plan. This plan then recommends 

maintenance measures and requests that the Town of Mammoth Lakes be redesignated 

as attainment for the federal PM-10 standard. 

1.2 PM STANDARDS AND HEALTH EFFECTS 

PM-10 stands for particulate matter less than 10 microns in diameter. For comparison a 

human hair is about 70 microns in diameter. The National Ambient Air Quality Standard 

(NAAQS, or federal standard) for PM-10 was set July 1, 1987 at 150 micrograms per 

cubic meter (μg/m3) for the 24 hour standard. Levels for the PM-10 standard were 

selected to help the people who may be sensitive to exposure to airborne particulate 

matter. (OAQPS 2005) 

Particles less than 10 microns are usually inhaled and retained in the deepest part of the 

lungs. Children, the elderly, those with cardiovascular and respiratory problems, and 

those with influenza are especially susceptible to increased respiratory problems and 
Mammoth Lakes AQMP 

2 

illnesses due to exposure to high levels of PM-10. In addition, some PM-10 sources emit 

particles which contain toxic and carcinogenic compounds. 

Wood smoke, which is a major contributor to the high PM-10 levels of Mammoth Lakes, 

includes several air pollutants aside from PM-10 that contribute to the health effects 

problems. These are carbon monoxide, hydrocarbons and polycyclic aromatic 

hydrocarbons (PAH’s). Wood burning is a major source of PAH’s which has been 

identified as a class of compounds containing carcinogens (Davis and Read 1989). 

Particulate matter from wood smoke is largely composed of particles less than 2.5 

microns or PM-2.5. Due to the smaller size of smoke particles, exposure to PM-2.5 poses 

additional health risks to sensitive populations at lower concentrations than PM-10. 

1.3 AREA DESCRIPTION AND POPULATION 

The Town of Mammoth Lakes is located on the eastern slopes of the Sierra Nevada 

mountains at an elevation of 7,861 feet (2,396 m). Figure 1-1 shows the relative location 

of Mammoth Lakes. The Town was incorporated in 1984 and has grown from a 

permanent population of 4,785 in 1990 to 8,234 in 2010. Included in the Town boundaries 

is Mammoth Mountain ski area which attracts about 1.2 to 1.5 million skiers each winter. 

During major winter weekends there are about 35,000 people in Mammoth Lakes. It is 

anticipated this figure will grow to about 45,000 to 52,000 people by 2025 (Town of 

Mammoth Lakes, 2007a). 

Most homes and rental units in Mammoth Lakes contain woodstoves or fireplaces. 

Temperature inversions during the winter season cause a buildup of wood smoke in the 

lower elevations of the town. In addition to wood smoke, particulates generated from resuspended road dust and cinders that are applied to roadways during snowstorms can 

add significantly to PM-10 levels after these roads dry. The combination of road dust, 

wood smoke and meteorological stagnations, especially during peak periods of the ski 

season, has been associated with elevated PM-10 in Mammoth Lakes. 

1.4 BOUNDARIES OF THE PM-10 PLANNING AREA 

The U.S. Environmental Protection Agency identified the boundaries in Figure 1-2 as the 

initial designation for the Group I area or Planning Area. Through the course of the 

development of this document it was determined that the boundaries for the Town of 

Mammoth Lakes are more appropriate for the PM-10 Planning Area. This is justified by 

the lack of significant sources outside the Town boundaries. The shrinking of the planning 

area boundaries is not expected to have any significant effects on the adequacy of the 

SIP, since all the sources affected by the controls discussed in the SIP are inside the 

Town boundaries. 

 
Mammoth Lakes AQMP 

3 

Figure 1-1 Mono County, CA boundary and Mammoth Lakes vicinity. 
Mammoth Lakes AQMP 

4 

Figure 1-2 Mammoth Lakes Planning Area 
Mammoth Lakes AQMP 

5 

1.5 NEED FOR PLAN UPDATE 

In the 23 years since the adoption of the 1990 AQMP, the conditions pertaining to PM10 in Mammoth Lakes have changed significantly. This AQMP update addresses 

improved air quality in Mammoth Lakes; a revised General Plan for the Town of 

Mammoth Lakes; updated traffic modeling for the Town; an updated chemical mass 

balance study; revisions to the GBUAPCD Rules; and a request to have Mammoth 

Lakes redesignated as attainment for the federal PM-10 standard. 

1.5.1 Redesignation Requirements 

As a result of the significant air quality improvements following the implementation of 

the 1990 AQMP, Mammoth Lakes has not exceeded the federal standard for PM-10 

since 1994. With that success and the projected maintenance of air quality through 

adopted implementation measures, the Great Basin Unified Air Pollution Control 

District recommends that the CARB request that the EPA redesignate the Mammoth 

Lakes Planning Area to attainment. To be formally redesignated to attainment, the 

AQMP must demonstrate that: 

 The area has monitored attainment of the air quality standard; 

 The area has a fully approved State Implementation Plan; 

 The U.S. EPA has determined that the improvement in air quality is due to 

permanent and enforceable reductions in emissions; and 

 The state has submitted, and U.S. EPA has approved, a maintenance plan for 

the area. 

This update to the AQMP fulfills the requirements for redesignation. It incorporates 

the latest monitoring data from Mammoth Lakes showing that the Planning Area has 

attained the federal standard for PM-10. The Plan includes existing and proposed 

measures to maintain PM-10 levels below the federal NAAQS for the next 10 years 

and beyond. It incorporates an updated vehicle miles traveled (VMT) analysis, 

residential wood combustion device inventory, and revised community growth 

estimates from the 2007 Town of Mammoth Lakes General Plan. 
Mammoth Lakes AQMP 

6 

2. 1990 AQMP Summary 

2.1 DEVELOPMENT OF THE PLAN 

In 1987, the Town of Mammoth Lakes (Town) and the Great Basin Unified Air Pollution 

Control District (APCD) began developing a plan to reduce air pollution from fireplaces, 

woodstoves and dust caused by vehicles traveling on roads treated with volcanic cinders. 

The cinders were applied as an anti-skid material on roads during the winter and became 

airborne when the roads dried. The Town and the APCD worked with an ad hoc advisory 

committee representing local businesses, government agencies, health professionals 

and the general public to develop an air pollution control strategy. In 1990, this strategy 

was adopted as the Air Quality Management Plan (AQMP) for the Town of Mammoth 

Lakes. (Ono, et al., 1990) 

2.2 PLAN SUMMARY 

The AQMP relied on controlling wood smoke by replacing old wood stoves and fireplaces 

with cleaner wood burning appliances and curtailing wood burning on days that could 

violate the air quality standard. The Town reduced road dust emissions by using vacuum 

street sweepers to remove volcanic cinders soon after the roads dried and through 

promotion of increased transit usage. After adoption of the AQMP, monitored air pollution 

levels dropped significantly in Mammoth Lakes. 

The federal air quality standard for particulate matter is measured as PM-10 and PM-2.5, 

which stands for particulate matter less than 10 microns and 2.5 microns in diameter. 

The AQMP was based on reducing PM-10 emissions to meet the federal 24-hour average 

standard of 150 μg/m3. After the adoption of the AQMP in 1990, three exceedances of 

the federal PM-10 standard were monitored in the first year. Following that only one 

exceedance of the federal PM-10 standard was measured in 1991 and none were 

measured in 1992 and 1993. The last measured exceedance of the federal PM-10 

standard was monitored in 1994 (Table 2-1). 

Although the federal standard for PM-10 is currently being met, the more stringent 

California Ambient Air Quality Standard for PM-10 is still violated in the Town. The state 

24-hour average PM-10 standard is set at 50 μg/m3. Violations of the state standard have 

declined significantly since the adoption of the AQMP. As seen in Table 2-1, the number 

of monitored state standard violations was as high as 56 days in 1993. Over the last four 

years (2009-12) the number of state standard violations has ranged from four to 31 per 

year. 

At the time of adoption, the Town’s wood smoke and street sweeping control measures 

were the most stringent in the state. Since then, other areas have recognized the success 

of these measures and adopted similar control requirements for their areas. 

PM-10 emission projections and air quality monitoring show that the adopted wood smoke 

and road dust control measures succeeded in bringing the area into attainment with the 
Mammoth Lakes AQMP 

7 

federal PM-10 standard. Additional measures; however, will be needed to meet the state 

PM-10 standard. 

2.3 1990 CONTROL MEASURES 

2.3.1 Wood Smoke 

The 1990 Air Quality Management Plan relied on regulations for reducing PM-10 

emissions from wood smoke by limiting the number of wood burning appliances to one 

EPA certified woodstove per dwelling, requiring change-outs of non-EPA certified 

woodstoves and fireplaces upon resale of a home or dwelling and by instituting no-burn 

days on days that could violate the standard. The plan also included a public awareness 

program to encourage compliance with no-burn days. 

2.3.2 Wood Stove & Fireplace Change-outs 

In 1990, it was estimated that there were 5,946 woodstoves and fireplaces with less than 

1% of those being EPA-certified. To reduce wood smoke emissions, it was required that 

upon resale of a property any fireplace or non-EPA certified woodstove must be replaced 

with an EPA Phase II certified wood stove or a pellet stove. As an alternative to 

replacement, non-EPA certified wood burning appliances can also be removed or 

otherwise rendered inoperable. . 

2.3.3 Public Awareness Program. 

The Town has a public awareness program to educate residents and visitors about the 

air pollution problem in Mammoth Lakes. During the winter, daily weather reports include 

a “red-yellow-green” burn day call to alert people to the no-burn day status for residential 

wood burning. Because about 80% of the people in town during the winter are visitors, 

they must be educated on a daily basis about the air pollution problem and the no-burn 

day program. The Town's public awareness program includes: 

 Daily radio and TV announcements of red, yellow or green burn days, including a 

no-burn day ticker on the local public access TV channel, 

 Newspaper advertisements with the (760) 934-1010 burn day status phone 

number, 

 Newspaper articles about local air pollution and no-burn days, 

 Tent cards and pamphlets for visitor rooms providing burning information, and 

 Woodburning handbooks published by the California Air Resources Board. 

2.3.4 No-burn Days. 

No-burn days are called when a meteorological inversion and calm wind conditions could 

persist for a given day. The calm air prevents the dilution and transport of air pollutants 

and allows PM-10 concentrations to build up in the evening from about 4:00 PM to 

midnight and then again in the morning from 6:00 to 10:00 AM. When calm weather is 

predicted, the Town's meteorologist may call a mandatory or a voluntary no-burn day 
Mammoth Lakes AQMP 

8 

based on the strength of the forecasted inversion and the population in town. The 

meteorologist indicates if it is a red, yellow or green burn day to let the public know if it is 

mandatory or voluntary no-burn day, or if it is okay to burn. Under the 1990 AQMP, 

appliances meeting the emissions requirements of the EPA were exempted from the noburn days. Because 85% to 90% of the woodstoves and fireplaces are now EPA certified 

appliances, pellet stoves, or gas appliances, only a small percentage of the wood burning 

appliances are now subject to the no burn days. To continue to achieve emission 

reductions, this updated AQMP removes the no burn day exemption for EPA certified 

appliances. 

2.3.5 Traffic Related Control Measures 

After winter storms, volcanic cinders are spread on the roadways in town to provide 

additional traction and prevent vehicles from sliding on the icy roads. These cinders are 

crushed into ever smaller pieces by passing vehicles. When the roads dry, vehicles kick 

up fine dust from the roadway. In the 1990 AQMP, road dust was found to contribute up 

to 44% of the PM-10 on days that violated the federal air quality standard. The AQMP 

relies on vacuum street sweeping to remove the cinders after the roads dry and a limit on 

traffic volume to prevent the problem from growing with the population. The traffic volume 

limit was set at 106,600 vehicle miles traveled on any day and is regulated through the 

approval of new developments by the Town. 

2.3.5.1 Vacuum Street Sweeping.

 

The Public Works Director is directed by the regulations to undertake a vacuum street 

sweeping program to reduce PM-10 emissions resulting from excessive accumulations 

of cinders and dirt. This program has been running continuously since the adoption of 

the 1990 AQMP. 

2.3.5.2 Traffic Volume. 

The traffic volume limit in the 1990 AQMP was based on the PM-10 impact in 1990 when 

daily peak traffic volume was estimated at 66,275 vehicle miles traveled (VMT). The Final 

Program Environmental Impact Report (FPEIR) to support the 2007 Town of Mammoth 

Lakes General Plan Update estimates the 2004 peak traffic volume at 74,051 VMT for 

2004. The FPEIR indicated that unconstrained vehicle traffic could reach 128,270 VMT 

on peak visitor days by 2024. However, it concluded that through transportation 

mitigation measures included in the General Plan FPEIR, VMT will not exceed the 

106,600 VMT limit (Town of Mammoth Lakes, 2007b). 

Since adoption of the General Plan, the Town has developed a revised traffic model. This 

model includes additional roadway segments and as a result, shows a higher current and 

future VMT. This AQMP relies on the updated model and the revised VMT numbers. 

Currently, District rule 431 and Town Ordinance (8.30.110) prohibits the approval of any 

new development or project that would cause projected vehicle traffic to exceed 106,600 

VMT. The Town’s revised traffic model combined with the updated Chemical Mass 

Balance study will lead to amendments to these regulations. If and when it can be reliably 
Mammoth Lakes AQMP 

9 

determined that a higher VMT level may be sustained without exceeding the NAAQS, due 

to restrictions from other emission sources or to refined analytic inputs and/or other 

methodologies, then the appropriate amendments to the Town’s Municipal Code and 

AQMP may be considered (Town of Mammoth Lakes, 2007b). 

2.4 AIR QUALITY IMPACTS 

The 1990 AQMP is based on reducing PM-10 emissions to meet the federal standard of 

150 μg/m3 for a 24-hour period. After its adoption, three exceedances of the federal PM10 standard were monitored in the first year. Following that one exceedance of the federal 

PM-10 standard was measured in 1991 and none were measured in 1992 and 1993. The 

last measured exceedance of the federal PM-10 standard was monitored in 1994. Table 

2-1 shows the actual number of monitored exceedances and the expected number of 

exceedances based on the proportion of sample days each year. Note that an expected 

number of exceedances is not calculated for years when the data capture rate is less than 

75% for any quarter. (US EPA, 2014)

Although the federal standard for PM-10 is currently being met, the more stringent 

California Ambient Air Quality Standard for PM-10 (50 μg/m3) is still violated in Mammoth 

Lakes. The number of monitored state standard violations was as high as 88 in 1990, the 

year the plan was adopted, but has declined significantly since then. Over the last four 

years of daily monitoring in the Mammoth Lakes (2009-12) the number of state PM-10 

standard violations has ranged from 5 to 46 per year. (US EPA, 2014)

2.4.1 Projected PM-10 Impacts 

The PM-10 analysis in the 1990 AQMP showed that two scenarios existed that could 

cause violations of the federal standard. One violation day was dominated by PM-10 

from wood smoke (95%), with 5% from road dust, while another violation day was 66% 

wood smoke and 44% road dust. The control strategy in the plan was designed to bring 

concentrations on both "design days" down to levels that would meet the standard. 

Chapter 6 has an updated analysis of PM-10 and PM-2.5 filter samples collected from 

2003 through 2011 that shows high PM days are still associated with wood smoke and 

road dust dominated days, but at concentrations that are below the federal standards.

2.5 1990 AQMP Succeeds in Achieving Federal Attainment 

PM-10 emission projections and air quality monitoring show that wood smoke and road 

dust control measures have succeeded in bringing the Town into attainment with the 

federal PM-10 standard. Furthermore, as discussed in Chapter 8, the currently adopted 

control measures are expected to be sufficient to maintain compliance with the federal 

standard into the future. The Town has been successful in meeting the federal PM-10 

standard; however, additional control measures will be needed to meet the more stringent 

state PM-10 standard. 

 
Mammoth Lakes AQMP 

10 

Table 2-1. Summary of PM-10 air quality standard violations for the Town of Mammoth Lak

Year 

Max 

PM-10 

(μg/m3) 

Number of 

Federal 

Exceedances 

(>150 μg/m3) 

Number of 

State 

Exceedances 

(>50 μg/m3) 

Number of 

Valid 

Sample 

Days 

Data 

Capture 

OK? 

Expected # 

of Federal 

Exceedances 

(>150 μg/m3) 

Expec

of St

Exceed

(>50 μg

1990 161 2 14 58 Y 12.6 88.1991 134 0 9 48 N 0 68.1992 138 0 14 60 Y 0 85.1993 178 1 10 59 Y 6.2 61.1994 92 0 10 58 Y 0 62.1995 122 0 6 58 Y 0 37.1996 74 0 4 51 Y 0 28.1997 112 0 6 59 Y 0 37.1998 106 0 3 37 N 0 29.

1999* 0 N 2000* 70 0 3 18 N 0 60.

2001 134 0 4 48 Y 0 30.2002 129 0 4 17 N 0 85.2003 74 0 3 86 N 0 12.2004 86 0 8 109 Y 0 26.2005 85 0 8 92 N 0 31.2006 78 0 7 110 Y 0 23.2007 67 0 5 115 Y 0 15.2008 138 0 17 164 Y 0 37.2009 118 0 26 365 Y 0 26 2010 104 0 44 348 Y 0 46.2011 128 0 38 360 Y 0 38.2012 56 0 5 342 Y 0 5.3 

*PM10 monitor site closed for building renovation. AQS data for 1990 - 2001 is 1 in 6 day PM-10 P2002 - Oct. 24, 2008 is 1 in 3 day PM-10 Partisol; Oct. 24, 2008 - 2012 is both 1 in 3 day Partisol anFDMS TEOM. Source: US EPA Air Quality System (US EPA, 2014)
Mammoth Lakes AQMP 

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3. Federal and State Air Quality Standards for Particulate Matter 

3.1 FEDERAL PM-10 AND PM-2.5 STANDARDS 

On July 1, 1987, EPA revised the NAAQS for particulate matter with a new PM-10 

indicator as the basis for the standards (52 FR 24634). The level of the federal PM-10 

standard was set at 150 μg/m3 for a 24-hour average concentration and 50 μg/m3 for an 

annual average concentration. The new PM-10 standard replaced the previous standard 

for total suspended particulates (TSP less than 30 microns in diameter). The change from 

the TSP standard to PM-10 was in response to updated information from health officials 

indicating adverse human health effects from the smaller PM-10 penetrating deep into 

the lower respiratory tract and lung tissue. 

In 1997, EPA retained the existing 24-hour and annual PM-10 standard after reviewing 

the PM NAAQS. However, EPA expanded the PM NAAQS by adding a new PM-2.5 

standard based on updated human health research impacts from fine-sized particles 2.5 

microns or less in diameter. The PM-2.5 standard was set at 65 μg/m3 for a 24-hour 

average concentration and 15 μg/m3 for an annual average concentration (62 FR 38652). 

In 2006, EPA reaffirmed the 24-hour PM-10 standard after reviewing the air quality criteria 

and PM NAAQS again. EPA concluded that the research “evidence continues to support 

a 24-hour averaging time for a coarse particulate standard, based primarily on evidence 

suggestive of associations between short-term (24-hour) exposure and morbidity effects 

and, to a lesser degree, mortality” (71 FR 61144-64233). However, effective December 

18, 2006, EPA revoked the annual average PM-10 standard based on the more recent 

studies indicating long-term health impacts were mainly related to PM-2.5 exposure. EPA 

also tightened the 24-hour average PM-2.5 standard by lowering the concentration level 

from 65 μg/m3 to 35 μg/m3 (71 FR 61144-64233). 

Table 3-1. National Ambient Air Quality Standard for Particulates* 

Pollutant Primary/ 

Secondary 

Averaging 

Time Level Form 

Particle 

Pollution 

Dec 14, 2012 

PM-2.5 

primary Annual 12 μg/m3 annual mean, averaged 

over 3 years 

secondary Annual 15 μg/m3 annual mean, averaged 

over 3 years 

primary and 

secondary 24-hour 35 μg/m3 98th percentile, averaged 

over 3 years 

PM-10 primary and 

secondary 24-hour 150 μg/m3

Not to be exceeded more 

than once per year on 

average over 3 years 

*U.S. EPA 2013 
Mammoth Lakes AQMP 

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3.2 CALIFORNIA CLEAN AIR ACT REQUIREMENTS 

The California Air Resources Board adopted new state PM standards in June of 2002, 

responding to requirements of the Children's Environmental Health Protection Act. This 

Act requires the evaluation of all health-based ambient air quality standards to determine 

if the standards adequately protect human health, particularly that of infants and children. 

The subsequent review of the PM standards resulted in the recommendation of more 

health-protective ambient air quality standards for PM-10 and a new standard for PM-2.5. 

The new California PM standards became effective in 2003. 

Table 3-2. California Ambient Air Quality Standard for Particulates*

Pollutant Annual Average 24-Hour Average 

PM-10 20 μg/m3 50 μg/m3

PM-2.5 12 μg/m3 - 

*California Air Resources Board, 2013 

3.3 MAMMOTH LAKES PM COMPLIANCE 

As discussed in the following section, air monitoring data for Mammoth Lakes shows that 

the area has been in compliance with the federal PM-10 standard since 1993, when the 

number of standard exceedances was less than 1.0 per year averaged over three years 

This compliance status has been maintained continuously since 1993. However, the area 

continues to violate the more stringent State PM-10 standard. 

The Town of Mammoth Lakes is designated as attainment/unclassified for the federal PM2.5 standard and attainment for the state PM-2.5 standard. These designations also 

apply to the larger Great Basin Valleys Air Basin, which includes all of Mono, Inyo and 

Alpine Counties in California. (CARB, 2013) 
Mammoth Lakes AQMP 

13 

4. Air Quality Data 

The air quality data section covers the ambient particulate matter monitoring and 

meteorological data. This information is incorporated into the air quality modeling and 

control strategy analysis along with emissions inventory data that is covered in 

subsequent chapters of this Plan. 

4.1 PM-10 AND METEOROLOGICAL MONITORING SITE 

Airborne pollutant and meteorological monitoring are conducted at the Gateway (also 

known as the Rite Aid/Do-It Yourself) shopping center in Mammoth Lakes. Four types of 

PM-10 monitors have been used at the monitoring site; a Size Selective Inlet (SSI) and a 

dichotomous sampler (dichot), which both measure once every six days, PM-10 Partisol, 

which measures once every 3 days, and a TEOM (Tapered Element Oscillating 

Microbalance) which provides daily and hourly PM-10 concentrations. The TEOM was 

often operated with a co-located PM-10 Partisol. Although each monitor is a U.S. EPA 

approved reference or equivalent method sampler, PM-10 concentration measurements 

can vary. Due to the 50oC inlet temperature of the TEOM, particulate matter from wood 

smoke can volatize and cause the mass measurement to be low as compared to the other 

PM-10 monitors. TEOM values during periods of heavy wood smoke can be estimated 

by multiplying the TEOM measured value by 1.8. In 2006, the TEOM was modified to an 

FDMS (Filter Dynamics Measurement System) TEOM. The FDMS TEOM can account 

for particulate matter volatilization and provide the correct mass. However, due to 

operational problems with the FDMS it was replaced with a regular TEOM in 2007. A 

new FDMS TEOM was installed in November 2008. PM-10 monitor data is not available 

for 1999 and 2000 because the building that housed the monitor was being renovated. 

The type of PM-10 monitor used in each year is identified in Table 2-1. 

4.2 PM-10 AND DATA SUMMARY 

Table 2-1 shows that the Mammoth Lakes Planning Area has not exceeded the federal 

24-hour NAAQS since 1994. From 1990 through 1994, five exceedences were recorded. 

Because of the sampling interval, this equates to an expected total of 21 exceedences 

with 19 occurring in 1990, prior to the adoption and implementation of the 1990 AQMP. 

Since 1990, only two exceedances of the 24-hour NAAQS were recorded – one in 1991 

and one in 1994. 

Although the federal standard for PM-10 is currently being met, the more stringent 

California Ambient Air Quality Standard for PM-10 is still violated in Mammoth Lakes. The 

state 24-hour average PM-10 standard is set at 50 μg/m3. As seen in Table 2-1, the 

number of monitored state standard violations was as high as 88 days in 1990, the year 

the AQMP was adopted. Violations of the state standard have declined since then. Over 

the last three years (2010-12), the average number of state PM-10 violations was around 

30 per year. 
Mammoth Lakes AQMP 

14 

4.3 PRE AQMP PM-10 VIOLATIONS 

Prior to the adoption of the 1990 AQMP, violations of the 150 μg/m3 24-hour National 

Ambient Air Quality Standard (NAAQS) for PM-10 were measured on seven occasions 

the Gateway Center monitoring site. Because the samples were being measured on a 

one every six day cycle, the actual number of violations was estimated to be higher. 

These violations occurred during the winter season 1985-86 through 1988-89. The 

highest measured PM-10 concentration was 210 μg/m3. Since 1995, there have been no 

violations of the 24-hour NAAQS and the highest recorded value was 136 μg/m3. 

Monitoring since 1991 has been daily. 

The measured exceedances evaluated in the 1990 AQMP occurred during periods of low 

average wind speed, less than 3.5 mph. Violations primarily occurred on weekends 

(Friday, Saturday, or Sunday) or during the holiday period around Christmas and New 

Year’s. Data analyzed for this Plan follow that same trend. 

4.4 PARTICULATE MATTER TREND 

The particulate matter trend has generally shown air quality improvement since the 

adoption of the 1990 AQMP. Figure 4-1 shows that the trend of quarterly average PM10 concentrations decreased following the adoption of the AQMP with a leveling over the 

last 10 years. Figure 4-2, shows that for the winter months (November-March) the 

average winter and peak winter concentrations were generally downward after control 

measures were implemented, but have started to increase since 2008. 

4.5 PM-2.5 Data 

PM-2.5 monitoring at the Gateway Center shows that since 2000, Mammoth Lakes has 

met the 24-hour and Annual NAAQS for PM-2.5 (35 and 12 μg/m3, respectively). The 

98th percentile and annual average PM-2.5 levels are shown in Table 4-1. 

Table 4-1 PM-2.5 Monitoring Results 

 98th Percentile 

Concentration 

(μg/m3) 

Annual Average 

2000 30.8 N/A 

2001 36.2 N/A 

2002 N/A N/A 

2003 30.5 7.48 

2004 24.7 N/A 

2005 26.9 N/A 
Mammoth Lakes AQMP 

15 

0

20406080

100120140160180

J-90 J-91 J-92 J-93 J-94 J-95 J-96 J-97 J-98 J-99 J-00 J-01 J-02 J-03 J-04 J-05 J-06 J-07 J-08 J-09 J-10 J-11 

PM-10 (micrograms per cubic meter)

Year

Figure 4-1, Mammoth Lakes PM-10

Quarterly Peaks & Averages (1990-2013)

Quarterly PM-10 AverageHighest Daily PM-10 During QuartQuarterly PM-10 TrendHighest Daily PM-10 Trend
Mammoth Lakes AQMP 

16 

0

20406080

100120140160180

PM‐10 (μg/m3)

Figure 4‐2, Mammoth Lakes PM‐10

Winter Season Peaks & Averages (1990‐2013)

Max Daily PM‐10 (NoAverage PM‐10 (NoveWinter Season Max DWinter Season Averag
Mammoth Lakes AQMP 

17 

5. Emissions Inventory 

The emissions inventory section covers the PM-10 emission estimates for residential 

wood combustion (RWC), resuspended road dust and cinders, mobile source tailpipe 

emissions and point sources. The methodology and data used to determine emissions is 

discussed for each source type. Because Mammoth Lakes exceeds the state 24-hour 

PM-10 standard, the emissions inventory is estimated for a peak 24-hour period. These 

emission estimates consider the large influx of visitors to Mammoth Lakes during the 

winter ski season. 

Road dust and vehicle emissions are provided separately for traffic within the boundaries 

of the Town of Mammoth Lakes and for highways 203 and US 395 that are located outside 

of the Town boundaries. Although vehicle-related emissions from roadways located 

outside the town are generated within the nonattainment area boundary, PM-10 

emissions from areas east of the Town do not contribute to the air quality problem in the 

Town. An analysis of wind speeds and directions on the high PM-10 days used for the 

receptor modeling analysis in Chapter 6 shows that 98% of the hourly winds were low (< 

2 m/s) and primarily from the west, which would push emissions from areas east of the 

Town away from the monitor location that was used for the receptor modeling analysis. 

Therefore, PM-10 emissions from areas outside of the Town boundaries are not 

considered relevant to the maintenance demonstration in Chapter 8 and were separated 

from the in-town emission estimates. The areas outside of the Town boundaries are also 

largely uninhabited public lands, therefore there is an absence of residences that would 

contribute wood smoke emissions to the emissions inventory. The in-town emissions 

inventory is considered to be the appropriate inventory for sources that are most likely to 

contribute to high PM-10 concentrations at the monitor site. 

The peak daily emissions inventory for the Mammoth Lakes Planning Area does not 

include emissions from unpaved road dust or construction activities. Emissions from 

these sources are seasonal and are absent during the winter when high PM10 

concentrations occur. Unpaved roads are either snow covered or muddy during the winter 

season and outdoor building and roadway construction activities generally do not take 

place until around May when the weather warms. 

5.1 WOODSTOVES AND FIREPLACES 

Emission rates for woodstoves and fireplaces are based on the type of wood burner, the 

type of wood burned, and the usage rate. The usage rate was based on the different 

burning habits of 1) condominium residents, 2) residents in single-family homes and 3) 

residents in apartments and mobile homes. Estimates for the annual and 24-hour PM-10 

emissions are calculated for wood burning. The annual emissions estimates, which are 

based on survey data, provide good information to improve the estimates for the peak 24-

hour period. 

5.2 NUMBER OF WOODSTOVES AND FIREPLACES 

The numbers of woodstoves and fireplaces are based on the numbers of condominiums, 

single-family homes, apartments and mobile homes, and the estimated number of 
Mammoth Lakes AQMP 

18 

woodstoves and fireplaces in each type of housing. Table 5-1 shows the estimated 

number of wood burning units from surveys for each housing type in the Planning Area. 

Table 5-1, Residential Wood Burning Device Count 

 Condominium Single 

Family 

Mobile 

home/ 

apartment 

 Total 

Fireplaces 264 29 0 293 

Woodstoves (EPA) 3,289 1,290 193 4,772 

Pellet Stoves 297 87 16 400 

Woodstoves 

(uncert) 116 106 9 231 

 3,966 1,512 2,18 5,696 

Town of Mammoth Lakes 2013 

A partial survey being conducted by the Mammoth Lakes Fire Protection District 

indicates a higher number of unregulated fireplaces (437 versus 293). The AQMP uses 

the lower number to maintain a conservative estimate of control measure effectiveness. 

Replacement of a larger number of fireplaces would create a greater reduction in PM-10 

than forecast by this AQMP. 

5.3 WOODSTOVE AND FIREPLACE USAGE 

The estimate of the amount of wood burned is based on a survey conducted during the 

winter of 2012 – 2013. The survey was sent to over 6,000 property owners and 4,500 

Post Office Box holders in Mammoth Lakes. 574 of the surveys were returned. Table 

5.2 summarizes the average amount of wood burned during the winter heating season in 

homes that have a wood burning device. 

Table 5-2, Amount of Wood Burned Annually in Homes With Wood Combustion Devices* 

Condominium Single-Family Mobile Home & Apartment 

Wood Burning Pellet Wood Burning Pellet Wood Burning Pellet 

 

1.4 cords 2000 lbs 2.4 cords 2400 lbs 2.3 cords 3000 lbs 

 

* Town of Mammoth Lakes 2013 

5.4 ANNUAL PM-10 EMISSIONS ESTIMATE FOR RWC DEVICES 

The emission estimates for RWC devices are based on the Environmental Protection 

Agency’s emission factors (US EPA AP 42). These emission factors are based on in situ 

tests of wood burning devices. Emission factors are given as grams of PM-10 per kilogram 
Mammoth Lakes AQMP 

19 

of dry wood burned. The emission factors are shown in Table 5-3. This table also 

summarizes the total emissions for each RWC device and housing type. Emissions for 

each RWC device are calculated using the following equation: 

PM-10 emissions/device = masswood x EF where: 

EF = 16.3 g/kg for uncertified woodstoves and fireplaces 

7.3 g/kg for EPA certified woodstoves 

2.1 g/kg for pellet stoves 

The cord density (800 kg per cord) is assumed for ponderosa pine which has a weight 

density of 10 kg/ft.3 A cord is approximately 80 ft.3 wood per cord (Davis and Read, 1989). 

Based on available data this is the best approximation for the Jeffrey and Lodgepole pine 

that is primarily burned in Mammoth Lakes. The total number of fireplaces and wood 

stoves is taken from Table 5-1, but this category is further broken down into uncertified, 

and EPA-certified based upon the Town of Mammoth Lakes building permit records for 

change outs and new construction. 

The annual emission estimate for PM-10 of 58,663 kg provides a good basis for 

comparison with a peak 24-hour emission estimate. The 24-hour emission estimate is 

critical since woodburning is a significant contributor to 24-hour PM-10 standard 

exceedances. 

5.5 24-HOUR PM-10 EMISSIONS ESTIMATE FOR RWC DEVICES 

To estimate the peak 24-hour emissions inventory for wood burning, it is assumed that 

all RWC devices are operating and burn an average of 2.4 ft.3 (or 24 kg) of wood per day. 

The amount of wood burned is based on the information provided through the Town’s 

2013 wood burning survey. Table 5-4 shows a summary of the estimates for the PM-10 

emissions from each type of wood burning device and from different housing types. With 

Table 5-3 Annual PM-10 Emission Estimates for Residential Wood Combustion 

 Condominiums Single Family 

Mobile Homes and 

Apartments 

RWC 

Device Emission 

Factor 

Wood/ 

Pellets Units 

PM-10 

kg 

Wood/ 

Pellets Units 

PM-10 

kg 

Wood/ 

Pellets Units 

PM-10 

kg 

Emissions 

Total (kg) 

Fireplace/ 

uncertified 

stove1

16.3 

1.17 

cords 380 5,798 2.4 cords 135 4,225 2.3 cords 9 270 10,292

Woodstove 

(EPA) 7.3 

1.4 

cords 3,289 26,891 2.4 cords 1,290 18,081 2.3 cords 193 2,592 47,564

Pellet 2.1 900 kg 297 561 1,090 kg 87 199 1,360 kg 16 46 806

 

 33,250 22,505 2,908 58,663
Mammoth Lakes AQMP 

20 

these assumptions, it is estimated that RWC devices contribute approximately 850 kg of 

PM-10 during a peak wood-burning day. 

Table 5-4 Peak 24-Hour Emission Estimates for Residential Wood Combustion 

 Condominiums Single Family 

Mobile Homes and 

Apartments 

RWC 

Device 

Emission 

Factor g/kg 

Fuel 

kg/day Units 

PM-10 

kg/day 

Fuel 

kg/day Units 

PM-10 

kg/day 

Fuel 

kg/day Units 

PM-10 

kg 

Emissions 

Total (kg) 

Fireplace/ 

uncertified 

stove 

16.3 19 380 118 27 135 59 19 9 3 180 

Woodstove 

(EPA) 7.3 19 3,289 456 19 1,290 179 19 193 27 662 

Pellet 2.1 9 297 6 11 87 2 14 16 0 8 

 

 579 240 30 850 

5.6 24-HOUR PM-10 EMISSIONS ESTIMATE FOR ROAD CINDERS 

The PM-10 emission estimate for resuspended road cinders is based on the AP-42 

methodology for estimating reentrained road dust emissions from paved roads (US EPA, 

Compilation of Air Pollution Emissions Factors, AP-42, 1995, updated). The formula for 

the emissions factor is: 

E = k(sL)0.91 x (W)1.02 where:

E = Emissions Factor 

k = Particle size multiplier 

sL = Road surface silt loading (g/m2) 

W = Average weight (tons) of the vehicles traveling the road 

The silt loading factor is taken from the calculations in the 1990 SIP and is estimated to 

be 8.7 g/m2, Statewide average vehicle weight is 2.4 tons (CARB, 1997), and the particle 

size multiplier from AP-42 is 1. (US EPA AP-42) This produces an emissions factor of 

17.49 grams of PM-10 per VMT. When multiplied by VMT per day, the result is the 

estimated mass of PM-10 per day from road dust (Table 5-5). Total peak day PM-10 

emissions from road dust is estimated at 2,522 kg/day based on peak traffic volume in 

2009 within the boundaries of the Town of Mammoth Lakes (see Figure 1.2). 

A separate PM10 emissions estimate is provided for road dust generated from traffic on 

US Highway 395 and the portion of Highway 203 that is outside the Town of Mammoth 

Lakes boundary. Although emissions in this area are generated within the larger 

nonattainment area boundary, the emissions from the areas to the east of the Town do 

not contribute to the air quality problem in the Town. An analysis of the wind speeds and 
Mammoth Lakes AQMP 

21 

directions on the high PM10 days used for the receptor modeling analysis shows that 

98% of the hourly winds were low (< 2 m/s) and primarily from the west, which would push 

emissions from these areas away from the Town. The planning area emissions inventory 

for road dust emissions were based on the winter 2008-09 vehicle traffic data for 

Highways 395 and 203 (Caltrans, 2014). This yielded an average of 53,319 vehicle miles 

travelled per day. Since road cinders are applied to Highways 203 and 395 in the winter 

the same emission factor used in the Town was applied. This yielded an estimate of 933 

kg/day for road dust emissions from areas outside of the Town. 

An annual emissions estimate for road dust was not calculated since it is not needed to 

evaluate compliance with the 24-hour PM-10 standard. 

*LSC, 2012a for In-town, and Caltrans, 2014 for Out-of-town 

5.7 VEHICLE TAILPIPE, TIRE AND BRAKE WEAR EMISSIONS 

PM-10 emissions from motor vehicle exhaust, tire and brake wear were determined by 

the California Air Resources Board using EMFAC2011 (CARB, 2014) . As discussed for 

road dust emissions, these emissions were estimated for vehicles operating within the 

Town of Mammoth Lakes boundary and those that were on Highways 203 and 395 in the 

portion of the nonattainment area that is outside of the town. Tailpipe, tire and brake wear 

were calculated to be 0.060 g/VMT in the Town and 0.046 g/VMT outside of the Town. 

Different emission factors were generated by EMFAC2011 to account for the vehicle 

speed ranges in-town (0-45 mph) as compared to the higher out-of-town vehicle speeds 

on highways 203 and US 395 (0-65 mph). Using the daily peak traffic volume of 144,192 

vehicle miles travelled for roadways in the Town and 53,319 for the highways 203 and 

395 for the remainder of the planning area, the vehicle emissions estimate is 9 kg/day in 

town and 2 kg/day out of town. 

An annual emissions estimate for tailpipe emissions was not calculated since it is not 

needed to evaluate compliance with the 24-hour PM-10 standard, 

 

Table 5-5. 24-Hour Road Dust Emissions 

Area 

Particle 

Size 

Multiplier 

Silt 

Loading 

Average 

Vehicle 

Weight 

Emissions 

Factor 

g/VMT 

2009 

VMT* 

Total 24-Hr 

PM-10 (kg) 

In-town 1 8.7 2.4 17.49 144,192 2,522 

Out-of-town 1 8.7 2.4 17.49 53,319 933 
Mammoth Lakes AQMP 

22 

5.8 INDUSTRIAL POINT SOURCES 

The Great Basin Unified Air Pollution Control District permits industrial sources within the 

Town of Mammoth Lakes. Those sources produce a total of 8 kg/day during the winter 

(Table 5-6). 

Table 5-6 Permitted Particulate Matter Sources Within the Mammoth Lakes AQMP 

Facility: equipment 

*Indicates facilities located in Town 

PM-2.5 PM-10 

Peak 

Winter 

Day 

(kg/day) 

Annual 

(kg/yr) 

Peak 

Winter 

Day 

(kg/day) 

Annual 

(kg/yr) 

7/11 Materials: concrete batch plant NA 1,998 NA 4,147 

CA Dept. Fish & Game - Hot Creek: 1 backup 

engine 0.04 1.6 0.04 1.6

Mammoth Hospital: 7 boilers, 1 fire & 2 backup 

engines 3.18 1,130 3.18 1,130

Mammoth Mountain*: 4 boilers, 19 backup engines 4.18 130 4.18 130

Mammoth Pacific: 2 engines 0.05 2.4 0.05 2.4

Marzano & Sons: concrete batch plant NA 1,801 NA 3,740

Monache Condominium*: 1 backup engine 0.05 2.6 0.05 2.6

Verizon (Mammoth H.S.)*: 1 backup engine 0.036 1.9 0.036 1.9

Verizon California - Mammoth Lakes*: 1 backup 

engine 0.03 1.4 0.03 1.4

Nonattainment Area Total 8 5,069 8 9,157

In-Town Total 4 136 4 136

GBUAPCD, 2014 

5.9 SUMMARY OF PM-10 EMISSIONS 

Woodburning and resuspended road cinders comprise almost all the PM-10 emissions 

during the winter. Motor vehicle exhaust, tire and brake wear, and industrial sources 

contribute approximately 1.4% of the area wide inventory. The current total PM-10 

emissions on a peak winter day in the Town of Mammoth Lakes and the larger 

nonattainment area are summarized in Table 5-7. 

Table 5-7. Summary of Peak 24 hour PM-10 Emissions (kg/day) 2012

Source 

In Town of 

Mammoth Lakes 

Nonattainment 

Area Total 

Residential Wood Combustion 850 850 

Road Dust/Cinders 2,522 3,455 

Tailpipe, Tire & Brake Wear 9 11 

Industrial Sources 4 8 

Total 3,385 4,324 
Mammoth Lakes AQMP 

23 

6. Receptor Modeling 

Receptor modeling is based on the idea that the total mass of the receptor (ambient 

sample) is a sum of the contributions from individual sources. Each source has a unique 

“fingerprint” of various proportions of chemical elements which comprise it. This 

fingerprint is expressed in fractions of the total (e.g., 20% potassium, 30% silica, 40% 

carbon, etc.). Knowing the composition of the ambient sample, and the compositions of 

the possible sources, one can estimate (using least-squares estimation) the fraction of 

each source contribution to the total ambient mass. This type of data manipulation is 

called receptor modeling because it bases its analysis of an air pollution scenario on 

information gathered at the receptor.

Another air pollution modeling method is dispersion modeling, which starts with precise 

information about source characteristics, terrain and meteorology to predict the pollutant 

concentrations at downwind receptor locations. Dispersion models are especially useful 

in predicting the effects of point source emissions, such as from industrial smokestacks. 

But their predictive accuracy is strained under low wind speed conditions and situations 

dominated by emissions from numerous small point sources, such as resuspended road 

dust and residential wood combustion, the precise conditions that characterize the air 

pollution problem in Mammoth Lakes. 

The receptor model does not directly consider the wind speed or source characteristics, 

other than chemical composition to determine the ambient impact of sources. So receptor 

modeling is particularly useful for performing the air quality analysis for the conditions that 

exist in Mammoth Lakes. 

6.1 AMBIENT PROFILES 

The Desert Research Institute of Reno, Nevada (DRI) conducted a chemical mass 

balance (CMB) study for Mammoth Lakes in 2013. DRI analyzed twelve PM-10 and four 

PM-2.5 filters (dates and concentrations shown in Tables 6-1 and 6-2) for elements and 

ions. The twelve PM-10 filters included the nine highest and 11th highest PM-10 filter 

concentration days since 2001, eight of which were since the start of 2008. The other 

four PM-10 filters are days for which high PM-10 and/or PM-2.5 concentrations were 

measured and both PM-10 and PM-2.5 filters are available for each day. Three of these 

four days had the highest PM-10 for days with PM-2.5 filters also. The other day had high 

PM-2.5 and high PM-2.5 to PM-10 ratios (indicative of large relative wood smoke impact). 

Because road dust is expected to be mostly in the larger particle sizes and wood smoke 

mostly in the smaller sizes (PM-2.5) analyzing both PM-10 and PM-2.5 for a few days 

provided supporting evidence for the estimates based on the PM-10 data. The full report 

is included as Appendix G. 

The chemical analysis included X-ray fluorescence (XRF), which quantified most of the 

chemical elements, ion chromatography for anions and cations, and light absorption. The 

XRF analysis provided the contributions from road dust elements, ion chromatography 
Mammoth Lakes AQMP 

24 

the contributions from sulfate and nitrate, and ammonium. The light absorption 

measurement is a good indicator of elemental carbon (EC) (diesel exhaust and wood 

smoke primarily). What the analysis could not identify that is important is organic carbon 

(OC), because the carbon-based Teflon filters interfere with measurements of carbon 

associated with the collected particulates. Because of this, organic carbon was estimated 

from the residual mass in the CMB analysis. 

Table 6-1. Dates with only PM-10 filters: 

Date PM-10 concentration 

1/1/2008 85.9 

2/9/2008 96.7 

2/27/2008 95.5 

2/21/2009 117.6 

1/2/2010 101.3 

1/29/2010 104.0 

2/13/2010 92.0 

1/12/2011 127.6 

Table 6-2. Dates with PM-10 and PM-2.5 filters: 

Date PM-10 PM-2.5 

12/17/2003 74.6 33.5 

1/13/2005 39.3 27.0 

1/19/2005 85.1 25.2 

1/22/2005 77.8 27.4 

6.2 SOURCE PROFILES 

6.2.1 PM-10 analysis 

The chemical source profiles, or fingerprints, were taken from the 1990 AQMP. The 

sources profiled were: 

 Mammoth Lakes road cinder storage 

 Mammoth Lakes paved road dust 

 idling diesel ski tour buses in Mammoth Lakes 

 fireplace burning a typical Mammoth Lakes wood mix 

 a Fisher woodstove with typical Mammoth Lakes wood mix 

Profiles for Mammoth Lakes woodstoves and fireplaces were used plus road dust and 

cinders. When running CMB it was found that due to their similar chemical fingerprints, 

significant collinearity occurred between the wood stove and fireplace sources, giving 

high uncertainty to wood stove contributions (sometimes significantly negative). CMB 
Mammoth Lakes AQMP 

25 

was run again not using the wood stove source, just fireplaces, cinders, and road dust. 

This gave better results. It was attempted to improve results by averaging the wood stove 

and fireplace profiles, but the quality of the results deteriorated. A weighted average of 

three parts fireplace to one part wood stove profile was also tried and results were not as 

good as simply using the fireplace profile. 

6.2.2 PM-2.5 analysis 

The PM-2.5 analysis had collinearity problems between woodstove and fireplace and 

between road dust and cinders. The analysis with the best results used fireplaces and 

road dust source profiles only. 

6.2.3 Fitting species 

CMB results can vary significantly based on the choice of fitting species selected. In the 

initial run, all species measured with available source analysis were used. This gave poor 

results. Species that were noted from the ambient data to represent the mix of sources 

were added and subtracted in a trial and error method until the best results were obtained. 

Attention was paid to squared correlation coefficient, the Chi square statistic and percent 

of mass explained performance measures (Watson, 2004). The fitting species included: 

soluble Cl, ammonium, soluble K, total K, Na, Al, Si, S, Ca, Ti, Fe, EC, OC, Ba, Sr, and 

Zn. 

6.3 CHEMICAL MASS BALANCE RESULTS 

CMB model version 8 (USEPA) was used to estimate source contributions to PM-10 and 

PM-2.5 for days with chemically speciated data. CMB analysis done in support of the 

1990 Air Quality Management Plan (AQMP, Ono et al, 1990) for Mammoth Lakes showed 

most of the PM-10 was due to road dust and residential wood combustion (RWC). One 

of the goals of the 2013 study was to try to determine if the relative contribution of RWC 

and road dust has changed since the1990 report (DRI, 2013). 

Results for the best fitting CMB analysis are shown in Table 6-3. Recommended 

performance measures (Watson, 2004) are % mass accounted for 100±20%, Rsquared>0.80, and Chi-squared < 4.0. For the PM-10 results (discounting the 1/12/2010 

sample), 10/11 cases have % mass 100±20%, all cases have R-squared>0.80, and 5/11 

meet the Chi-squared <4.0 criteria. For the PM-2.5 results, three out of four met the mass 

criteria and all four met the R-squared and chi-squared criteria. 

The percent of each sample attributed to each source is shown in Table 6-4. On average, 

residential wood combustion contributed about 64% of the PM-10, road dust plus cinders 

contributed about 33%, according to the CMB results (DRI, 2013). 
Mammoth Lakes AQMP 

26 

DRI, 2013 

Table 6-4. CMB Percent Contributions by Road Dust (RD), and Residential Wood 

Combustion (RWC) 1987-88 and 2003-2011 Data Sets 

1990 AQMP PM-10 Source Percentages 2013 AQMP PM-10 Source Percentages 

Date Conc. RD% RWC% Date Conc. RD% RWC% 

12/26/1987 125.9 2.3 97.7 12/17/2003 74.6 25.3 74.7 

12/30/1987 132.8 1.3 98.7 1/19/2005 85.1 33.7 66.3 

12/31/1987 142.8 2.5 97.5 1/22/2005 77.8 32.5 67.5 

1/1/1988 117.4 10.3 89.7 1/1/2008 85.9 39.5 60.5 

1/22/1988 143.8 33.7 66.3 2/9/2008 96.7 24.3 75.7 

1/23/1988 157.8 41.2 58.8 2/27/2008 95.5 39.4 60.6 

2/3/1988 104.3 31.5 68.5 2/21/2009 117.6 32 68 

2/5/1988 148.2 33.8 66.2 1/2/2010 101.3 27.7 72.3 

2/6/1988 160 31.2 68.8 1/29/2010 104 36 64 

2/13/1988 137.6 38.8 61.2 2/13/2010 92 33.8 66.2 

2/14/1988 144 45.2 54.8 

2/19/1988 148.5 28.7 71.3 

1987-88 study average 25 75 This study average 32.4 67.6 

DRI, 2013 

 

Table 6-3. CMB attribution results and performance statistics. 

DATE SIZE Conc. FP RD CIND SUM % mass R2 Chi2

12/17/03 10 74.6 53.0 9.6 10.2 72.8 97.5 0.94 3.70

01/13/05 10 39.3 31.1 3.6 1.7 36.5 92.7 0.92 3.76

01/19/05 10 85.1 51.8 18.1 11.5 81.3 95.5 0.93 4.39

01/22/05 10 77.8 47.5 16.9 8.7 73.0 93.8 0.94 3.70

01/01/08 10 85.9 53.4 24.6 14.8 92.9 108.1 0.93 4.73

02/09/08 10 96.7 68.0 10.2 13.8 92.0 95.1 0.94 3.35

02/27/08 10 95.5 52.6 26.1 12.7 91.3 95.6 0.90 6.40

02/21/09 10 117.6 91.7 26.6 21.0 139.3 118.5 0.94 3.89

01/02/10 10 101.3 100.4 23.2 19.0 142.6 140.8 0.90 6.88

01/29/10 10 104.0 65.8 24.5 16.8 107.1 103.0 0.93 4.52

02/13/10 10 92.0 68.9 25.9 13.9 108.7 118.2 0.91 6.09

01/12/11 10 127.6 43.9 2.2 1.8 47.9 37.5 0.82 8.77

12/17/03 2.5 40.6 28.6 1.5 30.0 74.0 0.96 0.90

01/13/05 2.5 32.7 27.5 0.6 28.1 86.0 0.81 3.90

01/19/05 2.5 30.5 28.1 2.2 30.3 99.3 0.89 2.73

01/22/05 2.5 33.2 27.6 1.9 29.5 89.0 0.92 2.00
Mammoth Lakes AQMP 

27 

For the winter 1987-1988 study (Ono et al, 1990), on average, fireplaces contributed 75% 

of the PM-10 and road dust 25%. Table 6-4 compares the results of the 1987-88 study to 

this study. Three of the days in the 1987-88 study showed wood smoke contributing 

>95% of the PM-10; the current study shows no high PM-10 days with greater than 75% 

of the PM-10 contributed from wood smoke (DRI, 2013). 

Furthermore, the peak contributions of road dust and residential wood combustion to PM10 appear to have diminished. A comparison of the results from the 1987-88 study to the 

2008-2010 study period showed that the average PM-10 contributions for the top three 

days in each study dropped from 107 to 72 μg/m3 for wood smoke and from 72 to 56 

μg/m3 for road dust. This represents about a 33% reduction in the ambient PM-10 

concentrations for both source categories that can be attributed to the implementation of 

the 1990 AQMP. (DRI, 2013). 

6.4 CHEMICAL MASS BALANCE SUMMARY AND CONCLUSIONS 

The question of the relative contributions of wood smoke and road dust to PM-10 in 

Mammoth Lakes was considered. Teflon filters from high PM-10 days between 2003 

and 2011 were subjected to chemical analysis with XRF, ion chromatography, and filter 

light absorption. Four days analyzed also had PM-2.5 filters that underwent chemical 

analysis. A major limitation was the inability to measure carbon on the filters. The filter 

light absorption provided a reasonable estimate of elemental carbon and the unexplained 

mass (on average 58% of PM-10 and 68% of PM-2.5) was assumed to be organic mass 

(OC*1.8). Estimates of the contribution of wood smoke and road dust were made using 

Chemical mass balance and a simple method based on abundance of crustal elements 

in the samples. For PM-10, CMB showed an average of 32% due to road dust and 68% 

due to residential wood combustion. This compares to 25% from road dust and 75% from 

residential wood combustion for the winter 1987-88 study. The CMB maximum 

contributions (average of three highest days) to PM-10 from road dust and residential 

wood combustion dropped by about 33% for each source category between 1987-1988 

and 2008-2010 (DRI, 2013). 
Mammoth Lakes AQMP 

28 

7. Control Measures 

In December of 1990, the Town of Mammoth Lakes adopted the Air Quality Management 

Plan (AQMP) for the Town of Mammoth Lakes. The AQMP relied on controlling wood 

smoke by replacing old wood stoves and fireplaces with cleaner wood burning appliances 

and curtailing wood burning on days that could violate the air quality standard. The Town 

reduced road dust emissions by using vacuum street sweepers to remove volcanic 

cinders soon after the roads dried. The 1990 control measures are described in Section 

2 and are summarized below. An assessment of their effectiveness follows: 

7.1 PARTICULATE EMISSIONS REGULATIONS 

As a part of the implementation program, the Town of Mammoth Lakes adopted Municipal 

Code Chapter 8.30, Particulate Emissions Regulations. Major controls in the Chapter 

8.30 regulations were: 

 Replacement or removal of existing uncertified residential wood combustion 

appliances at the time of sale of a property; 

 Limit the maximum number of residential wood combustion appliances in new 

construction to one certified appliance plus one pellet fueled appliance; 

 Institute voluntary and mandatory wood burning curtailment days; 

 Implement a public education Program; 

 Implement a vacuum street sweeping program; and 

 Limit peak VMTs to 106,600. 

7.2 CONTROL MEASURES OVERVIEW AND EFFECTIVENESS 

7.2.1 Wood Stove & Fireplace Change-outs 

In 1990, there were 5,946 woodstoves and fireplaces with less than 1% of those being 

EPA-certified. In 2013, the number of wood burning appliances is estimated at 5,696 with 

approximately 91% of the appliances being EPA certified woodstoves (Town of Mammoth 

Lakes, 2013)). 

Although the number of wood burning appliances decreased by roughly 4% from 1990 to 

2013, wood smoke emissions went down by about 50% as a result of replacing old wood 

stoves and fireplaces with EPA-certified wood stoves, pellet stoves and gas fueled 

appliances. This reduced wood burning PM-10 emissions on permissive burn days from 

2,087 kg/day to 850 kg/day during this same time period. 

There are indicators that wood heating has decreased since the adoption of the 

regulations in the AQMP. Town of Mammoth records through June of 2013 show that of 

the total of 5,414 change outs between December of 1990 and March of 2013, 577 were 

replaced with propane fueled appliances. It is expected that this trend will continue as 

older residences are torn down and replaced or renovated. Many of the older buildings 

in town have poor insulation and rely on electric heat as their primary heat source. 
Mammoth Lakes AQMP 

29 

Occupants of these older residences tend to use more wood as a cost-effective 

alternative to electricity or propane and the amount of wood needed is higher. As these 

properties are upgraded, their residential wood combustion use should decline. 

Anecdotally, there appeared to be an initial decline in personal fuelwood gathering based 

on data maintained by the Mammoth Ranger District. (Kusumoto 2007 and 2013) Those 

records showed a decline of approximately 30% in the volume of wood collected from 

1999 through 2007. However, since that time, personal fuelwood gathering has 

increased. The increase follows the spike in fuel prices in 2007 and the recession 

beginning in 2008. It also appears to coincide with the slight rebound in peak winter PM10 levels shown in Figure 4-2. 

Since 1990, most new condominiums were approved for construction without 

woodstoves. Since the adoption of the 2007 General Plan, the Town has prohibited wood 

burning appliances in new multi-unit developments (Town of Mammoth Lakes, 2007). 

This prohibition is incorporated in the updated Chapter 8.30 of the Mammoth Lakes 

Municipal Code. 

To enforce the change out requirements, the Town of Mammoth Lakes worked with local 

real estate agents to assure that the seller requirements were disclosed. It also instituted 

a program that permitted purchasers to assume responsibility for completing the change 

out provided that the assumption was in writing and filed with the Town. The Town 

obtained copies of all recorded real estate transactions from the County Recorder and 

cross-checked those transactions with building permit records to assure that property 

sales and transfers complied with the Particulate Emissions Regulations. As a result of 

staffing reductions in the Town, these follow-up programs lapsed in the last five to ten 

years. The GBUAPCD and the Town have agreed to conduct an inventory of real estate 

sales for comparison with change out records and to pursue compliance for noncompliant 

properties. 

Although the rule adopted in 1990 limited the installation of solid fuel burning appliances 

to EPA-certified Phase II woodstoves, EPA has recently created another certification 

program for EPA Phase II qualified fireplaces and fireplace retrofit devices. Due the 

Phase II test requirements, fireplaces were not allowed to be tested under the original 

EPA certification program. They can now be tested under this new program and if the 

fireplaces or fireplace retrofit devices are listed by the US EPA as Phase II qualified, they 

will be allowed to be installed in the Town of Mammoth Lakes. This change is codified in 

the Town of Mammoth Lakes regulations with the adoption of this AQMP 

(http://www.epa.gov/burnwise/fireplacelist.html#retrofits). 

7.2.2 Public Awareness Program. 

As described in Section 2, the Town implemented a public awareness program beginning 

in 1990. All components of the program except for the rental unit tent cards continue to 

be fully implemented. The tent card program has not been maintained in recent years 

and the Town is now investigating having additional cards printed for visitor 
Mammoth Lakes AQMP 

30 

accommodations. Restoring the tent card program will aid in getting no-burn day 

compliance (see below). 

7.2.3 No-burn Days. 

No-burn days are called when a meteorological inversion and calm wind conditions could 

persist for a given day. The calm air prevents the dilution and transport of air pollutants 

and allows PM-10 concentrations to build up from about 4:00 PM to midnight and then 

again from 6:00 to 10:00 AM. When calm weather is predicted, the Town's meteorologist 

may call a mandatory or a voluntary no-burn day based on the strength of the forecasted 

inversion and the Town's population. The meteorologist indicates if it is a red, yellow or 

green burn day to let the public know if it is mandatory, voluntary or if it is okay to burn. 

At the beginning of the program, 10 to 14 mandatory no-burn days were called each 

winter. Over the past six winters, the Town has averaged one mandatory and one 

voluntary no-burn day per winter (Daugherty, 2013). A survey of a residential 

neighborhood and a condominium complex, which was primarily occupied by visitors, 

showed that full-time residents did not comply with the no-burn day calls, while visitors 

were more responsive, but not fully compliant (Satterfield, 1994a). The survey showed a 

negative 36% compliance rate for residents (more wood burned on no burn days) and a 

positive 35% compliance rate for visitors. The negative compliance rate for the residents 

was due to having more residents burn on the no-burn survey days than were burning on 

the survey days when burning was allowed. Since the resident population in the survey 

was small, the negative value is likely within the statistical uncertainty of the survey and 

the compliance rate for full-time residents should be considered around zero. Because 

visitors make up 80% of the population, they had a significant influence on the overall 

town average. The combined town average with visitors and residents is about 21% 

compliance on no-burn days (Satterfield, 1994a). This is short of the expected 50% 

compliance rate that was expected in the plan. There have been no compliance checks 

for no-burn days since the 1994 study. The effect of the no-burn day compliance shortfall 

on air quality trends is evaluated in the Maintenance Demonstration section of this report. 

In December 2006, a significant change was made to GBUAPCD Rule 431 to make all 

wood burning appliances, except pellet stoves, subject to no-burn day requirements. 

Previous to the rule change, only non-EPA certified wood burning appliances were 

prohibited from being used on no-burn days. EPA certified wood stoves were exempted 

from the no-burn days and could still be operated. Since 85% to 90% of the non-EPA 

certified wood burning appliances had been replaced since the adoption of the AQMP in 

1990, the large majority of wood stoves were exempt from the no-burn days. Therefore, 

the removal of the exemption for EPA certified wood stoves is expected to significantly 

reduce PM-10 on no-burn days. This change in the exemption will also simplify 

enforcement of the no-burn days as it eliminates the difficulty of pinpointing non-compliant 

appliance locations, especially in multi-unit buildings. This rule was adopted by the 

GBUAPCD and is codified in the Town of Mammoth Lakes regulations with the adoption 

of this AQMP. 
Mammoth Lakes AQMP 

31 

7.2.4 Traffic Related Control Measures 

After winter storms, volcanic cinders are spread on the Town's roadways to provide 

additional traction and prevent vehicles from sliding on the icy roads. These cinders are 

crushed into ever smaller pieces by passing vehicles. When the roads dry, vehicles kick 

up fine dust from the roadway. In the 1990 AQMP, road dust was found to contribute up 

to 44% of the PM-10 on days that violated the federal air quality standard. The 1990 

AQMP relied on vacuum street sweeping to remove the cinders after the roads dry and a 

limit on traffic volume to prevent the problem from growing with the population. The traffic 

volume limit was set at 106,600 vehicle miles traveled on any day and is regulated through 

the approval of new developments by the Town. 

In conjunction with the 2007 update of the Town of Mammoth Lakes General Plan, an 

updated traffic model was prepared. This new model incorporated additional roadway 

segments increasing the baseline VMT calculations. 

7.2.5 Vacuum Street Sweeping. 

A test of the effectiveness of the street sweeper showed that PM-10 emissions could be 

reduced by 68% after use of the Town's Johnson vacuum street sweepers (Satterfield, 

1994b). Assuming that it takes two days to clean the heavily trafficked streets, this 

equates to an overall control efficiency of about 34% for street sweeping. This is 

consistent with the control efficiency assumption used in the 1990 AQMP. The 34% 

reduction is also consistent with the CMB analysis that found that ambient PM-10 

contributions from road dust have been reduced by 32% from the levels prior to adoption 

of the AQMP. 

7.2.6 Traffic Volume. 

To provide the most current data for this plan update, the Town of Mammoth Lakes 

contracted with LSC Transportation Consultants, Inc. for an updated Vehicle Miles 

Traveled Analysis using a revised traffic model and growth projections from the 2007 

Town General Plan. 

In 1990 a similar VMT study was completed in combination with the 1990 AQMP. The 

methodology used in the 1990 study and this VMT study are similar. Both studies are 

based on a travel demand model that assumes full buildout of the Town’s General Plan 

in the future. Both studies include all of the Town’s major roadways. The main difference 

is the extent of the roadways analyzed in each study. The 1990 study had a total of 10.9 

miles of roadways on 8 different roads (with 17 segments) for the existing year 1990 VMT, 

while the future year 2005 had a total of 15.8 miles of roadways on 10 different roads 

(with 31 segments). In contrast, the updated study’s VMT analysis included 93.1 miles 

of roadways on 420 different roads (with 1,037 segments) for both the existing and future 

analysis years (LSC, 2012a).. 
Mammoth Lakes AQMP 

32 

To reconcile the VMT estimates, the VMT in the current TransCAD model was estimated 

for only those roadway segments included in the 1990 study. As shown in the right 

columns in Table 7-2, a total of approximately 80,586 existing VMT and 110,641 future 

VMT are estimated on those roadways included in the 1990 study. Of the total existing 

VMT in the current TransCAD model network (144,192), about 56 percent are reflected 

on the roadways included in the 1990 study. Similarly, of the total future VMT in the 

current model (179,708), about 62 percent occur on roadways included on the 1990 

study. The remaining VMT occurs on the smaller roads that were not included in the 1990 

study. Note that these figures are based on peak-day conditions, consistent with the 1990 

study (LSC, 2012b). 

The following findings are made regarding the VMT on the roadways included in the 1990 

Study: 

 Overall, the VMT in Mammoth Lakes has increased from approximately 66,275 in 

1990 to approximately 80,856 in 2009 based on the roadway segments evaluated in 

1990. This equates to a total increase of approximately 22 percent over 19 years. 

 In 1990, the forecast indicated that the existing VMT would increase by more than 

double (approximately 222 percent) by 2005. Given that the VMT in 2009 was only 

slightly higher than the VMT in 1990, this high rate of growth has not occurred. 

 The 2005 VMT forecasts made in 1990 are much higher than the 2030 forecasts in 

the current TransCAD model for the same roadway segments, reflecting that the 

growth rate has decreased since 1990 and future development is expected to occur 

at a slower rate. Based on the current TransCAD model, VMT on the roadways 

included in the 1990 study is expected to increase by a total of 37 percent from 2009 

to 2030. 

 The roadway segments evaluated in 1990 account for 56% of the total traffic on all 

roadways in the current TransCAD model for 2009 and 62% of the 2030 VMT. The 

Emissions Inventory in this AQMP uses all the roadway segments identified in the 

current TransCAD model. 

It should be noted that the increase in VMT from 1990 to 2009 was spread over a larger 

roadway network, with the addition of roads away from the town center. Although the 

additional roads contributed to an increase in VMT, they also dispersed the road dust 

emissions over a larger area. This meant that the increase in VMT did not affect monitored 

PM-10 concentrations at the Gateway Center in proportion to the increase in overall 

roadway emissions within the town. To account for the VMT change over the current 

road network, the maintenance demonstration in Chapter 8 re-examines the relationship 

of VMT using the current traffic model to the ambient impact at the PM-10 monitoring site. 
Mammoth Lakes AQMP 

33 

7.3 SUMMARY OF THE EFFECT OF CONTROL MEASURES ON AMBIENT PM-10 

CONCENTRATIONS 

With the implementation of the control measures from the 1990 AQMP, PM-10 levels in 

the Town of Mammoth Lakes have declined significantly. The 1990 AQMP estimated 

4,253 kg/day of PM-10 for the peak 24-hour period and forecast 8,030 kg/day for the peak 

24 hour total PM-10 emissions by 2005 absent any controls. (Ono et al. 1990) The 

updated emissions estimate shows 3,385 kg/day PM-10 in 2012, which is a 20% 

reduction in emissions since 1990 when the AQMP was adopted. This reduction was 

achieved despite a 72% population increase from 4,785 in 1990 to 8,234 in 2010. The 

reduction in emissions is divided as follows: 

Table 7-1. Change in Peak 24-Hour In-Town Emissions 1990-2012 

 1990 2012 Difference 

RWC devices 1,839 850 -989 

Road dust/cinders 2,390 2,522 132 

Tailpipe, tire & brake wear 23 9 -14 

Industrial (in-Town) 1 4 3 

 4,253 3,385 -868 

7.4 AMENDMENTS TO 1990 CONTROL MEASURES 

Most of the changes to the implementing regulations of the Town of Mammoth Lakes MC 

8.30 revise outdated sections or make non-substantive technical edits. The three 

meaningful amendments are: 

 Section 8.30.040 B. This section is modified to clarify that no new wood burning 

appliances may be installed in multi-family developments. Prohibition of new wood 

burning appliances in multi-family projects has been the policy of the Town. The 

proposed revision formalizes that practice and implements General Plan Policy 

R.10.3. 

 Section 8.30.080, Mandatory Curtailment. This section has been modified to 

include all wood burning appliances, except pellet stoves, in the no-burn day 

program. Currently, EPA certified stoves are exempted under Town regulations, 

but are required to participate under the District regulations. This revision 

eliminates ambiguity between the Town and District regulations and better protects 

the community’s air quality on those days forecast to exceed 130 micrograms per 

cubic meter. 

 Section 8.30.100 B. This section sets a limit for vehicle miles traveled (VMT) within 

the town. The current limit is one hundred six thousand six hundred (106,600) 

VMT on any given day. Proposed development projects and other Town approved 

activities which affect vehicle trips are evaluated against this limit. Projects, 

programs, or policies which would cause an exceedence of this limit would have 
Mammoth Lakes AQMP 

34 

to incorporate higher levels of traffic mitigation or potentially be denied. The 

revised traffic model for the community incorporates additional roadway segments 

and revises VMT projections based on updated traffic counts and current modeling 

technologies. It shows and estimated VMT at General Plan buildout of one 

hundred seventy nine thousand seven hundred eight (179,708) for the revised 

model roadway segments. The air quality modeling shows that this overall level 

of traffic will not cause an exceedence of the NAAQS and is suggested as the VMT 

limit for the AQMP. 

The full text of the amended regulations is found in Appendix C. 

7.5 ANTI-BACKSLIDING RULE - CAA SECTION 110(l) 

Clean Air Act (CAA) Section 110(l) prohibits the adoption of rule revisions that would 

interfere with attaining the federal standard or making reasonable further progress toward 

attainment. This is sometimes referred to as the anti-backsliding rule. The rule changes 

discussed in Section 7.4 were considered in the growth projections for the anticipated 

town buildout in the modeling analysis in Sections 8.3 and 8.4. That analysis 

demonstrated the rule revisions will not interfere with the attainment or maintenance of 

the PM-10 standard and therefore, would comply with the CAA Section 110(l). The 

modeling projections demonstrated that the highest design day concentrations would 

peak out at 100.0 μg/m3 and 104.8 μg/m3 for the high wood smoke and high road dust 

days, respectively. This is well below the federal standard of 150 μg/m3. 

.
Mammoth Lakes AQMP 

35 
Mammoth Lakes AQMP 

36 

8. Maintenance Demonstration 

This section will cover the effects of increased population and visitors on PM-10 

emissions on ambient PM-10 concentrations. Receptor modeling results from Chapter 6 

will be used with design day concentrations and the projected emissions inventory to 

determine the future ambient PM-10 concentrations that will result from population and 

visitation growth. All of the emissions and ambient PM-10 projections are based on the 

in-town emissions inventory, which is the relevant inventory of sources that most likely 

contributed to PM-10 concentrations measured at the Gateway Center, where the 

samples were taken for the receptor modeling analysis discussed in Chapter 6. The 

results of the receptor modeling analysis were used for the proportional roll-back analysis 

that was applied for this maintenance demonstration. 

8.1 EMISSIONS AND POPULATION GROWTH PROJECTIONS 

The 2007 Town of Mammoth Lakes General Plan evaluated population in terms of People 

at One Time (PAOT). PAOT is the number of people in town on a peak winter Saturday. 

PAOT is expected to grow from 34,265 in 2007 to 52,000 in 2025. 2025 was considered 

the build out year by the General Plan. With the slowdown in development as a result of 

the recent recession, actual growth has been substantially less than forecasted. 

Nonetheless, the buildout number from the General Plan has been used as the year 2030 

projected population in both the RWC and VMT analyses. This provides the required 10-

year maintenance period with sufficient lead time to allow for redesignation. 

Tables 8-1 and 8-2 show the expected PM-10 emissions to growth with continued 

implementation of existing controls. Table 8-3 summarizes the peak daily PM-10 

emissions for each source category for 1990, 2012, and projections to 2030. Note that 

the vehicle-related emissions for 2012 are based on VMT for 2009 because traffic counts 

showed there was little change in the average wintertime traffic volume between 2009 

and 2013. In 2012, the average winter traffic count on highway 203 the primary route in 

and out of the Town was about 10% lower than in 2009. (Caltrans, 2014) 

Table 8-1. Peak Roadway Emissions Per Day 2012-2030

 2012 2030 

Emission Factor in g/VMT VMT Emissions VMT Emissions

In-town 

Road Dust 17.49 144,192 2,522 kg 179,708 3,143 kg

Tailpipe,Tire & Brake Wear 0.06 144,192 9 kg 179,708 11 kg

In-Town sub-total 2,531 kg 3,154 kg

Out-of-town 

Road Dust 

Tailpipe,Tire & Brake Wear 

17.49

0.05

53,319 

53,319 

933 kg

2 kg

66,452 

66,452 

1,162 kg

3 kg

Out-of-town sub-total 935 kg 1,165 kg

Planning Area Total 3,466 kg 4,319 kg
Mammoth Lakes AQMP 

37 

Table 8-2. Peak Residential Wood Combustion Emissions Per Day 2012-2030 

2012 2030 

Devices Emissions Devices Emissions

Non certified stoves & fireplaces 524 180 kg 64 21 kg

Certified stoves 4,772 662 kg 5,569 779 kg

Pellet stoves 400 8 kg 430 8 kg

Total 5,696 850 kg 6,063 802 kg

Table 8-3 Peak Winter 24-hour PM-10 Emissions for Planning Area (kg/day)

1990 2012 2030 

Residential Wood Combustion 1,839 850 802

Road Dust & Vehicle Emissions (In-town) 2,413 2,531 3,154

Road Dust & Vehicle Emissions (Out-of-Town) NA 935 1,165

Industrial Sources 1 8 8

Total 4,253 4,324 5,129

VMT projections for 2030 for the out-of-town emissions from traffic on Highways 203 and 

US 395 assume traffic will increase in proportion to the in-town VMT increase with buildout 

projections from the General Plan. This is a fair assumption, since these highways are 

the primary route into and out of the Town of Mammoth Lakes. A secondary bypass route 

exists, but it receives relatively little traffic. Out-of-town vehicle emissions are not included 

in the maintenance demonstration in Chapter 8.3, but are included in the transportation 

conformity budget for the planning area as discussed in Chapter 10. 

PM-10 emissions generated in the Planning Area are primarily from wood smoke from 

residential wood combustion and resuspended road dust. The attainment emissions 

inventory for Mammoth Lakes is based on estimated daily PM-10 emissions for 2012. 

Emission estimates for 2012 are typical of emissions in the Planning Area over the 3-year 

period (2010-2012) when PM-10 compliance was determined from monitoring 

evaluations. Table 8-3 shows that total peak daily emissions decreased from 1990 to 

2012 and are currently estimated at 3,420 pounds per day. 

8.2 DESIGN DAY SELECTION FOR AMBIENT PM-10 FORECAST 

For air quality planning purposes the design day concentration is the monitored PM-10 

concentration that is used to determine if an area is attainment with the federal standard. 

For PM-10 it is statistically the fourth highest daily monitored concentration measured 

over the last three calendar years. Since PM-10 was monitored daily at the Gateway 

Center during 2010-2012, the fourth highest concentration taken from the last three years 

is the used as the design concentrations. This design concentration can then be used to 

forecast ambient PM-10 concentrations and future compliance with the federal PM-10 

standard (see Chapter 8.3). 

 
Mammoth Lakes AQMP 

38 

Table 8-4 Four Highest Monitored PM-10 Concentrations At 

Gateway Center, Mammoth Lakes, CA (2010-2012) 

Year Number of 

Samples 

1st Hi 

(μg/m3) 

2nd Hi 

(μg/m3)

3rd Hi 

(μg/m3) 

4th Hi 

(μg/m3) 

2010 339 101 100 99 89 

2011 355 102 81 81 79 

2012 330 56 53 51 48 

Table 8-4 shows the four highest monitored PM-10 concentrations for the three year 

period from 2010 through 2012. The fourth highest PM-10 concentration from this period, 

and therefore the design concentration is 99 μg/m3 measured on January 2, 2010. It 

should be noted that all of the monitor values shown in this table were measured during 

the winter months from December through March, which is consistent with the highest 

PM-10 days that the AQMP is intended to mitigate. 

8.3 PROPORTIONAL ROLL-BACK METHOD FOR CONTROL STRATEGY 

ANALYSIS 

The effect of PM-10 emissions increases or decreases on the ambient PM-10 

concentration can be determined by using a linear rollback method of calculation. This 

method is based on the assumption that the ambient concentration due to a given source 

is proportional to the emissions from that source. The emissions are based on sources 

within the boundaries of the Town because they directly impact PM10 concentrations at 

the monitor site. It should be noted that the following form of the rollback equation 

includes background PM-10 concentration. The background concentration for Mammoth 

Lakes is about 5 μg/m3 based on the winter time PM-10 data from Simis Ranch a sparsely 

populated location near Mono Lake, CA (about 20 miles north of Mammoth Lakes). The 

data was averaged for calm winter days that would be meteorologically similar to days 

when high PM-10 levels occur in Mammoth Lakes. The background concentration 

represents an ambient PM-10 concentration that is due to sources that are not accounted 

for in the emissions inventory, and will not be reduced by local control measures. These 

background sources may be regional or global in origin. 

CT = ΣCi + Cb = Σ[Cdi (Ei/Edi)] + Cb

CT = Total PM-10 concentration 

Cb = Background concentration, 5 μg/m3 

Ci = PM-10 concentration due to source i 

Cdi = Design day source contribution from source i 

Ei = PM-10 emissions from source i 

Edi = Peak PM-10 emissions from source i 
Mammoth Lakes AQMP 

39 

As was described in the 1990 AQMP, Mammoth Lakes’ air pollution episodes are 

characterized by two different scenarios. When temperatures are lower, road dust and 

cinders are bound up in ice and snow and wood heating demands are higher, wood 

smoke is the dominant contributor to PM-10. When temperatures are warmer, melting 

snow and drying pavement releases road dust and wood burning demands are lower, 

road dust comprises a much higher fraction of PM-10. This leads to air pollution episodes 

that may be dominated by either wood smoke or road dust. The proportional roll-back 

analysis tested both cases. The results in Table 6-4 were used to estimate the 

contributions for the two design day PM10 forecasts. The high wood smoke day is based 

on the sample collected on 2/9/2008, which had 75% of the PM-10 attributed to residential 

wood combustion with the remainder coming from road dust. The high road dust day is 

based on the sample collected on 2/27/2008, which had 39% of the PM-10 attributed to 

road dust and cinders with the remainder coming from residential wood combustion. Due 

to the lack of evidence in the CMB analysis and their relatively low emissions as compared 

to road dust and wood smoke, some emission categories were considered negligible for 

the purpose of the PM-10 forecast. This included emissions from industrial sources, tail 

pipes, and brake wear. 

To determine the ambient source contributions for the two design day scenarios, use the 

following peak day 2012 emissions for Edi: 

Edi = 850 kg/day for fireplaces and wood stoves 

= 2522 kg/day for In-town road dust and cinders 

= negligible for all other sources 

For the wood burning dominated design day assume 75% of the design day concentration 

minus background (example, Cdi = 0.75 x (99 – 5) = 70.5) is due to fireplaces and 

woodstoves and the remainder is attributed to road dust and cinders: 

Cdi = 70.5 μg/m3 for fireplaces and wood stoves 

= 18.8 μg/m3 for road dust and tailpipe 

Likewise, for the high road dust and cinders design day, assume 39% is attributable to 

road dust and cinders and the remainder is due to fireplaces and woodstoves: 

Cdi = 57.3 μg/m3 for fireplaces and wood stoves 

= 36.7 μg/m3 for road dust and tailpipe 

=negligible for all other sources 

Effective future emission changes on the ambient contributions can be estimated by using 

emissions data for 2030 as shown in table 8-3 for the variable Ei. 

Ei = 802 kg/day for fireplaces and wood stoves 

= 3,143 kg/day for in-town road dust and cinders 

= negligible for other sources 
Mammoth Lakes AQMP 

40 

8.4 EFFECT OF GROWTH ON PM-10 CONCENTRATIONS 

These results show that, with current control measures, growth could result in a 0.4% to 

a 6.5% increase in worst-case ambient PM-10 concentrations over the next 15 years. 

Table 8-5 demonstrates that no exceedences of the NAAQS for PM-10 are expected 

through 2050 with existing control measures. This is also shown in Figure 8.1. Tables 8-

6 and 8-7 and Figures 8-2 and 8-3 Show the contributions by source for high residential 

combustion days and for high road dust contribution days. 

Table 8-5. Future PM-10 Concentrations for Residential Wood Combustion and 

Road Dust Design Days 

 2012 2030 2050* 

High RWC Design Day 99.0 μg/m3 100.8 μg/m3 100.8 μg/m3

High Road Dust Design Day 99.0 μg/m3 104.8 μg/m3 104.8/m3

*Assumes no growth after buildout in 2030 

Figure 8-1 Design Day Projection for High Residential Wood Combustion 

and Road Dust Days

0

50

100

150

200

250

1990 2012 2030 2050

PM‐10 μg/m3

Road Dust

Residential Wood

Combustion

Federal PM‐10 Std. = 150 μg/m3
Mammoth Lakes AQMP 

41 

Table 8-6 Forecasted PM-10 Design Day Concentrations by Source for High 

Residential Wood Combustion Day 

Source Category 1990 2012 2030 2050 

Background 5 μg/m3 5 μg/m3 5 μg/m3 5 μg/m3

Road Dust 5 μg/m3 23 μg/m3 29 μg/m3 29 μg/m3

Residential Wood 

Combustion 195 μg/m3 71 μg/m3 66 μg/m3 66 μg/m3

Vehicles* 5 μg/m3 negligible negligible negligible 

Industrial Sources negligible negligible negligible negligible 

Total 210 μg/m3 99 μg/m3 100 μg/m3 100 μg/m3

 

0

50

100

150

200

250

1990 2012 2030 2050

μg/m3

Figure 8-2 Design Day Projection for

High Residential Wood Combustion Day 

Vehicles

Residential Wood Combustion

Road Dust

Background and Industrial
Mammoth Lakes AQMP 

42 

Table 8-7 Forecasted PM-10 Design Day Concentrations by Source for 

High Road Dust Day 

Source Category 1990 2012 2030 2050 

Background 5 μg/m3 5 μg/m3 5 μg/m3 5 μg/m3

Road Dust 93 μg/m3 37 μg/m3 46 μg/m3 46 μg/m3

Residential Wood Combustion 112 μg/m3 57μg/m3 54 μg/m3 54 μg/m3

Vehicles* negligible negligible negligible negligible 

Industrial Sources negligible negligible negligible negligible 

Total 210 μg/m3 99 μg/m3 105 μg/m3 105 μg/m3

*Vehicle tailpipe and brake wear emission amount to less than 0.3 μg/m3 except for the 1990 RWC case. 

0

50

100

150

200

250

1990 2012 2030 2050

μg/m3

Figure 8-3 Design Day Projection for

High Road Dust Day

Vehicles

Residential Wood Combustion

Road Dust

Background and Industrial
Mammoth Lakes AQMP 

43 

9. Contingency Plan and Maintenance Measures 

9.1 CONTINGENCY PLAN REQUIREMENTS 

Section 175A of the Clean Air Act requires that maintenance plans include contingency 

provisions to assure that any air quality violation of the NAAQS that occurs after the 

redesignation of the area as attainment is promptly corrected. As per guidance provided 

by the US EPA, (Calcagni, 1992) the maintenance plan should identify the measures to 

be adopted and a schedule and procedures for action. This plan takes a two-tiered 

approach to address contingency measures; 1) to adopt additional measures with this 

plan to strengthen existing rules and to prevent NAAQS violations, and 2) to commit to 

adopt additional measures if the standard is violated in the future. 

9.1.1 Additional Control Measures Adopted with this Plan 

Section 172(c)(9) of the CAA requires that SIPs include contingency measures. 

Such plan shall provide for the implementation of specific measures to be 

undertaken if the area fails to make reasonable further progress, or to attain the 

national primary ambient air quality standard by the attainment date applicable 

under this part. Such measures shall be included in the plan revision as 

contingency measures to take effect in any such case without further action by the 

State or the Administrator. 

In subsequent NAAQS implementation regulations and SIP approvals/disapprovals 

published in the Federal Register, the EPA has issued guidance that the contingency 

measure requirement could be satisfied with already adopted control measures, provided 

that the controls are above and beyond what is needed to demonstrate attainment with 

the NAAQS (76 FR 57891). Thus, an already adopted control measure with an 

implementation date prior to the milestone year or attainment year would obviate the need 

for an automatic trigger mechanism. 

The analysis in this Plan shows that the adopted control measures for the Town of 

Mammoth Lakes are sufficient to maintain compliance with the NAAQS for PM-10 with a 

substantial buffer in the event that the measures do not fully achieve the same level of 

PM-10 reduction going forward that has been achieved to date. The Plan indicates a 

future design day PM-10 level of 100.8 μg/m3 on high residential wood combustion days 

and 104.8 μg/m3 (Table 8-5) on high road dust days. This is 45 μg/m3 (30%) lower than 

the NAAQS of 150 μg/m3. 

Despite the attainment of the Federal NAAQS, the Town of Mammoth Lakes still exceeds 

the California 24-hour standard for PM-10. Therefore, this Plan incorporates additional 

measures to continue to improve the community’s air quality. 

These measures include amending the Town of Mammoth Lakes Particulate Emissions 

Regulations to match GBUAPCD Rule 431, requiring all wood burning fireplaces and 
Mammoth Lakes AQMP 

44 

stoves, whether certified or not, to comply with no-burn days. These additional measures 

have strengthened the existing rules and were shown by the modeling analysis in 

Sections 8.3 and 8.4 that the changes will not interfere with attaining or maintaining 

compliance with the federal standard as required by CAA Section 110(l). Any new 

facilities in the Planning Area that may emit air pollution will be subject to the District’s 

new source review rules (209-A, 216 and 216-A). Facilities that qualify as a major source 

under the US EPA federal permitting guidelines will also be subject to federal PSD 

(Prevention of Significant Deterioration) permitting requirements (40 CFR 51.166 and 

52.21). 

9.1.2 Commitment for Additional Measures if the Standard is Violated 

If a monitored violation of the federal PM-10 standard occurs in the Town of Mammoth 

Lakes or the surrounding nonattainment area, the Town and the District will investigate 

the cause of the violation(s). A violation of the standard will be considered to be any 

exceedance of the PM-10 standard (150 μg/m3) that causes the annual average number 

of exceedances over a three year period to exceed 1.0 days per year; in other words, four 

or more exceedances in any continuous three year period. The number of exceedances 

will exclude days that are considered to be exceptional events such as smoke from 

wildfires, as provided for under the EPA’s Exceptional Event Rule. (72 FR 13560) 

Within 18 months of the violation, the Town and District will adopt additional control 

measures needed to meet the PM-10 NAAQS. Depending on the cause of the violation 

these control measures may include the following: 

 Reducing the no burn day trigger threshold from a target of 130 to 100 μg/m3, if 

residential wood smoke is found to be a significant contributor. 

 Implementing measures to reduce the use of volcanic cinders or to improve street 

clean up procedures on roadways during the winter, if road dust is found to be a 

significant contributor. 

9.2 MAINTENANCE MEASURES 

CAA Sec 175A and US EPA guidance (Calcagni, 1992) require additional measures in 

the maintenance plan to track the progress of the plan, and to continue air quality 

monitoring. 

9.2.1 Triennial Progress Reports 

The US EPA requires areas to track the progress of maintenance plans. (Calcagni, 1992) 

This would include updating the emissions inventory, assessing air quality trends and reevaluating modeling assumptions. The Town and the District will commit to submitting 

progress reports every third year starting in 2017 to track the progress of the maintenance 

plan. Progress reports will include an update on PM-10 air quality, a revised peak daily 

emission inventory for all sources in the planning area, a reassessment of the modeled 
Mammoth Lakes AQMP 

45 

air quality trend using the modeling assumptions in Section 8.3, and additional information 

that may be relevant to the air quality program in the Town. 

9.2.2 Commitment to Continue PM-10 Monitoring 

The District will continue to maintain monitoring network integrity and, with the Town, 

continue to monitor PM-10 in accordance with 40 CFR Part 58, (1) to verify the attainment 

status of the area as required by the US EPA (CAA Sec 175A, Calcagni, 1992) and (2) to 

implement the no burn day program, which relies on daily PM-10 monitoring. Although 

the intention is to continue monitoring indefinitely in order to implement the no burn day 

program, the Town and the District will commit to continue ambient PM-10 monitoring for 

at least 20 years following the redesignation of the area to attainment in order to comply 

with CAA Sec 175A(b). 

9.3 CONTINGENCY AND MAINTENANCE PLAN CONCLUSIONS 

The success of the existing control measures demonstrates that PM-10 concentrations 

have been significantly reduced to a level that contingency measures are not required to 

maintain compliance with the federal standard. Nonetheless, additional measures have 

been incorporated into the AQMP to assist in further reductions of PM-10 levels with the 

goal of improved compliance with the California Ambient Air Quality Standard for PM-10. 

These additional measures have strengthened the existing rules and as such are 

consistent with CAA Section 110(l) to avoid adopting measures that would interfere with 

attainment of the federal standard. The Town and the District will commit to the 

continuation of the air quality program in the Mammoth Lakes through the implementation 

of control measures, performing ambient monitoring and providing periodic updates on 

the progress of the Plan. 
Mammoth Lakes AQMP 

46 

10. Transportation Conformity 

10.1 BACKGROUND 

Transportation conformity is a way to ensure that Federal funding and approval are given 

to those transportation activities that are consistent with air quality goals. It ensures that 

these transportation activities do not worsen air quality or interfere with the "purpose" of 

the SIP, which is to meet the NAAQS. Meeting the NAAQS often requires emissions 

reductions from mobile sources. 

According to the Clean Air Act, transportation plans, programs, and projects cannot: 

 Create new NAAQS violations; 

 Increase the frequency or severity of existing NAAQS violations; or 

 Delay attainment of the NAAQS. 

Transportation conformity requirements contained in Great Basin Unified Air Pollution 

Control District Regulation XII require that federal actions and federally funded 

transportation projects conform to SIP rules and that they do not interfere with efforts to 

attain federal air quality standards. Transportation sources were found to contribute to 

the nonattainment problem in Mammoth Lakes and PM-10 from paved roads. Peak 

winter-time emissions from road dust and vehicle emissions were estimated at 3,466 

kilograms per day in the Mammoth Lakes Planning Area (see Table 8-1). This includes 

2,531 kg/day in the Town of Mammoth Lake and 935 kg/day outside of the Town on 

Highways 203 and US 395. Future PM-10 emission projections for 2030 and beyond is 

for road dust and vehicle emissions to increase to 3,154 kg/day in the Town and 1,165 

kg/day outside of the Town (see Table 8-3). 

 

In terms of transportation plans and transportation improvement programs (TIPs), 

FHWA/Federal Transit Administration’s joint conformity determination is based on a 

quantitative demonstration that projected motor vehicle emissions from the planned 

transportation system do not exceed the motor vehicle emissions budget established in 

the SIP. If the transportation plan or TIP cannot meet the motor vehicle emissions budget, 

then changes may be needed to the transportation plan or TIP, or the SIP. If conformity 

is not determined according to the timeframes established in the regulations, a conformity 

"lapse" will occur. When conformity lapses, Federal projects may proceed only if they are 

exempt from transportation conformity (e.g., safety projects), TCMs in an approved SIP, 

or project phases that have already received funding commitments by FHWA or FTA. 

10.2 PLANNING ASSUMPTIONS 

Forecasts in this plan are based on the projections in the Town of Mammoth Lakes 

General Plan. Both growth in VMT and changes in the numbers of residential wood 

burning appliances assume full build-out of the community at the maximum densities 

identified in the General Plan. To be consistent with this plan, analyses should be based 
Mammoth Lakes AQMP 

47 

on projected peak daily wintertime emissions in the Town and average daily wintertime 

(January-March) emissions on Highways 203 and US 395 outside of the Town, but within 

the boundaries of the planning area. 

Motor Vehicle Emissions Budget 

The motor vehicle emissions for in-town traffic is based on the build-out assumptions 

contained in the Town of Mammoth Lakes General Plan. As set forth in the Mammoth 

Lakes Vehicle Miles Traveled Analysis (LSC, August, 2012) for the year 2030, traffic 

volume in Mammoth Lakes will reach 179,708 VMT per day, producing 3,154 kg of PM10. 

Emissions projections for 2030 for out-of-town traffic on Highways 203 and US 395 

assume traffic will increase in proportion to the in-town VMT increase with buildout 

projections from the General Plan. This is a fair assumption, since these highways are 

the primary route into and out of the Town of Mammoth Lakes. A secondary bypass route 

exists, but it receives relatively little traffic. For the year 2030 and beyond, average 

wintertime traffic on these out-of town highways may increase from 53,319 in 2012 to 

66,452 vehicle miles travelled per day in 2030, producing 1,165 kg/day of PM-10 

emissions. 

Combining the in-town and out-of-town future wintertime emissions for 2012 results in an 

overall motor vehicle emission budget of 3,466 kg per day and for 2030 yields the overall 

motor vehicle emissions budget for the planning area of 4,319 kg per day. Projects that 

may result in wintertime emissions in excess of these budgets shall incorporate measures 

to reduce emissions or revise the AQMP to demonstrate through additional controls or 

other methods that the increase in emissions will not result in a violation of the NAAQS 

for PM-10. 
Mammoth Lakes AQMP 

48 

11. General Conformity 

General conformity is the federal regulatory process for preventing major federal actions 

or projects from interfering with air quality planning goals. Conformity provisions ensure 

that federal funding and approval are given only to those activities and projects that are 

consistent with state air quality implementation plans (SIPs). Conformity with the SIP 

means that major federal actions will not cause new air quality violations, worsen 

existing violations, or delay timely attainment of the national ambient air quality 

standards (NAAQS). Current federal rules require that federal agencies use the 

emissions inventory from an approved SIP’s attainment or maintenance demonstration 

to support a conformity determination. 

General conformity requirements contained in District Regulation XIII require that 

federal actions and federally funded projects conform to SIP rules and that they do not 

interfere with efforts to attain federal air quality standards. A conformity determination is 

currently required for any federally funded (non-transportation) project or action that 

takes place in a moderate PM-10 nonattainment and maintenance areas that have the 

potential to exceed a de minimis PM-10 emissions threshold of 100 tons per year. In 

order to maintain the stringency of control requirements in the Mammoth Lakes 

Planning Area under a maintenance plan, the District will retain the 100 tons of PM-10 

per year de minimis emissions threshold for triggering a conformity determination as 

currently required under District Regulation XIII. 
Mammoth Lakes AQMP 

49 

12. Redesignation Request 

States may ask U.S. EPA to redesignate an area “attainment” if: 

 the area has monitored attainment of the air quality standard; 

 the area has a fully approved State Implementation Plan; 

 U.S. EPA has determined that the improvement in air quality is due to permanent 

and enforceable reductions in emissions; 

 the state has submitted, and U.S. EPA has approved, a maintenance plan for the 

area; and, 

 the area has met all other applicable federal CAA requirements. 

As described in Chapter 8, the Town of Mammoth Lakes last exceeded the federal PM10 24-hour standard in 1994. Attainment of the PM-10 standard is a direct result of the 

implementation of control measures by the Town of Mammoth Lakes as described in the 

1990 Air Quality Management Plan for the Town of Mammoth Lakes. 

The daily data collected by the Great Basin Unified Air Pollution Control District in 

Mammoth Lakes demonstrates that no more than 1.0 exceedances of the NAAQS have 

occurred over the last three years as is required to demonstrate attainment of the federal 

standard. In fact, the data show that there have been no exceedances during the last 19 

years. 

Applying a proportional roll back analysis to the PM-10 present and future emissions this 

document demonstrates that no more than 1.0 exceedances per year would be expected 

through the next 20 year planning period and beyond. With continued implementation of 

the control measures, attainment will be maintained. 

The District finds that the Mammoth Lakes PM-10 Planning Area has attained the federal 

PM-10 standard and requests the California Air Resources Board recommend to the US 

Environmental Protection Agency that the area be redesignated from nonattainment to 

attainment with the federal PM-10 standard. 
Mammoth Lakes AQMP 

50 

13. References 

52 FR 24634. Federal Register, Revisions to the National Ambient Air Quality Standards 

for Particulate Matter, July 1, 1987. 

52 FR 29384. Federal Register, August 7, 1987. 

62 FR 38652. Federal Register, National Ambient Air Quality Standards for Particulate 

Matter, July 18, 1997. 

71 FR 61144-64233. Federal Register, National Ambient Air Quality Standards for 

Particulate Matter 10/17/06. 

72 FR 13560. Federal Register, Treatment of Data Influence by Exceptional Events,

March 22, 2007. 

76 FR 57891. Federal Register, Approval of Air Quality Implementation Plans; South 

Coast Attainment Plan for 1997 8-hour Ozone Standard, September 16, 2011. 

Calcagni, 1992. Calcagni, John, Procedures for Processing Requests to Redesignate 

Areas to Attainment, US EPA, September 4, 1992. 

Caltrans, 2014. Traffic Counts on Highways 203 and US 395 in Mammoth Lakes Planning 

Area (1993-2013), Caltrans, March 27, 2014. 

CARB, 1997. Entrained Road Dust from Paved Road Travel, California Air Resources 

Board, July 2, 1997. 

CARB, 2013a. Area Designations Maps / State and National, 4/22/13, website accessed 

May 2, 2013, www.arb.ca.gov, 4/22/13. 

CARB, 2013b. Ambient Air Quality Standards, California Air Resources Board, web site 

accessed June 4, 2013, http://www.arb.ca.gov/research/aaqs/caaqs/pm/pm.htm. 

CARB, 2014. Mobile Source Emissions Inventory using EMFAC2011, last updated 

January 2013, California Air Resources Board, website accessed March 28, 2014, 

http://www.arb.ca.gov/emfac/. 

EPA, 2013. National Ambient Air Quality Standard for Particulates, US EPA, website 

accessed May 2, 2013, www.epa.gov/ttn/naaqs/standards/pm/s_pm_index.html. 

EPA, 2014. Air Quality System, US EPA, website accessed March 14, 2014, 

http://www.epa.gov/ttn/airs/airsaqs/. 

EPA, 2013. Emissions Factors & AP 42, Compilation of Air Pollutant Emission Factors,

Last Updated December 28, 2011, US EPA, website accessed June 15, 2013, 

www.epa.gov/ttn/chief/ap42/index.html. 
Mammoth Lakes AQMP 

51 

Daugherty, 2013. Jennifer Daugherty, Associate Planner, Town of Mammoth Lakes, 

personal communication. 

Davis and Read, 1989. Guidance Document for Residential Wood Combustion Emission 

Control Measures, 1989. 

DRI, 2013. Chemical Analysis of PM10 and PM2.5 Filters from Mammoth Lakes, Desert 

Research Institute Division of Atmospheric Sciences, Reno, Nevada, May 21, 2013. 

GBUAPCD, 2014. Great Basin Unified Air Pollution Control District, Permitted Particulate 

Matter Sources Within the Mammoth Lakes AQMP, March 2014. 

Kusumoto, 2007 and 2013. Scott Kusumoto, Inyo National Forest, personal 

communication. 

LSC, 2012a. Mammoth Lakes Vehicle Miles Traveled Analysis, Sara Hawley and Leslie 

Suen, LSC Transportation Consultants, Inc., Tahoe City, California, August 3, 2012. 

LSC, 2012b. Mammoth Lakes Vehicle Miles Traveled Analysis – Comparison with 1990 

Study, Sara Hawley and Leslie Suen, LSC Transportation Consultants, Inc., Tahoe City, 

California, September 10, 2012. 

OAQPS, 2005. Review of the National Ambient Air Quality Standards for Particulate 

Matter: Policy Assessment of Scientific and Technical Information. U.S. Environmental 

Protection Agency Office of Air Quality Planning and Standards, Research Triangle Park, 

North Carolina, December, 2005 

Ono, 1990. Ono, Duane, William Taylor and Debra Lawhon, (1990), Air Quality 

Management Plan for the Town of Mammoth Lakes, Great Basin Unified Air Pollution 

Control District and the Town of Mammoth Lakes, Bishop, CA, November 30, 1990. 

Satterfield, 1994a. No Burn Day Compliance Study for the Town of Mammoth Lakes, 

California, Charles G. Satterfield, Satterfield & Associates, June Lake, California, June 

16, 1994. 

Satterfield, 1994b. Street Sweeper Efficiency Study for the Town of Mammoth Lakes, 

Charles G. Satterfield, Satterfield & Associates, June Lake, California, June 13, 1994. 

Town of Mammoth Lakes, 2007a. Town of Mammoth Lakes General Plan, 2007. 

Town of Mammoth Lakes, 2007b. Final Environmental Impact Report for the Town of 

Mammoth Lakes 2005 General Plan Update, 2007. 

Town of Mammoth Lakes, 2013. Building Permit Records as of 6/30/13. 
Mammoth Lakes AQMP 

Appendix A 

Glossary 
1 

Glossary 

AAQS (Ambient Air Quality Standards): Health and welfare based standards for clean 

outdoor air that identify the maximum acceptable average concentrations of air 

pollutants during a specified period of time. (See NAAQS) 

Air Pollutants: Amounts of foreign and/or natural substances occurring in the 

atmosphere that may result in adverse effects on humans, animals, vegetation, and/or 

materials. 

Ambient Air: The air occurring at a particular time and place outside of structures. Often 

used interchangeably with "outdoor" air. 

APCD (Great Basin Unified Air Pollution Control District): The regional agency with 

authority to regulate stationary, indirect, and area sources of air pollution (e.g., power 

plants, highway construction, and housing developments) within Inyo, Mono, and Alpine 

counties, and governed by a district air pollution control board composed of the elected 

county supervisors and representatives of cities within the district. 

AQMP (Air Quality Management Plan): A Plan prepared by an APCD, for a county or 

region designated as a nonattainment area, for the purpose of bringing the area into 

compliance with the requirements of the national and/or California Ambient Air Quality 

Standards. AQMPs designed to attain national ambient air quality standards are 

incorporated into the State Implementation Plan (SIP). 

Attainment: Compliance with the National and/or California Ambient Air Quality 

Standards (NAAQS OR CAAQS). 

CAA (Federal Clean Air Act): A federal law passed in 1970 and amended in 1977 and 

1990 which forms the basis for the national air pollution control effort. Basic elements of 

the act include national ambient air quality standards for major air pollutants, air toxics 

standards, acid rain control measures, and enforcement provisions. 

California Ambient Air Quality Standard: Standards set by the State of California for the 

maximum levels of air pollutants which can exist in the outdoor air without unacceptable 

effects on human health or the public welfare. These are generally more stringent than 

NAAQS. 

CARB (California Air Resources Board): The State's lead air quality agency, consisting 

of a nine-member Governor-appointed board. It is responsible for attainment and 

maintenance of the State and federal air quality standards, and is primarily responsible 

for motor vehicle pollution control. It oversees county and regional air pollution 

management programs. 

Emission Standard: The maximum amount of a pollutant that is allowed to be 

discharged from a polluting source such as an automobile or chimney. 
2 

GBUAPCD: The Great Basin Unified Air Pollution Control District. 

Indirect Source: Any facility, building, structure, or installation, or combination thereof, 

which generates or attracts mobile source activity that results in emissions of any 

pollutant (or precursor). Examples of indirect sources include employment sites, 

shopping centers, housing developments, airports, commercial and industrial 

development, and parking lots and garages. 

Maintenance Plan: In general, a plan that details the actions necessary to maintain air 

quality standards. In particular, the federal Clean Air Act requires maintenance plans for 

areas that have been redesignated as attainment areas. 

Mobile Sources: Moving sources of air pollution such as automobiles, motorcycles, 

trucks, off-road vehicles, boats and airplanes. 

NAAQS (National Ambient Air Quality Standards): Standards set by the federal U.S. 

EPA for the maximum levels of air pollutants which can exist in the outdoor air without 

unacceptable effects on human health or the public welfare. 

Nonattainment Area: A geographic area identified by the U.S. EPA and/or CARB as 

not meeting either NAAQS or CAAQS standards for a given pollutant. 

PM (Particulate Matter): Solid or liquid particles of soot, dust, smoke, fumes, and 

aerosols. 

PM-10 (Particulate Matter less than 10 microns): A major air pollutant consisting of tiny 

solid or liquid particles of soot, dust, smoke, fumes, and aerosols. The size of the 

particles (10 microns or smaller, about 0.0004 inches or less) allows them to easily 

enter the air sacs in the lungs where they may be deposited, resulting in adverse health 

effects. PM-10 also causes visibility reduction and is a criteria air pollutant. 

PM-2.5 (Particulate Matter less than 2.5 microns): A major air pollutant consisting of 

tiny solid or liquid particles, generally soot and aerosols. The size of the particles (2.5 

microns or smaller, about 0.0001 inches or less) allows them to easily enter the air sacs 

deep in the lungs where they may cause adverse health effects, as noted in several 

recent studies. PM2.5 also causes visibility reduction, 

SIP (State Implementation Plan): A document prepared by each state describing 

existing air quality conditions and measures which will be taken to attain and maintain 

national ambient air quality standards (see AQMP). 

Smoke: A form of air pollution consisting primarily of particulate matter (i.e., particles). 

Other components of smoke include gaseous air pollutants such as hydrocarbons, 

oxides of nitrogen, and carbon monoxide. Sources of smoke may include fossil fuel 

combustion, agricultural burning, and other combustion processes. 
3 

Stationary Sources: Non-mobile sources such as power plants, refineries, and 

manufacturing facilities which emit air pollutants; can include area sources depending 

on context. 

U.S. EPA (United States Environmental Protection Agency): The federal agency 

charged with setting policy and guidelines, and carrying out legal mandates for the 

protection of national interests in environmental resources. 

VMT: Total vehicle miles traveled by all or a subset of mobile sources. 

Visibility: The distance that atmospheric conditions allow a person to see at a given 

time and location. Visibility reduction from air pollution is often due to the presence of 

sulfur and nitrogen oxides, as well as particulate matter. 
Mammoth Lakes AQMP 

 Appendix B 

Residential Wood 

Burning Survey 2013 

Summary 
Home Heating Survey Summary Report: 

Prepared by: Megan Rybacki, Planning Intern 

The home heating survey was sent to over 6,000 out-of-town property owners, 4,500 Town P.O. Box holders and 

200 private P.O. boxes. Out of these 10,700 property owners and renters there were 574 respondents to the 

survey. The variety of respondents whom participated in the survey gives the town an accurate snapshot of data 

that can be used to analyze the community’s home heating habits. 

Over 85% of the respondents indicated that they owned property in Mammoth Lakes and 75% of these 

homeowners purchased their homes after the woodstove ordinance was put into effect in 1990. Of the indicated 

property owners there were 295 condominiums, 178 single family homes and approximately 44% these property 

owners consider themselves full time occupants during the winter months of November through March. The 

remaining 15% of the survey respondents indicated that they were renters and 92% of these renters consider 

themselves full occupants during the winter months of November-March. The rental residence respondents 

include 30 condominiums, 28 apartments, 27 single family homes and 1 mobile home. 

Only 156 (28%) of the survey respondents indicated that a wood burning appliance was their homes primary 

source of heat. Out of these primary wood burning responses 50% are operating a wood burning appliance and 

over 25% are operating a pellet burning appliance. 34 people are operating an EPA phase II appliance, while 

another 34 are operating an EPA phase I appliance, 24 people are operating a fireplace with an insert, and 13 

people are operating a non-compliant woodstove or fireplace. The majority of these respondents are using 

approximately 1-3 cords of wood per average winter season. 

Over 77% of the survey participants are using an alternative home heating device as their primary source of heat, 

including various propane devices as the most specified appliance. 

General findings show that 93% of the respondents are only burning dry wood, however 3 respondents admitted 

to burning their trash. Other poor burning techniques were revealed in this process. Based on these responses and 

a significant number of respondents whom indicated interest in becoming educated on the proper techniques of 

burning, I believe that it would be beneficial for the town to produce educational information on burning wise and 

specify items that are detrimental to the air quality and their home heating appliance when burned. 

In addition to these findings the Town’s cinder “concerns” were validated by many of the respondent’s 

suggestions that the usage and maintenance of cinders used on the town’s roadways is a large factor in generating 

poor air quality. Based on the survey results and the findings that will be identified in the air filter analysis, it 

could become beneficial for the town to analyze cinder usage and begin to consider other de-icing agents. 

Almost 80% of the respondents were aware that the town issues no burning and burning curtailment days. Over 

200 full time and part time residents also concluded that they would like to become a part of the Air Quality 

Notify Me list. 

In conclusion of the survey results, gathered changeout data, public outreach strides, and fewer federal air quality 

regulation compliance issues it is evident that the Town has taken great strides to begin to meet more stringent air 

quality state regulations. Attached are informative graphs and raw data generated from the survey results. 
Home	Heating	Survey

1	/	21

85.14% 487

14.86% 85

Q1	Do	you	own	or	rent	your	property

in	Mammoth?

Answered:	572	 Skipped:	0

0% 20% 40% 60% 80% 100%

Own

Rent

Own

Rent

Total 572

Answer	Choices Responses
Home	Heating	Survey

2	/	21

25.62% 124

74.38% 360

Q2	Have	you	owned	your	property

since	before	1990?

Answered:	484	 Skipped:	88

0% 20% 40% 60% 80% 100%

Yes

No

Yes

No

Total 484

Answer	Choices Responses
Home	Heating	Survey

3	/	21

0% 0

64.46% 312

26.24% 127

9.30% 45

Q3	Have	you	replaced	or	installed

your	woodstove	or	home	heating

device	with	a	new	model	after	1990?

Answered:	484	 Skipped:	88

0% 20% 40% 60% 80% 100%

I	don't	know

Yes

No

I	don't	know

I	don't	know

Yes

No

I	don't	know

Total 484

Answer	Choices Responses
Home	Heating	Survey

4	/	21

0% 0

16.99% 96

23.54% 133

8.67% 49

6.73% 38

44.07% 249

Q4	How	often	is	your	property

occupied	during	November-March?

Answered:	565	 Skipped:	7

0% 20% 40% 60% 80% 100%

Never

Less	than	30

days

1-2	months

2-3	months

3-4	months

Full	time

occupancy

Never

Less	than	30	days

1-2	months

2-3	months

3-4	months

Full	time	occupancy

Total 565

Answer	Choices Responses
Home	Heating	Survey

5	/	21

36.17% 204

5.50% 31

57.45% 324

1.24% 7

0% 0

Q5	What	type	of	residence	do	you

own	or	rent?

Answered:	564	 Skipped:	8

0% 20% 40% 60% 80% 100%

Single	family

home

Rental

apartment

Condominium

Mobile	home

Other	(please

specify)

Single	family	home

Rental	apartment

Condominium

Mobile	home

Other	(please	specify)

Total	Respondents:	564

Answer	Choices Responses
Home	Heating	Survey

6	/	21

27.76% 156

67.62% 380

4.63% 26

Q6	Is	a	pellet	or	wood	burning

device	your	home's	primary	source

of	heat?

Answered:	562	 Skipped:	10

0% 20% 40% 60% 80% 100%

Yes

No

Not

applicable

Yes

No

Not	applicable

Total 562

Answer	Choices Responses
Home	Heating	Survey

7	/	21

44.13% 248

12.63% 71

77.05% 433

Q7	What	type	of	heating	device	do

you	use	to	heat	your	home?	(	Please

select	multiple	answers	if

applicable.)

Answered:	562	 Skipped:	10

0% 20% 40% 60% 80% 100%

Wood	burning

device

Pellet

burning

device

Other

Wood	burning	device

Pellet	burning	device

Other

Total	Respondents:	562

Answer	Choices Responses
Home	Heating	Survey

8	/	21

27.08% 65

32.50% 78

29.17% 70

11.25% 27

Q8	Please	identify	the	type	of	wood

burning	appliance	you	use.

Answered:	240	 Skipped:	332

0% 20% 40% 60% 80% 100%

Fireplace

with	insert

EPA	certified

woodstove

(Phase	1)

EPA	certified

woodstove

(Phase	2)

Non-certified

stove	or

fireplace

Fireplace	with	insert

EPA	certified	woodstove	(Phase	1)

EPA	certified	woodstove	(Phase	2)

Non-certified	stove	or	fireplace

Total 240

Answer	Choices Responses
Home	Heating	Survey

9	/	21

97.20% 104

62.62% 67

Q9	If	you	are	able,	please	identify

the	make	and	model	of	your	wood

burning	appliance.

Answered:	107	 Skipped:	465

Make:

Model:

Total	Respondents:	107

Answer	Choices Responses
Home	Heating	Survey

10	/	21

48.32% 115

21.85% 52

13.45% 32

11.76% 28

4.62% 11

Q10	How	many	cords	of	wood	do	you

burn	in	an	average	winter	season?

(A	cord	is	understood	to	be	128

cubic	ft.	of	wood	or	wood	stacked	to

be	4ft	x	4ft	x	8ft.)

Answered:	238	 Skipped:	334

0% 20% 40% 60% 80% 100%

Less	than	1

cord

1-2	cords

2-3	cords

3-4	cords

5	or	more

cords

Less	than	1	cord

1-2	cords

2-3	cords

3-4	cords

5	or	more	cords

Total 238

Answer	Choices Responses
Home	Heating	Survey

11	/	21

31.51% 75

59.24% 141

9.24% 22

Q11	How	do	you	obtain	your

firewood?

Answered:	238	 Skipped:	334

0% 20% 40% 60% 80% 100%

Cut	yourself

Purchase

from...

Other	(please

specify)

Cut	yourself

Purchase	from...

Other	(please	specify)

Total	Respondents:	238

Answer	Choices Responses
Home	Heating	Survey

12	/	21

63.57% 89

0.71% 1

4.29% 6

17.14% 24

22.14% 31

Q12	Where	do	you	purchase	your

firewood	from?

Answered:	140	 Skipped:	432

0% 20% 40% 60% 80% 100%

Greg

Cook/Mammoth

Firewood...

High	Country

Lumber

Do	it	Center

Out	of	town

Other	(please

specify)

Greg	Cook/Mammoth	Firewood	Company

High	Country	Lumber

Do	it	Center

Out	of	town

Other	(please	specify)

Total	Respondents:	140

Answer	Choices Responses
Home	Heating	Survey

13	/	21

1.30% 3

3.46% 8

14.29% 33

28.57% 66

52.38% 121

Q13	How	long	is	your	wood

seasoned	before	you	burn	it?

Answered:	231	 Skipped:	341

0% 20% 40% 60% 80% 100%

A	week

A	few	weeks

A	couple

months

3-6	months

6	months	to

over	a	year

A	week

A	few	weeks

A	couple	months

3-6	months

6	months	to	over	a	year

Total 231

Answer	Choices Responses
Home	Heating	Survey

14	/	21

30.30% 70

22.51% 52

47.19% 109

Q14	How	many	days	do	you	burn

wood	during	a	typical	winter	month?

Answered:	231	 Skipped:	341

0% 20% 40% 60% 80% 100%

1-10	days

10-20	days

20-30	days

1-10	days

10-20	days

20-30	days

Total 231

Answer	Choices Responses
Home	Heating	Survey

15	/	21

92.64% 214

1.30% 3

0% 0

8.66% 20

Q15	Do	you	burn	anything	other

than	dry	wood	in	your	stove?

Answered:	231	 Skipped:	341

0% 20% 40% 60% 80% 100%

I	only	burn

dry	wood

Trash

Coal

Other	(please

specify)

I	only	burn	dry	wood

Trash

Coal

Other	(please	specify)

Total	Respondents:	231

Answer	Choices Responses
Home	Heating	Survey

16	/	21

46.77% 29

29.03% 18

14.52% 9

9.68% 6

Q16	How	many	bags	of	pellets	do

you	use	in	an	average	winter

season?	(A	pallet	of	pellets	equals	1

ton	and	there	are	50	bags	in	a	ton.

One	bag	is	equal	to	40lbs.)

Answered:	62	 Skipped:	510

0% 20% 40% 60% 80% 100%

Less	than	50

bags

50-75	bags

75-100	bags

more	than	100

bags

Less	than	50	bags

50-75	bags

75-100	bags

more	than	100	bags

Total 62

Answer	Choices Responses
Home	Heating	Survey

17	/	21

47.04% 119

63.64% 161

0.40% 1

15.02% 38

Q17	Please	specify	your	alternative

heat	source.	(Please	select	all

choices	that	apply.)

Answered:	253	 Skipped:	319

0% 20% 40% 60% 80% 100%

Electric

heating

device

Propane	gas

heating

device	(ga...

Geothermal/So

lar	heating

device

Other	(please

specify)

Electric	heating	device

Propane	gas	heating	device	(gas	fireplace,	insert,	logs,	etc,.)

Geothermal/Solar	heating	device

Other	(please	specify)

Total	Respondents:	253

Answer	Choices Responses
Home	Heating	Survey

18	/	21

79.48% 430

20.52% 111

Q18	Are	you	aware	that	the	town

calls	no	burn	days	when	the	air

quality	is	forecasted	to	be	poor?

Answered:	541	 Skipped:	31

0% 20% 40% 60% 80% 100%

Yes

No

Yes

No

Total 541

Answer	Choices Responses
Home	Heating	Survey

19	/	21

32.16% 174

40.30% 218

40.30% 218

Q19	Would	you	be	interested	in

improving	the	air	quality	in

Mammoth	Lakes?

Answered:	541	 Skipped:	31

0% 20% 40% 60% 80% 100%

Not

interested

I	would	like

to	become

more	educa...

I	would	like

to	receive

email	or	t...

Not	interested

I	would	like	to	become	more	educated	in	proper	burning

techniques.

I	would	like	to	receive	email	or	text	updates	on	burning

restrictions	and	no	burn	days.

Total	Respondents:	541

Answer	Choices Responses
Home	Heating	Survey

20	/	21

27.78% 150

23.33% 126

46.30% 250

24.26% 131

10.37% 56

Q20	If	the	town	developed	a

program	to	reduce	emissions	I

would	be	interested	in	participating

in	the	following	choices...

Answered:	540	 Skipped:	32

0% 20% 40% 60% 80% 100%

Not

interested

A	woodstove

changeout

program

Home

weatherizatio

n	program

Educational

outreach

program

Other	(please

specify)

Not	interested

A	woodstove	changeout	program

Home	weatherization	program

Educational	outreach	program

Other	(please	specify)

Total	Respondents:	540

Answer	Choices Responses
Home	Heating	Survey

21	/	21

100% 490

0% 0

100% 490

61.22% 300

0% 0

0% 0

0% 0

0% 0

97.76% 479

100% 490

Q21	Thank	you	for	completing	the

home	heating	survey.	Enter	the

following	information	for	a	chance

to	win	a	Von's	gift	card!	(Please

enter	physical	address	and	include

unit	number	to	ensure	that	the

Town	does	not	receive	duplicate

entries.	Please	provide	your	name

for	your	chance	to	win	$150	gift	card

to	Von's.)

Answered:	490	 Skipped:	82

Name:

Company:

Address:

Address	2:

City/Town:

State:

ZIP:

Country:

Email	Address:

Phone	Number:

Total	Respondents:	490

Answer	Choices Responses
Mammoth Lakes AQMP 

Appendix C 

Town of Mammoth Lakes 

Municipal Code 

Chapter 8.30 (Revised) 
Town of Mammoth Lakes 

Municipal Code 

Chapter 8.30 

Particulate Emissions Regulations 

Sections: 

8.30.010 - Purpose. 

8.30.020 - Definitions. 

8.30.030 - Standards for regulation of solid fuel burning appliances. 

8.30.040 - Limitations on number of appliances. 

8.30.050 - Replacement of noncertified appliances upon sale of property. 

8.30.060 - Opacity limits. 

8.30.070 - Prohibited fuels. 

8.30.080 - Mandatory curtailment. 

8.30.090 - Pollution reduction education programs. 

8.30.100 - Road dust reduction measures. 

8.30.110 - Fees. 

8.30.120 - Penalties. 

8.30.010 - Purpose. 

The purpose of this chapter is to improve and maintain the level of air quality of the town 

so as to protect and enhance the health of its citizens by controlling the emissions of 

particulate matter into the air of the community of Mammoth Lakes. 

8.30.020 - Definitions. 

For the purpose of this chapter: 

A. "EPA" means the United States Environmental Protection Agency. 

B. "EPA-certified appliance" means any wood or other solid fuel burning appliance for 

space or water heating or cooking that meets the Phase II performance and emission 

standards of the Environmental Protection Agency. Phase II requirements are 4.1 

grams per hour particulate emission for catalytic appliances and 7.5 grams per hour for 

noncatalytic appliances. Pellet fueled wood heaters and EPA Phase II qualified 

fireplaces and fireplace retrofit devices shall be considered as meeting Phase II 

requirements. All other solid fuel burning appliances shall be considered noncertified. 

C. “Opacity” means the amount of light obscured by particulate matter in the air as may 

be measured using EPA Method 9 (40 CFR 60, App. A). 

D. "Pellet fueled wood heater" means any heater designed to heat the interior of a 

building that operates on pelletized wood and has an automatic feed. 
E. "Permanently inoperable" means modified in such a way that the appliance can no 

longer function as a solid fuel appliance or easily be remodified to function as a solid 

fuel appliance. Permanent conversion to other fuels, such as gas, is permitted. 

F. "Solid fuel burning appliance, heater or device" means any fireplace, wood burning 

heater or coal stove or structure that burns wood, coal or any other nongaseous or 

nonliquid fuels, or any similar device burning any solid fuel used for aesthetic, water 

heating, or space heating purposes. 

8.30.030 - Standards for regulation of solid fuel burning appliances. 

A. No solid fuel burning appliance shall be permitted to be installed within the town 

unless the appliance is certified as meeting the emission requirements of the U.S. 

Environmental Protection Agency (EPA) for Phase II certification. 

B. The restrictions of this section shall apply to all solid fuel burning appliances including 

unregulated fireplaces. 

C. For the purposes of enforcing this chapter, the Town shall keep a record of all 

certified appliances installed in Mammoth Lakes in accordance with this chapter and of 

properties which have been determined to conform to the requirements of this chapter. 

8.30.040 - Limitations on number of appliances. 

A. Single Family Dwellings. No more than one EPA-certified appliance may be installed 

in any new single family detached dwelling. Existing properties with one or more 

existing solid fuel burning appliances may not install additional solid fuel burning 

appliances. One pellet fueled wood heater per dwelling shall be allowed in addition to 

the one EPA-certified appliance. 

B. Multi-Unit Residential Developments. No solid fuel burning appliance may be 

installed in any new multi-unit residential development; however, one pellet fueled wood 

heater per dwelling may be installed in a multi-unit residential development. 

C. Commercial or Lodging Developments. No solid fuel burning appliance shall be 

installed in any new commercial or lodging development project. 

D. Solid fuel burning appliances shall not be considered to be the primary form of heat 

in any new construction. 

E. No new and replacement appliances shall be installed without first obtaining a 

building permit from the Town. All installations shall require an inspection and approval 

by the building division prior to operation. 

F. Verification of compliance shall be certified by an inspector of the Town’s building 

division. 
8.30.050 - Replacement of noncertified appliances upon sale of property. 

A. Prior to the completion of the sale or transfer of a majority interest in any developed 

real property within the town, all existing noncertified solid fuel burning appliances shall 

be replaced, removed, or rendered permanently inoperable. If the buyer assumes 

responsibility for appliance replacement or removal in writing on a form approved by the 

Community and Economic Development Director, the deadline for such action shall be 

extended to 60 calendar days from the date of completion of the sale or transfer. The 

buyer shall contact the building division no later than 60 calendar days from the date of 

completion of sale to schedule an inspection. 

B. The building division shall inspect the appliance(s) in question to assure that they 

meet the requirements of this chapter. Within five working days from the date of the 

inspection, the building division shall issue a written certification of compliance or 

noncompliance for the affected property. If the inspection reveals that the subject 

property does not comply with the requirements of this chapter, all noncomplying solid 

fuel burning appliances shall be replaced, removed, or rendered permanently 

inoperable. In this event, reinspection shall be required prior to certification of 

compliance. 

C. No building permit shall be issued for an increase in habitable area of a structure that 

has not complied with the requirements of this section. 

D. Existing appliances certified as meeting EPA Phase I requirements or Oregon 

Department of Environmental Quality requirements are not subject to the replacement 

requirements. 

E. Pursuant to Section 1102.6(a) of the California Civil Code, sellers of residential real 

property shall disclose to purchasers of such property the provisions of this chapter. 

This disclosure obligation shall be satisfied by providing to each purchaser a “Local 

Option Real Estate Transfer Disclosure Statement” specified by the Town and by 

providing a copy of this chapter. 

F. If developed real property is to be sold which does not contain a solid fuel burning 

appliance, a form approved by the building division, containing the notarized signatures 

of the seller, the buyer, and the listing real estate agent attesting to the absence of any 

fuel device, may be accepted in lieu of an inspection. A written exemption shall be 

issued by the building division. 

G. No appliance(s) removed under the provisions of this section may be replaced 

except as provided by this chapter. 

H. This section shall not be applicable to National Forest permittees located west of Old 

Mammoth Road in Sections 4 and 9 of Township 4 S., Range 27 E., MDBM, or National 

Forest permittees located above 8,500 feet elevation above sea level. 
8.30.060 - Opacity limits. 

No person shall cause or permit emissions from a solid fuel burning appliance to be 

readily visible, for a period or periods aggregating more than three minutes in any onehour period. Emissions created during a 15 minute start-up period are exempt from this 

regulation. Readily visible emissions means smoke easily seen when viewed against 

any contrasting background including, but not limited to native conifers or a blue sky 

and may be equated with an opacity limit of 20 percent or greater as designated by the 

shade No. 1 on the Ringelmann Chart. 

8.30.070 - Prohibited fuels. 

Burning of any fuels or materials other than the following fuels within the town shall be 

in violation of this chapter: 

A. Untreated wood; 

B. Uncolored paper, including newspaper; and 

C. Manufactured logs, pellets, and similar manufactured fuels. 

8.30.080 - Mandatory curtailment. 

A. The Town Manager shall appoint an air quality manager. The duty of the air quality 

manager shall be to determine when curtailment of solid fuel combustion in the town is 

necessary, notify the community that curtailment is required, and make such other 

determinations as are necessary to carry out the objectives of this chapter. 

B. Determination that curtailment is required shall be made when PM-10 levels have 

reached 130 micrograms/m3 or when adverse meteorological conditions are predicted 

to persist. Should it be determined that 130 micrograms/m3 is not a low enough 

threshold to prevent the Town from violating the National Ambient Air Quality Standard 

for 24 hours (NAAQS, 24 hours), that threshold may be lowered by resolution of the 

Town Council. 

C. Upon the determination that curtailment is required, the air quality manager shall 

contact all radio stations and television stations in Mammoth Lakes and have them 

broadcast that it is required that there be no wood or other solid fuel burning. The air 

quality manager shall also record a notice on a telephone line dedicated to this purpose 

and post a notice in the Town offices. The air quality manager may utilize additional 

methods of communication to effectively inform Mammoth Lakes’ residents and visitors 

of burning restrictions. Upon such notice, all wood and other solid fuel combustion shall 

cease. 
D. All dwelling units being rented on a transient basis which contain a solid fuel burning 

appliance shall post, in a conspicuous location near the appliance, a notice indicating 

that no-burn days may be called and informing the tenants about sources of information 

on no-burn days. 

E. All persons renting units which contain a solid fuel burning appliance shall inform 

their tenants that solid fuel burning may be prohibited on certain days and that the 

person signing the rental agreement shall be responsible for assuring that the no-burn 

requirements are obeyed during the rental period identified on the rental agreement. 

F. For residences where a solid fuel burning appliance is the sole means of heat, these 

curtailment regulations do not apply. For a residence to be considered as having solid 

fuel as its sole source of heat, the owner must apply to the building division for an 

exemption and the department must inspect the residence and certify that no other 

adequate source of heat is available to the structure. Adequate source shall mean that 

the alternate source of heat cannot produce sufficient heat for the residence without 

causing a hazard. A written exemption will then be granted. Where an adequate 

alternate source of heat is determined to have been removed from the structure in 

violation of the building codes, a sole source exemption shall not be issued. Sole source 

exemptions shall not be granted for nonresidential uses. 

G. Pellet fueled heaters shall not be subject to the provisions of this section. 

H. This section shall not apply to National Forest permittees located west of Old 

Mammoth Road, in Sections 4 and 9 of Township 4 S., Range 27 E., MDBM, or 

National Forest permittees located above 8,500 feet elevation above sea level. 

8.30.090 - Pollution reduction education programs. 

The Town Manager or his/her designee is directed to undertake such public education 

programs as are reasonably calculated to reduce particulate air pollution within the 

town, including particulate emissions from sources other than solid fuel burning 

appliances. In addition to the notification measures listed in Section 8.30.080.C, the 

public education programs shall include additional measures to inform the public of 

burning curtailment requirements. 

8.30.100 - Road dust reduction measures. 

A. The Public Works Director shall implement a vacuum street sweeping program to 

reduce PM-10 emissions resulting from excessive accumulations of cinders and dirt. 

B. The Town shall, in its review of proposed development projects, incorporate 

measures which reduce projected total vehicle miles traveled. Examples of such 

measures include, but are not limited to, circulation system improvements, mass transit 

facilities, private shuttles, and design and location of facilities to encourage pedestrian 

circulation. The goal of the Town's review shall be to limit peak vehicle miles traveled to 
179,708 on any given day on the roadway segments evaluated in the Mammoth Lakes 

Vehicle Miles Traveled Analysis (LSC, August, 2012). 

8.30.110 - Fees. 

A fee shall be charged for the inspection and permitting services of the Town. The fee 

shall be established in the Town master fee schedule. 

8.30.120 - Penalties. 

A. It is illegal to violate any requirements of this chapter. Any owner of any property 

which is in violation of the requirements of this chapter shall be guilty of an infraction. 

Any person operating a solid fuel burning appliance in violation of this chapter is guilty 

of an infraction. The third violation by the same person within a 12 month period shall 

constitute a misdemeanor. Prosecution of any violation of Subsection 8.30.080.E, 

relating to exemptions from curtailment, may be against the property owner, the 

occupant, or both. 

B. Violation of any portion of this chapter may result in assessment of civil penalties 

against the property and against an individual person or persons in accordance with 

Chapter 1.12, General Penalty. 

C. Each and every day a violation exists is a new and separate violation. Right to 

appeal, hearings, and collection of civil penalties shall be pursuant to the procedures set 

forth in Chapter 8.20, Nuisances. 

D. Nothing in this section shall prevent the Town from pursuing criminal penalties or 

using any other means legally available to it in addressing violations of this chapter. 

E. Whenever necessary to make an inspection to enforce any of the provisions of this 

code, or whenever the air quality manager or his/her authorized representative has 

reasonable cause to believe that there exists in any building or upon any premises any 

condition which violates the provisions of this chapter, the air quality manager or 

authorized representative may enter such building or premises at all reasonable times 

to inspect the same or to perform any duty imposed upon the air quality manager by this 

code; provided, that if such building or premises be occupied, he/she shall present 

proper credentials and request entry; and if such building or premises be unoccupied, 

he/she shall first make a reasonable effort to locate the owner or other persons having 

charge or control of the building or premises and request entry. If such entry is refused, 

or if the owner or person having charge or control of the building or premises cannot be 

contacted, the air quality manager or authorized representative shall have recourse to 

every remedy provided by law to secure entry. 
Mammoth Lakes AQMP 

Appendix D 

VMT Estimates for Days of 

Air Quality Monitoring – 

2003 to 2011 

(LSC, 2013) 






Mammoth Lakes AQMP 

Appendix E 

Mammoth Lakes 

Vehicle Miles Traveled Analysis 

(LSC, 2012) 
 

TECHNICAL MEMORANDUM 

DATE: August 3, 2012 

TO: Ellen Clark, Town of Mammoth Lakes 

 

FROM: Sara Hawley, PE and Leslie Suen, EIT, LSC Transportation Consultants, Inc. 

SUBJECT: Mammoth Lakes Vehicle Miles Traveled Analysis 

As requested, LSC Transportation Consultants, Inc. has completed the analysis of Vehicle Miles 

Traveled (VMT) for the Town of Mammoth Lakes for use in the preparation of a Greenhouse 

Gas (GHG) inventory and an update to the 1990 Air Quality Management Plan. This memo 

presents the townwide VMT by roadway speed, as well as a limited analysis of VMT for external 

trips. 

VMT by Travel Speed 

Using the 2011 Town of Mammoth Lakes TransCAD Travel Model, VMT was calculated and 

grouped into speed classes based on the 85th-percentile roadway speed, as shown in Table 1. 

VMT is calculated by multiplying the length of a roadway segment by the volume on that 

roadway. A map of the roadway speeds for all the roads in the model can be found in Appendix 

A, attached. Also shown in Appendix A are all the roadways included in the VMT analysis, which 

total approximately 240 roadways with 1,037 segments. The model reflect a typical winter 

Saturday, which will subsequently be called a ‘peak day’ throughout this report. Peak day 

conditions for both existing 2009 and future 2030 (reflecting build out of the general plan) 

scenarios were taken directly from the model. As indicated, a total of approximately 144,192 

VMT are estimated to be generated in Mammoth over the course of an existing peak winter day, 

and approximately 179,708 VMT are estimated to be generated on a peak day in the future. 

This indicates a 25 percent increase by the time that buildout of the General Plan occurs 

(estimated at the year 2030). 

In order to estimate annual average day conditions, peak day VMT was factored using Caltrans 

data along State Route (SR) 203. Specifically, daily traffic volumes at six locations on SR 203 

within the Town of Mammoth Lakes were reviewed. As shown in Table 2, the percent decrease 

between peak month average daily traffic (Peak Month ADT) and annual average daily traffic 

(AADT) ranges from approximately 17 percent to 29 percent. The weighted average percent 

decrease is calculated to be about 23 percent. This reduction was applied to the model’s peak 

day VMT results, in order to estimate the VMT on an annual average day. As shown on the right 

side of Table 1, a total of approximately 111,287 VMT are estimated to be generated in 

TRANSPORTATION PLANNING AND 

TRAFFIC ENGINEERING CONSULTANTS 

2690 Lake Forest Road, Suite C 

Post Office Box 5875 

Tahoe City, California 96145 

(530) 583-4053 • FAX: 583-5966 

www.lsctahoe.com • info@lsctahoe.com 
Mammoth Lakes VMT Page 2 August 3, 2012 

 

Mammoth over the course of an existing annual average day, and approximately 138,698 VMT 

are estimated to be generated on an average day in the future. 

In 1990 a similar VMT study was completed in combination with the Air Quality Management 

Plan for the Town of Mammoth Lakes (November 30, 1990). The methodology used in the 1990 

study and this VMT study are similar. Both studies are based on a travel demand model that 

assumes full buildout of the Town’s General Plan in the future. Both studies include all of the 

Town’s major roadways. The main difference is the extent of the roadways analyzed in each 

study. The 1990 study had a total of 10.9 miles of roadways on 8 different roads (with 17 

segments) for the existing year 1990 VMT, while the future year 2005 had a total of 15.8 miles 

of roadways on 10 different roads (with 31 segments). In contrast, this study’s VMT analysis 

included 93.1 miles of roadways on 420 different roads (with 1,037 segments) for both the 

existing and future analysis years. The higher number of miles of roadways included in this 

VMT analysis produces higher VMT estimates than the 1990 study. Additional comparison 

between the two studies can be found in the attached memo Mammoth Lakes Vehicle Miles 

Traveled Analysis – Comparison with 1990 Study (LSC, September 10, 2012). 

External VMT 

LSC reviewed information provided in the existing model at the two external points representing 

trips to/from Highway 395 - one on SR 203 east of Meridian Boulevard and one on Mammoth 

Scenic Loop north of town. Nearly all (approximately 97 percent) of the trips that enter and exit 

the model area use SR 203 to the east. A total of 8,880 vehicles are estimated to pass through 

the external points over the course of a peak day (total in both directions). Of the total number of 

trips generated in the Mammoth Lakes model area, about 15 percent are external trips, meaning 

they have either an origin or destination outside the model area. It should be noted that as the 

peak day of traffic activity is a winter Saturday, these figures do not reflect the many recreational 

trips occurring on a Friday or Sunday. 

Trip Types 

External trips can be broken down into the following five model trip types: 

• home-based work 

• home-based shopping 

• home-based recreation 

• home-based other 

• other to other (example: work to shopping) 

The large majority of the external trips (approximately 88 percent) are home-based recreation 

trips, such as a trip made by a person staying in Bishop and skiing in Mammoth Lakes, or 

staying in Mammoth and going elsewhere for recreation. The remaining 12 percent of trips are 

equally distributed among the other trip types, with approximately 3 percent of each trip type, as 

shown in Table 3. 

Future external trips were also obtained from the model, and they are presented in Table 4. 

Again, the majority (85 percent) of the future external trips are generated by home-based 

recreation trips. 

Residents vs Visitors 
Mammoth Lakes VMT Page 3 August 3, 2012 

 

Trips going through the external points in the model were reviewed with respect to trips made by 

residents versus visitors. A precise breakdown cannot be provided based on available data. 

However, it is assumed that the majority of the external trips on a peak winter day are made by 

visitors, given that most of the external trips are “home-based recreation” trips, which is a trip 

type primarily associated with visitors. It is also expected that the majority of home-based 

shopping trips are made by visitors. The remaining trip types (home-based work, home-based 

other, and other to other) are not assumed to be made by visitors. 

Similarly, the split of residents versus visitors for internal trips cannot be provided based on 

available data. However, a general breakdown can be made based on the number of resident 

dwelling units and visitor dwelling units. In the TransCAD model, there are about 5,600 existing 

resident dwelling units and 5,000 visitor dwelling units (which include single-family vacation 

homes and lodging units). As the trip generation rate in the model is slightly higher for 

residential units, the total number of trips generated by residents is nearly equal to the total trips 

generated by visitors. Furthermore, the trip lengths for internal trips made by residents and 

visitors are assumed to be similar. Therefore, the resident/visitor split for VMT internal to 

Mammoth Lakes is estimated to be roughly a 50/50 split. 

Residence Locations of Commuters 

Data from the US Census 2010 indicates that more than half (approximately 57 percent) of 

persons who work in Mammoth Lakes also reside in Mammoth Lakes. About 12 percent of 

persons employed in Mammoth Lakes live in Bishop, California, with the remaining 31 percent 

residing in various locations throughout the Eastern Sierra. Of the workers commuting to 

Mammoth Lakes from external points, about 58 percent are estimated to reside in points to the 

north of Mammoth along US 395 and 42 percent are estimated to live to the south. Detailed 

percentages for each town in the Eastern Sierra are shown in Figure 1. Note the census data 

includes the Mammoth Yosemite Airport within the Mammoth Lakes analysis area. 

Of all workers residing in Mammoth Lakes, almost all (approximately 96 percent) are employed 

in Mammoth Lakes. In other words, very few persons living in Mammoth Lakes leave the 

community to go to work. 

Residence Locations of Visitors 

The residence locations of visitors traveling to Mammoth Lakes from more remote destinations 

was reviewed, based upon data provided in the Town of Mammoth Lakes Winter Survey

(Leisure Trends Group, 2007). Based on this survey, and shown in Figure 2 the home regions 

of all visitors to Mammoth include: 

• Greater Los Angeles Area – 29% 

• Outside California – 17% 

• Orange County – 16% 

• San Diego County – 14% 

• Central Valley and Northern California – 13% 

• Central Coast – 11% 

The top home states for the 17 percent of visitors from outside California are Nevada, Maryland, 

Texas, Washington, Idaho, Arizona, Oregon and Utah (each state representing four percent or 

less of all visitors). 
Mammoth Lakes VMT Page 4 August 3, 2012 

 

Trips to/from Mammoth Yosemite Airport 

According to the 2007 Winter Survey, almost all respondents arrived via private automobile and 

no respondents reported flying to the Mammoth Yosemite Airport. This is unsurprising since 

commercial air service was not available at this time, but has since become available. Many 

hotels in Mammoth provide a free shuttle service to and from the airport in connection with flight 

times, and rental cars and taxi service are available at the airport. While it is difficult to quantify 

exactly how many trips from various locations may have shifted from driving to flying since air 

service started, it is probable that at least a small portion of previous driving trips are now made 

by air. However, this shift is likely to be accompanied by a certain number of new airport-related 

trips including employee and passenger trips to and from Mammoth, and new visitors. Overall, 

the net change to VMT associated with airport-related trips is likely negligible relative to total 

daily trip volumes. 

Estimate of Total External VMT 

In order to determine the total VMT associated with activity in the Town of Mammoth Lakes, the 

VMT of the external part of the external trips (i.e. outside of the model area) needs to be 

considered. In VMT analyses for communities with high levels of visitor/tourism activity, some 

portion of the trip length that occurs outside the model area is typically allocated to the study 

community. For example, in recent VMT analyses conducted in Shasta County and in the Lake 

Tahoe area, 50 percent of the external VMT were allocated to the study area. For the purposes 

of this analysis, 100 percent of the external VMT is allocated to Mammoth Lakes. 

To estimate the external VMT, the approximate mileage between Mammoth and each of the 

external locations shown in Figures 1 and 2 was estimated for each trip type. Of the homebased recreation trips, about 10 percent are assumed to be made to/from the Bishop area, 

reflecting that some visitors stay overnight at locations near Mammoth as a part of their trip, and 

that visitors staying in Mammoth will recreate in locations outside of the town itself. The 

remainder is allocated proportionately to the various points of visitor origin indicated in the 2007 

survey. Multiplying the mileage by the number of external trips for each trip type yields the 

external VMT by trip type, as shown in Table 5. 

Note all external VMT was calculated based on the TransCAD traffic model which estimates a 

busy winter Saturday, which when the highest traffic volumes occur in Mammoth Lakes but may 

not be when the peak external trips occur. A general estimation can be made of average annual 

daily VMT by reducing the peak VMT by 23 percent, which is the same percent internal VMT 

was reduced, as shown in Table 5. 

Total Yearly VMT 

Total VMT for one year is estimated based on the assumption that visitors’ home regions are 

similar in the summer and winter, as indicated in the Town of Mammoth Lakes Winter Survey

(Leisure Trends Group, 2007) and Town of Mammoth Lakes Summer Survey (Leisure Trends 

Group, 2008). Adding the existing internal annual average VMT (111,287) to the external annual 

average VMT (1,730,000) yields a total of about 1,841,000 VMT per annual average day. 

Multiplying this total by 365 days per year yields about 672 million existing VMT per year. A 

similar calculation can be done for future VMT, which results in a total of about 705 million VMT 

per year in 2030. 





Mammoth Lakes AQMP 

Appendix F 

Mammoth Lakes 

Vehicle Miles Traveled Analysis 

Comparison with 1990 Study 

(LSC, 2012) 
 

TECHNICAL MEMORANDUM 

DATE: September 10, 2012 

TO: Ellen Clark, Town of Mammoth Lakes 

 

FROM: Sara Hawley, PE and Leslie Suen, EIT, LSC Transportation Consultants, Inc. 

SUBJECT: Mammoth Lakes Vehicle Miles Traveled Analysis – Comparison with 1990 Study 

As requested, LSC Transportation Consultants, Inc. has completed an additional analysis of Vehicle 

Miles Traveled (VMT) for the Town of Mammoth Lakes to compare the 2012 VMT analysis to the 

previous 1990 Air Quality Management Plan (AQMP) VMT Study. First, the VMT on each roadway in 

the 1990 study was estimated, and the results are listed in Table A. As discussed in the 2012 VMT 

analysis memorandum, there are more miles of roadway included in the current TransCAD model 

than in the 1990 study. The VMT in the current TransCAD model was estimated for only those 

roadway segments included in the 1990 study. As shown in the right columns in Table A, a total of 

approximately 80,586 existing VMT and 110,641 future VMT are estimated on those roadways 

included in the 1990 study. Of the total existing VMT in the current TransCAD model network 

(144,192), about 56 percent are reflected on the roadways included in the 1990 study. Similarly, of 

the total future VMT in the current model (179,708), about 62 percent occur on roadways included 

on the 1990 study. The remaining VMT occurs on the smaller roads that were not included in the 

1990 study. Note that these figures are based on peak-day conditions, consistent with the 1990 

study. 

The following findings are made regarding the VMT on the roadways included in the 1990 Study: 

• Overall, the VMT in Mammoth Lakes has increased from approximately 66,275 in 1990 to 

approximately 80,856 in 2009. This equates to a total increase of approximately 22 percent 

over 19 years. 

• In 1990, the future forecast indicated that the existing VMT would increase by more than 

double (approximately 222 percent) by 2005. Given that the VMT in 2009 was only slightly 

higher than the VMT in 1990, this high rate of growth has not occurred. 

• The future (2005) VMT forecasts made in 1990 are much higher than the future (2030) 

forecasts in the current TransCAD model, reflecting that the growth rate has decreased since 

1990 and future development is expected to occur at a slower rate. Based on the current 

TransCAD model, VMT on the roadways included in the 1990 study is expected to increase 

by a total of 37 percent from 2009 to 2030. 

TRANSPORTATION PLANNING AND 

TRAFFIC ENGINEERING CONSULTANTS 

2690 Lake Forest Road, Suite C 

Post Office Box 5875 

Tahoe City, California 96145 

(530) 583-4053 • FAX: 583-5966 

www.lsctahoe.com • info@lsctahoe.com 
Table A: Vehicle Miles Traveled (VMT) Comparison

Roadway From To Existing (1990) Future (2005) Exis

(20

SR203/Main Street Meridian Blvd Minaret Road 23,625 27,790 2

 

Lake Mary Road Minaret Road Twin Lakes Parking Lot 5,700 11,215 

 

Meridian Blvd Majestic Pines Road Highway 203 6,650 25,150 1

 

Old Mammoth Road Main Street Ranch Road 11,900 Old Mammoth Road1 Ranch Road Red Fir Rd - 

Sherwin Creek (Old Mammoth Road Extension)2 Old Mammoth Road South 0.1 miles - 350 

 

Forest Trail Main Street Minaret Road 1,500 1,500 

 

Canyon Blvd Lake Mary Road3 Canyon Lodge Parking 2,400 4,980 

 

Lakeview Blvd Canyon Lodge Parking Canyon Blvd (East) 5,000 7,100 

 

Kelley/Majestic Pines4 Lake Mary Road Meridian Blvd 750 2,800 

 

Majestic Pines Extension Meridian Blvd Old Mammoth Road - 3,000 

 

SR203/Minaret Road Main Street Scenic Loop Road 8,750 16,160 

 

Minaret Road Main Street Old Mammoth Road - 26,235 

 

Total 66,275 146,915 

Total VMT of all roadways included in the 2011 TransCAD Model 14

Portion of VMT included on the 1990 Study roadways 

Note 1: The segment of Old Mammoth Road from Ranch Road to Red Fir Road did not exist in 1990.Note 2: The Old Mammoth Road Extension is not included in the TransCAD model.Note 3: In the 1990 VMT Study, Canyon Blvd is assumed to start at Minaret Road, consistent with its previous alignment. Note 4: The Majestic Pines Extension is not included in the TransCAD model. Source: LSC Transportation Consultants, Inc.

20,635

Estimated VMT in 1990 

Air Quality Management 

Plan Study

2011 

1
Mammoth Lakes AQMP 

Appendix G 

Chemical Analysis of PM10 and 

PM2.5 Filters from 

Mammoth Lakes 

(DRI, 2013) 
1

Chemical Analysis of PM10 and PM2.5 filters from 

Mammoth Lakes 

Final Report 

Prepared by: 

Mark C. Green 

Division of Atmospheric Sciences 

Desert Research Institute 

2215 Raggio Parkway 

Reno, NV 89512 

Prepared for the Town of Mammoth Lakes 

May 21, 2013 

 
2

Chemical Analysis of PM10 and PM2.5 filters from Mammoth Lakes 

Introduction 

A study was conducted to try to gain understanding regarding source contributions to high PM10 

values recorded at the Mammoth Lakes Gateway air quality monitoring site. 

DRI proposed to analyze fifteen PM10 and five PM2.5 filters (dates and concentrations shown in 

Tables 1 and 2) for elements and ions. The fifteen PM10 filters included the nine highest and 

11th highest PM10 filter concentration days since 2001, eight of which were since the start of 

2008. The other five PM10 filters are days for which high PM10 and/or PM2.5 concentrations 

were measured and both PM10 and PM2.5 filters are available for each day. Three of these five 

days had the highest PM10 for days with PM2.5 filters also. The other two days had high PM2.5 

and high PM2.5 to PM10 ratios (indicative of large relative wood smoke impact). Because the 

road dust is expected to be mostly in the larger sizes and wood smoke is mostly in the small sizes 

(PM2.5) analyzing both PM10 and PM2.5 for a few days will be informative and will provide 

supporting evidence for our estimates based on the PM10 data. 

The samples proposed to be analyzed are listed below. 

Table 1. Dates with only PM10 filters: 

Date 

PM10 

concentration 

12/21/2001 134.2 

2/13/2002 129.3 

1/1/2008 85.9 

2/9/2008 96.7 

2/27/2008 95.5 

2/21/2009 117.6 

1/2/2010 101.3 

1/29/2010 104.0 

2/13/2010 92.0 

1/12/2011 127.6 

Table 2. Dates with PM10 and PM2.5 filters: 

Date PM10 PM2.5

3/14/2001 55.0 35.2

12/17/2003 74.6 33.5

1/13/2005 39.3 27.0

1/19/2005 85.1 25.2

1/22/2005 77.8 27.4
3

Filters for the three days in 2001 and 2002 were not provided to DRI for analysis. Chemical 

analysis of filters was done on the remaining samples listed above, and included twelve PM10 

filters and four PM2.5 filters. 

The chemical analysis included X-ray fluorescence (XRF, giving most elements), ion 

chromatography (anion and cations), and light absorption. The XRF analysis provides the road 

dust elements, ion chromatography the contributions from sulfate and nitrate, and ammonium 

(associated with nitrate and sulfate). The light absorption measurement is a good indicator of 

elemental carbon (EC) (diesel exhaust and wood smoke primarily). What the analysis cannot do 

that is important is organic carbon (OC), because the Teflon filters that have been collected 

cannot provide that. Organic carbon was estimated as a residual. 

Chemical analysis results 

Total PM10 concentrations and component concentrations by date are shown in Table 3. 

Table 3. PM10 concentrations and measured or reconstructed major species concentrations by 

date. The residual is calculated as the total PM10 concentration – (soil+SO4+NO3+NH4+sea 

salt+ EC). It was assumed that all unaccounted for mass is organic mass (OM) and the ratio of 

organic mass to organic carbon is 1.8. 

Date conc stp soil SO4 NO3 NH4 seasalt EC residual OC

12/17/03 74.6 22.3 0.32 0.64 0.02 0.30 9.1 41.9 23.3

01/13/05 39.3 5.5 0.28 0.40 0.02 0.07 10.2 22.8 12.7

01/19/05 85.1 34.1 0.33 0.49 0.02 0.25 9.0 40.9 22.7

01/22/05 77.8 28.9 0.27 0.40 0.00 0.28 8.3 39.7 22.0

01/01/08 85.9 44.3 0.60 0.69 0.03 0.37 9.8 30.2 16.8

02/09/08 96.7 25.2 0.30 0.38 0.02 0.20 6.8 63.8 35.4

02/27/08 95.5 44.6 0.40 0.38 0.05 0.11 7.5 42.5 23.6

02/21/09 117.6 51.6 0.79 0.80 0.05 1.12 7.6 55.6 30.9

01/02/10 101.3 44.6 0.29 0.48 0.00 2.68 7.6 45.6 25.4

01/29/10 104.0 47.3 0.36 0.54 0.04 0.68 6.7 48.4 26.9

02/13/10 92.0 41.2 1.10 0.50 0.23 0.34 7.9 40.7 22.6

01/12/11 127.6 4.3 0.16 0.16 0.00 0.07 5.4 117.4 65.2

Because only Teflon filters were available, OC and EC could not be analyzed. Reconstructed 

mass calculations (using the IMPROVE protocol, Pitchford et al., 2007) showed that for most 

days, reconstructed mass was far less than measured mass. This is expected when there is a 

significant contribution from carbonaceous aerosol as with residential wood combustion, and 

other ambient sources of carbon, such as in road dust. 

Elemental carbon was estimated from filter light absorption (Chow et al., 2010) as EC=(babs)/10 

where babs is filter light absorption in inverse megameters (Mm-1) and EC concentration is in 

μg/m3

. EC concentration was then added to the reconstructed mass. The residual of measured 
4

mass – reconstructed mass was assumed to be organic mass (OM), which was assumed to be 1.8 

times OC (as used in the IMPROVE algorithm). Thus OC is the residual/1.8. 

From Table 3 it can be readily seen that OC, EC, and soil are the only significant contributors to 

PM10 concentrations. The nitrate is expected to be biased low as it tends to volatilize off the 

filter, especially after exposure to x-rays in a vacuum as occurs during the XRF analysis prior to 

analyzing for nitrate with ion chromatography. It should be noted here that the PM10 

concentration of 127.6 μg/m3

 on 1/12/2011 is probably in error. The soil and EC concentrations 

are not consistent with such a high mass concentration and the TEOM FDMS data for the day 

was only 27.7 μg/m3

. The TEOM FDMS and filter PM10 were usually close in magnitude. 

Table 4 shows the same information as Table 3 for the PM2.5 samples. 

Table 4. PM2.5 concentrations and measured or reconstructed major species concentrations by 

date. To be comparable to the PM10 data, the concentrations have been adjusted to standard 

temperature and pressure as defined by EPA (25°C, 760mm Hg). 

Date conc stp soil SO4 NO3 NH4 seasalt EC residual OC

12/17/03 40.6 1.19 0.24 0.45 0.03 0.12 7.8 30.8 17.1

1/13/05 32.7 0.50 0.24 0.39 0.03 0.04 10.2 21.4 11.9

1/19/05 30.5 1.89 0.26 0.28 0.03 0.07 8.8 19.2 10.7

1/22/05 33.2 1.60 0.21 0.29 0.02 0.08 8.3 22.7 12.6

For PM2.5, most of the mass is EC and residual (assumed OM). Table 5 shows the percentage of 

each chemical component that was in the fine mode (PM2.5) for the four days with both PM10 and 

PM2.5 chemically speciated data. 

Table 5. Percent of each chemical component that is in the fine mode. 

PM10 stp soil SO4 NO3 NH4 seasalt EC OC

12/17/03 54.4 5.3 76.4 70.3 144.8 40.1 85.1 73.4

1/13/05 83.2 9.0 86.9 97.8 158.6 60.0 99.8 93.5

1/19/05 35.9 5.5 78.1 57.5 133.1 29.3 97.9 46.9

1/22/05 42.7 5.5 75.1 70.8 27.4 100.7 57.1

As expected most of the sulfate, nitrate, and EC are in the fine mode and most of the soil is in the 

coarse mode. For 12/17/03 and 1/13/05 most of the OC is in the fine mode as would be expected 

with wood smoke. For 1/19/05 and 1/22/05 only about half to a little more than half of the 

estimated OC is in the fine mode. It should be noted that the fine/coarse mode OC split is highly 

uncertain because OC in both size ranges was estimated from a residual. 

Diurnal patterns in PM10 concentrations 

Consideration of diurnal patterns in PM10 concentrations may provide insight into likely sources 

of high PM10. Hourly PM10 concentrations for chemical analysis days in 2009 and 2010 are 
shown in

which giv

had morn

Figure 1.

2/21/200

Table 6. 

days befo

Date

12/17/2

1/13/2

1/19/2

1/22/2

2/21/2

1/2/2

1/29/2

2/13/2

1/12/2

Figure 2 

measurem

which dr

n Figure 1. T

ves values si

ning and eve

. TEOM FD

9. 

 Comparison

ore 2009 a st

Filter

003 74

005 39

005 85

005 77

009 117

010 101

010 1

010

011 127

gives hourly

ments. These

rives off mos

This period h

imilar to the

ening peaks a

DMS hourly c

n of filter PM

tandard TEO

TEOM

4.6 60.4

9.3 29.

5.1 4

7.8 40.

7.6 116.

1.3 97.

04 107.

92 8

7.6 26.

y PM10 conc

e were meas

st of the vola

had hourly m

e filter based

although the

concentratio

M10 and TE

OM was used

TEOM/Filt

4 0

2 0

6 0

1 0

2 0

3 0

6 1

7 0

8 0

centrations f

ured using a

atile compou

5

measurement

d concentratio

e timing of th

ons for 1/2/2

OM PM10 f

d. From 200

ter

0.81

0.74

0.54

0.52

0.99

0.96

1.03

0.95

0.21

for days in 2

a standard TE

unds includin

ts using the T

on measurem

he peaks var

010, 1/29/20

for days with

09 and after,

2003 and 200

EOM which

ng much of t

TEOM FDM

ments (Table

ried. 

010,2/13/201

h chemical s

, a TEOM FD

05 with chem

h heats the sa

the organic m

MS monitor 

e 6). All day

10 and 

speciation. F

DMS was us

mical speciat

ample to 50°

material in w

ys 

or 

sed. 

tion 

°C 

wood
smoke an

filter-bas

Figure 2.

Figure 3 

and Febr

frame wi

concentra

period sh

expected

peaks are

traffic rel

however 

levels ha

the stand

peak in P

2009-201

sample. T

late even

nd ammoniu

sed PM10 as

. TEOM hou

shows avera

ruary) for the

ith standard T

ations are sim

hows somew

d because the

e of very sim

lated (e.g. ro

that volatile

ve decreased

dard TEOM, 

PM10 seen g

12 period sh

This suggest

ning to morni

um nitrate. D

 shown in T

urly PM10 c

age TEOM P

e 2001-2008

TEOM (200

milar and diu

what higher c

e standard TE

milar concent

oad dust) and

e compounds

d by an amo

thus maskin

gives the sam

ows higher v

ts that the inf

ing and that 

During these 

able 6. 

concentration

PM10 by hou

 and 2009-2

01-2008) and

urnal pattern

concentration

EOM volatil

tration both 

d that concen

s (e.g. wood 

unt equal to 

ng any trend 

me concentra

values likely

fluence of w

the earlier r

6

days, the TE

ns for 12/17/

ur of day for

012 periods

d the period w

ns both show

ns overnight 

lizes a portio

periods, sug

ntrations hav

smoke) also

the volatile 

in time. We

ations for bot

y due to less 

wood smoke r

ise in PM10

EOM PM10

/2003, 1/19/

r winter mon

. This essent

with TEOM

w morning an

 (from about

on of the wo

ggesting that 

ve changed l

o contribute

component 

e can also no

th time perio

volatilizatio

relative to ro

0 may be driv

0 was much l

/2005, and 1/

nths (Decem

tially corresp

M FDMS (200

nd evening p

t 9pm to 8 am

ood smoke. T

 this peak is 

little over tim

to the morni

of the wood

ote that the e

ods until afte

on of wood s

oad dust incr

ven mainly b

less than the

/22/2005. 

mber, January

ponds to the

09-2012). Th

peaks. The l

m). This is 

The morning

almost entir

me. It is pos

ing peak and

d smoke lost 

arlier evenin

er 9pm when

smoke from 

reases durin

by road dust

y, 

e time 

he 

latter 

g

rely 

ssible 

d the 

by 

ng 

n the 

the 

g 

t. 
Figure 3.

for the 20

2008 per

Methodo

Chemica

PM10 an

1990 Air

of the PM

the curre

changed 

Source p

PM10 an

Source p

fireplace

significan

uncertain

again not

improved

profiles, 

part woo

profile. 

. Average P

001-2008 an

riod mostly w

ology for CM

al mass balan

nd PM2.5 for

r Quality Ma

M10 was due

nt study is to

since the199

rofiles used f

nalysis 

rofiles were 

s were used 

nt collinearit

nty to wood s

t using the w

d results. It 

but the qual

d stove prof

M10 by hour

nd 2009-2012

was standard

MB 8 runs f

nce (CMB) v

r days with c

anagement P

e to road dus

o try to deter

90 report. 

for CMB 

taken from 

plus road du

ty occurred b

stove contrib

wood stove s

was attempt

ity of the res

file was also 

r of day for w

2 periods. Th

d TEOM. 

for Mammo

version 8 (US

chemically s

lan (AQMP

st and residen

rmine if the 

the 1990 AQ

ust and cinde

between the 

butions (som

ource, just fi

ted to improv

sults deterior

tried and res

7

winter month

he 2009-201

oth Lakes P

SEPA) was 

speciated dat

, Ono et al, 1

ntial wood c

relative cont

QMP. Profil

ers. When ru

wood stove

metimes sign

fireplaces, cin

ve results by

rated. A we

sults were no

hs (Decembe

12 period ha

M10 and PM

used to estim

ta. CMB ana

1990) for M

combustion (

tribution of 

les for Mam

unning CMB

e and fireplac

nificantly ne

nders, and ro

y averaging t

eighted avera

ot as good a

er, January, 

ad TEOM FD

M2.5 

mate source 

alysis done in

Mammoth Lak

(RWC). One

RWC and ro

mmoth Lakes 

B it was foun

ce sources, g

egative). CM

oad dust. Th

the wood sto

age of 3 part

as simply usi

and Februar

DMS; the 20

contribution

n support of

kes showed m

e of the goal

oad dust has 

woodstoves

nd that 

giving high 

MB was run 

his gave mu

ove and firep

ts fireplace t

ing the firepl

ry) 

001-

ns to 

f the 

most 

s of 

s and 

ch 

place 

o 1 

lace 
8

PM2.5 analysis 

The PM2.5 analysis had collinearity problems between wood stove and fireplace and between 

road dust and cinders. The analysis with the best results used fireplaces and road dust source 

profiles only. 

Fitting species 

CMB results can vary significantly based on the choice of fitting species selected. In the initial 

run, all species measured with available source analysis were used. This gave poor results. 

Species that were noted from the ambient data to represent the mix of sources were added and 

subtracted in a trial and error method until the best results were obtained. Attention was paid to 

squared correlation coefficient, the Chi square statistic and percent of mass explained 

performance measures (Watson, 2004). The fitting species included: soluble Cl, ammonium, 

soluble K, total K, Na, Al, Si, S, Ca, Ti, Fe, EC, OC, Ba, Sr, and Zn. 

 
9

CMB results 

Results for the best fitting CMB analysis are shown in Table 7. Recommended performance 

measures (Watson, 2004) are % mass accounted for 100±20%, R-squared>0.80, and Chi-squared 

< 4.0. For the PM10 results (discounting the 1/12/2010 sample), 10/11 cases have % mass 

100±20%, all cases have R-squared>0.80, and 5/11 meet the Chi-squared <4.0 criteria. For the 

PM2.5 results, three out of four met the mass criteria and all four met the R-squared and chisquared criteria. 

Table 7. CMB attribution results and performance statistics. 

DATE SIZE conc stp FP RD CIND SUM % mass R2 Chi2

12/17/03 10 74.6 53.0 9.6 10.2 72.8 97.5 0.94 3.70

01/13/05 10 39.3 31.1 3.6 1.7 36.5 92.7 0.92 3.76

01/19/05 10 85.1 51.8 18.1 11.5 81.3 95.5 0.93 4.39

01/22/05 10 77.8 47.5 16.9 8.7 73.0 93.8 0.94 3.70

01/01/08 10 85.9 53.4 24.6 14.8 92.9 108.1 0.93 4.73

02/09/08 10 96.7 68.0 10.2 13.8 92.0 95.1 0.94 3.35

02/27/08 10 95.5 52.6 26.1 12.7 91.3 95.6 0.90 6.40

02/21/09 10 117.6 91.7 26.6 21.0 139.3 118.5 0.94 3.89

01/02/10 10 101.3 100.4 23.2 19.0 142.6 140.8 0.90 6.88

01/29/10 10 104.0 65.8 24.5 16.8 107.1 103.0 0.93 4.52

02/13/10 10 92.0 68.9 25.9 13.9 108.7 118.2 0.91 6.09

01/12/11 10 127.6 43.9 2.2 1.8 47.9 37.5 0.82 8.77

12/17/03 2.5 40.6 28.6 1.5 30.0 74.0 0.96 0.90

01/13/05 2.5 32.7 27.5 0.6 28.1 86.0 0.81 3.90

01/19/05 2.5 30.5 28.1 2.2 30.3 99.3 0.89 2.73

01/22/05 2.5 33.2 27.6 1.9 29.5 89.0 0.92 2.00

The percent of each sample attributed to each source is shown in table 8. On average, residential 

wood combustion contributed about 2/3 of the PM10, while traffic (road dust + cinders) 

contributed about 1/3, according to the CMB results. 

 
10

Table 8. Percent of each sample attributed to fireplaces, road dust, and cinders. January 12, 

2011 not included as this date had an apparent mass problem as discussed earlier. January 13, 

20o5 was not included in the PM10 list because it had low PM10 concentrations and thus does 

not represent a high PM10 day. 

DATE SIZE conc stp FP% RD% CIND%

12/17/03 10 74.6 72.9 13.2 14.0

01/19/05 10 85.1 85.3 10.0 4.7

01/22/05 10 77.8 63.7 22.2 14.1

01/01/08 10 85.9 65.0 23.1 11.8

02/09/08 10 96.7 57.5 26.5 16.0

02/27/08 10 95.5 73.9 11.1 15.0

02/21/09 10 117.6 57.5 28.5 13.9

01/02/10 10 101.3 65.8 19.1 15.1

01/29/10 10 104.0 70.4 16.3 13.3

02/13/10 10 92.0 61.4 22.9 15.7

12/17/03 2.5 40.6 28.6 4.5

01/13/05 2.5 32.7 95.2 4.8

01/19/05 2.5 30.5 97.7 2.3

01/22/05 2.5 33.2 92.6 7.4

Average PM10 93.1 67.4 19.3 13.4

Average PM2.5 34.3 78.5 4.7

For the winter 1987-1988 study (Ono et al, 1990), on average, fireplaces contributed 75% of the 

PM10 and road dust 25%. Table 9 compares the results of the 1987-88 study to this study. Three 

of the days in the 1987-88 study showed wood smoke contributing >95% of the PM10; the 

current study shows no high PM10 days with greater than 75% of the PM10 contributed from 

wood smoke. 

Furthermore, the peak contributions of road dust and residential wood combustion to PM10 

appear to have diminished. For the 1987-88 study average contributions to PM10 from road dust 

and fireplaces for the three highest impact days were 72 and 107 μg/m3

, respectively. For the 

2008-2010 period these fell to 56 and 72 μg/m3. This represents a 32% drop in road dust 

concentrations and 33% drop in residential wood combustion concentrations on high impact 

days. 

 
11

Table 9. CMB percent contributions to PM10 by road dust (RD) and residential wood 

combustion (RWC) for the winter 1987-88 study and this study (2003-2011). Road dust and 

cinders contributions are combined into RD . 

Date Conc RD% RWC%

12/26/1987 125.9 2.3 97.7

12/30/1987 132.8 1.3 98.7

12/31/1987 142.8 2.5 97.5

1/1/1988 117.4 10.3 89.7

1/22/1988 143.8 33.7 66.3

1/23/1988 157.8 41.2 58.8

2/3/1988 104.3 31.5 68.5

2/5/1988 148.2 33.8 66.2

2/6/1988 160 31.2 68.8

2/13/1988 137.6 38.8 61.2

2/14/1988 144 45.2 54.8

2/19/1988 148.5 28.7 71.3

12/17/03 74.6 25.3 74.7

01/19/05 85.1 33.7 66.3

01/22/05 77.8 32.5 67.5

01/01/08 85.9 39.5 60.5

02/09/08 96.7 24.3 75.7

02/27/08 95.5 39.4 60.6

02/21/09 117.6 32.0 68.0

01/02/10 101.3 27.7 72.3

01/29/10 104.0 36.0 64.0

02/13/10 92.0 33.8 66.2

1987‐88 study average 25.0 75.0

This study average 32.4 67.6

A simple alternative method for estimating source attributions 

Another estimate of crustal type sources (road dust and cinders) as percent of total PM was made 

by computing reconstructed fine soil (IMPROVE equation) and adding estimated associated 

carbonaceous aerosol mass (EC + 1.8*OC). Cinders have essentially no carbon, but road dust is 

about 10% OC and about 1% EC. As an upper limit it was assumed that OC and EC are 

proportional to the reconstructed soil at the same ratio as in road dust and this is added to the 

reconstructed soil calculation. The results (Table 10) show a higher average contribution from 

road dust and cinders (about 49%) than the CMB analysis (about 35%). Note: this method 

assumes organic and elemental carbon at the same abundance as in road dust and may be 

expected be an overestimate of carbon in road dust + cinders as cinders have essentially no 

carbon. It may thus represent an upper limit to the road dust and cinder contribution to PM10. 
12

Table 10. Comparison of contribution of crustal elements from mass reconstruction calculations 

(soil+rd C) and CMB analysis (rd+cind). 

date soil+rd C%rd+cind%

12/17/03 35.9 27.1

01/19/05 48.2 36.3

01/22/05 44.7 35.0

01/01/08 62.0 42.5

02/09/08 31.3 26.1

02/27/08 56.2 42.5

02/21/09 52.8 34.2

01/02/10 52.9 29.6

01/29/10 54.7 38.6

02/13/10 53.9 36.6

average 49.3 34.8

Analysis of days with both PM10 and PM2.5 speciated data 

Four days have both PM10 and PM2.5 speciated data. For these days, by subtraction of the 

PM2.5 attribution from the PM10 attribution we can get a value for PM coarse (PM10-PM2.5) 

attribution. These results are shown in Table 11. 

Table 11. CMB attribution (μg/m3

) to wood smoke (FP) and road dust (rd+cind) by size fraction 

for four days with chemically speciated PM2.5 and PM10. 

DATE SIZE stp conc FP rd+cind

12/17/03 10 74.6 53.0 19.7

12/17/03 2.5 40.6 28.6 1.5

12/17/03 coarse 34.0 24.5 18.3

1/13/05 10 39.3 31.1 5.4

1/13/05 2.5 32.7 27.5 0.6

1/13/05 coarse 6.6 3.6 4.7

1/19/05 10 85.1 51.8 29.5

1/19/05 2.5 30.5 28.1 2.2

1/19/05 coarse 54.6 23.7 27.3

1/22/05 10 77.8 47.5 25.5

1/22/05 2.5 33.2 27.6 1.9

1/22/05 coarse 44.6 19.8 23.6

average 10 69.2 45.8 20.0

2.5 34.3 27.9 1.6

coarse 34.9 17.9 18.5
13

 Table 11 shows that over 90% of the PM10 mass attributed to road dust and cinders is in the 

coarse mode, as would be expected. However, on average for these days only a little more than 

60% of the wood smoke (FP) is attribute to the fine mode, with about 40% in the coarse mode. 

This is somewhat unexpected, as a large majority of wood smoke is expected to be in the fine 

mode. The result is also contrary to the 1987-88 study which found the vast majority of the 

wood smoke impact in the fine mode. The attribution in the current study was largely a result of 

having a large residual in the reconstructed mass due to the inability to measure carbon on Teflon 

filters. The main question regards the “missing mass” which was assumed to be organic mass. If 

it is organic mass then what is it from if not wood smoke? Some would be associated with road 

dust, but not the levels needed. Some also would be from motor vehicles, but again this would 

almost all be expected to be in the fine mode. It is possible the reconstructed soil equation used is 

not appropriate for the local conditions and this would affect the residual used to estimate 

organic carbon. There could also be some water accounting for the missing mass, but 

concentration of hygroscopic compounds such as sulfate and nitrate are low and mainly in the 

fine mode, so this would not be expected to account for much. Because the wood smoke is 

present along with road dust, the road dust may become coated with wood smoke, thus causing a 

significant fraction of the wood smoke associated organic mass to be in the coarse mode. 

Summary and conclusions 

The question of the relative contributions of wood smoke and road dust to PM10 in Mammoth 

Lakes was considered. Teflon filters from high PM10 days between 2003 and 2011 were 

subjected to chemical analysis with XRF, ion chromatography, and filter light absorption. Four 

days analyzed also had PM2.5 filters that underwent chemical analysis. A major limitation was 

the inability to measure carbon on the filters. The filter light absorption provided a reasonable 

estimate of elemental carbon and the unexplained mass (on average 58% of PM10 and 68% of 

PM2.5) was assumed to be organic mass (OC*1.8). Estimates of contribution of wood smoke 

and road dust were made using Chemical mass balance (CMB) and a simple method based on 

abundance of crustal elements in the samples. For PM10 CMB showed an average of 32% due 

to road dust and 68% due to residential wood combustion. This compares to 25% from road dust 

and 75% from residential wood combustion for the winter 1987-88 study. The CMB maximum 

contributions (average of 3 highest days) to PM10 from road dust and residential wood 

combustion dropped by about 1/3 for each source category between 1987-1988 and 2008-2010. 

 A simpler method using reconstructed soil from the IMPROVE equation and adding organic 

mass and elemental carbon in the ratio found in Mammoth Lakes road dust gave an average of 

49% contribution of road dust to PM10. There is likely some impact from other sources such as 

vehicle exhaust to the PM10 although these impacts are expected to be small in comparison to 

wood smoke and road dust. The relative contribution of wood smoke may have decreased since 

the 1990 AQMP was produced. The extent of any such decrease cannot be reliably determined 

with the data available. Additional measurements, chemical analysis and data analysis would be 

necessary to gain more confidence in the results.
14

References 

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surrogate for elemental carbon. J. of Air & Waste Mgmt. Assoc.,60 1365-1375. 

Ono, D.; Taylor, W., Lawhon, D. (1990). Air Quality Management Plan for the Town of 

Mammoth Lakes. November 30, 1990. http://www.gbuapcd.org/mlaqmp.htm. Accessed 

May 2013. 

Pitchford, M.L.; Malm, W.C.; Schichtel, B.A.; Kumar, N.K.; Lowenthal, D.H.; Hand, J.L. 

(2007). Revised algorithm for estimating light extinction from IMPROVE particle 

speciation data. J. Air Waste Manage. Assoc., 57(11):1326-1336. 

Watson, J. G. et al. (2004). Protocol for Applying and Validating the CMB Model for PM2.5 and 

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http://www.epa.gov/scram001/models/receptor/CMB_Protocol.pdf. Accessed May 2013.