# Alaska Department of Environmental Conservation

Amendments to:

State Air Qua l ity Control Plan

Vol. III: Appendices

(Appendices to: Volume II, Section III.A Statewide Carbon Monoxide Control Program & Volume II, Section III.B Anchorage Transportation Control Program)



## Adopted

August 5 th 

## , 2009

### The State of Alaska’s State Air Quality Control Plan Volume III
, Appendix to Volume II of this p lan , is amended to include the following documents:
Volume II, Section III.A Statewide Carbon Monoxide Control Program, Appendix III.A is amended by removing the following regulations:
• 18 AAC 52 Emissions Inspection and Maintenance Requirements for Motor Vehicles, as

amended through May 17, 2008; and
replacing them with the following regulations:
• 18 AAC 52 Emissions Inspection and Maintenance Requirements for Motor Vehicles, as

amended through August 5 th 

### , 2009.
Volume II, Section III.B Anchorage Transportation Control Program, adopted by the Anchorage Assembly May 26, 2009, and adopted into the State Air Quality Control Plan August 5 th 

### , 2009 is amended as follows:
• Appendix III.B.1 is amended by adding the following document:
• Anchorage Assembly Resolution No. 2009-144, dated May 26, 2009, a resolu tion of the Municipality of Anchorage adopting the Anchorage Carbon Monoxide Maintenance Plan.
• Appendix III.B.3 is amended by adding the following document:
• Anchorage 2007 Carbon Monoxide Emission Inventory and 2007-2023 Emission Projections, prepared by the Municipality of Anchorage, dated April 2009.
• Appendix III.B.6 is amended by adding the following document:
•Analysis of Probability of Complying with the N ational Ambient Air Quality Standard for Carbon Monoxide in Anchorage between 2007 and 2023, prepared by the Municipality of Anchorage, dated April 2009.
• Appendix III.B.8 is amended by adding the following documents:

• South Central Clean Air Ordinances AMC 15.30 and 15.35.
• Appendix III.B.9 is amended by adding the following document:
• Municipality of Anchorage Ordinance No. 2008-84(S), adopted by the Anchorage Assembly July 15, 2008, which repeals Anchorage Assembly Ordinance No. 2007- 122(S), and reinstates Anchorage Municipal Code Chapter 15.80 Vehicle Inspection and Maintenance Program; Chapter 15.85 Requirements, Specifications, and

### Procedures for Motor Vehicle Emission Inspection and Maintenance (I/M) Program; and section 9.30.155E of this code.
• Appendix III.B.10 is amended by adding the following documents:
• Estimation of Background Carbon Monoxide Concentrations for Anchorage ProjectLevel Conformity Analyses, no date ; and

• Affidavit of Oral Hearing.

# Alaska Department of Environmental Conservation



# Amendments to:

State Air Quality Control Plan

Vol. III: Appendices
Appendix III.A “18 AAC 52 Emissions Inspection and Maintenance Requirements for Motor Vehicles” 

# Adopted August 5 th 

# , 2009

## DEPARTMENT OF

ENVIRONMENTAL CONSERVATION

18 AAC 50 Air Quality Control

18 AAC 52 Emissions Inspection and Maintenance Requirements for Motor Vehicles

Adopt ed

August 5, 2009

Sean Parnell Governor

Larry Hartig Commissioner

### The le ad in language of 18 AAC 50.030 is amended to read:

18 AAC 50.030. State air quality control plan. Volumes II and III of the State Air

Quality Control Plan for implementing and enforcing the provisions of AS 46.14 and this

chapter, as amended through Aug ust 5 , 2009 [FEBRUARY 20, 2009], are adopted by reference.

The plan includes the following documents which are also adopted by reference:



## . . .

(Eff. 1/18/97, Register 141; am 6/21/98, Register 146; am 9/4/98, Register 147; am

1/1/2000; Register 152; am 12/30/2000; Register 156; am 9/21/2001, Register 159; am

1/27/2002, Register 161; am 3/2/2002, Register 161; am 5/3/2002, Register 162; am 2/20/2004,

Register 169; am 6/24/2004, Register 170; am 10/1/2004, Register 171 ; am 12/14/2006, Register

180; am 12/30/2007, Register 184; am 5/17/2008, Register 186; am 7/25/2008, Register 187; am

11/9/2008, Register 188; am 5/6/2009, Register 190; am__/__/____, Register ___)

Authority: AS 46.03.020 AS 46.14.030 Sec. 30, ch. 74, SLA 1993

AS 46.14.020 AS 46.14.140

18 AAC 52.005 (c)(1)(A)(ii) amended to read:

(ii) the vehicle is a model year (MY) 2006 [2004] or newer;
if the vehicle is a model year 2006 or [2004 OR ] newer, the vehicle’s first

inspection is due when the current calendar year equals the vehicle model

y ear plus six [ FOUR ] years ; subsequent inspections are due every two

years after the year the vehicle’s first inspection is due ;

### Register ____, ________ 2009 ENVIRONMENTAL CONSERVATION

2 1

18 AAC 52.005(f) is amended to read:

(f) The I/M requirements of this chapter do not apply to

(1) a 1967 or older mo tor vehicle;

(2) repealed 02/18/2006;

(3) a gasoline-powered motor vehicle that has an unladen weight of 12,001 pounds or heavier;

(4) a test vehicle for which the department has issued a written exemption;

(5) a military tactical vehicle such as a tank;

(6) a motorcycle, golf cart, all -terrain vehicle, snow machine, and motor-driven cycle (moped);

(7) a motor vehicle that has been or will be in Alaska for less than 30 days; [ OR ]

(8) an electric vehicle ;
(9) a motor vehicle for which the Div ision of Motor Vehicles has issued

historic vehicle plates; or

(10) a motor vehicle for which the D ivision of Motor Vehicles has issued

custom collector vehicle plates.

(Eff. 2/1/94, Register 129; am 6/24/94, Register 130; am 1/4/95, Register 133; am 1/1/97,

Register 140; am 1/1/98, Register 144; am 1/1/2000, Register 152; am 3/27/2002, Register 161;

am 02/18/2006, Register 177; am 5/17/2008, Register 186; am__/__/____, Register ___)

Authority: AS 46.03.010 AS 46.14.030 AS 46.14.510

AS 46.03.020

### Register ____, ________ 2009 ENVIRONMENTAL CONSERVATION

3 18 AAC 52.060 (d)(1)(A) is amended to read :
(A) the motorist's adjusted gross income, as computed for the preceding

year and reported to the United States Department of the Treasury, Internal Revenue

Service (IRS), is at or below the poverty leve l as determined under the United States

Department of Health and Human Services poverty guidelines for this state publis hed at

74 Fed. Reg . 4199-4201(January 23, 2009 ) [73 F ED . R EG . 3971 – 3972 (J ANUARY

23, 2008)], adopted by reference in this chapter; fo r a time extension under this

subparagraph, the motorist must submit a copy of the motorist's federal income tax return

filed for the year preceding the extension request; or



## . . .

(Eff. 2/1/94, Register 129; am 6/24/94, Register 130; am 1/4/95, Register 133; am 1/1/97,

Register 140; am 1/1/98, Register 144; am 1/1/2000, Register 152; am 3/27/2002, Register 161 ;
am 02/18/2006, Register 177; am 5/17/2008, Register 186 ; am__/__/____, Register ___)

Authority: AS 46.03.020 AS 46.14.030 AS 46.14.510

18 AAC 52.990(78) is amended to read:

(78) “new vehicle” means a vehicle

(A) that is a 2006 [2004] model year vehicle or newer ; and

(B) with a model year number that is no lower than the number of the

current calendar year minus six [FOUR]

.

### Register ____, ________ 2009 ENVIRONMENTAL CONSERVATION

4 18 AAC 52. 990 is amended by adding new paragraphs to read:

(79 ) “historic vehicle” has the meaning given in 13 AAC 40.010.

(80 ) “custom collector vehicle” has the meaning given in AS 28.90.990.

(Eff. 2/1/94, Register 129; am 6/24/94, Register 130; am 1/1/97, Register 140; am 1/1/98,

Register 144; am 1/1/2000, Register 152; am 12/30/2000, Register 156; am 3/27/2002, Register

161; am 02/18/2006, Register 177 ; am__/__/____, Register ___)

Authority: AS 46.03.010 AS 46.14.030 AS 46.14.510

AS 46.03.020

# Alaska Department of Environmental Conservation



# Amendments to:

State Air Quality Control Plan

Vol. III: Appendices Appendix III. B.1
“Anchorage Assembly Resolution No. 2009

- 144” 

# Adopted
August 5 th 

# , 2009

# Alaska Department of Environmental Conservation



# Amendments to:

State Air Quality Control Plan

Vol. III: Appendices Appendix III. B. 3 “Anchorage 2007 Carbon Monoxide Emission Inventory and 2007-2023 Emission Projections” 

# Adopted
August 5 th 

# , 2009Appendix to Section III.B.3



# Anchorage 2007 Carbon Monoxide Emission Inventory and 2007 – 2023 Emission Projections

Municipality of Anchorage Air Quality Program Environmental Services Division Department of Health and Human Services April 2009Appendix to Section III.B.3



## Preface

This document discusses the methodology used to prepare the base year 2007 CO emission inventory and emission projections for the 2007 – 2023 period covered by the Anchorage maintenance plan.Appendix to Section III.B.3

i Table of Contents



### INTRO DUCTION................................................................................................................... ............... 1 OVERVIEW HYBRID EMISSION ESTIMATION ME THODOLOGY................................................. 1
INVENTORY BO UNDARY

............................................................................................................. ..... 1 ANCHORAGE TRANSPORTATION MODEL AND INVENTORY GR ID SYST EM......................... 3 TIME-OF-DAY ESTIMATES OF CO EMI SSIONS ............................................................................. 5 MOTOR VEHICLE EMISSI ONS ........................................................................................................ . 6 Estimation of Warm-up Idle Emissions ........................................................................................... ............................7
Estimation of On-Road Travel Emissions......................................................................................... ........................13 

### AIRCRAFT OPERATION EMISSION S ............................................................................................ 18
RESIDENTIAL WOOD BURNI NG EMISSI ONS .............................................................................. 20
EMISSIONS FROM NATURAL GAS COMB USTION FOR SPACE HEATING ............................ 22 OTHER MISCELLANEOU S SOURCE S .......................................................................................... 23
Use of NONROAD to Estimate Emis sions from Snowmobiles, Snow Bl owers, Welders, Air Compressors
and Other Miscellan eous Sources ................................................................................................ ............................23
Railroad Emissions............................................................................................................. ........................................25
Marine Vessel Emissions........................................................................................................ ...................................26 

### EMISSIONS FROM P OINT SOURCE S............................................................................................ 27 Source Descriptions and Emis sion Estimation Information ........................................................................ .............28 Summary of Point Source Emissions.............................................................................................. ..........................28 

### EMISSIONS SUMMA RY .............................................................................................................. ..... 29 2007 Base year Area-wide CO Inventory29 Projected Area-wide CO E missions (2007-2023) .....................

.................................... .....................29 

### COMPILATION OF MICRO-ARE A INVENTORY FOR TURNAGAIN MONITORING STATION . 31

REFERE NCES.......................................................................................................................................

Attachment 1 Warm-up Idle Emission Calculations
Attachment 2 Sample Calculation of On-road Travel Emissions and MOBILE6 Input Files for 2002 and 2004
Attachment 3 Marine Vessel Emission Calculation
Attachment 4 2002 Emission Inventory Results by GridAppendix to Section III.B.3

i List of Figures

Figure 1 Anchorage No nattainment Boundary Compared with Expanded Inventory Area........................2
Figure 2 Anchorage In ventory Grid System....................................................................................... ...........4
Figure 3 MOBILE6 Emission Factors as a Function of Speed and Therma l State.................................. 16
Figure 4 Projected Area-wide CO Emissions (200 7 -2023) ..................................................................... 30
Figure 5 CO emissions dist ribution in Anchorage ............................................................................... ...... 32
Figure 6 Aerial photo of Turnagain micro-inventory area boundary ........................................................ 33
Figure 7 Projected CO Emissions in Turnag ain CO Micro-inventory Area 2007 – 2023 ........................ 35
Figure 8 CO emission rate by time-of-day in Turnagain CO micro-inventory area (2007)...................... 36Appendix to Section III.B.3

ii List of Tables

Table 1 CO Emission Inventory Time Periods and Apporti onment of Characteristic Source Activity 5 Table 2 Factors involved in computation of thermal state of vehicle at critical points in a vehicle trip. 7 Table 3 Assumed warm-up idle duration by trip purpose and origin 8 Table 4 Average soak time prior to trip start 9 Table 5 Idle emission look up table for calendar year 2000 10 Table 6 Idle CO adjustment factors 11 Table 7 Block heater plug-in rates (%) by time-of-day, trip origin and trip purpose after media campaign promoting block heater use 12 Table 8 Estimated warm-up idle emissions by time-of-day Anchorage inventory area 13 Table 9 Speed Adjustment Factors 15 Table 8 Transportation Model VMT Estimates and Projections 13 Table 9 VMT Categories Generated for Each Grid 13 Table 10 Soak distributions used in MOBILE6 modeling with comparable operating mode fractions used in MOBILE5b/Cold CO modeling 16
Table 11 On-road travel em issions by time-of-day 18
Table 12 24-hour CO e missions estimates from aircraft at ANC and Merrill Field in 2002 19 Table 13 Projected aircraft operations and CO emissions at ANC 19 Table 14 Projected Aircraft Operations and CO Emissions at Merrill Field Airport 20 Table 15 Estimation of residential wood burning CO emission factors for Anchorage 21 Table 16 Estimated Anchorage-wide 24-hour CO emissions from residential wood burning 21
Table 17 Methods of Home Heating in Anchorage (ASK Ma rketing & Research, 1990) 22 Table 18 Peak winter season natural gas consumption rates and CO emission rates in Anchorage (1990) 22 Table 19 CO Emissions from natural gas combustion (excludes power generation) 23
Table 20 Estimation of NONROAD CO emissions in 2007 24 Table 21 CO emissions from NONROAD sources (2007-2023) 25
Table 22 Alaska Railroad emission estimates 2007-2023 26 Table 23 Estimated CO emissions from the Port of Anchorage 27 Table 24 Point Source CO Emissions Summary 28 Table 25 Sources of Anchorage CO emissions in 2007 base year in Anchorage inventory area 29 Table 26 Total CO emitted during typical 24-hour winter day in the Anchorage bowl inventory area 30 Table 27 Sources of CO Emissions in Turnagain Micro-inventory Area 2007 Base Year 34 Table 28 Total CO emitted during typical 24-hour winter day when CO is elevated in Turnagain micro-inventory area 34Appendix to Section III.B.3

1 

### Introduction

This document provides technical support and just ification for the methods used to prepare the maintenance demonstration for Anchorage, submitted as a revision to the Alaska State Implementation Plan (SIP). As part of the plan revision, a comprehensive invent ory of the sources of CO emissions for base year 2007 was compiled. Historically, violations of the CO NAAQS have occurred most often on winter weekdays, therefore a 24-hour inventory was prepared that reflects ambient temperatures, traffic volumes and other emission source activity levels ex perienced on a typical winter “design day” in 2007. In April 2007 an air quality conformity analysis was prepared when the Anchorage Long Range Transportation Plan was amended to include the Knik Arm Crossing. The most recent population, employment, and land use assumptions and forecasts were used in the development of this analysis. Specific forecasts were developed for analysis years 2007, 2017 and 2027. This demographic data was used to generate the 2007 base year CO inventory for the maintenance plan revisions. In addition this data was used directly or interpolated to generate forecasts for 2009, 2011, 2013, 2015, 2017, 2019, 2021 and 2023. The methodology employed to develop the 2007 base year emission inventory and projections through 2023 was very similar to that employed to develop pr evious emission in ventories for the CO attainment plan in 2000 and the maintenance plan in 2004.



### Inventory Boundary

The Anchorage nonattainment area boundary was establ ished in 1978. Upon EPA’s approval of the maintenance plan in 2004, the area encompassed by this boundary became the maintenance area. The inventory boundary contains this maintenance area plus some additional area to the south and west where significant residential and commercial growth has occurred over the past two decades. For this reason, the inventory area was expanded slightly to encompass areas not included in the nonattainment area. The boundary of the maintenance area is shown along with the expanded inventory area in Figure 1. The inventory area encompasses approximately 200 square kilometers of the Anchorage Bowl.Appendix to Section III.B.3

2 Figure 1. Anchorage Maintenance Area Boundary with Expanded Inventory AreaAppendix to Section III.B.3

3 

### Anchorage Transportation Model and Inventory Grid System

The CO inventory was based in large part on traffic activity outputs from the Anchorage Transportation Model. The Anchorage Transportation Model is used by AMATS * and the Municipality of Anchorage to evaluate transportation plans and programs. It was validated against measured traffic volumes in base year 2002 and utilizes the latest planning assumptions to forecast future travel activity.. The model was developed using TransCAD travel demand modeling software. Because TransCAD is a GIS-based model, post-processing software coul d be used to overlay a grid system on the inventory area. The post-processor was used to disaggregate the inventory area into grid cells, each one square kilometer in size. Transportation activity estimates (e.g., vehicle miles of travel, number of trip starts, and vehicle speeds) were produced for each of the cells. The grid location of every roadway link in the transportation network is known. Thus, the attributes of a particular roadway link (e.g., traffic volume, speed, and prior travel time) could be assigned to a particular gr id. If a roadway link crossed the boundary between two or more grids, its attributes were assigned to the appropriate grid in relation to the proportion of the length of link contained in each grid. In other words, if 80% of a roadway link lies within a particular grid, 80% of the vehicle travel is assigned to that grid and 20% to the other grid. Demographic information (population, number of dwelling units, income, and employment information) is collected by census tract. Because most census tr acts in Anchorage are larger in size than the onekilometer grids, the demographic characteristics of a particular grid had to be estimated from lower resolution census tract data. If, for example, a par ticular census tract was comprised of three one kilometer grids, the population and employment in t hat census tract was divided equally among the three grids contained in the census tract. This demographic information was helpful in developing gridded estimates of non-vehicular source activities, like wood burning and space heating where the amount of activity (i.e. wood burning or residential space heat ing) was assumed to be related to the number of dwellings in a grid. Emissions from other area sources such as Ted Stevens Anchorage International Airport, Merrill Field, marine vessel operations at the Port of Anchorage and railroad activity in the rail yard and haul routes were assigned to the grids where the activity takes pl ace. Similarly, emissions from point sources such as electrical power plants were assigned to the grid where the source is located. The Anchorage emission inventory gr id system is shown in Figure 2.

* AMATS stands for Anchorage Metropolitan Area Transportation Solutions. AMATS is the designated metropolitan planning organization for the Municipality of Anchorage. It is responsible for prioritizing federal transportation funding. It is also responsible for air quality planning in the Municipality.Appendix to Section III.B.3

4 Figure 2 Anchorage Inventory Grid SystemAppendix to Section III.B.3

5 

### Overview of Hybrid Emissi on Estimation Methodology

Between 1997 – 2003, the Municipality of Anchorage (M OA), Fairbanks North Star Borough and Alaska Department of Environmental Conservation (ADEC) invested a great deal of effort quantifying the sources of CO emissions in Anchorage and Fairbanks, particularly those from cold starts and warm-up idling. Sierra Research, working under contract with ADEC, performed cold temperature emission tests on 35 vehicles in Anchorage and Fairbanks during the winters of 1998-99 and 2000-2001. This testing showed that cold start /warm-up idle emissions are a very important source of CO emissions and using engine block heaters is an effective way to reduce emissions. MOBILE6 alone would ordinarily be used to quantif y vehicle emissions. Ho wever, a conventional MOBILE6 approach to computing vehicle emission rates does not adequately address the emissions impact of extended warm-up idling at the beginning of a trip nor does it provide a means to estimate the emission reductions resulting from engine block heater use. To address these limitations, a “hybrid” approach was developed to quantify motor vehicle emissions. This hybrid approach utilizes idle emissions data generated from the Sierra Research emission testing 1 to estimate warm-up idle emissions while MOBILE6 is used to estimate the emissions that occur duri ng the travel mode. The MOBILE6 model was run with supplemental speed (SFTP) correction factors disabled. The purpose of the SFTP speed correction factors is to refl ect the increase in emissions that occur during aggressive driving (e.g. hard accelerations and decelerations). During the winter of 1999-2000, Sierra Research performed a study in Anchorage and Fairbanks that showed that winter driving in Alaska had almost none of the high speed, high acceleration rate driving that is represented by the SFTP speed correction factors. 2 For this reason, MOBILE6 was run with these correction factors disabled



### Time-of-Day Estimate s of CO Emissions

Separate estimates of mobile CO emissions were prepared for the morning commute (7 a.m. – 9 a.m.), the evening commute (3 p.m. – 6 p.m.) and combined off-peak periods (6 p.m. – 7 a.m. and 9 a.m. – 3 p.m.). These estimates relied on time-of-day activity estimates (e.g., number of trip starts and VMT) generated by the Anchorage Transportation Model. A 24-hour inventory was compiled by summing the separate emission contributions from each time period. Activity estimates for non-vehicular sources were available on a 24-hour basis only, however. Time-ofday estimates had to be developed from these 24-hour values. For some sources (e.g. airport, natural gas combustion), activity was assumed to be continuous throughout the day and emissions were apportioned accordingly. Fireplace and wood stove usage is more likely to occur in the evening after 6 p.m. For this reason, 90% of all wood burning activity was assumed to take place during the off peak time period. Table 1 shows the specific time periods inventor ied and gives examples of the types and levels of activity characteristic of those time periods. (Note that the 2-hour AM peak comprises 8.3% of a 24-hour day, the 3-hour PM peak comprises 12.5% of the day, and the 19-hour off peak period comprise 79.2% of the day.)Appendix to Section III.B.3

6 Table 1. CO emission inventory time periods and apportionment of characteristic source activity % of activity occurring within each time period

Source Categor y AM Peak. 7 a.m. – 9 a.m. PM Peak. 3 p.m. – 6 p.m. Off-Peak periods 9 a.m. – 3 p.m. 6 p.m.

– 7 a.m. Comments

motor vehicle idle and travel emissions From model (~16%) From model (~27%) From model (~57%) Travel activity higher in AM and PM peak periods
Residential wood burning 3.0% 7.0% 90.0% Most burning in evening

space heating 8.3% 12.5% 79.2% Evenly distributed through day

Ted Stevens Int'l Airport 8.3% 12.5% 79.2% Evenly distributed through day

Merrill Field 8.3% 12.5% 79.2% Evenly distributed through day

Miscellaneous / Other * 8.3% 12.5% 79.2% Evenly distributed through day

Point Sources 8.3% 12.5% 79.2% Evenly distributed through day * Miscellaneous/other emissions are comprised largely of sources related to construction and industrial activity like generator sets, welding activities, and pumps.



### Motor Vehicle Emissions

A great deal of effort was devoted to developing a credible highway motor vehi cle emissions inventory that reflected real world conditions and driver behavior in Anchorage. Unlike the inventories prepared as part of previous air quality attainment plans, this inventory explicitly quantifies the CO emissions that occur during cold starts and lengthy warm-up idles that precede many vehicle trips. Separate estimates were made of the emissions associated with the initial warm-up idle period and the after-idle, “on-road” trip period. Sample calculations for warm-up idle emissions can be found in Attachment 1. Attachment 2 contains a sample calculation of “on-road” emissions along with copies of MOBILE6 input files used to compute on-road emission factors for analysis years 2007 and 2017. As discussed earlier, a hybrid appr oach utilizing locally-generated cold temperature idle emission data in combination with the MOBILE6 model was employed to compute motor vehicle emissions. An essential element of this hybrid approach is the use of “thermal state tracking” to determine how warmed up a vehicle is at three critical points in the vehicle trip . These three critical points and the important factors involved in computing the thermal state of the vehicles operating in each of these three points in the trip are described in Table 2.Appendix to Section III.B.3

7 Table 2. Factors involved in computation of thermal state of vehicle at critical points in a vehicle trip.

Critical point in trip Factors involved in computation of thermal state of vehicle 1. Immediately prior to start-up How long, and at what temperature the vehicle has been parked before it was started (i.e. length of cold soak) 2. After warm-up idle, immediately prior to travel portion of trip Length of cold soak and subsequent idle

3. During travel portion of trip (within grid of interest) Duration of prior cold soak and warm-up idle, length of trip (miles) and average speed.

Intuitively, the effect of each of the three factors on the thermal state or degree of warmth of a vehicle is fairly obvious. One would expect th at vehicles that are parked for long periods of time would be in a colder thermal state than those parked for short periods; a long warm-up idle period would result in a warmer thermal state than a short idle; and long travel time at a high rate of speed would result in a warmer vehicle than a short trip at slow speeds

. An elaborate spreadsheet was developed that incorporates the results of the thermal state ca lculations described above along with post processor outputs from the Anchorage Transportation Model, outputs from the MOBILE6 model, warm-up idle emission data from research conducted in An chorage and Fairbanks and from locally-derived information on driver idling behavior. This spreads heet allowed for separate computation of warm-up idle emissions and on-road trip emissions. Estimation of Warm-up Idle Emissions Three key sources of information were required to estimate idle emissions: (1) the duration of the idle period preceding the trip; (2) the amount of time since the vehicle last operated and has been cooling or “soaking” in ambient conditions; and (3) the idle emission rate. The idle emission rate is largely a function of engine and catalyst temperature and thus is dependent on idle duration and soak time.

Idle Duration Idle duration was quantified by the MOA Air Quality Program during the winter of 1997-98 as part of the Anchorage Driver Behavior Study. 3 The objective of this field study was to observe and document winter season driver idling behavior prior to the beginning of a trip. Over 1300 start up idles were observed and documented at various times and locations in Anchorage. In addition to documenting the duration of each of the idles, the trip origin (e.g., home, work, shopping, etc.), time of day, ambient temperature, weather and windshield icing conditions we re also recorded. One important objective of the study was to develop estimates of median idle duration by trip purpose* and time-of-day. Because drivers were not questioned, the trip purpose was not known. Nevertheless, a methodology was developed to use data collected in the study to estimate idle duration for home-based work (HBW), home-based other (HBO) and non home-based (NHB) trips for each time-of-day. The methodology used to develop these estimates is described in Appendices A and C of the Anchorage Driver Behavior Study. The idle duration assumptions used to develop CO inventories for 2007, 2009, 2011, 2013,

* The Anchorage Transportation model now categoriz es all travel into eight trip purposes instead of three. The original three t rip categories (HBW =:home-based work , HBO =home based other , and NHB = non home-ba sed have been expanded into seven separate categories. The m odel now provides estimates of the number of trip starts in the following categories: (1) HBW = home-based work, (2) HBSCH = home- based school, (3) HBS = home-based shopping, (4) HBO = home-based other, (5 ) NHBW = non home-based work, (6) NHBNW = non home-based non-work ; and (7) TRK = truck .Appendix to Section III.B.3

8 2015, 2017, 2019, 2021 and 2023 are shown in Table 3. The longest idle duration was associated with home-based trips (work, school and shopping) during the 7 a.m. – 9 a.m. time period.*

Table 3. Assumed warm-up idle duration by trip purpose and origin (in minutes)

Trip Type Trip origin AM Peak 7 a.m. – 9 a.m. PM Peak 3 p.m. – 6 p.m. Off-Peak Periods 9 a.m. – 3 p.m. 6 p.m. – 7 a.m. home 7 3 3 Home-based work work 3 1 3 home 7 2 2 Home-based school school 1 1 1 home 7 2 1 Home-based shopping shopping 1 1 1 home 7 2 2 Home-based other other 1 1 1 Non home-based work NA 3 3 2Non homebased, non-work NA 1 1 1

Truck NA 3 3 1 It should be noted that during the ten years since this survey data was collected, a number of changes have occurred that could have changed idling beh avior among Anchorage drivers. One change of particular note is the increasing proliferation of remote “auto start devices” that allow drivers to start their vehicles remotely. Recent survey data sug gest that approximately 27% of Anchorage vehicles are now equipped with such devices. The effect of auto starts on idle times in Anchorage has not been studied. Even if the use of auto starts has increased average idle duration, the effect on overall CO emissions is likely small. A 2001 study performed by Sierra Research examined the effect of idle duration on the CO emissions that occur over the course of a typical vehicle trip of 7.3 miles. 4 Sierra found that overall CO emissions for trips preceded by a 2-minute idle (281.4 grams) were greater than those preceded by a 15-minute idle (246.7 grams). Thus, it is possible that the use of remote starters may actually reduce overall CO emissions is the idle time following a cold start is limited to 15 minutes or less. Overall trip emissions would increase, however, if idle times following an auto start were extended to 20 minutes or more. More recently Sierra examined the possible impact of auto starts on CO emissions in Fairbanks, Alaska where the prop ortion of vehicle equipped with these devices approaches 50%. They concluded that if drivers opted to use these devices for extended idling (20 minutes or longer) CO emissions could increase by 0.18 tons per day. This amounts to an increase of about 0.5% in total CO emissions in Fairbanks.

Soak Time Vehicle emissions of CO are highest just after startup and decrease rapidly as the engine warms. The emissions that occur during start up are largely a function of how long the engine has been shut off and cooling at ambient temperatures. Because these data suggest that soak time is a critical factor in determining vehicle CO emissions, it was important to develop credible estimates of soak times in Anchorage as part of the CO emission inventory preparation. Fortunately, information was available from a local tr avel survey that allowed average vehicle soak times to be estimated for the a.m., mid-day, p.m. and night periods by trip purpose. Hellenthal and Associates

* 35% of home-based trips were assumed to begin with cars parked in garages and 65% outside. Warm-up idle time for cars parked inside was not quantified in the idling study but was assumed to be 30 seconds. The idle times shown in Table 3 reflect the weighted aver age of idle times for garage and outside-parked vehicles.Appendix to Section III.B.3

9 conducted a household travel behavior survey of 1,548 Anchorage households between February 25 and April 12, 1992. 5 Soak times were estimated by examinin g travel logs from the survey. Drivers recorded the time when each trip began and ended. The time elapsed between the end of one trip and the beginning of the succeeding trip was presumed to be equal to the soak time for that driver’s vehicle. Estimates of average soak times derived from the Hellenthal travel behavior survey are shown in Table 3. Morning home-based trips for work, school and shopping have the longest average soak time (12 hours) while NHB trips and home-based trips originating at locations other than home have the shortest average soak time (one hour).
Table 4. Average soak time prior to trip start (in hours)

Trip Type Trip origin AM Peak 7 a.m. – 9 a.m. PM Peak 3 p.m. – 6 p.m. Off-Peak Periods 9 a.m. – 3 p.m. 6 p.m. – 7 a.m. home 12 3 3 Home-based work work 5 5 5 home 12 2 2 Home-based school school 0.5 0.5 0.5 home 12 2 2 Home-based shopping shopping 1 0.5 0.5 home 12 2 2 Home-based other other 1 1 1 Non home-based work NA 4 5 3 Non home-based, non-work NA 1 1 1 Truck NA 2 2 2

Estimation of Idle Emissions as a Function of Idle Duration and Soak Time Emission data from the testing Sierra Research conducted in Anchorage and Fairbanks during the winters of 1998-99 and 2000-2001 were used to construct a lookup table that provided an estimate of the warm-up idle emissions (in grams CO per start) as a function of idle duration and soak time. CO andHC emissions were measured during the first 20 minutes following a cold start. The values in the lookup table were revised slightly from those used in the Year 2000 attainment plan to reflect the supplemental data collected by Sierra Research in the winter of 2000-2001. The revised lookup table is shown in Table 5. The values were utilized in the emission inventory spreadsheet to compute idle emissions. No data were collected from commercial trucks during t he idle study. These comprise a small part of the total vehicle population and are largely low-emitting heavy-duty diesel vehicles (HDDV). These vehicles were assumed to emit CO at 30% the rate of the average light duty vehicles (LDVs) that make up the majority of the Anchorage vehicle population. Th is assumption is roughly consistent with MOBILE6 model estimates for HDDV versus LDV emission factors.Appendix to Section III.B.3

1 0 Table 5. Idle emission look up table for calendar year 2000 (with ethanol-blended gasoline) CO emissions (in grams per start) as a function of soak time and idle duration

Pre-Soak

Time (hrs) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0.00 1.6 3.2 4.8 6.4 8.0 9.5 11.1 12.7 14.3 15.9 17.4 19.0 20.6 22.2 23.8 0.17 1.9 3.5 5.1 6.7 8.3 9.9 11.4 13.0 14.6 16.2 17.8 19.4 20.9 22.5 24.1 0.25 2.4 4.0 5.6 7.2 8.7 10.3 11.9 13.5 15.1 16.7 18.2 19.8 21.4 23.0 24.6 0.50 4.8 6.4 8.0 9.6 11.1 12.7 14.3 15.9 17.5 19.1 20.6 22.2 23.8 25.4 27.0 1.00 11.1 14.3 15.9 17.5 19.1 20.7 22.3 23.8 25.4 27.0 28.6 30.2 31.7 33.3 34.9 1.50 16.4 23.8 26.1 27.7 29.3 30.8 32.4 34.0 35.6 37.2 38.8 40.3 41.9 43.5 45.1 2.00 20.8 32.6 36.7 38.5 40.1 41.7 43.3 44.9 46.4 48.0 49.6 51.2 52.8 54.4 55.9 2.50 24.5 39.9 46.6 49.1 50.7 52.3 53.9 55.5 57.1 58.7 60.2 61.8 63.4 65.0 66.6 3.00 27.5 45.9 55.3 58.9 60.6 62.2 63.8 65.4 67.0 68.6 70.1 71.7 73.3 74.9 76.5 4.00 32.0 55.0 68.8 74.8 77.5 79.1 80.7 82.3 83.8 85.4 87.0 88.6 90.2 91.8 93.3 5.00 35.1 61.1 78.0 86.3 90.0 91.9 93.5 95.1 96.6 98.2 99.8 101.4 103.0 104.6 106.1 6.00 37.2 65.3 84.3 94.4 99.1 101.2 102.8 104.4 106.0 107.6 109.2 110.7 112.3 113.9 115.5 7.00 38.6 68.2 88.6 100.0 105.3 107.8 109.5 111.0 112.6 114.2 115.8 117.4 119.0 120.5 122.1 8.00 39.6 70.1 91.5 103.8 109.7 112.5 114.1 115.7 117.3 118.9 120.4 122.0 123.6 125.2 126.8 9.00 40.3 71.4 93.5 106.4 112.7 115.6 117.3 118.9 120.5 122.1 123.7 125.3 126.8 128.4 130.0 10.00 40.7 72.3 94.8 108.2 114.7 117.8 119.6 121.2 122.7 124.3 125.9 127.5 129.1 130.6 132.2 12.00 41.2 73.4 96.4 110.3 117.0 120.4 122.1 123.7 125.3 126.9 128.5 130.1 131.6 133.2 134.8 Revised Year 2000 Idle Emissions (assumes 2.7% EtOH and Year 2000 Anchorage I/M)
Initial Idle Time (min)

The cold temperature idle data collected by Sierra Research provides a “snapshot-in-time estimate” of cold start emissions from the fleet in 2000-2001. Since this data was collected, a number of changes have occurred that have and will continue to change fl eet-wide idle emissions factors. The ethanolblended gasoline program, in place at the time that Sierra Research collected this idle emission data, was discontinued in 2003. The fleet is being cont inually replaced with newer and presumably cleaner vehicles. The net effect of this fleet turnover is a continual reduction in the id le CO emission rate over time. In 2010 the new car test exemption for the V ehicle Inspection and Maintenance (I/M) Program will be extended from four to six years. This will presumably increase the idle emission rate very slightly relative to the current four-year exemption period. * The effect of all these changes on idle emissions can be modeled using MOBILE6. Conformity analysis guidance recommends using MOBILE6 emission factors at 2.5 mph to estimate idle emissions. Thus, predicted reductions in the MOBILE6 emission factor at 2.5 mph were used to adjust the initial 2000- 2001 idle data from Sierra. MOBILE6 can be used to estimate the idle CO reduction from fleet turnover on overall idle CO emission rates over time relati ve to the 2000-2001 period when the Sierra data was collected. MOBILE6 can also be configured to help estimate the effect of CO controls such as the ethanol-blended gasoline program (which was discontinued in 2003) and of the I/M program on idle emissions. The hybrid model utilizes a look-up tabl e derived from MOBILE6 model runs that contains adjustment factors that account for fleet turnover, and changes in ethanol gasoline and I/M requirements. These adjustment factors are shown in Table 6. For example, in order to determine the idle emission factor for a cold start trip (soak time > one hour) in the year 2011 (assuming that the I/M program remains in place the ethanol-blended gasoline program is not reinstituted), the data and Table 5 would be multiplied by an adjustment factor of 0.52 to yield the idle emission rate. Thus, idle emissions for a trip with a 3 minute idle following a 10-hour cold soak is computed as follows: 2011 idle EF = (Yr 2000 Idle EF for 3 min idle after 10 hr cold soak) x (adj factor for 2011) = 94.8 grams x 0.52 = 49.3 grams

* Extending the new car grace period from four to six years is expected to diminish the effectiveness of I/M in reducing CO emissions during idling by less than 2%.Appendix to Section III.B.3

11 Table 6. Idle CO adjustment factors Estimation of idle CO based on 2000-2001 Sierra Data
Warm Start Idle (Cold Soaks < one hour) Cold Start Idle (Cold Soaks >= one hour)

Year w IM & oxy w IM, no oxy no IM, no oxy Year w IM & oxy w IM, no oxy no IM, no oxy 2000 1.00 1.15 1.39 2000 1.00 1.15 1.39 2007 0.64 0.70 0.82 2007 0.61 0.64 0.83 2008 0.58 0.63 0.74 2008 0.55 0.61 0.75 2009 0.55 0.59 0.71 2009 0.52 0.57 0.72 2010 0.53 0.57 0.68 2010 0.50 0.55 0.69 2011 0.51 0.54 0.65 2011 0.48 0.52 0.66 2012 0.49 0.52 0.62 2012 0.46 0.50 0.63 2013 0.47 0.50 0.60 2013 0.44 0.48 0.61 2014 0.45 0.48 0.58 2014 0.43 0.46 0.59 2015 0.44 0.47 0.57 2015 0.41 0.45 0.58 2016 0.43 0.46 0.55 2016 0.40 0.44 0.56 2017 0.42 0.45 0.54 2017 0.39 0.43 0.55 2018 0.41 0.44 0.53 2018 0.38 0.42 0.53 2019 0.40 0.43 0.52 2019 0.37 0.41 0.52 2020 0.39 0.42 0.51 2020 0.36 0.40 0.51 2021 0.39 0.41 0.50 2021 0.36 0.39 0.51 2022 0.38 0.41 0.49 2022 0.35 0.39 0.50 2023 0.38 0.41 0.49 2023 0.35 0.39 0.49 Note: Shaded cells in table above reflect adjustment factors used to model actual or anticipated changes in implementation of ethanol-blended gasoline and I/M programs. Ethanol was discontinued in 2003 and I/M is slated to continue indefinitely.

Modeling the Effect of Engine Block H eater Usage on Warm-up Idle CO Emissions Quantifying the benefits of engine block heater use was a principal objective of emission studies conducted by Sierra Research in 1998-1999 and 2000-2001. This research showed that in the year 2000, engine block heaters reduced CO emissions by an average of 86 grams after a cold start. For the purpose of estimating the effect of block heater use on CO emissions in this inventory, the absolute benefit of block heater use on CO reducti ons was presumed to proportional to the average idle CO emission rate of the fleet. Thus the absolute reductions from block heater usage were expected to decline over time as the fleet is replaced with newe r, lower emitting vehicles. To account for idle emission changes resulting from fleet turnover, an d from changes in ethanol-blended gasoline and I/M requirements that have or are slated to occur, discount factors were used to adjust the 86 gram per start CO reduction estimated from block heater usage in 2000-2001. These discount factors are shown in Table 6. An example of how these discount factors are used along with the 2000-2001 Sierra data to compute idle emissions is shown in the exam ple below for analysis year 2013.Appendix to Section III.B.3

1 2 Compute block heater reduction in 2013: Year 2000 block heater CO reduction = 86 grams pr cold start
Year 2013 cold start idle discount factor (assume I/M with no oxy gasoline) = 0.48 Year 2013 block heater reduction = 86 g x 0.48 = 41.2 grams per cold start

Between 1999 and 2008, the municipality hired a publi c opinion research firm to perform annual telephone surveys to estimate engine block heater plug-in rates among Anchorage drivers at ambient temperatures below 15 ° F. 6 The survey firm estimated at-home plug-in rates before and after the MOA and ADEC began a television, radio and print media campaign aimed at increasing plug-in rates among Anchorage drivers. For morning trips that begin at home initial survey data suggested that plug-in rates increased from about 10% in October 1999 to about 20% after the campaign. Since the initial survey, the MOA and ADEC have had on-going public awareness and incentives programs to encourage block heater use. Survey data suggest that some additional increases in plug-in rates may have occurred, however, for the purpose of the maintenance demonstr ation, the plug-in rate was assumed static at 20%. In Anchorage almost all block heater usage occurs at home because electrical receptacles are not generally available at work places and other locati ons. For this reason, the emission inventory spreadsheet was configured to assign plug-in benefits only to trips that begin at home during the 7 a.m. – 9 a.m. period and for the first portion (9 a.m. – 3 p.m.) of the off-peak period. Trips beginning at work, shopping centers, and other “non-home” locations were assumed to have a zero plug-in rate. Home-based morning trips comprise a small fraction of all trips taken over the entire day. When this is considered, the overall plug-in rate for all trips taken during the day is about 2%. The plug-in rate assumptions used to model block heater benefits in the spreadsheet are shown in Table 7.
Table 7. Block heater plug-in rates by time-of- day, trip origin and trip purpose after media campaign promoting block heater use

Trip Type Trip origin AM Peak 7 a.m. – 9 a.m. PM Peak 3 p.m. – 6 p.m. Off-Peak Periods 9 a.m. – 3 p.m. 6 p.m. – 7 a.m. home 20% 0% 10% Home-based work work 0% 0% 0% home 20% 0% 0% Home-based school school 0% 0% 0% home 10% 0% 0% Home-based shopping shopping 0% 0% 0% home 20% 0% 5% Home-based other other 0% 0% 0%

Non home-based work NA 0% 0% 0% Non home-based, non-work NA 0% 0% 0% Truck NA 0% 0% 0%

The transportation model post-processor provides data on the number of trips generated within each grid cell for a particular time period for each of the seven trip purposes. The emission inventory spreadsheet uses this data along with user-supplied data on idle duration (Table 3), soak time (Table 4), per start idle emission estimates (Table 5), idle emission adjustment factors (Table 6) and block heaterAppendix to Section III.B.3

1 3 usage rates (Table 7) to estimate total idle emissions for each grid cell. A spreadsheet algorithm was

developed that utilizes post-processor employment and household data from each grid cell to estimate the proportion of trips that originate at home versus work or “other” locations for each of the seven trippurposes. The largest plug-in benefits were accrued in grid cells with large numbers of morning homebased trips because plug-ins rates are the highest for those trips.

Summary of Warm-up Idle Emissions Estimates for 2007-2023 Results of the spreadsheet calculation of warm-up idle emission estimates are summarized in Table 8. These estimates include estimated reductions resulting from block heater use.
Table 8. Estimated warm-up idle em issions by time-of-day Anchorage inventory area - (all values in tons per day)

Calendar

Year AM Peak 7 a.m. – 9 a.m. PM Peak 3 p.m. – 6 p.m. Off-Peak Periods 9 a.m. – 3 p.m. 6 p.m. – 7 a.m. Total 24-hour Idle Emissions
2007 5.56 3.68 7.11 16.35
2009 4.81 3.19 6.19 14.19
2011 4.45 2.95 5.73 13.13
2013 4.15 2.75 5.35 12.25
2015 3.95 2.62 5.10 11.67
2017 3.80 2.52 4.90 11.21
2019 3.65 2.45 4.77 10.87
2021 3.54 2.42 4.69 10.65
2023 3.47 2.41 4.67 10.54

Estimation of On-Road Travel Emissions
On-road travel emissions were estimated on a grid -by-grid basis using travel outputs (vehicle miles traveled or VMT and speed by road facility category* and trip purpose). The post processor also provided information that was used to indirectly develop grid-by-grid estimates of the thermal state†. of vehicles operating on each facility type These estima tes of the travel activity and characteristics were used in conjunction with emission factor estimates generated by MOBILE6 with supplemental FTP speed correction factors disabled to better reflect winter season driving behavior in Alaska.

VMT Estimation The Anchorage Transportation Model and its post-processor were used to estimate VMT within each of the grids in the inventory area. The transportation model was validated against 2002 traffic data and

* The post-processor developed estimates of VMT and speeds for five facility categories which include (1) freeways and ramps; (2 ) major arterials; (3) minor arterials; (4) collectors; and (5) local roads. In addition, the post-processor estima ted “intrazonal” VMT, travel that occurs within a traffic analysis zone and not explicitly account ed for by the travel demand model.

† The thermal state of a vehicle mode is dependent on the soak time, idle duration, and the amount of time spent traveling on th e road before arriving in the grid of interest. Warm engines emit less CO than cold ones.Appendix to Section III.B.3

1 4 meets FHWA standards. 7 Past model estimates of VMT have agreed closely with count-based estimates from the Highway Perfor mance Monitoring System (HPMS). 8 Transportation model estimates

and projections of VMT are shown in Table 8. No adjustments were made to transportation model estimates because of their close agreement with previous HPMS-based VMT estimates. For the maintenance projections prepared for this pl an, transportation model runs were made for 2007, 2017, and 2027. VMT for intervening years (2009, 2011, 2013, 2015, 2019, 2021, and 2023) was estimated by interpolation. Because there are 5 facility categories and 7 trip purposes, the VMT in each one-kilometer grid was separated into 35 (5 x 7) different categories, each with potentially different travel activity characteristics. The number of VMT categories grows to 36 when intrazonal VMT is considered. (Intrazonal trips are defined as trips that begin and end within the same transportation analysis zone in the Transportation Model. All intrazonal VMT was presumed to be on local roads.) The travel accrued within each of these seven purposes was assigned a different operating mode depending on the idle duration, soak time, and prior travel time associated with each. Thus, freeway travel accrued by home-based work trips was likely assigned a different CO emission rate than freeway travel accrued by non home-based work trips. Thus, the VMT within a single one-kilometer grid could be disaggregated into 36 different operating modes (and emission rates) depending on the trip purpose and facility type.
Vehicle Speed Estimation The Anchorage Transportation Model and its post-pro cessor provide estimates of vehicle speeds by facility category and time-of-day. Thus for each grid, the post-processor generates an estimate of the average speed of vehicles traveling on freeways, major arterials, minor arterials, collectors and local streets. The speed estimates for these facility categories are average speeds and include periods when vehicles are stopped at signals or in traffic. Thus speed estimates generated by the model change in relation to the amount of congestion on the network. If network capacity is not expanded in relation to growth in VMT, slower speeds result. Because the primary purpose of the transportation model is to evaluate the capacity needs of the roadway and transit network, the speed outputs generated by the model are not considered to be as important as VMT. Unlike VMT, modeled speed es timates are usually not reconciled to observed network values. Thus modeled vehicle speed esti mates can deviate substantially from observed speeds. Indeed, the vehicle speed estimates generated by the Anchorage Transportation Model were significantly higher than those measured in a recent tr avel time study conducted by the Municipality and the Alaska Department of Transportation in October – November 1998. 9 Because speed is an important variable in the esti mation of CO emissions, the emission inventory spreadsheet was used to apply linear speed adjustment factors to the speed outputs from the model to bring them into closer agreement with speeds observed in the travel time study. In the travel time study, average vehicle speed was measured on freeways and major arterials during the AM, PM and off peak periods. Because data were not available for minor arterials and collectors, speed adjustment factors for these facility categories were assumed to be identical to the adjustment factors determined for major arterials. The speed adjustment factors incorporated into the emission inventory spreadsheet are shown in Table 9.Appendix to Section III.B.3

1 5 Table 9. Speed Adjustment Factors

Facility Category Time Period Observed Average Speed Oct – Nov 1998 MOA travel time study (MPH) Predicted Average Speed Anchorage Transportation Model (1996) (MPH) Speed Adjustment Factor

Freeways AM Peak. 56.6 49.2 1.0 Freeways Off-peak 61.2 48.0 1.0 Freeways PM Peak. 57.8 49.2 1.0 Major Arterials AM Peak. 29.7 40.2 0.74 Major Arterials Off-peak 29.4 35.1 0.84 Major Arterials PM Peak. 24.7 39.5 0.63 Minor Arterials AM Peak. --- 38.7 0.74 Minor Arterials Off-peak --- 36.2 0.84 Minor Arterials PM Peak. --- 38.5 0.63 Collectors AM Peak. --- 30.1 0.74 Collectors Off-peak --- 28.7 0.84 Collectors PM Peak. --- 29.8 0.63

Note that model output freeway speeds were significantly different from observed speed but they were not adjusted (i.e., adjustment factor = 1.0). The travel time study did not include ramps in the estimation of observed freeway speed. However, the transportation model included on-ramps and off-ramps in the model as part of the freeway category. The hig her speeds observed in the travel time study were presumed to be the result of not including ramps in speed measurements. The freeway speed outputs from the model were deemed reasonable and no adjustment was applied. A default speed of 15 miles per hour was assigned to all VMT on local roadways and 25 miles per hour for intrazonal travel.

Estimation of Vehicle Thermal State One of the most important variables in the estimation of vehicle CO emissions du ring the travel mode is the thermal state of the engine. Cold vehicles emit significantly more CO. The thermal state of the vehicle at any given point in a trip is a function of its soak time (the time since the engine was last running and start-up), the amount of time it was warmed-up prior to the trip, and the amount of prior travel time: Operating mode = 

## ƒ (soak time, idle duration, prior travel time) MOBILE6 allows the user to supply assumptions regar ding the soak distribution of the vehicles started by time-of-day and emission factor estimates are ve ry sensitive to these assumptions. Modeled emissions are significantly higher when a large pr oportion of vehicles are assumed to have had long soak times. Sierra Research developed a method that allowed the computed thermal state of the vehicle with a given soak, idle and travel time to be translated into the operating mode fractions used to model on-road emission factors for the MOBILE5b/Cold CO-based Anchorage attainment plan. However, MOBILE6 no longer uses the operating mode fraction as a model input. Instead, Sierra identified six soak distributions that correspond to the bag fractions used in the attainment plan.Appendix to Section III.B.3

1 6 Table 10 compares the bag fraction approach used in the attainment plan to the soak distribution approach used in the maintenance plan. To develop the maintenance inventory, the VMT accrued by a particular trip type (e.g. home-based work trips begi nning at home) was assumed to be characterized by one of six possible thermal states. For example, if transportation model outputs indicated that this VMT was in the coldest thermal state, MOBILE6 was run with a soak distribution in which 41.8% of the vehicles were assumed have a soak time of 10 minut es and 58.2% of vehicles a soak time of 12 hours or more. If transportation model outputs indicated that the VMT was in the hottest thermal state, 94% of the VMT was accrued by vehicles with a soak time of 10 minutes and just 6% by vehicles with a soak time of 12 hours or more. MOBILE6 emission factors for “cold VMT” were significantly higher than “hot VMT.”
Table 10. Soak distributions for MOBILE6 with comparable operating mode fractions used in MOBILE 5b/Cold CO Model

Thermal

State Operating Mode Fraction (input for MOBILE5b/Cold CO Model) PCCN / PCHC / PCCC * Soak Distribution % of vehicles soaked for 10 min vs. 12 hours (input for MO BILE6 Model) 27.9 / 20.0 / 27.9 41.8% 10 min, 58.2% 12 hours 22.9 /25.0 / 22.9 52.2% 10 min, 47.8% 12 hours 17.9 / 30.0 / 17.9 62.7% 10 min, 37.3% 12 hours 12.9 / 35.0 / 12.9 73.1% 10 min, 26.9% 12 hours

7.9 / 40.0/ 7.9 83.6% 10 min, 16.4% 12 hours Cold

Hot 2.9 / 45.0 / 2.9 94.0% 10 min, 6.0% 12 hours

Figure 3 MOBILE6 On-road emission factor as a function of speed and thermal state 2007 Anchorage emission inventory

0 5 10 15 20 25 30 35

10 20 30 40 50 60 Vehicle SpeedCO Emission (grams pr mile) cold

hot

* PCCN = % of VMT accrued by non-catalyst-equipped vehicles operating in cold start mode, PCHC = % of VMT accrued by catalyst an d noncatalyst vehicles operating in hot start mode; and PCCC = % of VMT accrued by catalyst-equipped vehicles operating in cold star t mode. The sum of these % do not add to 100%. The unspecified portion is the % of VMT accrued by vehicles in the hot-stabilized mode. (I f PCCN/PCHC/PCCC = 22.9 /25.0 / 22.9, then the % VMT accrued in the hot stabilized mode would be 100 – (22.9+25.0) = 52.1%.Appendix to Section III.B.3

1 7 Note: The discontinuities at 15 and 35 mph in Figure 3 reflect a change in the facility type inputs to MOBILE6. All VMT accrue d at speeds above 35 mph was assumed to be on freeways and all local road VMT was assigned a default speed of 15 mph. All other VMT was assumed to be accrued on arterials. An extensive look-up table was then developed for the emission inventory spreads heet that allowed one of the six soak distributions in Table 10 to be assi gned on the basis of the various possible soak times, idle durations, and prior travel times. Soak time and idle duration were supplied as user inputs in the spreadsheet and were based on the local driver behavior studies discussed in the earlier section on estimation of idle emissions. These user inputs varied by time-of-day and trip purpose. The third variable necessary in the estimation of operating mode was the average prior travel time of the vehicles traveling within the grid of interest. If vehicl es had long prior travel times they were likely to be in a fully warm state, and hence, a large proportion of the VMT accrued in the grid would be in the hot fraction. Anchorage Transportation Model post-processor outputs were used to estimate prior travel time. The post-processor provides separate estimates of the amount of VMT accrued by vehicles that began their trips less than 505 seconds ago and more than 505 seconds ago. A spreadsheet algorithm was then developed to estimate average prior travel time for the VMT accrued within each grid by facility type and trip purpose. The end result of this work was a spreadsheet look-up table that allowed the assignment of a particular soak distribution or thermal state for each the 36 different categories of VMT in each grid. Separate assignments were provided by facility category and for the trip purposes within each facility category. Because the emission factor is a function of the so ak distribution, different emission factors were assigned to the VMT within each grid depending on the time-of-day, trip purpose, and facility type.

MOBILE6 Model
The MOBILE6 emission factor model was used to esti mate travel emissions. MOBILE6 was run with Supplemental Federal Test Procedure (SFTP) speed correction factors disabled. The SFTP speed correction factors are used to model the so called “aggressive driving component” of the drive cycle used to compute emission factors. The effects of SFTP were disabled in the model to reflect observed drive cycle behavior in Alaska. Sierra Research conducted studies in Anchorage and Fairbanks to characterize the behavior of Alaskan drivers in the winter. As one might expect, they found a low proportion of driving in hard acceleration or hard deceleration modes when roads are often icy. They determined that the old FTP, without the so-called “aggressive driving supplement”, fairly approximated the winter drive cycle in Alaska. The primary e ffect of excluding the SFTP was to reduce emission factors computed for the on road portion of trip emissions. However, disabling the SFTP emission component in MOBILE6 has the secondary effect of reducing the benefits of fleet turnover on future emissions. In other words, using MOBILE6 with SFTP disabled provides a more pessimistic maintenance forecast than the “default” version of the model with SFTP factors enabled. Vehicle registration distributions were based on data from detailed parking lot surveys conducted by ADEC during the winters of 1999 and 2000. The as sumptions about the age distribution of vehicles were compared to parking lot survey data collected in 2007. There was very little difference in the age distributions determined in 1999 and 2001 and the more recent data. All these surveys indicated that the in use vehicle population is newer t han suggested by vehicle registration data.
Odometer measurements collected by the Anchorage I/M program allowed mileage accumulation rates of vehicles subject to I/M requirements to be estima ted. Default mileage accumulation rates were used for diesels and other I/M exempt vehicles. MOBILE6 was configured to reflect the fact that ne w car I/M test exemption period will be extended from four to six years beginning in January 2010. Thus, the MOBILE6 input files reflect the four-year new car exemption in place in Anchorage in analysis years 2007 and 2009. For 2011 and beyond, , the input files MOBILE6 reflect a six year new car exemption. When the CO reduc tion provided by I/M in analysis years 2007 and 2009 was modeled with MOBILE6, an I/M program effectiveness of 85% andcompliance rate of 90% among non-OBD vehicles was assumed. The compliance rate for OBDAppendix to Section III.B.3

1 8 equipped vehicles was assumed to be slightly higher, 93%. Attachment 2 contains copies of the input files used to generate emission factors for the 2007 base year inventory and for 2011. Copies of input files for 2009, 2013, 2015, 2017, 2019, 2021 and 2023 are available upon request.

Calculation of On Road CO Emissions An Excel spreadsheet was developed to assemble the information necessary to calculate CO emissions from on road travel in each grid cell. As disc ussed earlier, the spreadsheet was used to compute the emission contributions of 36 possible different cat egories of travel, with varying speeds and operating modes. The emissions from these various categorie s of travel were then summed to determine on-road emissions in each grid using the following formula:

On-road emissions = 

### ) .....()......... () ( 36 21 22 1 36

1 1 

### EFVMT EFVMT EFVMT

i 

### × ×+× 

# ∑

= Summary of On-road Travel Emissions Estimates for 2007-2023 Results of the spreadsheet calculation of travel emissions are shown by time of day in Table 11. Note that emissions increase slightly between 2009 and 2011 due to the termination if the I/M program and then decline slowly thereafter.

Table 11. On road travel emissions by time-of-day (all values in tons per day)

Calendar

Year AM Peak 7 a.m. – 9 a.m. PM Peak 3 p.m. – 6 p.m. Off-Peak Periods 9 a.m. – 3 p.m. 6 p.m. – 7 a.m. Total 24-hour Travel Emissions 2007 8.01 14.27 28.76 51.04 2009 7.03 12.53 25.39 44.95 2011 6.72 11.95 24.15 42.82 2013 6.34 11.24 22.73 40.32 2015 6.09 10.77 21.78 38.64 2017 5.89 10.34 21.12 37.35 2019 5.77 10.21 20.72 36.70 2021 5.65 10.05 20.41 36.11 2023 5.60 10.01 20.39 36.01



### Aircraft Operation Emissions

In June of 2005 Sierra Research, Inc. prepared the “Alaska Aviation Inventory” for the Western Regional Partnership (WRAP). 10 They compiled air pollutant emission estimates for airports across Alaska including Ted Stevens Anchorage International Airpor t (ANC) and Merrill Field Airport in Anchorage. Both summer and winter CO emissions associated with aircraft operation for various pollutants were estimated for the year 2002. Sierra collaborated with CH2MHill to collect the specific information on aircraft operations at ANC and Merrill Field necessary for input into the Federal Aviation Administration’s EDMS Model (Version 4.2). EDMS was used to gener ate estimates of CO emissions from aircraft and aircraft support equipment. In EDMS, aircraft support equipment includes both ground support equipment (GSE) and on-board auxiliary power units (APUs) that are used to provide power to aircraftAppendix to Section III.B.3

1 9 when on the ground. Winter season CO emissions estimates for ANC and Merrill are shown in Table 12.
Table 12. 24-hour CO emissions estimates from ai rcraft at ANC and Merrill Field in 2002

Aircraft Support Equipment APU and GSE (tons per day) Aircraft (tons per day) TOTAL

ANC 8.21 3.32 11.53
Merrill 0.00 0.63 0.63

ANC is currently revising their master plan. The dr aft Master Plan contains an analysis of historical trends in aircraft operations and projections through 2027. The draft Plan projects an average annual growth rate of 2.4% between 2005 and 2027. Historical data on total operations in 2002 when Sierra prepared their emissions estimates were used along with the growth projections in the draft Master Plan to project future emissions from ANC. Emissions were presumed to grow in direct proportion to total operations. Results are shown in Table 13.
Table 13 Projected aircraft operations and CO emissions at ANC

Calendar Year Estimated or Projected Annual Aircraft Operations CO Emissions (tons per day) 2002 (base year of Sierra inventory ) 309,236 11.53 2007 331,708 12.37 2009 347,845 12.97 2011 363,982 13.57 2013 379,810 14.16 2015 395,327 14.74 2017 410,845 15.32 2019 435,440 16.24 2021 460,036 17.16 2023 484,631 18.07

Winter CO emissions from Merrill Field were computed in a similar manner. Sierra’s 2002 CO emissions estimate (0.633 tons/day) was scaled upward in proportion to the projected increase in aircraft operations at Merrill. The Merrill Field Master Plan (2000) contains growth projections for the period 1997 through 2020. Annual operations are projected to increase from 187,190 in 1997 to 270,800 in 2020. Assuming linear growth, CO emissions can be projected for the period 2007-2023. These projections are shown in Table 14.Appendix to Section III.B.3

2 0 Table 14 Projected Aircraft Operat ions and CO Emissions at Merrill Field Airport

Calendar Year Estimated or Projected Aircraft Operations CO Emissions (tons per day) 1997 187,190 2002 (base year of Sierra inventory ) 205,366 0.633 2007 223,542 0.689 2009 230,813 0.711 2011 238,083 0.734 2013 245,353 0.756 2015 252,624 0.779 2017 259,894 0.801 2019 267,165 0.823 2021 274,435 0.846 2023 281,706 0.868



### Residential Wood Burning Emissions

The basic assumptions used in the preparation of emission estimates from residential wood burning were not changed from those used in the Year 2000 Anchorage Attainment Plan. Assumptions regarding wood burning activity levels (i.e. the nu mber of households engaging in wood burning on a winter season design day) were corroborated by a telephone survey c onducted by Ivan Moore Research (IMR) in 2003. IMR asked approximatel y 600 Anchorage residents whether they had used their fireplace or woodstove during the preceding day. The survey was conducted when the preceding day had a minimum temperature between 5 and 15 degrees F. Survey results were roughly consistent with the assumptions used in the attainment plan in ventory. The basic assumptions used to estimate wood burning were based on data from a telephone survey 11 performed by ASK Marketing and Research in 1990. The ASK survey asked Anchorage re sidents how many hours per w eek they burned wood in their fireplace or wood stove. * Because the AP-42 emission factors for fireplaces and wood stoves are based on consumption in terms of the amount of wood (dry weight) burned, hourly usage rates from the survey had to be converted into consumption rates. Ba sed on discussions between MOA and several reliable sources (OMNI Environmental Services, Virginia Poly technic Institute, Colorado Department of Health), average burning rates (in wet weight) of 11 pounds per hour for fireplaces and 3.5 pounds per hour for wood stoves were assumed for the Anchorage area. Residential wood burning assumptions are detailed in Table 15.

* A previous telephone survey attempted to quantify wood consumption directly by asking residents how much wood (e.g., cords) the y burned each winter. Many residents had difficult quantifying their consumption in this manner, for this reason the 1990 survey asked about hours of usage per week.Appendix to Section III.B.3

21 Table 15. Estimation of residential wood burning CO emission factors for Anchorage

Device Average use per weekday

(hours per household per day) Average dry weight of wood

consumed (lbs per hour)* Average amount of wood burned per household (dry lbs / day) Estimated wood burning CO emissions per

household (lbs/day)
Fireplaces 0.156 7.15 lbs/hr 1.11 0.141

Wood Stoves 0.032 2.275 lbs/hr 0.073 0.006 TOTAL Fireplaces + woodstoves 0.188 ------ 1.18 0.147

* The moisture content of wood burned was assumed to be 35%. Thus, dry burning rates were 65% of wet rates. ** The wood stove emission factor was determined by assuming that the wood stove population in Anchorage is comprised of equal proportions of conventional, catalyst, and non-catalyst stoves. The emission factor above was calculated as the weighted average of the AP-42 emission factors for each stove type. AP-42, 5 th Edition (Oct 1996)

Survey results suggest wood burning rates are relatively low in the Anchorage area. The vast majority of wood burning is “pleasure burning;” very few residents need to burn wood for primary or supplemental heat. If the average fire in the fireplace and/or woodstove is assumed to last three hours, Table 15 suggests that about 1 in every 16 households in Anchorage burns wood on a typical winter weekday. The Anchorage Transportation Model post-processor provided information on the number of households in each grid. The calculated CO emission rate of 0.147 lbs of CO per day was assigned to each household in a grid. Thus wood burning emissions we re highest in grids with high housing density. Projecting future trends in wood heating in Anchor age is difficult. On one hand, anecdotal evidence suggests that fewer wood burning appliances are being installed in new homes in Anchorage. This is consistent with trends being observ ed nationally. On the other hand, increases in natural gas prices could result in increases in wood heating. For the purpose of this inventory, residential wood burning was assumed to increase in direct proportion with the number of households in the Anchorage inventory area. Area-wide wood burning emissions for the period 2007 - 2023 are shown in Table 16.
Table 16. Estimated Anchorage-wide 24-hour CO emissions from residential wood burning

Calendar Year Number of Households in Inventory Area 24-Hour Emissions (tons)
2007 84,936 6.24
2009 86,582 6.36
2011 88,229 6.48
2013 89,875 6.60
2015 91,522 6.72
2017 93,168 6.84
2019 94,045 6.91
2021 94,923 6.97
2023 95,800 7.04Appendix to Section III.B.3

2 2 

### Emissions from Natural Gas Combustion for Space Heating

The methodology used to compute natural gas space heating emissions for the maintenance demonstration is identical to that used in the Year 2000 Anchorage CO Attainment Demonstration and the 2004 Anchorage CO Maintenance Plan. A telephone survey conducted by ASK Marketing and Research in 1990 12 indicated that natural gas is the fuel used for virtually all space heating in Anchorage. ASK survey results are shown in Table 17.
Table 17. Methods of Home Heating in Anchorage (ASK Marketing & Research, 1990)

Natural gas 88.2% Electricity 9.2%

Fuel oil 0.2%

Wood / other 1.3%

Don't know 1.1%

Total 100.0%

Enstar distributes natural gas to Kenai, Anchorage and other parts of Southcentral Alaska. According to Enstar, in 1996 approximately 80% of their gas sales were to Anchorage. 13 Table 19 indicates that about 88% of all homes in Anchorage are heated with natural gas. A small fraction of homes are heated by wood or fuel oil. Wood heating has already been quantified separately in the inventory. The consumption of fuel oil for space heating was small in 1990 and likely even smaller in 2007. Calculated area-wide CO emissions from space heating with fuel oil are negligible (less than 25 pounds per day) and are not included in the inventory. Finally, the emissions associated with electrical heating occur at the generation plant. These emissions are accounted for separately in the point source inventory. A detailed report of natural gas sales to residentia l, commercial and industrial customers was available for calendar year 1990 * for Southcentral Alaska. 14 Peak winter usage rates were estimated for residential customers and for commercial/industrial cu stomers from this report. Demographic data (i.e. number of households, number of employees) were used to estimate per household consumption rates for residential customers and per employee consumption for commercial/industrial customers. The most recent AP-42 CO emission factors (July 1998) for uncontrolled residential furnaces (40 lbs CO/ 10 6 ft 3) ) and small boilers (84 lbs CO/ 10 6 ft 3) ) were used to characterize residential and commercial space heating emission. Calculated peak natural gas consum ption and emission rates are shown in Table 18.
Table 18 Peak winter season natural gas consumption rates and CO emission rates in Anchorage (1990)

Consumption Rate per Day AP-42 Emission Factor (lbs. per 10 6 ft 3 ) CO Emission Rate

(lbs per day)

Residential 658 ft 3 per household 40 0.0263 per household

Commercial/ Industrial 434 ft 3 per employee 84 0.0364 per employee

* Although data from more recent years was available, the repor ting format had changed and less deta iled data were available. Unlike the 1990 report, natural gas consumption was not reported separately fo r residential, commercial/industrial, and power generation custom ers.Appendix to Section III.B.3

2 3 On an area-wide basis, CO emissions from natural gas combustion were calculated by multiplying the CO emission rates in Table 19 by the number of households and employees in the inventory area. Table 19 presents the results of this calculation for the period 2007 – 2023. Emissions resulting from the combustion of natural gas for power generation are excluded. These emissions are accounted for separately in the point source inventory.
Table 19 CO Emissions from natural gas combustion (excludes power generation)

Calendar

Year Number of Households in Inventory Area Number of Employees in Inventory Area Calculated Total Natural Gas

Consumption (mcf) CO Emissions from Natural Gas Combustion

(tons/day)
2007 84,936 145,516 119,127 3.77
2009 86,582 146,755 120,749 3.82
2011 88,229 147,994 122,372 3.86
2013 89,875 149,234 123,994 3.91
2015 91,522 150,473 125,617 3.95
2017 93,168 151,712 127,238 3.99
2019 94,045 153,731 128,693 4.04
2021 94,923 155,750 130,148 4.09
2023 95,800 157,769 131,602 4.14

CO emissions from natural gas combustion were also calculated on a grid-by-grid basis by multiplying the emission rate per household or per employee by the number of households or employees in each grid. Thus, grid cells with a large number of households and/or employees were assigned the greatest emissions.



### Other Miscell aneous Sources

Use of NONROAD to Estimate Emissions from Snowmobiles, Snow Blowers, Welders, Air Compressors and Other Miscellaneous Sources
As a starting point for this analysis, the EPA NONROAD model (version 2005) was run for base year 2007. The model provides estimates of non-road equipment types and activity levels for Anchorage. These model outputs were reviewed carefully to assess whether or not nonroad equipment populations and usage (i.e., hours per year) were reasonable. The NONROAD model uses a top-down approach in which state-level equipment populations are allocated to counties on the basis of activity indicators that are specific to certain equipment types. Anchorage is the major wholesale and retail distribution center for the state. Because the NONROAD model activity indicator is based on the number of businesses within a particular SIC code, the model has a tendency to over-allocate the equipment to Anchorage and ignore usage that occurs outside the Anchorage area. For example, the NONROAD estimate for generator sets is likely heavily skewed by sales to non-Anchorage customers who come to Anchorage to purchase a generator for use in areas outside of the power grid. The default model outputs are given in terms of av erage monthly, year-round use. These outputs were adjusted to reflect the fact that activity levels for non-road sources would be expected to be reduced onAppendix to Section III.B.3

2 4 a typical midwinter exceedance day when ambient temperatures are near 0 ° F. The activity levels of all-terrain vehicles, motorcycles, pressure washers, air compressors and pumps are likely substantially reduced in midwinter. Pressure washer activity, for example, was assumed to be 10% of that estimated by NONROAD. Other sources were also adjusted significantly from the NONROAD model’s default outputs. These local adjustment factors are shown in Table 20. It is important to note, that without adjustment, the NONROAD model’s estimate of CO emi ssions from the sources listed in the table is 120.8 tons per day in 2007, whereas total motor vehicle emissions (idle plus travel) are estimated to be just 67.1 tons per day. Given what is known about the CO problem in Anchorage, clearly something is amiss. After the activity adjustment factors are applied to the NONROAD model estimates, the total contribution from the sources listed in the table is 9.1 tons per day. Default output emissions from commercial and residential snowblowers were also reduced. Anchorage climatological records indicate that CO exceedanc es are typically preceded by cold, clear weather without snow. Thus, snowblower acti vity is likely to be lower on elev ated CO days. For this reason the NONROAD estimate of residential and commercial snowblower activity was cut by 50%. The NONROAD model default estimate for the snowmachine population in Anchorage is 34,985. Although there are a considerable number of snowmobile s in Anchorage, virtually all use occurs outside of the nonattainment area. Snowmobile use in Anchorage is banned on public land throughout the Anchorage nonattainment area because of safety and noise issues. Although there is some use in surrounding parklands, (i.e., Chugach State Park) these areas are located at least three miles from the emission inventory area boundary. However, there is likely to be some small amount of engine operation for maintenance purposes, etc. This was assumed to average about 0.1 hours per unit per month inside the inventory area. This usage rate is about 50 times lower than the NONROAD default value. Finally, some of the NONROAD model outputs were clearly unreasonable. For example, there is no commercial logging activity in the Anchorage bowl. For this reason, the NONROAD model’s estimate of CO emissions from logging equipment chain saws was disregarded. The NONROAD estimate of “other” chainsaw use was cut by 80% to reflect that little garden or home wood cutti ng activity is likely to take place in mid-winter.
Table 20 Estimation of NONROAD CO emissions in 2007

Number of Units EPA NONROAD Model Estimate of

CO emissions (unadjusted) Activity Adjustment Factor Revised CO Inventory Estimate (tons/day) air compressors 251 0.83 0.50 0.42 ATVs 14,481 0.90 0.02 0.02 chainsaws 6,159 0.56 0.20 0.14 concrete saws 144 0.60 0.25 0.15 forklifts 94 0.41 1.00 0.41 generator sets 4,758 7.13 0.25 1.78 pressure washers 1,898 3.08 0.10 0.31 pumps 1,227 1.73 0.25 0.43 snowblowers commercial 864 2.26 0.50 1.13 snowblowers residential 9,517 1.02 0.50 0.51 snowmobiles 34,985 96.73 0.02 1.93 welders 419 2.10 0.50 1.05 other 91,767 3.47 varies 0.84 TOTAL NONROAD 120.83 9.12Appendix to Section III.B.3

2 5 In order to estimate future year emissions (2009 through 2023) the sources listed in Table 20 were increased in proportion to growth in households or employment. If the nonroad road source was primarily related to household activities, the growth in emissions was assum ed to be proportional to the projected growth in the number of households in the inventory area. These household- related sources include snowmobiles, motorcycles and generator sets. If the nonroad source was primarily related to commercial activity, growth in emissions was assumed to be tied to growth in employment. Commercial or employment-related sources include welders, pumps and air compressors.
The emissions from the sources listed above were apportioned among the grid cells that make up the inventory area by using the number of households or employment in the grid as a surrogate for source activity. Activities that would normally primarily o ccur in residential areas (snowmobiles, residential and commercial snowblower use, ATVs and motorcycles) were apportioned on the basis of the number of households in each grid. Activities that would normally occur in commercial or industrial areas (welders, pumps, and air compressors), were apportioned on the basis of the amount of employment in each grid.
Table 21 CO emissions from NONROAD sources (2007-2023)

Calendar Year CO Emissions from NONROAD Sources (tons/day)
2007 9.12
2009 9.24
2011 9.35
2013 9.47
2015 9.59
2017 9.70
2019 9.82
2021 9.93
2023 10.04

Railroad Emissions
Because railroad emissions are a relatively insignificant source of CO, no changes have been made to the estimates or methodology employed in the 2004 CO Maintenance Plan. The Alaska Railroad (ARR) supplied data on line haul and switchyard fuel consum ption to the Alaska Department of Environmental Conservation for calendar year 1999. Total fuel consumption in the Anchorage switchyard was estimated to be 370,000 gallons during calendar year 1999. ARR also provided data on line haul fuel consumption between milepost 64 and 146. Annual fuel consumption along this 82-mile section of track was estimated to be 771,000 gallons. Only 14 miles of track (roughly MP 104 through MP 118) are inside the emission inventory area. The proportionate share of consumption within the inventory area was estimated to be 131,600 gallons. Twenty-four hour consumption rates were calculated by dividing annual totals by 365. EPA guidance 15 provides separate emission factors for yard and line haul emissions. These factors, expressed on a gram per gallon basis, were appli ed to ARR fuel consumption estimates to compute emissions. Railroad fuel consumption and emissions are summari zed in Table 22. Switchyard emissions were distributed to the three grid cells that encompass the rail yard in the Ship Creek area of Anchorage. The rail route in Anchorage crosses 15 grids cells in the Anchorage inventory area. Line haul emissions were distributed equally among these 15 grid cells.Appendix to Section III.B.3

2 6 Table 22 Alaska Railroad emission estimates 2007-2023

Consumption

(gal/year) Consumption (gal/day) Locomotive Emission

Factor (grams/gal) CO emissions (tons/day) Yard 370,000 1,014 38.1 0.04 Line Haul 131,634 361 26.6 0.01 Total 501,634 1,375 0.05

Although railroad activity is expected to increase in future years, above the activity levels reported in 1999, the emissions increases that might be expected from this growth are likely to be offset by improvements in locomotive control technology. The Alaska Railroad recently replaced 28 of their 62 locomotives with new models that produce less pollu tion and are more fuel efficient. In addition, between 2002 and 2007, the railroad equipped two-thirds of their locomotives with devices that reduce the amount of time locomotives idle in the Anchorage switchyard and reduce fuel consumption. For the purpose of this analysis, CO emissi ons from the ARR were assumed to remain the same through 2023. Although this is a crude assumption, the significance of ARR emissions is very small. Hence, refining these future year projections would have a negligible effect on the overall inventory.

Marine Vessel Emissions
The Port of Anchorage serves primarily as a receiv ing port for goods such as containerized freight, iron, steel and wood products, and bulk concrete and petroleum. Commercial shipping lines, including Totem Ocean Trailer Express and Horizon Lines bring in four to five ships weekly into the Port. The Port is currently undergoing a significant expansion that is intended to modernize the facility and double its size. In 2005, over 5 million tons of comm odities moved across the Port’s docks.
Despite the magnitude of this activity at the Port, CO emissions are relatively small. In June 2005, Pechan and Associates prepared an emission inventory for the ADEC that estimated winter and summer season CO emissions from the Port for the year 2002. 16 This report provided an estimate of total emissions that occur from all four modes of commercial marine activity for the winter (defined as October through March). These four modes include cruise, reduced speed zone (RSV), maneuvering, and hotelling. However, as defined for modeling purposes, the cruise and RSV modes occur far from Port. Cruise mode activity occurs more than 25 miles form Port and the RSV mode occurs 2 miles or more from Port. Because cruise and RSV mode CO emissions occur so far from Port and therefore have little or no influence on CO concentrations in the Anchorage CO maintenance area, these emissions were excluded from this inventory. * In addition to the 2002 inventory, the Pechan inventory also includes a forecast of winter CO emissions for 2005 and 2018. Interpolation and extrapolation was used to estimate CO emissions from Port of Anchorage marine activity from 2007 – 2023. These estimates are shown in Table 23.

* Cruise and RSV emissions account for about 56% of total winter CO emissions. Therefore only 44% of the emissions in the Pecha n inventory were included in this inventory.Appendix to Section III.B.3

2 7 Table 23. Estimated CO emissions from the Port of Anchorage

Year Estimated CO emissions (tons per day) 2007 0.09 2009 0.10 2011 0.11 2013 0.12 2015 0.12 2017 0.13 2019 0.13 2021 0.13 2023 0.13



### Emissions from Point Sources

Point source emissions estimates for the year 200 5 served as the basis for the 2007 base year point source emission inventory prepared for this maintenance plan and projections through 2023. Point source emissions were expected to grow in relation to the number of households. Thus the emission estimates for 2005 were adjusted upward in proportion to the growth in the number of households in the inventory boundary area. ADEC is responsible for issuing operating permits to all stationary sources that have fuel-burning equipment with a combined rating capacity of greater than 100 million Btu per hour. The MOA also issues operating permits to all point sources in Anchorage with a combined rating capacity of greater than 35 million Btu per hour. The ADEC and MOA permit systems were used to inventory all stationary sources that are required to obtain such permits in the Anchorage non-attainment area. In addition, point sources that produce more than 10 tons per year (TPY) of CO (minor sources) were individually quantified to achieve a more precise estimate of the minor source contribution to the overall emission inventory from stationary sources. The identification of minor sources was accomplished by contacting fuel distributors in Anchorage. We determined whether any facilities consumed sufficient q uantities of fuel to exceed the annual 10 TPY of CO threshold. Using EPA's emission factors, AP-42 (f ifth edition), fuel quantit ies equivalent to 10 TPY of CO were compared to sales of fuel to large users. This identified potential 10+ TPY of CO point sources. This approach determined that only permitted sources in Anchorage emitted more than 10 TPY of CO. The ADEC point source computations were based on annual information provided by the source. The emission factors were from the most current version of AP-42. The ADEC calculated daily point source emissions for a typical wintertime day during the peak CO season by dividing the annual activity levels by the number of days per year. Actual facility operating information was available for 2005. Source emission estimates were based on actual fuel consumption and operations rather than permit allowable emissions. Based on ADEC-issued air quality permits, there are six point sources in the Anchorage non-attainment area. Estimated annual emissions from each sour ce for 2005 and projected daily emissions for the 2007-2023 period are listed in the table at the end of this section. Three of the six point sources identified in the Anchorage inventory were gas-fired (p rimarily natural gas) electrical generating facilities. Other sources include a sewage sludge incinerator, and two bulk fuel storage facilities.Appendix to Section III.B.3

2 8 Source Descriptions and Emission Estimation Information
There are three point sources that are located outside the non-attainment area. Two are located on military bases at Elmendorf Air Force Base and Fort Richardson. These facilities were excluded from the base year inventory because the CO emissions on these two military facilities are not considered significant contributors to the Anchorage attainment problem. The third facility is Anchorage Municipal Light and Power Sullivan Power Plant. It is located approximately two kilometers east of the northwest corner boundary of the nonattainment area. Even though this source is located outside the boundaries of both the attainment area and emission inventory area, it is included in the inventory. Emissions from the Sullivan Plant were assigned to the furthest northwest grid in the inventory area. This grid is located approximately 2 kilometers west of the power plant. The ADEC used facility-reported information and AP-42 emission factors to estimate emissions for each of the six point sources. The methodology and emission factors used to estimate actual emissions at each facility is available upon request. The ADEC Operating Permit system results in t he collection of the emission information through requirements for annual and triennial emission reports, on-site inspections, the reporting of source test data and quarterly production levels and fuel usage, and interactions with each source. In addition, there was no CO emission control equipment identifi ed on any of the sources included in the inventory. Therefore, 100% of the emission estimates resulti ng from the application of the AP-42 factors identified above was assumed for the inventories. Based on the above information, the application of a Rule Effectiveness factor did not appear to be appropriate and was not included for any of the point sources included in this inventory. Summary of Point Source Emissions
The estimates of actual emissions for a typical winter day (in tons per day) at each point source for the year 2005 and the projections for 2007 through 2023 are provided in Table 24.
Table 24 Point Source CO Emissions Summary (tons per day)

Projected Daily CO Emissions based on growth in number of households

Owner 2005 2007 2009 2011 2013 2015 2017 2019 2021 2023 Tesoro Alaska Petroleum Company, Anchorage Terminals I & II 0.00 0.00 0.00 0.00 0.00 0.00 0. 00 0.00 0.00 0.00 Anchorage Water & Wastewater Utility, Point Woronzof, John Asplund Wastewater Treatment Facility 0.26 0.27 0. 27 0.28 0.28 0.29 0. 30 0.30 0.30 0.30 Chugach Electric Association, International Station Power Plant 0.01 0.01 0.01 0. 01 0.01 0.01 0.01 0.01 0.01 0.01 Anchorage Municipal Light & Power, George Sullivan Plant Two 0.93 0.95 0. 97 0.99 1.00 1.02 1. 04 1.05 1.06 1.07 Anchorage Municipal Light & Power, Hank Nikkels Plant One 0.07 0.07 0.07 0.07 0.07 0.07 0. 08 0.08 0.08 0.08
Flint Hills Resources Alaska, LLC 0.01 0.01 0.01 0. 01 0.01 0.01 0.01 0.01 0.01 0.01

TOTAL POINT SOURCE EMISSIONS 1.28 1.31 1.33 1.36 1.38 1.41 1.43 1.45 1.46 1.47Appendix to Section III.B.3

2 9 

### Emissions Summary

2007 Base Year Area-wide CO Inventory
Based on the methodology outlined in the previous sect ion, total CO emissions from all sources in the inventory area were calculated for a typical winter weekday in 2007, when conditions are conducive to elevated CO concentrations. Total area-wide CO emissions are estimated to be 100.7 tons per day. Motor vehicles account for an estimated 65.1% of these area-wide emissions.

Table 25 Sources of Anchorage CO emissions in 2007 base year in Anchorage inventory area

Source Category CO Emitted (tons per day) % of total*

Motor vehicles 67.4 66.7% Aircraft – Ted Stevens Anchorage International and Merrill Field Airport Operations 13.1 12.9%
Wood burning – fireplaces and wood stoves 6.2 6.2%
Space heating – natural gas 3.8 3.7% Miscellaneous (snowmobiles, snow removal, welding, rail, marine, etc.) 9.3 9.2% Point sources (power generation, sewage sludge incineration) 1.3 1.3%

TOTAL 101.0 100.0%

Projected Area-Wide CO Emissions (2007-2023)
As described in the previous sections, CO emissions for the Anchorage inventory area were projected for each of the source categories for a 24-hour day in 2007, 2009, 2011, 2013, 2015, 2017, 2019, 2021 and 2023. Results are tabulated in Table 26. Area-wide CO emissions for the period 2007-2023 are plotted in Figure 4. CO emissi ons decline over time due to expected improvements in emission controls on newer vehicles. Total area-wide CO emissions ar e expected to increase slightly because of the growth of other sources such as Ted Stevens Anchorage International Airport. Nevertheless, total CO emissions projected for 2023 (88.3 tons per day) are approximately 12.5% lower than emissions in base year 2007 (101.0 tons per day).Appendix to Section III.B.3

3 0 Table 26 Total CO emitted during typical 24-hour winter day in the Anchorage bowl inventory area (tons per day)

motor vehicles aircraft

year idle mode travel mode Stevens Int'l Airport Merril Field wood burning space heating rail/ marine nonroad Point Sources TOTAL CO EMISSIONS 2007 16.3 51.0 12.4 0.7 6. 2 3.8 0.2 9.1 1.3 101.0 2008 15.3 48.0 12.7 0.7 6. 3 3.8 0.2 9.2 1.3 97.4 2009 14.2 45.0 13.0 0.7 6. 4 3.8 0.2 9.2 1.3 93.7 2010 13.7 43.9 13.3 0.7 6. 4 3.8 0.2 9.3 1.3 92.6 2011 13.1 42.8 13.6 0.7 6. 5 3.9 0.2 9.4 1.3 91.4 2012 12.7 41.6 13.8 0.7 6. 5 3.9 0.2 9.4 1.3 90.2 2013 12.2 40.3 14.1 0.8 6. 6 3.9 0.2 9.5 1.3 88.9 2014 12.0 39.5 14.4 0.8 6. 7 3.9 0.2 9.5 1.3 88.3 2015 11.7 38.6 14.7 0.8 6. 7 4.0 0.2 9.6 1.3 87.6 2016 11.4 38.0 15.0 0.8 6. 8 4.0 0.2 9.6 1.3 87.2 2017 11.2 37.3 15.3 0.8 6. 8 4.0 0.2 9.7 1.3 86.7 2018 11.0 37.0 15.8 0.8 6. 9 4.0 0.2 9.8 1.3 86.8 2019 10.9 36.7 16.2 0.8 6. 9 4.0 0.2 9.8 1.4 87.0 2020 10.8 36.4 16.7 0.8 6. 9 4.1 0.2 9.9 1.4 87.1 2021 10.6 36.1 17.2 0.8 7. 0 4.1 0.2 9.9 1.4 87.3 2022 10.6 36.1 17.6 0.9 7. 0 4.1 0.2 10.0 1.4 87.8 2023 10.5 36.0 18.1 0.9 7. 0 4.1 0.2 10.0 1.4 88.3

Figure 4.
Projected Area-wide CO Emissions in Anchorage (2007-2023)

0.0 20.0 40.0 60.0 80.0 100.0 120.0

2007 2009 2011 2013 2015 2017 2019 2021 2023CO Emissions (tons per day)

other (nonroad, rail, marine) point sources space heating fireplaces and woodstoves aircraft motor vehiclesAppendix to Section III.B.3

31 

### Compilation of Micro-Area Inventor y for Turnagain Monitoring Station

The area-wide CO inventory discussed in the previous section will be necessary to prepare the motor vehicle emission budget for use in future region-wi de air quality conformity determinations. However, this “area-wide view” of emissions is not very useful in analyzing the factors leading to high CO concentrations at particular locations in Anchorage. Monitoring data, including a saturation monitoring study conducted in 1997-98 have demonstrated t hat CO concentrations vary widely throughout Anchorage and that some areas are more prone to high concentrations and have a greater potential to violate the national ambient air quality standard. The Turnagain monitoring station, located in a Spenard-area neighborhood, has the highest CO concentrations of all the monitoring stations in An chorage. Maximum 8-hour concentrations are typically 10 to 20% higher than the next highest site called Garden in east Anchorage. During the 1997-98 CO Saturation Study 8-hour CO concentrations at Turnagain were the highest among the 20 sites included in the study. 17 An analysis of the probability of exceeding the national ambient air quality standard has been performed for both the Turnagain and Garden sites. This analysis suggests that the probability of violating the standard at Turnagain at current CO emis sion levels is about 1 in 50 while the probability of violating at the Garden station is less than 1 in 1,000. 18 For this reason, it was decided that the Turnagain site should be used for the maintenance demonstration. In order to perform this demonstration, CO emissions in the area immediatel y surrounding the Turnagain site must be known for base year 2007 and projected through 2023. Because the Anchorage inventory data is disaggregated into one-kilometer 2 grids, CO emissions can be analyzed in the area immediately surrounding the Turnagain station. A nine-square kilometer area including and surrounding the Turnagain site was selected for analysis. The area selected is shown in Figure 5. As can be seen in the figure, the emissi ons in the nine grids comprising this analysis area are among the highest in the inventory area. Figure 6 shows that precise location of the Turnagain monitoring station in relation to the area selected for the micro-inventory. In 2007, this nine square kilometer area contained an estimated population of 19,776. Total estimated employment was 9,005. This area is one of the most densely populated areas in the Anchorage bowl.Appendix to Section III.B.3

3 2 Figure 5 CO emissions distribution in Anchorage (Turnagain micro-inventory area boundary noted with red border)Appendix to Section III.B.3

3 3 Figure 6 Aerial photo of Turnagain micro-inventory area boundary

2007 Base Year CO Micro-Inventory for Turnagain Site
Results of the 2007 base year micro-inventory for the nine-kilometer 2 area surrounding the Turnagain station are shown in Table 26. Total CO emissions in the micro-inventory area are estimated to be 6.01 tons per day. Motor vehicles account for an estimated 73.4% of the emissions in the area. Note that there is no contribution from aircraft oper ations or point sources in the area.Appendix to Section III.B.3

3 4 Table 27 Sources of CO Emissions in Turnagain Micro-inventory Area 2007 Base Year

Source Category CO Emitted (tons per day) % of total

Motor vehicles 4.42 73.4% Aircraft – Ted Stevens Anchorag e Internationa l and Merrill Field Airport Operations --- ---

Wood burning – fireplaces and wood stoves 0.62 10.3%

Space heating – natural gas 0.28 4.6% Miscellaneous (snowmobiles, snow removal, welding, rail, marine, etc.) 0.70 11.7% Point sources (power generation, sewage sludge incineration) ---

TOTAL 6.01 100.0%

Projected CO Emissions in the Turnagain Micro-Inventory Area (2007-2023)

Projected emissions in the Turnagain micro-inventory area are tabulated for the period 2007-2023 in Table 27. CO emissions decline steadily between 2007 and 2023. By 2023 CO emissions in the Turnagain area are projected to decline by about 20% from the 2007 base year.

Table 28 Total CO emitted during typical 24-hour winter day when CO is elevated in Turnagain micro-inventory area (tons per day)

Motor Vehicles Area Sources

idle mode travel mode wood burning space heating other TOTAL CO EMISSIONS 2007 1.16 3.26 0.62 0.28 0.70 6.01 2009 1.08 3.04 0.62 0.28 0.70 5.73 2011 1.00 2.83 0.63 0.28 0.71 5.45 2013 0.96 2.74 0.63 0.28 0.71 5.33 2015 0.92 2.65 0.64 0.28 0.71 5.21 2017 0.89 2.56 0.65 0.28 0.72 5.10 2019 0.86 2.47 0.65 0.28 0.72 4.98 2021 0.83 2.40 0.66 0.28 0.72 4.90 2023 0.81 2.34 0.66 0.29 0.73 4.83Appendix to Section III.B.3

3 5 Figure 7 Projected CO Emissions in Turna gain CO Micro-Inventory Area 2007-2023

0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00

2007 2009 2011 2013 2015 2017 2019 2021CO Emissions (tons per day)

Other
Space Heating
Fireplace or Woodstove

Motor Vehicles

Time-of-Day Inventory at Turnagain
CO sources vary by time-of-day. For example, idle emissions are an important source of CO during the morning commute hours but less so during other times of day. For this reason, separate estimates of CO emissions were generated for each of the 200 grid cells that comprise the Anchorage inventory area for the AM Peak (7 AM – 9 AM), the PM Peak (3 PM – 6 PM) and Off Peak (6 PM – 7 AM, 9 AM – 3 PM) periods. Time-of-day emission results by grid for base year 2007 are summarized in Attachment 4. Results for other analysis years thr ough 2023 are available by request. Figure 8 shows that CO emission rates vary cons iderably by time-of-day in the Turnagain microinventory area. Time-of-day modeling suggests that CO emission rates are highest during the AM Peak (7 AM – 9 AM). CO concentrations at the Turnagain site are typically highest during morning hours, corresponding with this period of peak emissions.Appendix to Section III.B.3

3 6 Figure 8 CO emission rate by time-of-day in Turnagain CO micro-inventory area (2007)

0 200 400 600 800 1,000 1,200

AM Peak PM Peak Off PeakCO emission rate (lbs/hr) other fireplace and wood stoves on-road travel warm-up idleAppendix to Section III.B.3

3 7 

### References

1 “Analysis of Alaska Vehicle CO Emission Study Data,” prepared by Sierra Research for the Municipality of Anchorage, February 3, 2000.

2 Cold Temperature Driving Cycle Development and Emission Testing, prepared for the Alaska Department of Environmental Conservation by Sierra Research, 2000.

3 “Winter Season Warm-up Driver Behavior in Anchorage,” Air Quality Program, Municipality of Anchorage, June 2001.

4 Fairbanks Cold Temperature Vehicle Testing: Warm-up Idle, Between-Trip Idle, and Plug-In, prepared for the Alaska Department of Environmental Conservation by sierra Research, Inc., July 2001

5 “Anchorage Travel Survey,” prepared by Hellenthal & Associates for the Municipality of Anchorage, 1992.

6 Anchorage Air Quality Telephone Survey reports, pr epared annually by Ivan Moore Research for the Municipality of Anchorage, 1999 - 2007.

7 Anchorage Travel Model Calibration and Validation Report , February 2005

8 1997 and 1998 Vehicle Miles of Tr avel in the Anchorage Bowl, prepared by Alaska Department of Transportation and Public Facilities and the Municipality of Anchorage, January 2000.

9 Anchorage Travel Time Study, November 1998.

10 Alaska Aviation Emission Inventory, prepared for the Alaska Department of Environmental Consearvation, June 2005.

11 “Air Quality Survey of Anchorage Residents,” prepared by ASK Marketing & Research for the Municipality of Anchorage, April 1990.

12 Ibid.

13 Personal communication with Dan Dieckgraff, Enstar Natural Gas, March 22, 2001.

14 FERC Form No. 2 (ED 12-88), submitted by ENSTAR Natural Gas Company, 1991.

15 EPA Technical Highlights Document, EPA420-F-97-051, December 1997.

16 Commercial Marine Inventories for Select Alaska Ports, prepared for the Alaska Department of Environmental Conservation by E.H. Pechan and Associates, June 2005.

17 Winter 1997-98 Anchorage Carbon Monoxide Sa turation Study, Municipality of Anchorage Department of Health and Hu man Services, September 1998.

18 Analysis of the Probability of Exceeding the CO Standard between 2007 and 2023, Municipality of Anchorage Department of Health and Human Services, April 2009.

# Alaska Department of Environmental Conservation



# Amendments to:

State Air Quality Control Plan

Vol. III: Appendices
Appendix III. B. 6

“ An alysis of Probability of Complying with the National Ambient Air Quality Standards for Carbon Monoxide in Anchorage between 2007 and 2023” 

# Adopted
August 5 th 

# , 2009Appendix to Section III.B.6 

### Appendix to Section III.B.6, Anchorage CO Maintenance Plan
Air Quality Program Municipality of Anchorage Department of Health and Human Services April 2009


## Analysis of the Probab ility of Complying with the National Ambient Air Quality Standard for CO in Anchorage between 2007 and 2023

Background

In July 2008, the Anchorage Assembly voted to modify the vehicle inspection and maintenance (I/M) program in Anchorage. The most nota ble change made was extending the new car I/M testing exemption from four to six years. As a result, the Anchorage CO Maintenance Plan must be revised, incorporated into the Alaska State Implementation Plan (SIP) for air quality and approved by the EPA. As part of these revisions , a new probabilistic maintenance demonstration must be prepared. This demonstration must include the effect of any changes to the CO control measures proposed in the revised Plan. In particular, the impact of the new six I/M testing exemption on prospects for future compliance with the national ambient air quality standard (NAAQS) must be assessed. Prior to the preparation of the previous Anchorage CO Maintenance Plan in 2004, the Municipality of Anchorage (MOA), the Alaska Department of Environmental Conservation (ADEC) and EPA Region 10 staff agreed that a probabilistic approach should be used in the Anchorage maintenance demonstration. The MOA, ADEC and EPA agreed that this demonstration must show a 90% or greater probability of meeting the national ambient air quality standard (NAAQS) in each year during the 2007-2023 lifetime of the Maintenance Plan. The MOA is using the same methodology used in the 2004 Plan in this revised maintenance demonstration. This methodology relies on conventional statistical methods to estimate the probability of complying with the NAAQS in the year 2007, the base year for the analysis. The “roll forward” technique, used in the previous maintenance demonstration, is used to estimate probability of complying with the standard in future years. This technique relies on CO emissions projections for years 2008 through 2023 to help estimate the probability of complying with the NAAQS during this time period.



### Method

Estimating the Probability of Complying with the NAAQS in Base Year 200 7 The NAAQS for CO is set at 9 ppm for an 8-hour average not to be exceeded more than once per year. Because the NAAQS effectively disregards the highest 8-hour average in determining compliance, the measure of whether a community meets the standard is determined by the magnitude of the second highest 8-hour average, or second maximum

. For this reason, this analysis focuses on the probability of the second maximum being above or below the 9 ppm NAAQS. Standard regression analysis techniques can be used to estimate the probability of complying with the CO NAAQS in 2007. By definition, a violation occurs when the second maximum concentration is higher than 9 ppm. The probability that this will or will not occur can be computed using the prediction interval. The prediction interval is defined mathematically as follows:Appendix to Section III.B.6 

## y

p = 

## y h + 

## t ( α ; n-2 ) 

## . s { pred } Equation 1

where

In this circumstance, we are interested only in the upper limit of the prediction interval * . In this case we want to compute the value corresponding to the upper 90 th percentile interval in base year 2007. If 2007 could be “repeated” numerous times, with the “normal” variety of meteorological conditions and other variables that effect CO concentrations, the second maximum concentration would fall at or below this value 90% of the time. This value is the base year 2007 design value (2007 DV 90% ). Over the past 30 years, CO monitoring has been conducted at ten permanent CO stations † and at numerous additional temporary stations throughout Anchorage and Eagle River. Data suggest that the Turnagain monitor, located in a residential area in west Anchorage, has the highest CO concentrations of the four monitors in the current network. (See analysis in the Attachment at the end of this report.) Although it is difficult to compare recent data from Turnagain with data collected from other sites a decade or more earlier, studies suggest that the CO concentrations at Turnagain are likely representative of the highest ambient CO concentrations encountered in Anchorage. For this reason, Turnagain was selected as the site for the maintenance demonstration. First and second maximum 8-hour CO concentrations measured at Turnagain are shown in Table 1. ‡

Table 1 1st and 2nd Maximum CO Concentrations at Turnagain Station (1999-2008) Highest 8-hour average CO Concentration (ppm) 2 nd Highest 8-hour average CO Concentration (ppm) 1999 10.1 7.6 2000 7.2 5.5 2001 9.8 7.7 2002 6.5 5.9 2003 8.3 6.7 2004 8.1 7.9 2005 5.7 4.6 2006 6.5 6.1 2007 5.5 5.3 2008 6.3 5.4

* This is known as a one-sided prediction interval. In this case we use the one-sided t-statistic when using Equation 1.

† For the purposes of this discussion, we define a permanent monitoring station as one that has employed Federal Reference Method monitors over the course of at least one CO season. Temporary monitoring was conducted with bag samplers in the 1980’s and more recently with portable industrial hygiene-type CO monitors. Temporary monitoring has been conducted at more than 30 locations in the Municipality.

‡ The Turnagain station began operation October 16, 1998; thus 1999 was the first complete year of data collected at this site.Appendix to Section III.B.6 An Excel spreadsheet was used to compute the upper 90 th percentile prediction interval from the second maximum concentrations at Turnagain using Equation 1. The results of this computation are plotted in Figure 1. Figure 1 shows that there was a 90% probability that the base year 2007 value would be less than or equal to 7.23 ppm. This computed concentration will serve as the base year 2007 design value for the roll forward analysis discussed later in this report.

Figure 1 90 th Percentile Prediction Interval Computed from Turnagain 2 nd Maximum

7.6

5.5 7.7

5.9 6.7 7.9

4.6 6.1
5.3 5.4 90%

90%

0 2 4 6 8 10 12

1999 2000 2001 2002 2003 2004 2005 2006 2007 20082nd max CO (ppm) 2007 DV 90% = 7.23 ppm

The precise probability of complying with the 9 ppm NAAQS in 2007 was also estimated with the spreadsheet. The probability associated with a second maximum of less than or equal to 9.0 ppm can be estimated through iteration. The one sided t-statistic associated with various probabilities can be used in Equation 1 until the desired 9.0 ppm value is bracketed within two prediction intervals (see Table 2). In this case the desired 9.0 ppm value falls very nearly at the 99.0% interval. Thus, the probability of complying with the NAAQS in 2007 was estimated to be approximately 99%. The chance of violating the NAAQS in 2007 was about 1-in-100.Appendix to Section III.B.6 Table 2 Second Maximum CO Concentration Associated with Various Upper Bound Prediction Intervals
Probability that 2007 CO Concentration will be less than Computed 2 nd Max Concentration Computed Second Maximum CO Concentration (ppm) 80.0% 6.64 90.0% 7.23 95.0% 7.78 97.5% 8.30 99.0% 8.99 99.9% 10.88

Estimating the Probability of Complying with the NAAQS between 2007 - 2023 One assumption implicit in using the roll forward method is that the second maximum CO concentration in any future year will be proportional to the magnitude of the CO emissions in that year relative to base year emissions in 2007. In other words, if CO emissions in a future year are projected to decrease by 10% re lative to base year 2007, the expected CO concentration in that future year will also decrease by 10%. If this occurs, there will be concurrent increase in the probability of complying with the NAAQS in that year.
CO emissions were estimated for the 9 kilometer 2 area surrounding the Turnagain CO monitoring station for base year 2007 using EPA-prescribed models such as the MOBILE6, NONROAD, AP-42 and the FHWA model EDMS to estimate CO emissions. § CO emissions in 2007 were estimated to be 5.99 tons per day (tpd) in the “micro-inventory area” surrounding Turnagain. The computed 90 th percentile concentration or 2007 DV 90% was 7.23 ppm. If one assumes that CO concentrations increase in direct proportion to emissions, the amount of CO that could be emitted in the Turnagain area and retain a 90% probability of complying with the standard can be computed as follows:

Amount of CO emissions associated with a 90% probability of complying with the NAAQS = (9.0 ppm / 2007 DV 2007 ) x CO emissions in 2007
= (9.0 ppm/7.23 ppm) x 6.01 tpd = 7.48 tpd

This computation suggests that if CO emissions in the Turnagain area increased from 6.01 tpd to 7.48 tpd, the probability of complying with the NAAQS would be 90%. In the same manner as shown above, the amount of emission s corresponding with other probabilities of compliance (i.e. 90%, 95%, 99%, etc.) can be readily computed with the spreadsheet. The spreadsheet was used to create a lookup table listing probabilities along with corresponding quantity of emissions. Table 3 shows the results of these spreadsheet computations. As would be expected, the probability of complying with the NAAQS increases with lower emission rates.

§ MOBILE6 is used to estimate vehicle emissions, NONROAD us used to estimate various nonroad sources such as snowmobiles and portable electrical generators, EDMS is used for airport operations and AP-42 is used to estimate various area sources such as natural gas space heating, fireplaces and wood stoves. These models and emission inventor y procedures are described more fully in the Anchorage CO Emission Inventory and Emission Projections 2007-2023, included as Appendix A of the Anchorage SIP submittal.Appendix to Section III.B.6 Table 3 CO Emission Rates Associated with Varying Probabilities of Compliance with the NAAQS at the Turnagain Station Probability that 2 nd Max CO Concentration will be

less than 9.0 ppm Corresponding CO Emission Rate (tpd) 99.9% 4.97 99.5% 5.39 99.3% 5.63 99.0% 6.02 98.0% 6.35 97.0% 6.60 96.0% 6.78 95.0% 6.96 94.0% 7.06 93.0% 7.16 92.0% 7.26 91.0% 7.37 90.0% 7.48

In addition to estimating base year 2007 CO emissions in the 9 kilometer 2 area surrounding Turnagain, emissions were projected through the year 2023. Projections were prepared using the aforementioned MOBILE6, NONROAD, AP-42, and EDMS modeling procedures. Population and employment forecasts prepared by the University of Alaska Institute of Economic and Social Research (ISER) were used to estimate key parameters necessary to estimate growth in vehicle travel ** , space heating, fireplace and woodstove use and other CO emission sources. The MOBILE6 model was configured to reflect that the four-year new car exemption will be extended to six years beginning January 2010. The results of this “micro-inventory” and forecast of CO emissions in the Turnagain area are shown in Table 4. The probability of complying with the NAAQS at the level of emissions projected for each year was determined from the lookup table (Table 3).

** The Anchorage Transportation Model was used to provide information on vehicle travel. It relies in large part on ISER projections in the de velopment of travel forecasts.Appendix to Section III.B.6 Table 4 Projected CO Emissions and Probabilities for Compliance with the NAAQS (2007-2023)

CO Emissions from Various Sources in the 9 km 2 Area Surrounding the Turnagain Station (all emissions in tons per day)

Year Motor Vehicles Fireplace or Woodstove Space Heating Other TOTAL CO EMISSIONS Probability of Compliance 2007 4.42 0.62 0.28 0.70 6.01 99.0% 2008 4.13 0.62 0.28 0.70 5.73 99.3% 2009 3.84 0.63 0.28 0.71 5.45 99.5% 2010 3.71 0.63 0.28 0.71 5.33 99.6% 2011 3.58 0.64 0.28 0.71 5.21 99.7% 2012 3.45 0.65 0.28 0.72 5.10 99.8% 2013 3.33 0.65 0.28 0.72 4.98 99.9% 2014 3.24 0.66 0.28 0.73 4.90 >99.9% 2015 3.15 0.66 0.29 0.73 4.83 >99.9% 2016 3.08 0.67 0.29 0.73 4.77 >99.9% 2017 3.01 0.67 0.29 0.74 4.71 >99.9% 2018 2.93 0.68 0.29 0.74 4.63 >99.9% 2019 2.85 0.68 0.29 0.74 4.56 >99.9% 2020 2.79 0.68 0.29 0.75 4.51 >99.9% 2021 2.72 0.68 0.29 0.75 4.45 >99.9% 2022 2.68 0.69 0.29 0.75 4.42 >99.9% 2023 2.64 0.69 0.30 0.76 4.38 >99.9%
Table 4 suggests that there is a very high likelihood of complying with the NAAQS at the Turnagain station. Although not shown here, a similar analysis was performed for the Garden station. That analysis indicated that there is an even greater likelihood of compliance at that site. The probability of compliance was greater than 99.9% each year between 2007 and 2023.



### Sensitivity Analysis The roll forward probability analysis present ed in the last section relies on modeled projections of future emissions. What happens to the estimated probabilities if these projections underestimated the growth in CO emissions between 2007 and 2023? This sensitivity analysis investigates the sensitivity of the probability estimates presented in Table 4 to assumptions regarding: 1. future growth in vehicle miles travel ed (VMT), vehicle starts and idling, and; 2. future growth of wood stove and fireplace use.

For the purpose of this analysis, we will adjust initial assumptions regarding VMT, and wood stove and fireplace use and re-compute the estimated probability of complying with the NAAQS during the 2007-2023 period. The manner in which each of these assumptions was revised is described in the next section.Appendix to Section III.B.6 Revised Assumptions Used in Sensitivity Analysis:
Future Growth in VMT, Vehicle Starts and Idling Imbedded in these emission computations is the assumption that amount of vehicle miles traveled (VMT) on streets in the 9 kilometer 2 area surrounding the Turnagain station will grow by about than 4% from 2007 levels. Although this appears to be a sensible assumption because the Turnagain area is an older area with little opportunity for significant growth in population, in this sensitivity analysis we will assume that the growth in VMT will be three times that projected by the Anchorage Transportation Model. In other words, we will assume that VMT and vehicle starts and idling will grow by 12% between 2007 and 2023 and determine how this affects the probability of compliance.
Future Growth in Wood Stoves and Fireplace Use Woodstove and fireplace emissions were assumed to grow in proportion to the growth in the number of households in the Turnagain micro-inventory area. During the 2007-2023 inventory period, wood heating emissions were projected increase by about 11%. Although recent telephone data suggest that Anchorage households do not plan to change their habits with regard to wood burning, there is a possibility that wood burning rates could increase in the next decade if households decide to heat with wood to avoid rising costs of heating with natural gas. For the purpose of this analysis we will assume that wood heating will grow 2% per year per household during the inventory period.

Results of Sensitivity Analysis The two revised assumptions used in this sens itivity analysis are summarized in Table 5. The combined impact of these revised assumptions on CO emissions in the Turnagain micro-inventory area and the consequent effect on probabilities of compliance during the 2007-2023 maintenance plan period is shown in Table 6. Table 6 suggests that even when the assumptions used in the sensitivity analysis are combined to create a “worst case scenario”, the probability of compliance with NAAQS is well above 90% each year. Even with higher rates of growth in vehicle travel and wood burning, CO emissions continue to decline. The probability of compliance remains at 99% or higher even with these higher growth rates. By 2018 the probability of compliance is near 100%.

Table 5 Comparison of Original Assumptions used in Maintenance Demonstration with Revised Assumptions used in Sensitivity Analysis

Original Assumptions used in Maintenance Demonstration and Probability Computations Revised “Worst Case” Assumptions Used in Sensitivity Analysis
Growth in VMT and Vehicle Starts and Idling 4% increase between 2007 and 2023 12% increase between 2007 and 2023

Fireplace and Woodstove Use No change in wood burning rates per household between 2007- 2023 2% growth in wood heating per yearAppendix to Section III.B.6 Table 6 Comparison of CO Emissions and Probab ilities of Compliance with the NAAQS Original Assumptions used in Maintenance Demonstration vs. Revised Assumptions used in Sensitivity Analysis

Original Assumptions Revised Assumptions in Sensitivity Analysis Estimated Total CO Emissions (tpd) Probability of Compliance Estimated Total CO Emissions (tpd) Probability of Compliance 2007 6.01 99.0% 6.01 99.1% 2008 5.73 99.3% 5.77 99.2% 2009 5.45 99.5% 5.51 99.4% 2010 5.33 99.6% 5.43 99.5% 2011 5.21 99.7% 5.33 99.6% 2012 5.10 99.8% 5.25 99.7% 2013 4.98 99.9% 5.16 99.8% 2014 4.90 >99.9% 5.12 99.8% 2015 4.83 >99.9% 5.07 99.9% 2016 4.77 >99.9% 5.04 99.9% 2017 4.71 >99.9% 5.01 99.9% 2018 4.63 >99.9% 4.96 >99.9% 2019 4.56 >99.9% 4.92 >99.9% 2020 4.51 >99.9% 4.89 >99.9% 2021 4.45 >99.9% 4.87 >99.9% 2022 4.42 >99.9% 4.86 >99.9% 2023 4.38 >99.9% 4.86 >99.9%Appendix to Section III.B.6 

## Attachment

Rank-Pair Order Comparison of CO Concentrations at Turnagain with Garden and Seward Highway Monitoring Stations
Permanent monitoring at Turnagain station began in October 1998 following the completion of a CO Saturation Monitoring Study during the winter of 1997-98. This study monitored CO concentrations at some 20 locations using temporary industrial hygiene-type monitoring devices. The saturation study indicated that the Turnagain site had the highest concentrations of all the sites in the study.
The permanent monitoring stations at Turnagain and Garden are located in older residential neighborhoods with relatively low traffic volumes on the roadways adjacent to the monitoring probe. The Seward Highway station (decommissioned in December 2004) was located at the intersection of two heavily traveled arterials, the Seward Highway and Benson Boulevard. In Anchorage CO monitoring is conducted at these permanent stations during the winter months defined as October through March.
Non-overlapping 8-hour maximum CO concentrations measured at the Turnagain, Garden and Seward Highway monitors were compared in rank-order to determine which site has the highest CO concentrations and the greatest potential for exceeding the national ambient air quality standard (NAAQS) for CO. A rank-order comparison involves sequentially ranking non-overlapping 8-hour average concentrations at the two sites being compared in descending order. In other words, the highest concentration measured at one site is compared to the highest concentration at the other, the second highest at the one site is compared to the second highest at the other, the third highest at one site is compared to the third highest at the other, and so on.
Rank-pair comparisons of data were performed only in time periods when data were available from both sites. In other words, in order to perform a fair comparison between two sites, the data compared was limited to periods when both sites were in operation and collecting valid data. Table 1 show the time periods when paired-data from Turnagain was compared to the other two stations. ††

Table A-1 Comparison Periods for Rank-Pair Analysis Stations Compared Comparison Period Turnagain with Garden 10/16/98 – 12/31/07 Turnagain with Seward Hwy 10/16/98 – 12/31/05
A spreadsheet program was constructed to identify the highest 50 non-overlapping 8-hour maximum CO concentrations at each site for the comparison periods shown in Table 1.

†† The Turnagain site did not begin operating until October 16, 1998 and monitoring was discontinued at the Seward Highway site on December 31, 200 4. Garden has been in more-or-less continuous operation since late 1970’s. When data comparis ons between two sites were performed the analysis was limited to time periods when both sites were collecting data.Appendix to Section III.B.6 Comparison of Turnagain and Garden Station CO Concentrations - October 1998 through December 2007
Results of the rank-order comparison between the Turnagain and Garden CO stations are shown in Figure 1. (Data used to construct this plot can be found at the end of this report.)

Figure A-1 Rank-Order Comparison of Highest Fifty Non-Overlapping 8-hour Average CO Concentrations Measured at the Turnagain and Garden Monitoring Stations October 1998–December 2007



### 0.0 2.0 4.0 6.0 8.0 10.0 12.0

1 6 11 16 21 26 31 36 41 46
RankMaximum 8-hour CO Concentration (ppm)



### Turnagain

Garden

Figure 1 shows that the 50 highest 8-hour average concentrations at the Turnagain station are about 12% to 25% higher than the corresponding rank-pair value at Garden. The greatest differences occur among the highest ranks. For example the highest 8-hour concentration at Turnagain is 23% higher than the highest value at Garden while the 50 th highest value at Turnagain is 13% higher than the corresponding 50 th highest value at Garden. On a rank-pair basis, the values at Turnagain are significantly and consistently higher than those at Garden. This is particularly true at the extreme (i.e. highest) concentrations. This would suggest that Turnagain has a greater potential of exceeding or violating the NAAQS than Garden. For this reason, data from the Turnagain station were used to perform the probabilistic analysis for the maintenance demonstration.Appendix to Section III.B.6 Comparison of Turnagain and Seward Highway Station CO Concentrations October 1998 through December 2004
A similar analysis was performed comparing data from the Turnagain station to Seward Highway. In this case the analysis was confined to the period October 16, 1998 to December 31, 2004 because the Seward Highway station was decommissioned at the end of 2004. The results of this analysis are shown in Figure 2.

Figure A-2 Rank-Order Comparison of Highest Fifty Non-overlapping 8-hour Average CO Concentrations measured at the Turnagain and Seward Highway Monitoring Stations October 1998 – December 2004



### 0.0 2.0 4.0 6.0 8.0 10.0 12.0

1 6 11 16 21 26 31 36 41 46
RankMaximum 8-hour CO Concentration (ppm)

Turnagain
Seward Hwy

Among the highest 50 paired 8-hour concentrations, concentrations at Turnagain are 12% to 38% higher than Seward. The largest differences between the two sites are observed in the very highest 8-hour concentrations where differences between rank-pairs are typically 30% or more. This would suggest that Turnagain has a considerably greater potential of exceeding or violating the NAAQS than Seward.

Conclusion
This analysis demonstrates that the Turnagain si te exhibits the highest CO concentrations and greatest potential for violating the NAAQS in the Anchorage network. It is therefore appropriate to use this site for analysis of long-term prospects for continued compliance with the NAAQS.Appendix to Section III.B.6 Turnagain Oct 1998 – Dec 2007 Garden Oct 1998 – Dec 2007

rank 8-hr avg (ppm) date end hour rank 8-hr avg (ppm) date end hour % Diff 1 10.14 1/6/99 19 1 8. 23 1/6/99 18 23.3% 2 9.78 12/16/01 20 2 7. 80 12/6/99 14 25.3% 3 8.27 12/6/03 1 3 6. 80 12/24/98 19 21.6% 4 8.11 1/5/04 18 4 6. 78 1/13/04 21 19.5% 5 8.06 12/24/98 23 5 6. 66 2/12/99 12 21.0% 6 7.88 1/4/04 20 6 6. 37 2/9/99 14 23.7% 7 7.74 11/14/01 12 7 6. 36 1/3/04 21 21.7% 8 7.69 12/16/98 24 8 6. 33 1/5/04 20 21.5% 9 7.61 1/3/04 21 9 6. 18 1/27/99 13 23.3% 10 7.61 2/23/99 12 10 6. 17 1/4/04 21 23.3% 11 7.48 1/1/04 22 11 6. 14 12/5/03 23 21.9% 12 7.40 12/18/01 17 12 6. 10 12/16/01 22 21.3% 13 7.31 2/8/99 11 13 5. 84 1/1/04 23 25.2% 14 7.24 12/6/99 14 14 5. 72 1/2/04 22 26.6% 15 7.23 12/5/01 15 15 5. 70 11/27/99 24 26.8% 16 7.21 1/16/00 3 16 5. 69 12/20/03 19 26.7% 17 7.16 11/28/99 1 17 5. 59 10/22/98 11 28.2% 18 6.53 11/29/06 16 18 5. 58 12/3/01 15 17.0% 19 6.50 2/23/99 3 19 5. 45 1/15/04 14 19.2% 20 6.49 2/6/02 12 20 5. 43 1/5/99 13 19.6% 21 6.30 12/3/01 16 21 5. 40 1/7/04 14 16.6% 22 6.28 12/8/01 1 22 5. 39 1/13/00 14 16.5% 23 6.13 2/18/01 6 23 5. 38 1/12/00 15 14.0% 24 6.13 11/14/01 3 24 5. 25 3/18/02 23 16.7% 25 6.11 1/24/06 12 25 5. 23 2/22/99 12 17.0% 26 6.09 2/11/99 9 26 5. 21 12/26/98 24 16.8% 27 6.09 1/17/06 14 27 5. 21 2/11/00 15 16.8% 28 5.96 2/22/99 13 28 5. 18 1/15/00 24 15.2% 29 5.95 12/4/01 16 29 5. 14 1/14/99 14 15.7% 30 5.93 11/10/99 12 30 5. 14 2/10/00 13 15.3% 31 5.90 1/4/99 24 31 5. 09 11/29/01 15 16.0% 32 5.90 12/1/01 5 32 5. 08 11/14/01 13 16.3% 33 5.87 1/13/04 1 33 5. 06 2/13/99 1 16.0% 34 5.86 1/25/02 12 34 5.06 1/17/06 14 15.8% 35 5.75 12/27/98 4 35 5. 00 11/22/99 14 15.0% 36 5.71 12/1/01 24 36 5.00 1/23/03 14 14.3% 37 5.69 1/28/05 11 37 4. 99 2/10/99 12 14.1% 38 5.68 11/15/98 24 38 4. 98 1/16/00 17 14.1% 39 5.65 11/25/06 12 39 4. 96 12/4/01 16 13.9% 40 5.61 2/9/99 13 40 4. 94 12/14/04 20 13.6% 41 5.58 12/14/01 15 41 4. 91 11/20/98 15 13.5% 42 5.56 12/12/99 3 42 4. 90 1/22/03 14 13.5% 43 5.50 12/19/07 14 43 4. 83 11/10/99 13 14.0% 44 5.48 11/7/98 2 44 4. 81 2/8/99 12 13.8% 45 5.46 1/12/00 13 45 4. 81 1/18/05 13 13.7% 46 5.44 2/1/02 13 46 4. 79 1/27/05 14 13.5% 47 5.40 11/25/06 3 47 4. 78 1/7/04 23 12.9% 48 5.37 1/14/04 2 48 4. 74 2/9/99 2 13.3% 49 5.36 12/26/03 16 49 4. 74 12/18/01 16 13.2% 50 5.35 12/27/02 15 50 4.74 2/6/02 13 12.9%

# Alaska Department of Environmental Conservation



# Amendments to:

State Air Quality Control Plan

Vol. III: Appendices
Appendix III. B. 8
“South Central Clean Air Ordinances AMC 15.30 and 15.35” 

# Adopted August 5 th 

# , 2009

### Chapter 15.30 SOUTH CENT RAL CLEAN AI R PROGRAM*

_

_________ *Cross references: South Central clean air authority commission, § 4.40.115 ; environmental protection, AMCR Title 15

.

State law references: Local program authorized, AS 46.14.400.

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_________ 15.30.010 Short title of chapter. 15.30.020 South Central Clean Air Authority. 15.30.030 Definitions. 15.30.035 South Central Clean Air Authority commission. 15.30.040 Director. 15.30.050 Air pollution inspections. 15.30.060 Air pollution episodes. 15.30.070 Confidentiality of records. 15.30.080 Limitations. 15.30.090 Compliance with federal and state law. 15.30.100 Registration of air contaminant sources; notification of completion. 15.30.110 Permit to operate air contaminant source. 15.30.120 Source reports. 15.30.130 Source tests. 15.30.140 Variance criteria. 15.30.150 Judicial review of action on variance. 15.30.160 Other limitations. (Repealed). 15.30.170 Rule

- making procedures. (Repealed). 15.30.180 Notice of violation. 15.30.190 Effect of compliance order. 15.30.200 Voluntary compliance. 15.30.210 Administrative hearings. 15.30.220 Appeals. 15.30.230 Enforcement.



### 15.30.010 Short titl e of chapter. This chapter may be known and cited as the South Central Clean Air Ordinance. (AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.30.020 South Central Clean Air Authority. A. A regional air pollution control authority called the South Central Clean Air Authority is hereby established within the boundaries of the municipality and the Matanuska-Susitna Borough. B. Subject to the powers granted by law to member governments, the South Central Clean Ai r Authority shall have primary responsibility for cont rol of air pollution from all sources within the boundaries of the member governments except wher e jurisdiction is reserved by law exclusively for the United States or the state, shall adopt and enforce rules and regulations that endeavor to achieve and maintain national and state ambient air quality standards and emission standards, and shall enforce this chapter and any rules and regulations promulgated pursuant thereto. (AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70) 

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### 15.30.030 Definitions. Unless separately defined in a rule or regulation promulgated pursuant to this chapter or unless the context clearly indicates otherwise, the following te rms used in this chapter or any rule or regulation promulgated pursuant thereto shall be defined as follows:
Air contaminant means dust, fumes, mist, smoke, fly as h, other particulate matter, vapor, gas o r an odorous substance, or a combination of these, but not including water vapor or steam condensate.
Air contaminant source means any source whatsoever at, from or by reason of which there is emitted or discharged into the atmosphere any air contaminant. Air pollutant means a material in the atmosphere, either from natural or manmade sources, in a concentration that reaches or exceeds a level that tends to have some adverse effect on human health or welfare, have some deleterious effect on anima l or plant life, or damage materials of economic value to society. Air pollution means the presence in the outdoor atmosphere of one or more air pollutants. Air quality control plan means the Alaska Air Quality Control Plan as approved by the administrator of the Environmental Protection Agency pursuant to those provisions of the federal Clean Air Act relative to stat e implementation plans.
Alteration means any addition to, any enlargem ent of, any replacement of, any majo r modification of, or any change in the design, capac ity, process or arrangement of, or any increase in, the connected loading of equipment or control apparatus that will affect the kind or amount of ai r contaminant emitted.
Ambient air and atmosphere mean any unconfined portion of the atmosphere or the outside air. Authority means the South Central Clean Air Authority. Best practical technology means the best system of technology available to correct the emission problem when considering cost of system, efficiency of the process, and commercial availability on the market. Borough means the Matanuska-Susitna Borough.
Commission means the South Central Clean Air Authority commission.
Director means the director of the South Central Clean Air Authority or his authorized representative.
Emission means a release of air contaminants into the environment. Equipment means any stationary or portable device or any part thereof capable of causing the emission of any air contaminant. Facility means a pollutant-emitting source or activity located on one or more contiguous o r adjacent properties and which is operated by the same person under common control.
Indirect source means a facility, building, structure or installation that attracts or may attract activity that results in emissions of a pollutant for which there is a national ambient air quality standard, including but not limited to highways and roads; parki ng facilities; retail, commercial and industrial facilities; recreation, amusement, sports and entertainment facilities; airports; office and governmental buildings; apartment and condominium buildings; and education facilities.
Installation means the placement, assemblage or construction of equipment or control apparatus at the premises where equipment, as defined in this section, or control apparatus will be used. 

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6/3/2009 htt p ://librar y 5.municode.com/default-te st/DocView/12717/1/239/243Marine installation means a movable or fixed petroleum exploration, production or extraction platform, or other offshore facility, in or on the waters located within the municipality, from which the emission of air contaminants occurs. Member government means the municipalities of Anchorage and the Matanuska-Susitna Borough.
Motor vehicle means any self-propelled vehicle des igned and used for transporting persons o r property, but excludes aircraft, vessels operated on water and vehicles operated exclusively on rails. National air quality standard means a national primary or secondary ambient air quality standard promulgated pursuant to the federal Clean Air Act. Opacity means the degree to which emissions reduce the transmission of light and obscure the view of an object in the background.
Owner means the person who owns, leases or supervises equipment, control apparatus or a stationary or mobile source of air contaminants.
Particulate matter and particulates mean finely divided solid or liquid particles in the air or in an emission, including but not limited to dust, smoke, fumes, spray and fog.

ppm means parts per million by volume.
Person means any individual, trust, estate, firm, co rporation, association, partnership or any officer, employee, department, agency, board, bureau or commission of the United States, a state o r any political subdivision thereof. Regulation means any regulation, ambient air qual ity standard, emission standard, limitation o r control or subsequently adopted additions or amendments thereto promulgated pursuant to this chapter. Standard cubic foot of gas means that amount of gas that would occupy a cube having dimensions of one foot on each side, if the gas we re free of vapor and at a pressure of 14.7 PSIA and a temperature of 70 degrees Fahrenheit.
Visible emissions means those gases or particulates, excluding uncombined water, that separately or in combination are visible upon release to the outdoor atmosphere. (GAAB 16.68.020, 16.70.010; AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70; AO No. 93-131, § 1, 10-26-93)

Cross references: Definitions and rules of construction generally, § 1.05.020

.



### 15.30.035 South Central Clean Air Authority commission. A. A South Central Clean Air Authority commission of six members shall be the governing body of the South Central Clean Air Authority, shall exercise all powers vested in that authority by law, and shall administer the provisions of this chapter within the member governments.
B. The commission shall consist of two assembly members and the mayor or his designee from each member government appointed in the manner provided by the law of that membe r government. The Anchorage commission members shall consist of the mayor or his designee and two assembly members appointed by the mayor. C. The term of each commission member shall be equal to the duration of his elected term o r until a vacancy occurs. When a vacancy occurs, a new member shall be appointed in the manner provided by the law of that member government for the appointment of commission members. D. The commission shall meet at least annually and shall elect annually from its membership a 

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6/3/2009 htt p ://librar y 5.municode.com/default-te st/DocView/12717/1/239/243presiding officer and such other officers as it deems appropriate. All officers shall serve terms o f one year and may be reelected to their positions. E. A quorum shall consist of four voting members of the commission. No action of the commission shall be taken or shall be effective ex cept upon concurrence of at least four voting members. F. The commission shall determine its own rules of procedure, order of business, and meeting places and times. G. Each commission member shall be compensated for his attendance at official commission meetings in the manner provided by the law of his member government. The Anchorage commission members shall be compensated in t he same manner as members of adjudicatory commissions pursuant to Section 4.05.050 . Each commission member may also be paid such per diem and travel expenses for meetings outside his member government as may be provided by the law of that member government. H. In order to effect the powers and duties of the authority, the commission shall: 1. Hear appeals from decisions of the di rector concerning applications for variances, permits or other entitlements, appeals from compliance orders and other decisions of the director for which appeals are authorized under Section 15.30.220 ; 2. Advise the mayors and assemblies of member governments regarding enactment o r revision of legislation affecting air quality within the authority; 3. Hold such public hearings as it deem s necessary for administration and enforcement of rules and regulations of the authority, member government ordinances and state law, compel the attendance of witnesses and the production of evidence, and adopt such rules of procedure as it finds reasonable and necessary for holding public hearings; and 4. Issue such orders in the exercise of its appellate jurisdiction as may be necessary to effect the provisions of this chapter. (AO No. 80-70)



### 15.30.040 Director. A. The administrative powers and duties of the authority shall be exercised by the director. B. The director shall be the director of the Anchorage member government's department o f health and human services.
C. The director shall: 1. Grant or deny applications for variances pursuant to Section 15.30.140

. 2. Grant or deny applications for permits for which application is made to the authority pursuant to this chapter.
3. Determine the existence of and order cu rtailment actions for air episodes consistent with Section 15.30.060

. 4. Enforce the provisions of this chapter and all regulations, rules, permits, variances o r orders pursuant thereto. 5. Serve as a nonvoting, ex officio member and secretary of the commission. D. The director shall have the power to: 1. Issue such enforcement orders as are necessary to control or reduce fugitive emissions pursuant to the law of a member government. 

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6/3/2009 htt p ://librar y 5.municode.com/default-te st/DocView/12717/1/239/2432. Require the owner or operator of air contaminant sources to install, maintain and operate emission or ambient air monitoring dev ices or both and to furnish data collected to the director. 3. Gather data concerning air polluti on within the authority, conduct research and investigation into the causes and prevention of air pollution and conduct other related and scientific and technical investigations. 4. Render general administrative services to the commission and its membe r governments and provide such other duties as may be assigned by the commission o r required to administer this chapter. 5. Contract for technical, professional, advisory, legal and other services that may be reasonable and proper for the performance of the authority's powers and duties, subject to the provisions of subsection 6 of this subsection. 6. Apply for, receive, administer and expend federal aid, state aid and other funds fo r the control of air pollution or the development and administration of programs related to that control in accordance with the approved budgets of each member government. (GAAB 16.70.020, 16.70.050, 16.70.060, 16.70.090; AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.30.050 Air polluti on inspections. The director or a duly authorized officer, employee or representative may at a reasonable time and upon presentation of a proper search warrant, w here required by the constitution of the United States or the state, enter and inspect the property and premises where an air contaminant source is located or is being constructed for the purpose of ascertaining the state of compliance with this chapte r and the rules and regulations promulgated pursuant thereto. No person may interfere with such inspection. (GAAB 16.70.080; AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.30.060 Air pollution episodes.
A. Concentration levels. An air pollution episode shall be declared when in the opinion of the director the concentration of air contaminants in the ambient air has reached or is predicted to reach any of the following levels:
1. Air alert. a. Sulfur dioxide: 365 micrograms per cubic meter of air or 0.14 parts per million (24-hour average). b. PM-10: 150 micrograms per cubic meter (24-hour average). c. Carbon monoxide: Ten milligrams per cubic meter or nine parts per million (eight-hour average).
2. Air warning. a. Sulfur dioxide: 800 micrograms per cubic meter of air or 0.3 parts per million (24-hour average). b. PM-10: 350 micrograms per cubic meter (24-hour average). c. Carbon monoxide: 17 milligrams per cubic meter or 15 parts per million (eight-hour average). 

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6/3/2009 htt p ://librar y 5.municode.com/default-te st/DocView/12717/1/239/2433. Air emergency. a. Sulfur dioxide: 1,600 micrograms per cubic meter of air or 0.6 parts pe r million (24-hour average). b. PM-10: 420 micrograms per cubic meter (24-hour average). c. Carbon monoxide: 34 milligrams per cubic meter or 30 parts per million (eight-hour average).
B. Air pollution episode plan. The director shall, in order to effect the purposes of this section, prescribe and publish an air pollution episode pl an that describes the curtailment actions, communication and public notification procedures to be employed when the concentration of ai r contaminants has reached or is predicted to reac h the concentrations set forth in subsection A of this section. The Anchorage Air Pollution Epis ode Plan is adopted by reference as part of this chapter. Copies of this plan shall be maintained at the mayor's office, department of health and human services, and office of emergency management.
C. Air quality advisory. The director or his designee shall issue an air quality advisory when, in his judgment, air quality or atmospheric dispersi on conditions exist that may cause injury to public health. (GAAB 16.70.100; AO No. 78-140; AO No. 79-80(AM) ; AO No. 80-2; AO No. 80-70; AO No. 86-111; AO No. 93-131, §§ 2--4, 10-26-93)



### 15.30.070 Confidentiality of records. Records and information other than emission data in the possession of the municipality which relate to production or sales figures or to proc esses or production techniques of the owner or operato r of an air contaminant source are considered confidential records of the municipality after application by the party that their public disclosure would tend to adversely affect his competitive position. (GAAB 16.70.120; AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.30.080 Limitations. This chapter does not: A. Grant to the director jurisdiction or authority with respect to air contamination existing solely within commercial and industrial plants, works or shops. B. Affect the relations between employers and employees with respect to or arising out of a condition of air contamination or air pollution. C. Supersede or limit the applicability of a law or ordinance relating to sanitation, industrial health or safety. (GAAB 16.70.130; AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.30.090 Compliance with federal and state law. Unless otherwise allowed by law and by this chapter or a regulation promulgated pursuant thereto, no person shall commit any act prohibited by, omit any act required by, or exceed any standard or limitation established by the feder al Clean Air Act, as amended, or by AS Title 46 , article 4, as amended, or by any valid rule, regulation, emission standard or limitation, ambient air quality standard or performance standard promulgated pursuant to either the federal or state legislation. 

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6/3/2009 htt p ://librar y 5.municode.com/default-te st/DocView/12717/1/239/243(AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70; AO No. 93-131, § 5, 10-26-93)



### 15.30.100 Registration of ai r contaminant sources; no tification of completion.
A. Registration required. Except as otherwise provided in subsection F of this section, no person shall construct, install or establish any of the following air contaminant sources within the territorial limits of the municipality without first registering that source with the director: 1. Any facility requiring a permit to operate pursuant to state or municipal law o r regulation for the control of air contaminants. 2. Any facility that can emit into the am bient air, without regard to whether air quality control equipment is operating, carbon monoxide, sulfur oxides or particulate matter in an amount that equals or exceeds five tons per year or hydrocarbons or nitrogen oxides in an amount that equals or exceeds ten tons per year. 3. Rock crushing or screening operations. 4. Coal- or oil-fired equipment having a rating that equals or exceeds 3,000 kilowatts o r 10,000,000 Btu's per hour. 5. Incinerators having a rated capacit y that equals or exceeds 250 pounds per hour. 6. Storage tanks, reservoirs or contai ners having a capacity that equals or exceeds 40,000 gallons and are used for the storage of petroleum liquids. 7. Marine installations within the municipality for more than 30 consecutive days in a year. B. Registration form; responsibility for registration. The owner or lessee of an air contaminant source or his agent shall register all facilities subject to registration on forms furnished by the director. The owner of the source shall be responsible for registration and shall verify the correctness of the information submitted.
C. Inventory of contaminant sources. The registration of each air contaminant source subject to registration and notification pursuant to subsection A of this section shall include a detailed inventory of contaminant sources and emissions related to such process; provided, however, that separate registration shall not be required for identical units of equipment or control apparatus installed, altered or operated in an identical manner on the same premises.
D. Notification of completion required. No person shall operate or cause the operation of an ai r contaminant source for which registration is r equired pursuant to this section without first notifying the director of the date upon which such source shall begin to operate.
E. Inspection. The director shall, within 30 days of receipt of notice of completion, inspect the facility, and shall issue a notice of violation if he finds that the construction, installation o r establishment of the facility is not in accord wi th the plans, specifications or other information submitted to the director or that the facility is ot herwise in violation of this chapter or regulation promulgated pursuant thereto.
F. Exception. Neither air contaminant source registration nor notification of completion shall be required for a point source of an air contaminant that has previously registered with the Cook Inlet Air Resources Management District, has previously issued a notice of completion to that district, and has not undergone significant alteration since such registration and issuance of the notice of completion. (GAAB 16.68.030; AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70) 

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### 15.30.110 Permit to operate air contaminant source.
A. Required for certain facilities. No person shall operate or cause the operation of a facility capable of emitting into the ambient air, regar dless of whether air quality control equipment is operating, an air contaminant from any of the following sources without first applying at least 30 days prior to either purchasing equipment or commencing construction of the facility and without first receiving a permit to operate from the director: 1. Industrial process units having a total design rate, capacity or throughput that equals or exceeds five tons per hour. 2. Fuel-burning equipment having a combined rating that equals or exceeds 35 million Btu's per hour. 3. A facility containing one or more incinerators, with a total combined rated capacity that equals or exceeds 500 pounds per hour.
B. Approval of plans. No person may construct, modify, replace or undertake a majo r alteration of a facility requiring a permit to operate until detailed plans and specifications are submitted to the director and approved. The dire ctor shall approve or reject such plans and specifications within 30 days of receipt of a co mplete set of such plans and specifications unless the director holds a public hearing pursuant to subsection C of this section. These plans and specifications shall include t he following information: 1. One set of plans and specifications, clearly indicating the layout of the facility, location of individual pieces of equipment and points of discharge. 2. One set of maps or aerial photographs of a scale of at least one inch to one mile indicating the location and zoning of the propos ed facility and, within a one-mile radius o f the facility, the land use and zoning of the surrounding area, all homes, buildings, watercourses, roads and other adjacent facilities, and the general topography. 3. An engineering report outlining the proposed methods of operation, the quantity and quality of material to be processed, the proposed use and distribution of the processed material, and a process flow diagram indicating the points of emission, including estimated quantities and types of air contaminants to be emitted. 4. A description and the specifications of all air quality control devices, including design criteria and other information indicating that such equipment is capable of complying with applicable federal, state and municipal emission requirements. 5. An evaluation of the effect on the surrounding ambient air of the emissions from the facility, if requested by the director. 6. Plans for emission reduction procedures during an air pollution episode if requested by the director.
C. Public hearing. The director may hold a public hearing concerning any application for a permit to operate if the director determines t hat public testimony is necessary before approval o r rejection of an application for a permit to operate and if the director provides public notice o f such hearing not less than 30 days prior to the hearing in a newspaper of general circulation. In such cases the director shall approve or reject the application within five days after conclusion of the public hearing.
D. Criteria for approval. Approval to construct a new air contaminant source or modify an existing facility requiring a permit to operate may not be granted unless the applicant shows to the satisfaction of the director that: 1. The new or modified source will not prevent or interfere with the attainment o r maintenance of any federal, state or municipal ambient air quality standard. 2. The new or modified source will operate without causing a violation of this chapter o r 

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6/3/2009 htt p ://librar y 5.municode.com/default-te st/DocView/12717/1/239/243any regulation, rule, permit or final order issued pursuant thereto. 3. The equipment incorporates the control technology required by federal, state and municipal law or regulation for the kind and amount of air contaminant emitted by the equipment.
E. Transfer; conditions. A permit to operate may:
1. Not be transferred without the written consent of the director. 2. Not be issued for a period greater than five years, after which the permit must be renewed for continued operation of the facility. 3. Include a compliance schedule approved by the director approving for the minimum time necessary to install the required control equi pment if the facility would or is emitting air contaminants in excess of federal, state or municipal emission standards o r limitations; provided, however, that a comp liance schedule for any facility emitting ai r contaminants subject to federal or state r egulation may not allow compliance later than the date provided by federal or state regulation. A permit including a compliance schedule must be reviewed and renewed every year of its duration. 4. Require that specific emission reduc tion procedures be taken during an air pollution episode.
F. Authority to impose additional requirements. The director may require an applicant for a permit to operate: to install, use and mainta in monitoring equipment; to sample emissions in accordance with methods prescribed by the direct or at locations, intervals and by procedures as may be specified; to provide source test por ts of the size, number and location as may be required and safe access to each port; to provi de emission data and information from analysis of any test samples; and to provide periodic reports on process emissions.
G. Notification of denial. If an application for a permit to operate is denied, the director shall notify the applicant in writing of the reasons.
H. Equipment requirements. Nothing in this section may be construed to authorize the directo r to require the use of machinery, devices or equipment from a particular supplier or produced by a particular manufacturer if the required emission standards may be met by machinery, devices or equipment available from other sources.
I. Fee. A reasonable fee in the amount set by the director will be charged for the issuance of a permit.
J. Compliance with applicable regulations. The issuance of a permit to operate shall neithe r relieve the owner of a facility r equiring a permit of the obligation to comply with all applicable federal, state or municipal emission standards and limitations nor prevent the director from issuing other orders pursuant to this chapter and the rules and regulations of the directo r promulgated pursuant thereto.
K. Revocation or suspension. A permit to operate may be revoked or suspended by the director if the conditions of the permit or applicable laws, rules or regulations are violated. (GAAB 16.68.090, 16.70.070; AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70; AO No. 93-131, § 6, 10-26-93)



### 15.30.120 Source reports. The air contaminant emission data required by Section 15.30.100 or 15.30.110 shall be compiled and submitted to the director at reasonable intervals upon the request of the director. (GAAB 16.68.050; AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70) 

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### 15.30.130 Source tests. A. The director may conduct or have conducted source testing in order to determine compliance with this chapter or any rule or regulation promulgated pursuant thereto. B. Testing to determine compliance with provisions of this chapter or any rule or regulation promulgated pursuant thereto shall be by methods of measurement approved by the directo r and undertaken in such a manner as to characterize the actual discharge into the ambient air. C. The cost, if any, to the municipality of any such source testing authorized by subsection A o f this section shall be a debt due the municipality from the owner or operator of such source and recoverable in any court of competent jurisdiction when such testing shall have proved the emission of air contaminants in violation of this chapter or any rule or regulation promulgated pursuant thereto. (GAAB 16.68.250; AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.30.140 Variance criteria. A. A person who owns or is in control of a plant, building, structure, establishment, process o r equipment may apply to the director for a vari ance from any emission standard or limitation promulgated pursuant to this chapter. The director may grant the variance, but only after public hearing following 30 days' notice, if the director finds that: 1. The emissions occurring or proposed to occur do not endanger human health o r safety; and 2. Compliance with the rules or regulations from which the variance is sought would produce serious hardship without equal or greater benefits to the public. B. No variance may be granted under this section until the director has considered the relative interest of the applicant, other owners of proper ty likely to be affected by the emissions, and the general public. C. A variance granted under subsection A of this section shall be for periods and unde r conditions consistent with the reasons fo r it and within the following limitations: 1. If a variance is granted on the grounds that there is no practicable means known o r available for the adequate prevention, abatement or control of the air pollution involved, it shall be effective only until the necessary means for prevention, abatement or control become known and available, subject to the ta king of substitute or alternate measures that the director may prescribe. 2. If a variance is granted on the grounds that compliance with the particula r requirement from which a variance is sought will necessitate the taking of measures which because of their complexity or cost will involve considerable hardship, it shall be effective for a period of time which in t he opinion of the director is necessary and reasonable. A variance granted on this ground shall contain a timetable for compliance with the particular requirement from which a variance is sought in an expeditious manne r and shall be for not more than five years. 3. If a variance is granted on the grounds that it is justified to relieve or prevent hardship of a kind other than that provided in subsections C.1 and C.2 of this section, it shall be for not more than one year. D. A variance granted under this section may be renewed on terms and conditions and fo r periods which would be appropriate for the initial granting of a variance. If complaint is made to 

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6/3/2009 htt p ://librar y 5.municode.com/default-te st/DocView/12717/1/239/243the director on account of the variance, no renewal of it shall be granted unless, after public hearing on the complaint following the notice, the director finds that renewal is justified. No renewal may be granted except upon application for renewal made at least 60 days before the expiration of the variance. Immediately upon receipt of an application for renewal, the directo r shall give public notice of it. E. The grant of a variance or renewal is not a right of the applicant but is within the discretion of the director. F. No variance or renewal granted under this section may be construed to prevent or limit the air pollution episode provisions of this chapter. (GAAB 16.70.110; AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.30.150 Judicial review of action on variance. A person adversely affected by the grant, denial or renewal of a variance by the director may obtain judicial review of the director's order by filing appeal within 30 days after the date of such order. Judicial review of the grant, denial or renewal of a variance may be had only on the grounds that the grant, denial or renewal was arbitrary or capricious. (GAAB 16.70.110; AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.30.160 Other limitations. (Repealed). (AO No. 80-70)



### 15.30.170 Rule-making procedures. (Repealed). (AO No. 80-70)



### 15.30.180 Notice of violation. When the director has evidence that a violation of this chapter or rule or regulation issued unde r this chapter has occurred, the director shall ser ve a written notice of violation upon the suspected violator. The notice shall specify the provisi on believed to be violated and the facts believed to constitute the violation and may include a compliance order that necessary corrective action be taken within a reasonable time. (GAAB 16.70.140; AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.30.190 Effect of compliance order. A compliance order issued pursuant to Section 15.30.180 shall become a final order unless within ten days after receipt of service of the not ice of violation and compliance order the person named requests in writing a hearing before the director in the manner provided in Section 15.30.210

. (GAAB 16.70.140; AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.30.200 Voluntar y com p liance. Pa g e 11 of 13 Cha p ter 15.30 SOUTH CENTRAL CLEAN AIR PROGRAM*

6/3/2009 htt p ://librar y 5.municode.com/default-te st/DocView/12717/1/239/243The director may make efforts to obtain voluntary compliance through warning, informal conference or other appropriate means. (GAAB 16.70.140; AO No. 78-140; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.30.210 Administra tive hearings. A. Upon the written request by any person aggrieved by any decision of the director made pursuant to this chapter or any rule or regulation in force pursuant thereto, including a decision to deny a permit to operate or the issuance of a compliance order, served on the director no later than ten days after that decision, the commission shall conduct a hearing to review the legality, appropriateness or wisdom of that dec ision. The hearing shall occur not later than 30 days after receipt of service of the request upon the director, and, after considering the evidence presented at the hearing, the commission shall af firm, modify or reverse the decision of the director except as otherwise provided by this chapter or a rule or regulation issued pursuant thereto. The director's decision shall not be stayed pending review by the commission unless the director so orders. B. If after a hearing held under subsection A of this section the commission finds that a violation of an ordinance, rule, regulation, permi t or variance has occurred, it shall affirm o r modify the compliance order previously iss ued or issue an appropriate compliance order fo r taking corrective action. If the commission finds that no violation has occurred, it shall rescind the previous order, if any. A compliance order issued as a part of a notice of violation or after a hearing may prescribe the date by which the viol ation shall cease and may prescribe timetables for necessary action in preventing, abating or controlling emissions. C. In connection with a hearing held under this section, the commission shall have power to, and upon application by a party to the hearing it shall have the duty to, compel the attendance of witnesses and the production of evidence on behalf of all parties. D. Upon unanimous consent of the commission, the commission may delegate, in writing, the authority to conduct administrative hearings under the provisions of this section to the director o f the department for the member government wherein the subject of the administrative hearing
arose. (AO No. 80-70; AO No. 93-131, § 7, 10-26-93)



### 15.30.220 Appeals. All appeals of any final decision of the commission shall be made to the Superior Court, Third Judicial District, no later than 30 days allowing that dec ision, pursuant to rule 601 et seq., of the Rules of Appellate Procedure for the state. Review of the court shall be limited to whether the decision of the commission or director is suppor ted by substantial evidence. A final appealable decision by the commission pursuant to this chapter must indicate that it is a final order and that a party disputing the decision has 30 days to appeal. (AO No. 80-70; AO No. 95-180, § 13, 9-26-95)



### 15.30.230 Enforcement. A. Notwithstanding any other provision of this chapter or other remedy provided by law, any person who violates any provision of this chapter or any regulation, rule, permit, variance or final order issued pursuant thereto shal l be subject to injunctive relief to restrain the person from continuing the violation or threat of violation. Upon application for injunctive relief and a finding 

### Pa g e 12 of 13 Cha p ter 15.30 SOUTH CENTRAL CLEAN AIR PROGRAM*

6/3/2009 htt p ://librar y 5.municode.com/default-te st/DocView/12717/1/239/243that a person is violating or threatening to violate any provision of this chapter or any rule, regulation, permit, variance or order issued pursuant to this chapter, the court shall grant injunctive relief to restrain the violation. B. In addition to any other remedy or pena lty provided by law, a person who violates any provision of this chapter or any regulation, ru le, permit, variance or final order issued pursuant thereto shall be subject to the civil, criminal and administrative remedies or penalties provided by the law of that member government wherein such violation occurred. (AO No. 80-70) 

### Pa g e 13 of 13 Cha p ter 15.30 SOUTH CENTRAL CLEAN AIR PROGRAM*

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### Chapter 15.35 SOUTH CENTRAL CL EAN AIR ORDINANCE REGULATIONS 15.35.010 Adoption of regulations. 15.35.020 Availability of copies. 15.35.030 Stationary source emissions

-- Short title. 15.35.040 Stationary source emissions

-- General definitions. 15.35.050 Stationary source emissions

-- Visible emission standards. 15.35.060 Stationary source emissions

-- Emission standards. 15.35.070 Stationary source emissions

-- Other emission limitations. 15.35.080 Stationary source emissions

-- Circumvention. 15.35.090 Stationary source emissions

-- Fugitive emissions. 15.35.100 Stationary source emissions

-- Open burning. 15.35.110 Mobile source emissions

-- Short title. 15.35.120 Mobile source emissions

-- Application. 15.35.130 Mobile source emissions

-- Definitions. 15.35.140 Motor vehicle emissions. 15.35.150 Motor vehicle fleet operation. 15.35.160 Motor vehicle inspection. 15.35.170 Motor vehicle owner liability.



### 15.35.010 Adoption of regulations. The municipality hereby adopts as ordinance the following regulations of the South Central Clean Air Ordinance as set forth in full in Sections 15.35.030

-- 15.35.170 of this chapter. A. Regulation 1: Stationary Source Emissions. B. Regulation 2: Mobile Source Emissions. (AO No. 78-141; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.35.020 Availability of copies. At least five copies of each regulation adopted in Section 15.35.010 shall be available for public inspection at the offices of the Anchorage Department of Health and Human Services. (AO No. 78-141; AO No. 80-2; AO No. 80-70; AO No. 85-8)



### 15.35.030 Stationary source emissions --Short title. This regulation may be known and cited as South Central Clean Air Ordinance Regulation 1: Stationary Source Emissions. (AO No. 78-141; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.35.040 Stationary source emissions--Ge neral definitions. Unless the context clearly indicates otherwise, the following terms used in this regulation shall be defined as follows: Anchorage bowl area means that area within the boundaries of the Municipality of Anchorage enclosed by a border beginning at the intersection of 61 degrees 18 minutes north latitude and 149 degrees 42 minutes west longitude, thence due south to 61 degrees 4 minutes north latitude, thence due west to 150 degrees 5 minutes west longitude, thence due north to 61 degrees 18 minutes north latitude, and thence due east to the point of beginning, 149 degrees 42 minutes west longitude. 

### Pa g e 1 of 8 Cha p ter 15.35 SOUTH CENTRAL CLEAN AIR ORDINANCE REGULATIONS

6/4/2009 htt p ://librar y 5.municode.com/default-te st/DocView/12717/1/239/244Fire chief means the Anchorage Fire Chief or his authorized representative.
Incinerator means any furnace used in the process of burning solid waste for the purpose o f reducing the volume of the waste by removing combustible matter.
Industrial waste means any material resulting from a production or manufacturing operation having no net economic value to the source producing it. Open burning means the burning of any matter in such manner that the products of combustion resulting from the burning are emitted directly into the atmosphere without passing through an approved stack, duct, vent or chimney but does not refer to the operation of safety flares for the purpose of protecting human life. Open, untreated areas means land upon which all of the natural vegetation has been removed and no successful measures have been taken to either revegetate or resurface the ground to prevent the emission of dust, vapors or other particulate matter into the atmosphere.
Smolder means to burn and smoke without flame. Stationary source means any building, structure, facility, installation or equipment that emits o r may emit any air contaminant and that contains apparatus to which this regulation applies. (AO No. 78-141; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.35.050 Stationary source emissions--Visib le emission standards. A. No person shall cause, permit or allo w the emission of any ai r contaminant, excluding portions of emissions containing condensed uncombined water vapor from any stationary source including air curtain incinerators to r educe visibility through the exhaust effluent by: 1. Greater than 20 percent for a period or periods aggregating more than three minutes in any one hour, except as provided in subsection 2 of this subsection; or 2. Twenty percent or greater for municipal wastewater treatment plant sludge incinerators. B. The opacity of an air contaminant shall be det ermined at the point of emission, except when the point of emission cannot be readily observed, in which case it may be determined at an observable point of the plume nearest the point of emission. C. This section shall not apply to smoke-generating equipment used by the director for the training, instruction or certification of persons to observe and determine the opacity of ai r contaminants, nor shall this section apply to smoke-generating equipment used by the fire chie f for instruction in firefighting, when such equipment is otherwise operated in compliance with applicable federal and state laws. (AO No. 78-141; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70; AO No. 93-131, § 8, 10-26-93)



### 15.35.060 Stationary source emissions--Em ission standards. A. Except as otherwise provided in subs ection B, no person shall cause, permit or allow emissions of particulate matter into the atmosphere from any stationary source in excess of 0.05 grains per standard cubic foot of exhaust gas. B. No person may cause, permit or allow emissions into the atmosphere from any single source or emission whatsoever any one or more of the following air contaminants, in any state or combination thereof exceeding the followi ng concentrations at the point of discharge: 1. Sulphur compounds calculated as sulphur dioxide (SO2 ) above 500 parts SO2 pe r 

### Pa g e 2 of 8 Cha p ter 15.35 SOUTH CENTRAL CLEAN AIR ORDINANCE REGULATIONS

6/4/2009 htt p ://librar y 5.municode.com/default-te st/DocView/12717/1/239/244million parts of exhaust gas; 2. Particulate matter as combustion contaminants calculated to 12 percent of carbon dioxide (CO2 ): a. 0.05 grains per standard cubic foot of exhaust gas except as noted in subsections b through g below; b. 0.04 grains per standard cubic foot of exhaust gas for asphalt batch plants constructed or modified after June 11, 1973; c. 0.08 grains per standard cubic foot of exhaust gas for incinerators equal to o r larger than 2,000 pounds per hour rated capacity; d. 0.10 grains per standard cubic foot of exhaust gas for those sources in operation prior to July 1, 1972, and for fuel-burning equipment using coal for fuel or for incinerators equal to or larger than 1,000 pounds per hour capacity; e. 0.15 grains per standard cubic foot of exhaust gas for fuel-burning equipment using more than 20 percent wood waste as fuel; f. 0.20 grains per standard cubic foot of exhaust gas for incinerators equal to o r larger than 200 pounds per hour rated capacity but equal to or less than 1,000 pounds per hour rated capacity; g. 0.30 grains per standard cubic foot of exhaust gas for incinerators less than 200 pounds per hour rated capacity. C. No person shall cause, permit or allow the emission of particulate matter from any stationary source that exceeds in any one hour the amount shown in the following table for the process weight rate allocated to such source:

TABLE 1
TABLE INSET:

Process Weight (lb./hr.) Emission Standards (lb./hr.) 100--299 0.6 300--499 1.2 500--699 1.8 700--999 2.2 1,000--1,999 2.8 2,000--2,999 4.1 3,000--3,999 5.4 4,000--4,999 6.5 5,000--5,999 7.6 6,000--6,999 8.6 7,000--7,999 9.5 8,000--8,999 10.4 9,000--9,999 11.2 10,000--14,999 12.0 15,000--19,999 15.0 

### Pa g e 3 of 8 Cha p ter 15.35 SOUTH CENTRAL CLEAN AIR ORDINANCE REGULATIONS

6/4/2009 htt p ://librar y 5.municode.com/default-te st/DocView/12717/1/239/244D. No person shall cause, permit or allow the emission of particulate matter onto the property of others except when such emissions comply with the requirements o f Sections 15.35.050 and 15.35.060 .A--C. (GAAB 16.68.130, 16.68.150; AO No. 78-141; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70; AO No. 93-131, § 9, 10-26-93)



### 15.35.070 Stationary s ource emissions--Other emission limitations. A. No person shall cause, allow or permit the emission of any air contaminant or water vapor, including but not limited to odorous matter, that tends to be injurious to or adversely affects human health, safety or welfare, animal or plant life, or property or interferes with the normal use and enjoyment of life, property or business. B. Nothing in this regulation shall be constr ued to impair any cause of action or legal remedy therefor of any person or the public for injuncti ve relief, injury or damages arising from the emission of any air contaminant in such place, manner or concentration as to constitute ai r pollution or a common law nuisance. C. The director may establish reasonable require ments that a building or stationary source be enclosed and ventilated in such a way that all the air, gases and particulate matter are effectively dispersed or treated for removal or destruction of odorous matter or other ai r contaminants before emission to the atmosphere. (GAAB 16.68.160, 16.68.170; AO No. 78-141; AO No . 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.35.080 Stationary source emissions --Circumvention. A. No person shall willfully cause, allow or permit the installation or use of any device or use any means which, without resulting in a reduction in the total amount of air contaminant emitted, conceals an emission of air cont aminant which would otherwis e violate these regulations. B. No person shall cause, allow or permit the i nstallation or use of any device or use of any means designed to mask the emission of an air contaminant which causes detriment to health, safety or welfare of any person. C. No person shall cause, permit or allow t he use of air for dilution of emission contaminants without affecting any total decrease in such cont aminants as a method to effect compliance with the requirements of this regulation. D. No person shall cause, permit or al low the use of stack heights that exceed good engineering practice or dispersion techniques to affect the degree of emission limitation required for control of air contaminants. (GAAB 16.68.180; AO No. 78-141; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70; AO No. 93-131, §

20,000--29,999 19.2 30,000--39,999 25.2 40,000--49,999 30.5 50,000--59,999 36.0 60,000--79,999 40.0 80,000--99,999 48.0 100,000--139,999 55.0 140,000 or more 65.0 

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6/4/2009 htt p ://librar y 5.municode.com/default-te st/DocView/12717/1/239/24410, 10-26-93)



### 15.35.090 Stationary source emissions --Fugitive emissions. A. No person shall cause, allow or permit particulate matter to be handled, transported o r stored without taking reasonable measures to pr event the particulate matter from becoming airborne. B. Within the boundaries of the municipality no person shall cause, allow or permit a building o r its appurtenances or a road to be constructed, altered, repaired or demolished without taking reasonable measures to prevent particulate matter from becoming airborne. C. Within the boundaries of the municipality no person shall cause, allow or permit untreated open areas, including but not limited to roads, parking lots or construction sites located within a private or public lot or roadway, to be improved, graded, excavated, repaired, demolished, altered or constructed without taking reasonable measures to prevent particulate matter from becoming airborne. D. The director shall publish guidelines he determines to be reasonable measures fo r controlling fugitive emissions, and compliance with such guidelines to the satisfaction of the director shall be deemed to fulfill the r equirements of subsections A through C. (AO No. 78-141; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.35.100 Stationary source emissions --Open burning. A. Within the boundaries of the municipality no person shall cause, suffer, permit or allow any open burning except the following unle ss otherwise prohibited by law: 1. Open burning for pleasure, religious, c eremonial, cooking or like social purposes and open burning from flares, torches, waste gas burners, incense burners and insect pots is allowed. 2. Open burning authorized by the fire chief for the disposal of dangerous materials is allowed, provided no alternate means of disposal is reasonably available. 3. Open burning authorized by the fire chief for instruction in the method of fighting fires or testing fire resistive materials and fire protection equipment is allowed provided that these outdoor fires have prior written approval from the director, and, unless waived by the department, the public shall be notified through the news media of the time, place and purpose of the exercise at least three da ys in advance of the activity. Prior written approval from the director and public notice shall not be required when such outdoo r fires do not exceed 30 inches in diameter. 4. Open burning for the disposal of trees and brush on property being developed fo r commercial or residential purposes or on property where the trees and brush were grown is allowed provided that: a. Open burning shall be allow ed only outside the Anchorage bowl area and only during the periods from April 1 through May 31 and August 15 through October 31; b. The person responsible for such open burning shall obtain a written permit fo r such fire from the fire chief and upon terms and conditions specifically approved by the director and shall comply with al l the laws and regulations of the director, the fire chief and all other governmental agencies regarding such fires; c. Tires or heavy petroleum products may not be used to start or maintain open 

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6/4/2009 htt p ://librar y 5.municode.com/default-te st/DocView/12717/1/239/244burning. 5. Open burning for the disposal of household refuse is allowed in the areas of the municipality where municipal or Alaska Pub lic Utilities Commission sanctioned refuse collection service is not available. 6. The burning of combustible construction debris, trees, brush and other vegetative matter is allowed in a commercial air cur tain combustion system properly operated and maintained according to the manufacturer's s pecifications, provided that the device has been registered with the director, that the operator obtains written approval from the director prior to operation, and that the operation of the device complies with all rules and regulations of the director, the fire chief and all other governmental agencies regarding such equipment. 7. Open burning for the disposal of small quantities of grass, leaves, weeds and othe r organic debris accumulated during winter months may be allowed without an open burning permit throughout the municipality during a ten-day period in the spring authorized by the mayor upon appropriate terms and conditions that take into consideration those factors described in subsection A.10. of this section. 8. Open burning for the disposal of small quantities of grass, leaves, brush, weeds and other organic debris may be allowed without an open burning permit in the area east o f the Bragaw Road/Elmore/Abbot Loop alignment and south of Tudor Road up to 24 days between May 1 and June 14 and up to 14 days between August 15 and October 15, when authorized by the mayor and upon appropriate terms and conditions that take into consideration those factors described in subsection A.10. of this section. 9. The fire chief, with the approval of the air pollution control officer or department, may issue open burning permits for the disposal of small quantities of grass, leaves, brush, weeds and other organic debris at such times and places and upon such terms and conditions as the fire chief and director deem appropriate in consideration of and consistent with those factors described in subsection A.10. of this section. 10. The fire chief, with the approval of the air pollution control officer or the department may issue open burning permits allowed by this section upon appropriate terms and conditions that take into consideration the ambient air quality, the achievement and maintenance of federal, state or municipal ambient air quality standards, meteorological conditions, the suitability of air pollution c ontrol devices for large quantities of waste, means of reducing fire hazards, the suitability of disposal by other available means, the amount and nature of waste to be burned, the proximity of the burn site to developed areas and the population density of the surrounding area. B. The director shall publish the dates during which open burning will be allowed along with appropriate terms and conditions to be followed while burning. C. The director may suspend or prohibit open burning at any time based on air quality considerations, or, upon consultation with the fire chief, for fire safety reasons. D. The fire chief, in consultation with the air pollution control officer, and upon appropriate terms and conditions that take into considerat ion those factors described in subsection A.10 o f this section, may issue written permits for the destruction of timber infested with spruce bark beetle during periods outside of the open burn periods designated in this section. E. The fire chief shall establish guidelines and may establish an appropriate fee schedule fo r the issuance of written permits authorized under this section. F. It shall be a rebuttable presumption that the person who owns or controls the property on which open burning occurs has caused or allowed said open burning. (GAAB 16.68.210; AO No. 78-141; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70; AO No. 93-131, § 11, 10-26-93; AO No. 93-210(S), § 1, 1-18-94; AO No. 95-196(S), §§ 1, 2, 10-17-95; AO No. 96-135(S), 

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### 15.35.110 Mobile source emissions--Short title. This regulation may be known and cited as the South Central Clean Air Ordinance Regulation 2: Mobile Source Emissions. (AO No. 78-141; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.35.120 Mobile source emissions--Application. The provisions of this regulation apply only to mobile sources within the boundaries of the municipality. (AO No. 78-141; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.35.130 Mobile source emissions--Definitions. Unless the context clearly indicates otherwise t he following terms used in this regulation shall be defined as follows:
Mobile source means a source capable of simultaneous motion and emission of ai r contaminants.
Motor vehicle means any self-propelled vehicle des igned and used for transporting persons o r property but excludes aircraft, vessels operated on water and vehicles operated exclusively on a rail o r rails. (AO No. 78-141; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.35.140 Motor vehicle emissions. A. No person shall operate, drive, cause or permit to be driven or operated any motor vehicle upon a public street or highway that emits any visible emission for a period in excess of five consecutive seconds except for those motor vehicles powered by compression ignition o r diesel-powered engines and except when the pres ence of uncombined water is the only reason an emission fails to meet this requirement. B. No person shall operate, drive, cause or permit to be driven or operated any diesel-powered motor vehicle that emits for a period in excess of ten consecutive seconds any air contaminant that obscures an observer's vision to a degree greater than 30 percent opacity. C. No person shall operate, drive, cause or permit to be driven or operated any motor vehicle that violates or exceeds any federal or stat e law, regulation, emission standard or limitation applicable to such motor vehicle for the cont rol of emissions of carbon monoxide, hydrocarbons or oxides of nitrogen. (AO No. 78-141; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.35.150 Motor vehicle fleet operation. The director by written notice may require the owner of any motor vehicle fleet operation o f more than five vehicles to certify annually that its motor vehicles are maintained in good working orde r 

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6/4/2009 htt p ://librar y 5.municode.com/default-te st/DocView/12717/1/239/244and, if applicable, in accordance with the motor vehicle manufacturer's specifications and maintenance schedules that may or tend to affect vi sible emissions. The director by written notice may require records pertaining to observations, tests, maintenance and repairs performed to control o r reduce visible emissions from individual motor vehi cles to be made available for review and inspection by the director. (AO No. 78-141; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.35.160 Motor vehicle inspection. The director by written notice may require the owner of any motor vehicle of a motor vehicle fleet operation or the owner of any motor vehicle that the director has reason to believe may be in violation of this regulation to make such moto r vehicle available for te sting for compliance with Section 15.35.140 of this regulation at a reasonable time and place. (AO No. 78-141; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70)



### 15.35.170 Motor vehicle owner liability. It shall be a rebuttable presumption that the owner of a motor vehicle that violates or exceeds any provision of this regulation has caused or permitt ed the operation or driving of that motor vehicle. (AO No. 78-141; AO No. 79-80(AM); AO No. 80-2; AO No. 80-70) 

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# Alaska Department of Environmental Conservation



# Amendments to:

State Air Quality Control Plan

Vol. III: Appendices
Appendix III. B. 9 “Municipality of Anchorage Ordinance 2008-84(S)” 

# Adopted August 5 th 

# , 2009

# Alaska Department of Environmental Conservation

Amendments to:
State Air Quality Control Plan Vol. III: Appendices

Appendix III. B. 10

“Estimation of Background Carbon Monoxide Concentrations for Anchorage Project-Level Conformity Analyses” & “Affidavit of Oral Hearing” 

# Adopted August 5 th 

# , 2009Appendix to Sections III.B.10 

### Appendix to III.B.10

Note: In addition to the document below, the State of Alaska will include Appendix III.B.10 containing the Anchorage Assembly Resoluti on (AR) adopting the revised CO Maintenance Plan and an affidavit of an oral hearing to be he ld by the State of Alaska. The AR and oral hearing are expected to occur in spring or early summer 2009. 

## Estimation of Background CO Concen tration for Anchorage Project-Level Conformity Analyses

Most project-level conformity analyses involve m odeling expected CO concentrations from projects related to major intersections with high traffic volumes. CAL3QHC modeling assumes that CO concentrations predicted at roadway receptors ar e the sum of two sources: (1) emissions from the roadway(s) and/or intersections being modeled; or (2) “background CO” from other roadways and emissions sources not directly accounted for in the model.

Typically, background CO is estimated from ba ckground or neighborhood-scale monitors in the vicinity. For example, a background CO estimate might be taken from measurements from a nearby residential neighborhood. Although this might make sense initially, this approach to estimating background CO is not appropriate in Anchorage.

In Anchorage, CO concentrations in some residential areas are substantially higher than those near major roadways. A CO monitoring study conducted in 1997-98 showed that CO concentrations measured at the Turnagain and Garden sites, whic h are located on relatively low volume residential streets were 20% to 50% higher than concentrations measured near major roadway intersections such as the Seward Highway & Benson Boulevard, Old Se ward & Dimond, or Lake Otis & Tudor. CO concentrations along these major arterials were lowe r even though their traffic volumes were an order of magnitude higher than the neighborhood sites. ‡‡

Thus, using CO values obtained from residential site s like the Garden or Turnagain site yields a background concentration estimate that is unrealistic ally high for modeling major roadway projects in Anchorage. Because most project level anal yses involve major roadways where mechanical turbulence is important in reducing CO concentrations , it is inappropriate to use data from residential sites to estimate the background value.

In order to better determine an appropriate background value for CAL3QHC modeling, CO data from two monitors near the intersection of Seward Hi ghway and Benson Boulevard were examined. The first site, known as the Seward Highway site, was located on the southwest corner of the intersection of Seward Highway & Benson Boulevard. §§ (See Figure 1.) It collected data from this location between 1987 and 2004. Monitoring was also conducte d at a second site, approximately 80 meters to the west on Benson Boulevard during the winter of 1997-98. For the purposes of this discussion this monitor will be called Benson Mid-block . Because this second monitor was setback further from the

‡‡ As noted in Section III.B.5, mechanical turbulence from vehicle traffic is believed to provide some localized atmospheric mixing and thus reduce CO levels on days when natural atmospheric mixing is very limited. Because traffic levels are low in residential area, less mechanical mixing occurs an d higher CO concentrations result. §§ The intersection of Seward Highway and Benson Boulevar d is the highest volume intersection in Anchorage. The 1997-98 CO Saturation Monitoring Study showed that co ncentrations at this inters ection were the highest of all intersections monitored. Other monitored intersec tions included Lake Otis & Tudor, Northern Lights & Boniface, Old Seward & Dimond, and Spenard & Minnesota.Appendix to Sections III.B.10 Seward Highway, it was less affected by the emissions from idling traffic queued up on Benson waiting for the red light at Seward Highway.

Figure 1

Aerial Photo of Intersection of Seward Highway and Blvd Seward Highway Monitor was locate d approximately 80 meters east of the Benson Mid-block Monitor

CO concentrations were approximately 19% lower at Benson Midblock than the Seward Highway site. The scatter plot in Figure 2 shows the relationship be tween paired hourly concentrations measured at these two locations. (Hourly values below 3 ppm were disregarded.) Seward Highway Monitor Benson Mid-block MonitorAppendix to Sections III.B.10 Figure 2

Relationship between hourly CO concentrations mea sured at the Seward High way Station and a midblock location 80 meters west (1997-98 data)

y = 0.8123x R 2 = 0.8448

0.0 2.0 4.0 6.0 8.0 10.0 12.0

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 Seward Highway CO (ppm)Benson - Midblock CO (ppm)

Although concentrations at the Benson Mid-block site were lower than those at the Seward Highway site, concentrations there were still probably u nduly influenced by the heavy traffic on Benson Boulevard to be considered a good background site. The probe for Benson Mid-block was located just 10 meters south of nearest traffic lane. If the probe for Benson Mid-block were to have been setback 50 or 100 meters from Benson Boulevard a more realistic background value for this busy midtown area might have been obtained. Nevertheless, concentrations at Benson Mid-block offer a more reasonable (and lower) estimate of the “true” bac kground concentration near major arterials than values obtained from monitors in Anchorage residential areas.
The Benson Mid-block monitor therefore provides a conservative or high estimate of background CO for CAL3QHC modeling. CO monitoring at Benson Mid-block was discontinued in the late 1990’s. Nevertheless, the present-day background value can be estimated using the regression relationship between the Seward Highway and Benson Mid-block sites. The methodology used to estimate the background CO va lue for 2008 is described below. A statistical approach, relying on the 90 th percentile prediction interval, was used to compute the background concentration for 2008 from data collected from the Seward Highway and Benson Mid-Block monitors. This methodology is similar in many wa ys to the probabilistic approach used in the Anchorage maintenance demonstration.Appendix to Sections III.B.10 1. Use the 90 th percentile prediction interval to compute the 90 th percentile value of the 2 nd maximum 8-hour average at Seward Highway in 2004. (Monitoring was discontinued in December 2004.)

90th Percentile Prediction Interval 2nd Maximum 8-hour Average at Seward Highway

11.8 12.2 11.6

9.8 9.5 9.9 11.0

8.4 10.5

7.0 7.9

6.5

4.8 5.2 4.7 5.4 5.5

0 2 4 6 8 10 12 14

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 20042nd max CO (ppm) 

### 2004 CO = 5.95 ppm 90th percentile prediction interval

2. Compute the corresponding 90 th percentile 8-hour concentration at Benson Midblock in 2004 using the slope of the regression rela tionship shown in Figure 2.

Benson Midblock 2004 (90 th percentile) = (5.95 ppm) x 0.8123 = 4.8 ppm (This value is the computed background CO concentration for 2004.)

3. Use MOBILE6 to project the background concentration in 2008 from the 2004 level. ***

MOBILE6 emission

factor @ 2.5 mph 8-hour CO (ppm) 1-hour CO** (ppm) 2004 45.307 4.8 6.9 2005 42.525 4.5 6.5 2006 37.043 4.0 5.6 2007 35.537 3.8 5.4 2008 33.722 3.6 5.1 ** In accordance with guidance, persistence factor of 0.7 was used to compute the 1-hr concentration from the 8-hr. i.e., 1 hr bkg CO (2008) = 3.6 ppm/0.7 = 5.1 ppm
The computed background CO concentration is therefore:

Background 8-hour CO = 3.6 ppm

Background 1-hour CO = 5.1 ppm

*** CAL3QHC guidance suggests that the background CO concentration should be adjusted downward over time in proportion to the decline in idle emissions projected by MOBILE6. The MOBILE6 emission factor at 2.5 mph is used as a surrogate for idle emissions.STATE

OF ALASKA

) ) ss. ______JUDICIAL DISTRICT

) AFFIDAVIT

OF ORAL HEARING I, Cynthia Heil, Acting Environmental Program Manager

of Department

of Environmental Conservation, being sworn, state the following: On July
13, 2009, at 12:30 pm, in Room
A,

at 619 Ship Creek Ave. Ste 249, Anchorage

Aic,

I presided over

a public hearing held

in accordance

with AS 44.62.2

10 for the purpose

of taking testimony

in connection

with the adoption

of changes

to

18 AAC

52 which would change

18 AAC 52.005

to increase

the time period during which

a new model year vehicle

is exempt from

a vehicle emissions

test and exempt vehicles with historic vehicle plates and custom collector plates from having

to participate

in the vehicle emissions testing program. The proposed changes

to 18 AAC 52.060 update

the federal reference

for poverty guidelines

for use
in economic hardship waivers.
The proposed changes

to 18 AAC 52.990
add definitions

of categories

for exempt vehicles. ADEC

is also amending

the State Air Ouality Control Plan which

is adopted

by reference

in 18 AAC 50.030. DATE:

C) Anchorage. Alaska/ C hiaHeil Acting Environmental Program Manager SUBSCRIBED

AND SWORN

TO before
me this iS day of 3 LkLA., op9. [NOTARY SEAL]

Notary Public

in and for the State
of Alaska My commission expires: LJD[. &ate ofAlaska NOTARY PUBLIC Eiln

D. Dreyer My Commission Bplces With Office