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Technical Support Document

Proposed Approval of PM10 Maintenance Plan for Truckee Meadows and 

Redesignation of Truckee Meadows to Attainment for the PM10 Standard

Additional Supporting Information 

for Notice of Proposed Rulemaking

USEPA, Region 9

September 11, 2015
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Table of Contents

I. Best Available Control Measure de minimis demonstration

II. PM10 from Secondary Particulates

III. Evaluation of the Motor Vehicle Emissions Budgets 

IV. Explanation of 2011 Inventory Updates
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I. de minimis Analysis for Best Available Control Measures (BACM) 

Demonstration

Table 1. de minimis Analysis of Design Day Contribution -- All Categories 

Source Categories

1999

Seasonal

Inventory 

(lbs/day)

1999 

Peak Season 

Inventory 

Percentage1

Design Day 

Percentage2

Design day 

contribution3 

μg/m3

BACM measure 

implemented

Paved streets/reentrained dust 12,031 42.7

66.3 142.5

040.031, 040.032

Street sanding 1,894 6.7 040.031

Residential wood combustion 6,804 24.1 16.9 36.2 040.051

Fugitive dust from construction 

activities 2,860 10.1 7.0 15.1 040.030

Other Stationary/Industrial Processes4 1,256 4.5

9.8 21.1

5.8 040.0305

Concrete production 616 2.2 2.8 below de minimis

Charbroilers 214 0.8 1.0 below de minimis

Mobile on-road 824 2.9 3.7 below de minimis

Mobile off-road 653 2.3 3.0 below de minimis

Unpaved roads 515 1.8 2.3 040.030

Other Fuel Combustion and Misc Area 519 2.0 2.3 below de minimis

Totals 28,188 100.1 100.0 215.0 20.8

Notes: 

1 Particulate Matter (PM10) State Implementation Plan for the Truckee Meadows Air Basin (Reno Planning Area) (“Serious 

Area Plan”), August 2002, Appendix B, Tables 1-2 and 1-3 

2 Serious Area Plan, August 2002, Table 4 (see "Percent Contribution on Exceedance Day")

3 215 μg/m3

is the 1st high in 1999; Serious Area Plan, August 2002, Table 4 (see 24-hour μg/m3)

4 Categories in “Other Stationary/Industrial Processes” include: Asphalt Production, Incinerators, Sand and Gravel Pits, Sand 

Blasting, Gold Mining/Assay Labs, Gypsum Wallboard Manufacturing, Miscellaneous.

5 Because the provisions of rule 040.030 apply to, but are not limited to: dismantling or demolition of buildings; public or private 

construction; mining; processing of sand, gravel, rock or dirt; and operation of machines or equipment, some of the source 

categories within Other Stationary/Industrial Processes would be regulated by rule 040.030.

Totals affected by rounding convention. 

Explanation and Summary

The Truckee Meadows Serious Area PM10 Plan provides a design day percentage for four categories: 

wood burning, re-entrained road dust, construction, and industrial/vehicle exhaust/other combustion. See 

Table 4. To determine the source categories above and below the de minimis cutoff, we relied on the 9.8 

design day percentage for industrial/vehicle exhaust/other combustion (I/VE/OC) group to then determine 

the μg/m3contribution from the largest emitting sources within I/VE/OC group. To do this we used the 

percentage of the inventory (e.g., 1999 Charbroilers inventory divided by the total 1999 inventory) and 

then multiplied the result times 9.8 μg/m3(i.e., the design day percentage for I/VE/OC). This provided an 

estimate of the μg/m3from the largest remaining I/VE/OC emitters to determine if any were above the 5 

μg/m3 or greater threshold requiring BACM. Based on the analysis, all source categories contributing 5 

μg/m3 or greater on the design day have EPA-approved, BACM-level rules. 
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II. PM10 from Secondary Particulates

The table below provides data comparing total PM10, ammonium nitrate, and ammonium sulfate measured at the Reno3 monitor (AQS 

site # 32-031-0016). Comparing the data provides an estimate of the amount and fraction of PM10 precursors in relation to total PM10. 

The EPA choose 2011, 2013, and 2014 as representative years, and then selected the five highest PM10 days with secondary particulate 

data available. Because we are concerned primarily with the highest PM10 days, only the five highest values above 50 μg/m3 were 

selected for each year. PM10 values less than 50 μg/m3 would have a disproportionate percentage of the PM10 from secondaries..For 

2014, no days above 50 μg/m3 occurred when speciation data was also collected. The results support EPA’s proposed determination that 

PM10 precursors do not contribute significantly to PM10 levels which exceed the standard in the area.

Date

Total PM10 on Highest Days

(November 1 – February 28)

(μg/m3)

Ammonium 

Nitrate 

(μg/m3)

Ammonium 

Sulfate 

(μg/m3)

Percent of 

PM10 from 

secondary 

particulates

Monitor

Reno3 Monitor

Galletti Plumbkit Sparks Reno3 South Reno Toll

1/12/2011 NA NA NA 64 NA NA 3.4 0.2 5.7%

12/26/2011 NA 71 NA 57 42 33 4.5 0.4 8.6%

1/21/2011 113 63 60 52 54 38 2.7 0.2 5.6%

1/6/2011 NA NA NA 51 NA NA 7.9 0.7 16.7%

1/15/2011 74 61 62 50 32 24 2.9 0.2 6.3%

12/18/2013 110 113 65 86 80 56 11.5 0.7 14.1%

12/13/2013 90 96 57 85 66 45 2.6 0.3 3.4%

12/17/2013 103 90 69 78 65 49 NA NA NA

12/27/2013 107 91 58 75 66 40 7.4 0.4 10.4%

12/31/2013 116 97 75 72 63 37 NA NA NA

1/7/2013 83 84 61 70 60 40 8.1 0.7 12.5%

1/8/2013 81 83 51 68 57 33 NA NA NA

1/22/2013 77 75 37 68 62 41 9.4 0.7 14.9%

NA: not available

Average (10 samples) 6.0 0.4 9.8%
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III. Evaluation of the Motor Vehicle Emissions Budgets 

Table 2. Evaluation of the Motor Vehicle Emissions Budgets in Redesignation Request and Maintenance Plan for the Truckee 

Meadows 24-Hour PM10 Non-Attainment Area, August 28, 2014 (“2014 PM10 Plan” or “Plan”).

Adequacy Review Criteria

(40 CFR part 93)

Is Criterion

Satisfied? Reference in SIP Document/Comments

Sec. 

93.118(e)(4)(i)

The plan was endorsed by the 

Governor (or designee) and was 

subject to a public hearing.

Y The Redesignation Request and Maintenance Plan for the Truckee Meadows 24-

Hour PM10 Non-Attainment Area, August 28, 2014 (“2014 PM10 Plan” or “Plan”) 

was noticed on July 25, August 11, and August 22, 2014 for public hearings on 

August 28, 2014 by the Washoe County District Board of Health (WCDBH). See

Reno Gazette-Journal Proof of Publication (received by Washoe County 

Controller on August 27, 2014). The 2014 PM10 Plan includes motor vehicle 

emissions budgets (MVEBs) for 2015, 2020, 2025, and 2030. WCDBH provided 

an opportunity for public comment prior to and during its August 28, 2014 

hearing. The MVEBs were adopted as part of the 2014 PM10 Plan by WCDBH on 

August 28, 2014. See Certificate of Adoption, WCDBH, dated August 28, 2014. 

The 2014 PM10 Plan was then submitted by the Nevada Division of 

Environmental Protection (NDEP) to EPA. See letter, Colleen Cripps, 

Administrator, NDEP, to Jared Blumenfeld, Regional Administrator, EPA Region 

9, dated November 7, 2014, with enclosures, submitting the 2014 PM10 Plan. 
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Sec. 

93.118(e)(4)(ii)

The plan was developed through 

consultation with federal, state and 

local agencies; full implementation

plan documentation was provided 

and EPA’s stated concerns, if any, 

were addressed.

Y The 2014 PM10 Plan and MVEBs were developed through consultation with 

federal, state and local agencies which participated in the Interagency 

Consultation Group. Members of the consultation group include: EPA, Regional 

Transportation Commission of Washoe County (the Metropolitan Planning 

Organization for the area), Federal Highway Administration, NDEP, Nevada 

Department of Transportation, and Truckee Meadows Regional Planning Agency. 

Written and verbal comments provided by the EPA during the development of the 

draft 2014 PM10 Plan and prior to the official public comment period immediately 

before adoption have been adequately addressed by the WCDBH. The EPA did 

not formally comment during the public comment period for the 2014 PM10 Plan. 

Sec. 

93.118(e)(4)(iii)

The motor vehicle emission budgets 

are clearly identified and precisely 

quantified.

Y The 2015, 2020, 2025, and 2030 budgets are clearly identified and precisely 

quantified in 2014 PM10 Plan (see p. 28). 

Sec. 

93.118(e)(4)(iv)

The motor vehicle emissions 

budget(s), when considered together 

with all other emission sources, is 

consistent with applicable 

requirements for reasonable further 

progress, attainment, or maintenance 

(whichever is relevant to the given 

implementation plan submission).

Y The EPA has determined that the MVEBs, when considered together with all 

other emission sources, are consistent with applicable requirements for 

maintenance of the PM10 National Ambient Air Quality Standard. The MVEBs 

include a safety margin which is explained on page 28 of the Plan. The safety 

margins were included in the emissions estimates used in the maintenance 

demonstration. Also see page 28 of the Plan.

The Plan does not include MVEBs for NOx and VOC because the District 

demonstrated, based on information in the Desert Research Institute’s February 

1988 report, PM10 Source Apportionment the Truckee Meadows, Nevada, for 

State Implementation Plan Development, Volume I: Modeling Methods and 

Results, Final Report, and recent air quality data showing secondary particulates 

comprise a small fraction of the total PM10 that secondary particulates formed by 

precursor emissions are an insignificant contributor to PM10 levels. The EPA 

concludes that PM10 precursor emissions do not contribute significantly to PM10

levels which exceed the standard in the Truckee Meadows area. 
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Sec. 

93.118(e)(4)(v)

The plan shows a clear relationship 

among the emissions budget(s), 

control measures and the total 

emissions inventory.

Y The emission inventories for all point, non-point, on-road mobile, and non-road 

mobile sources of direct PM2.5 are described in Appendix C of the 2014 PM10

Plan. Adopted control measures are described in Chapter 4, Appendix A, and 

Appendix B of the 2014 PM10 Plan. The budgets are described in Chapter 6 of the 

2014 PM10 Plan. The budgets are consistent with the inventories in Appendix C 

that is relied on for the maintenance demonstration in Chapter 6 of the 2014 PM10

Plan. 

Sec. 

93.118(e)(4)(vi)

Revisions to previously submitted 

control strategy or maintenance plans 

explain and document any changes to 

any previous submitted budgets and 

control measures; impacts on point 

and area source emissions; any 

changes to established safety margins 

(see §93.101 for definition), and 

reasons for the changes (including 

the basis for any changes to emission 

factors or estimates of vehicle miles 

traveled).

Y On July 13, 2009, the NDEP submitted the Redesignation Request and 

Maintenance Plan for the Truckee Meadows 24-Hour PM10 Non-Attainment Area

(“2009 PM10 Plan”) to EPA as a revision to the Nevada SIP. The 2009 PM10 Plan 

established MVEBs for 2009, 2013, 2018, and 2020, and the budgets included 

safety margins. The EPA found the MVEBs in the 2009 PM10 Plan adequate, 75 

FR 27776 (May 18, 2010), but did not take action on the plan. 

The 2014 PM10 Plan supersedes the 2009 PM10 Plan and includes amended 

emissions inventories, maintenance demonstration, and MVEBs (including 

amended safety margins). . The Washoe County Air Quality Management 

Division (WCAQMD) provides documentation for the amended emissions 

inventories, maintenance demonstration, and MVEBs (and safety margins) in

chapter 6 and appendices A, B, and C of the 2014 PM10 plan and in the 2011 

Periodic Emissions Inventory. Among other changes, the MVEBs in the 2014 

PM10 Plan reflect updated vehicle activity forecasts prepared by the Regional 

Transportation Commission, an updated emissions factor model (MOVES), 

updated paved road fugitive dust emissions factors published by EPA (in AP-42, 

section 13.2.1.3 (dated January 2011), and a locally-developed silt content value 

(instead of using a default value) for use in calculating PM10 from vehicle travel

on unpaved roads.

Sec. 

93.118(e)(5)

EPA has reviewed the State’s 

compilation of public comments and 

response to comments that are 

required to be submitted with any 

implementation plan.

Y Prior to and during the hearing on the 2014 PM10 Plan, WCDBH received only 

one public comment, and it was supportive of adoption of the Plan. The 

comment, from the Regional Transportation Commission, was included in the 

Plan submittal. No issues that might have affected our approval of the budgets 

were raised by the public. 
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IV. Explanation of 2011 Inventory Updates

The table below explains the reasons for changes to 2011 emissions inventory when 

comparing the 2011 Periodic Emissions Inventory (dated November 2012) with the 2011 

Emissions Inventory in the Appendix C of the Redesignation Request and Maintenance Plan for 

the Truckee Meadows 24-Hour PM10 Non-Attainment Area (“2014 Plan”) (dated August 28, 

2014).

Source Category

2011 Emissions 

(lbs/day)

Explanation3

2014 

Plan1 

2012 NEI 

submittal2 Difference 

Paved Road Fugitive 

Emissions 1,453 3,820 2,367 

Predictive Emission Factor equations from 

AP-42, section 13.2.1.3, updated January

2011.

Unpaved Road Fugitive 

Emissions 2,623 13,540 10,917 

Recalculated using updated silt loading 

factors (comparing states/local agencies with 

similar climate/geography) and applied extra 

control measures (projected road paving), 

based on guidance/direction from Karina 

O'Connor during the SIP development 

process.

On-Road Mobile 1,183 1,568 385 

The Regional Transportation 

Commission updated VMT (e.g., from 

economic impacts), used new traffic demand 

model (i.e., TransCAD instead of EMMA),

and then ran new forecast.

Notes: 

1 2014 Plan, Appendix C, August 28, 2014.

2 2011 Periodic Emissions Inventory, Washoe County, Nevada, November 2012.

3 For paved road fugitive emissions, see 2014 Plan, Appendix B.2. For unpaved road fugitive and on-road 

mobile emissions, see September 2, 2015, email from Yann Ling-Barnes, Washoe County Health 

District to John Ungvarsky, USEPA Region 9.