Washington DC-MD-VA 1997 PM2.5 Maintenance 

Plan

Prepared by:

Metropolitan Washington Council of Governments

for the 

District Department of the Environment

Maryland Department of the Environment

Virginia Department of Environmental Quality

on behalf of the

Metropolitan Washington Air Quality Committee

May 22, 2013
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013

Table of Contents

1. Introduction............................................................................................................................ 1

2. Background............................................................................................................................ 1

3. USEPA Maintenance Plan Requirements.............................................................................. 3

4. Attainment Inventory............................................................................................................. 4

4.1 USEPA Requirements...................................................................................................... 4

4.2 Washington DC-MD-VA Approach ................................................................................ 5

5. Maintenance Demonstration .................................................................................................. 6

5.1 USEPA Requirements...................................................................................................... 6

5.2 Washington DC-MD-VA Approach ................................................................................ 6

5.2.1 Mobile Source Emissions Budgets ........................................................................... 8

5.2.2 Control Measures for Maintenance of Good Air Quality ....................................... 13

6. Air Quality Monitoring Network......................................................................................... 18

6.1 USEPA Requirements.................................................................................................... 18

6.2 Washington DC-MD-VA Approach .............................................................................. 18

7. Verify Continued Attainment .............................................................................................. 20

7.1 USEPA Requirements.................................................................................................... 20

7.2 Washington DC-MD-VA Approach .............................................................................. 20

8. Contingency Measures......................................................................................................... 21

8.1 USEPA Requirements.................................................................................................... 21

8.2 Washington DC-MD-VA Approach .............................................................................. 21

8.2.1 Exceedance of the Attainment Year Emissions Inventory ..................................... 21

8.2.2 Near Term Contingency Measures for Air Quality Exceedances........................... 22

8.2.3 Long Term Contingency Measures......................................................................... 22

8.2.4 Contingency Measure Implementation Schedule ................................................... 23

List of Figures

Figure 2-1: Washington DC-MD-VA 1997 PM2.5 NAAQS Nonattainment Area ........................ 2

Figure 5-1: Washington DC-MD-VA 24 Hour PM2.5 Trends...................................................... 10

Figure 5-2: Washington DC-MD-VA Annual PM2.5 Trend Chart............................................... 10

Figure 5-3: Large EGUs in the Washington DC-MD-VA Area .................................................. 14

Figure 6-1: Washington DC-MD-VA PM2.5 Monitoring Sites.................................................... 19
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013

List of Tables

Table 2-1: Washington DC-MD-VA Nonattainment Area Jurisdiction Listing with FIPS Codes.1

Table 4-1: 2007 Attainment Year Inventory.................................................................................. 5

Table 5-1: Growth Assumptions Used in Emission Inventory Projections................................... 6

Table 5-2: Washington DC-MD-VA SO2, NOX, and Primary PM2.5 Emissions from 2007 to 

2025................................................................................................................................................. 7

Table 5-3: Comparison of SO2 Emissions from On-Road Sources to the Total SO2 Inventory.... 9

Table 5-4: Washington DC-MD-VA Maintenance Plan Tier 1 On-Road Mobile Source 

Emissions Budgets...........................................................................................11

Table 5-5: Washington DC-MD-VA Maintenance Plan Tier 2 On-Road Mobile Source 

Emissions Budgets...........................................................................................11

Table 8-1: Contingency Control Measures.................................................................................. 22

List of Appendices

Appendix A1: List of MARAMA technical support documents for the development of point

(EGU & Non-EGU), area, and nonroad mobile (except NMIM emissions for 

2025) emissions inventories for 2007, 2017, and 2025 (Washington, DC-MD-VA 

PM2.5 Nonattainment Area) (TSDs & appendices available on a CD on request)

Appendix A2: 2007/17/25 Point (EGU & NEGU), Area, Nonroad (NMIM & MAR) Emissions 

Summary by SCC & Onroad Emissions Summary by Vehicle Type (Available on 

a CD on request)

Appendix B1: Technical support document for the development of nonroad mobile (except 

marine, airport, and railroad) emissions inventories for 2025 (Washington, DCMD-VA PM2.5 Nonattainment Area)

Appendix B2: 2025 Nonroad Mobile (NMIM) Input / Output Files (Available on a CD on 

request)

Appendix C1: Technical support document for the development of onroad mobile emissions 

inventories for 2002, 2007, 2017, and 2025 (Washington, DC-MD-VA PM2.5

Nonattainment Area)

Appendix C2: 2002/07/17/25 MOVES Input / Output Files (Available on a CD on request)

Appendix D: Washington DC-MD-VA State Compromise Overview: PM 2.5 Maintenance Plan 

Motor Vehicle Emissions Budgets

Appendix E: Notices and Public Comments and Responses
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 1

1. Introduction

The District of Columbia, the State of Maryland, and the Commonwealth of Virginia are 

submitting this maintenance plan for the Washington DC-MD-VA 1997 fine particulate (PM2.5) 

National Ambient Air Quality Standard (NAAQS) nonattainment area to the United States 

Environmental Protection Agency (USEPA) in support of the Washington DC-MD-VA 

redesignation request for that standard. This document demonstrates that PM2.5 air quality in the 

Washington DC-MD-VA area will remain compliant with the 1997 PM2.5 NAAQS, as measured 

by a monitoring network that meets all federal requirements. This plan includes mobile vehicle 

emissions budgets for the interim year of 2017 and the out year of 2025. It also contains 

contingency measures that will be implemented in the unlikely event that the area experiences an 

exceedance of the 1997 PM2.5 NAAQS. 

2. Background

In July 1997, USEPA established two new PM2.5 standards: an annual standard of 15.0 

μg/m3and a 24-hour standard of 65 μg/m3. USEPA designated the Washington DC-MD-VA 

area as nonattainment for the 1997 PM2.5 NAAQS with an effective date of April 5, 2005 (70 FR 

944, 1/5/2005). Table 2-1 provides the jurisdictions within the Washington DC-MD-VA 1997 

PM2.5 nonattainment area, and Figure 2-1 depicts the map of the area.

Since these designations were made, PM2.5 air quality in the Washington DC-MD-VA 

area has improved such that the air quality is significantly better than required by the 1997 PM2.5

NAAQS. The Washington DC-MD-VA region’s federal reference monitors have demonstrated 

compliance with the 65 μg/m3daily standard since the inception of the PM2.5 monitoring 

programs within each state. The federal reference monitors have demonstrated compliance with 

the 15.0 μg/m3annual standard since 2005. The most recent design value for the 24-hour 

standard, based on 2009-2011 data, is 26 μg/m3, and the most recent design value for the annual 

standard, based on 2009-2011 data, is 10.8 μg/m3. 

Table 2-1: Washington DC-MD-VA Nonattainment Area Jurisdiction Listing with FIPS Codes

Maryland Jurisdictions Virginia Jurisdictions

Charles County (24-017) Fairfax County (51-059)

Frederick County (24-021) Prince William County (51-153)

Montgomery County (24-031) Arlington County (51-013)

Prince Georges County (24-033) Loudon County (51-107)

City of Fairfax (51-600)

City of Falls Church (51-610)

City of Manassas (51-683)

City of Manassas Park (51-685)

Washington D.C. (11-001) City of Alexandria (51-510)
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 2

Figure 2-1: Washington DC-MD-VA 1997 PM2.5 NAAQS Nonattainment Area
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 3

These improvements in air quality are due to permanent and enforceable emissions 

reductions of sulfur dioxide (SO2) and nitrogen oxides (NOX), the precursors to PM2.5, and also 

in reductions of primary PM2.5 emissions. This document provides a maintenance plan, as 

required under § 175A of the federal Clean Air Act (CAA), to ensure that the citizens of the 

Washington DC-MD-VA area enjoy the benefits of healthy air quality that complies with the 

1997 PM2.5 NAAQS for a minimum of 10 years, through 2025. This maintenance plan supports 

the redesignation request that the District of Columbia, the State of Maryland, and the 

Commonwealth of Virginia have submitted to USEPA concurrently with this document. 

3. USEPA Maintenance Plan Requirements

The redesignation process provides that a state may petition USEPA to redesignate a 

nonattainment area as attainment and that USEPA may approve the redesignation subject to 

certain criteria being met. Section 107(d)(3)(E) stipulates one of these criteria, that USEPA must 

fully approve a maintenance plan that meets the requirements of § 175A. A state may submit 

both the redesignation request and the maintenance plan at the same time, and rulemaking on 

both may proceed on a parallel track. All applicable nonattainment area requirements must 

remain in place. The maintenance plan constitutes a SIP revision and must provide for 

maintenance of the relevant NAAQS in the area for at least 10 years after redesignation, 

including additional measures to ensure prompt correction of any violation of the NAAQS. The 

state must also submit a SIP revision 8 years after the original redesignation request is approved 

to provide for maintenance of the NAAQS for an additional 10 years following the first 10-year 

period. USEPA provided guidance dated September 4, 1992 on the redesignation request and 

maintenance plan process in the memorandum from John Calcagni, Director, Air Quality 

Management Division to Regional Air Directions entitled Procedures for Processing Requests to 

Redesignate Areas to Attainment (redesignation guidance). Other requirements are provided in 

40 CFR 51 Subpart Z, entitled Provisions for Implementation of PM2.5 National Ambient Air 

Quality Standards (implementation rule). Additional guidance was received in the development 

of this maintenance plan from USEPA regional staff.

USEPA requires the following provisions to ensure maintenance of the NAAQS:

 States must develop an attainment emissions inventory to identify the level of emissions 

in the area that is sufficient to attain the NAAQS.

 States may generally demonstrate maintenance by showing that future emissions of a 

pollutant or its precursors will not exceed the level of the attainment inventory over the 

10-year period following redesignation.

 Once an area has been redesignated, states must continue to operate an appropriate air 

quality monitoring network in order to verify the area's attainment status.

 States must ensure that each has the legal authority to implement and enforce all 

measures necessary to attain and maintain the NAAQS. States must verify continued 

attainment by indicating how maintenance plan progress will be tracked.
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 4

 Contingency measures must be available to promptly correct any NAAQS violation.

The District of Columbia, the State of Maryland, and the Commonwealth of Virginia 

have developed a maintenance plan that meets all USEPA requirements and demonstrates that 

because of permanent and enforceable measures, emissions over the 10 years following

redesignation approval will remain below the 2007 attainment year levels while allowing for 

growth in population and vehicle miles traveled. The period covered by this maintenance plan is 

2007 through 2025. Further, the District of Columbia, the State of Maryland, and the 

Commonwealth of Virginia commit to submitting a second 10-year maintenance plan, if still 

required for this standard.

The District of Columbia, the State of Maryland, and the Commonwealth of Virginia 

have developed an emissions inventory in accordance with USEPA guidance that identifies the 

level of emissions sufficient to achieve the 1997 PM2.5 NAAQS. This attainment inventory 

consists of the actual emissions for a year during the three-year period associated with the 

monitoring data showing attainment of the 1997 PM2.5 NAAQS, that is, 2007. The plan includes 

a demonstration that emissions will remain beneath the 2007 levels for a 10-year period by 

keeping in place key elements of the current federal and state regulatory programs and putting in 

place additional controls. 

The District of Columbia, the State of Maryland, and the Commonwealth of Virginia will 

continue to operate and maintain its air quality monitoring network. The jurisdictions have the 

legal authority to implement and enforce specified measures necessary to attain and maintain the 

NAAQS.

In addition to maintaining key elements of regulatory programs, the District of Columbia, 

the State of Maryland, and the Commonwealth of Virginia will acquire air quality and source 

emissions data to track attainment and maintenance. The maintenance plan includes contingency 

measures, as necessary, to promptly correct any NAAQS violation that occurs after redesignation 

of the area. 

The following sections provide detail on each of the above requirements, and the 

Washington DC-MD-VA area’s approach to meeting each requirement.

4. Attainment Inventory

4.1 USEPA Requirements

The District of Columbia, the State of Maryland, and the Commonwealth of Virginia 

must develop an attainment year emissions inventory to identify the level of emissions sufficient 

to achieve the NAAQS. This inventory should be consistent with USEPA's most recent guidance 

on emission inventories for nonattainment areas available at the time. It should also include 

emissions during the time period associated with the monitoring data showing attainment of the 

1997 PM2.5 NAAQS. Where a state has made an adequate demonstration that air quality has 

improved as a result of the SIP, the attainment inventory will generally be the actual inventory 

during the time period the area attained the standard. The inventory must be based on annual 

emissions of SO2, NOX, and primary PM2.5 in units of tons per year (tpy) during the attainment 
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 5

year. Volatile organic compounds (VOC) and ammonia (NH3) must also be included if they are 

determined to be significant contributors to PM2.5 air quality issues.

4.2 Washington DC-MD-VA Approach

The District of Columbia, the State of Maryland, and the Commonwealth of Virginia 

have developed an attainment year emissions inventory that identifies the level of emissions 

sufficient to achieve the 1997 PM2.5 NAAQS. The attainment inventory consists of the actual 

emissions for the year during the three-year period associated with the monitoring data showing 

attainment of the ozone standard, that is, 2007. The 2007 inventory is appropriate to use because 

it represents the typical inventory for the three-year period demonstrating attainment of the 

standard. The 2007 inventory is consistent with USEPA guidance; is based on annual emissions 

of SO2, NOX, and primary PM2.5 during 2007; and contains a list of sources and emissions in tpy. 

VOC and NH3 were determined to be insignificant for the PM2.5 NAAQS for the Washington, 

DC-MD-VA PM2.5 nonattainment area, and for this reason they are not included in the 

attainment inventory. This determination was based on USEPA’s policy regarding VOC and 

NH3 as they relate to fine particle formation in the atmosphere as noted in the implementation 

rule (72 FR 20591, 4/25/2007). A detailed description of the procedures used to develop the 

attainment year inventory is contained in the Appendix A1, Appendix B1, and Appendix C1.

Table 4-1: 2007 Attainment Year Inventory

Pollutant Point Area NonRoad Onroad Total

District of Columbia, Emissions in tpy

SO2 612 1,241 234 68 2,156

NOX 789 1,547 3,300 7,512 13,148

PM2.5 53 1,120 246 272 1,691

Maryland, Emissions in tpy

SO2 176,880 1,078 550 319 178,827

NOX 30,365 3,222 10,406 47,279 91,272

PM2.5 5,048 4,385 899 1,757 12,088

Virginia, Emissions in tpy

SO2 5,956 3,414 867 220 10,457

NOX 6,701 4,166 13,111 36,848 60,826

PM2.5 446 4,022 1,053 1,422 6,944

Washington DC-MD-VA 1997 PM2.5 Nonattainment Area, 

Emissions in tpy

SO2 183,449 5,733 1,652 607 191,441

NOX 37,855 8,936 26,817 91,639 165,247

PM2.5 5,547 9,528 2,198 3,452 20,724
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 6

5. Maintenance Demonstration

5.1 USEPA Requirements

States may demonstrate maintenance of the NAAQS by showing that future emissions of 

a pollutant or its precursors will not exceed the level of the attainment inventory. The 

demonstration should be for a period of 10 years following the redesignation. The projected 

inventory should consider future growth, including population and industry. It should also be 

consistent with the attainment inventory, and it should document data inputs and assumptions. 

All elements of the demonstration should be consistent with current USEPA guidance. 

Enforceability through regulations must also be demonstrated.

Any assumptions concerning emission rates must reflect permanent, enforceable 

measures. States generally cannot take credit for reductions unless there are regulations in place 

requiring those reductions or the reductions are otherwise shown to be permanent. Therefore, 

states are expected to maintain the implemented control strategy despite redesignation to 

attainment unless such measures are shown to be unnecessary for maintenance or are replaced 

with measures that achieve equivalent reductions. Emission reductions from source shutdowns 

can be considered permanent and enforceable to the extent that those shutdowns have been 

reflected in the SIP and all applicable permits have been modified accordingly.

5.2 Washington DC-MD-VA Approach

The 2017 and 2025 emissions were developed by projecting the 2007 emissions using the 

best available growth rates and projections, as noted in Table 5-1. Table 5-2 demonstrates how 

future projected emissions of SO2, NOX, and primary PM2.5 will not exceed the levels of the 

Washington DC-MD-VA attainment inventory for a minimum of 10 years following 

redesignation. 

Table 5-1: Growth Assumptions Used in Emission Inventory Projections

Category Level of Detail Source

Stationary/Industrial Source 

Growth

Source/Unit/Process 

Specific

AEO

State/Federal Requirements

Area and Non-Road Mobile Source 

Growth Category Specific Metropolitan Washington Council of Governments Cooperative Forecasts, AEO, USEPA estimates, etc.

Vehicle Miles Traveled Growth Jurisdiction-specific Metropolitan Washington Council of Governments 

Transportation Planning Board
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 7

Table 5-2: Washington DC-MD-VA SO2, NOX, and Primary PM2.5 Emissions from 2007 to 2025

SO2 Emissions in tpy

Year Point Area NonRoad Onroad Total (tpy)

2007 183,449 5,733 1,652 607 191,441

2017 28,183 4,139 433 560 33,315

  -155,265 -1,594 -1,218 -47 -158,125

2025 28,377 3,862 517 531 33,287

  -155,071 -1,871 -1,134 -76 -158,153

NOX Emissions in tpy

Year Point Area NonRoad Onroad1 Total (tpy)

2007 37,855 8,936 26,817 91,639 165,247

2017 22,481 9,009 17,600

41,709

(Tier 1:41,709; Tier 2: 50,051) 90,799

  -15,374 73 -9,217 -49,930 -74,448

2025 23,044 9,342 14,719

27,400

(Tier 1: 27,400; Tier 2: 32,880) 74,504

  -14,811 406 -12,098 -64,239 -90,743

Primary PM2.5 in tpy

Year Point Area NonRoad Onroad1 Total (tpy)

2007 5,547 9,528 2,198 3,452 20,724

2017 5,656 9,632 1,579

1,787

(Tier 1: 1787; Tier 2: 2,144) 18,654

  109 104 -619 -1,665 -2,070

2025 5,693 9,725 1,269

1,322

(Tier 1: 1,350; Tier 2: 1,586) 18,010

  146 198 -928 -2,129 -2,714

1

Transportation buffers were added to the onroad mobile emissions for NOX and PM2.5 for 2017 and 2025 to 

develop 2-tier (Tier 1 and Tier 2) mobile budgets for the two years. These mobile budgets are shown in brackets. 

See Section 5.2.1 for details of the development of mobile budgets. 

Mobile source emissions were calculated using USEPA’s MOVES2010a mobile source 

inventory model. These estimates are based on vehicle-specific registration data obtained from 

each jurisdiction. Mobile source emission projections included the National Low Emission 

Vehicle Program (40 CFR 86 Subpart R); the 1994 Tier 1 Rule (40 CFR 86 Subpart A); the 2004 

Tier 2 and Low Sulfur Gasoline Rule (40 CFR Part 80 Subpart H, 40 CFR Part 85, and 40 CFR 

Part 86); and the 2004 and 2007 Heavy-Duty Diesel Vehicle Rules (40 CFR Part 86 Subpart P). 

All jurisdictions were modeled with Phase II Reformulated Gasoline (RFG) and an enhanced I/M 

program for all analysis years. More information on the development of these inventories may be 

found in the Technical Support Document (Appendix C1).

Emissions for non-road vehicles and equipment except for marine, rail, and locomotives 

were calculated using NMIM2008 (version NMIM20090504), which used NONROAD2008a 

model (version July 2009). This version of NONROAD2008a is USEPA’s most recently 

approved emissions estimation tool for the above mentioned nonroad sources. Area, marine, rail, 

and locomotive emissions were calculated using the most updated practices and inputs. More 
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 8

information on the development of these inventories may be found in the Appendix A1 and

Appendix B1.

5.2.1 Mobile Source Emissions Budgets

Transportation conformity is a way to ensure that federal funding and approval are given 

to those transportation activities that are consistent with air quality goals. Transportation 

activities should not worsen air quality or interfere with an area’s continued compliance in 

regards to the 1997 PM2.5 NAAQS. The federal transportation conformity rule is codified in 40 

CFR Part 93, subpart A, entitled Determining Conformity of Federal Actions to State or Federal 

Implementation Plans (transportation conformity rule). This rule applies to areas designated as 

nonattainment for one or more NAAQS or that have been redesignated to attainment with

federally approved air quality maintenance plans. 

The responsible transportation planning entity for the Washington DC-MD-VA 1997 

PM2.5 nonattainment area is the Metropolitan Washington Council of Governments (MWCOG)

Transportation Planning Board (TPB). In the transportation conformity process, overall 

emissions estimates by analysis year that take into account future traffic activity and projects 

expected to be completed are compared to a base year, a no build scenario, or emission budgets. 

Emission budgets are used in this determination only if USEPA has approved or found adequate 

emissions budgets that have been submitted as a SIP revision. For PM2.5, the pollutant itself and 

potentially all its various precursors would require analysis. NH3 and VOC are precursors, 

however, they are not considered significant overall contributors to PM2.5 air quality issues, as 

noted in the implementation rule at 40 CFR 51.1002(c)(3). For other pollutants and precursors, 

the highway contribution to those emissions may be insignificant. In that case, the transportation 

conformity rule allows such pollutants and precursors to be exempt from conformity analysis 

under certain circumstances:

40 CFR 93.109 (k) Areas with insignificant motor vehicle 

emissions. Notwithstanding the other paragraphs in this section, an 

area is not required to satisfy a regional emissions analysis for 

§93.118 and/or §93.119 for a given pollutant/precursor and 

NAAQS, if EPA finds through the adequacy or approval process 

that a SIP demonstrates that regional motor vehicle emissions are 

an insignificant contributor to the air quality problem for that 

pollutant/precursor and NAAQS. The SIP would have to 

demonstrate that it would be unreasonable to expect that such an 

area would experience enough motor vehicle emissions growth in 

that pollutant/precursor for a NAAQS violation to occur. Such a 

finding would be based on a number of factors, including the 

percentage of motor vehicle emissions in the context of the total 

SIP inventory, the current state of air quality as determined by 

monitoring data for that NAAQS, the absence of SIP motor vehicle 

control measures, and historical trends and future projections of the 

growth of motor vehicle emissions. . . 
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 9

The District of Columbia, the State of Maryland, and the Commonwealth of Virginia are

herein making a finding that regional highway emissions of SO2 are insignificant contributors to 

the PM2.5 air quality of the Washington DC-MD-VA area. The finding will become final if 

USEPA concurs and approves this maintenance plan. This finding is due to the fact that the 

regional highway SO2 emissions inventory constitutes a very small fraction of the overall 

emissions inventory in the Washington DC-MD-VA area as shown in Table 5-3.

Table 5-3: Comparison of SO2 Emissions from On-Road Sources to the Total SO2 Inventory

Year Metro DC Total SO2

Emissions, tpy

On-Road SO2

Emissions, tpy

Percent On-Road 

SO2

2007 191,441 607 0.3

2017 33,315 560 1.7

2025 33,287 531 1.6

Additionally, PM2.5 air quality in the region is good and getting better. Figure 5-1 and 

Figure 5-2 provide the regional trends in PM2.5 air quality for the federal reference method 

monitoring sites. The design value for the Washington DC-MD-VA region is 10.8 μg/m3for 

years 2009-2011, 4.2 μg/m3beneath the standard. As noted in Table 5-3, the contribution of onroad mobile SO2 emissions is expected to decline in both the 2017 and 2025, as compared to 

2007. Therefore, it is highly unlikely that any increase in growth assumptions or activity data, 

beyond those already included in the on-road SO2 emissions estimation methodology, could 

account for an exceedance or violation of the 1997 PM2.5 NAAQS annual standard. For these 

same reasons, the likelihood of on-road emissions of SO2 contributing to an exceedance of the 

1997 PM2.5 24-hour standard is even smaller.
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 10

Figure 5-1: Washington DC-MD-VA 24 Hour PM2.5 Trends

Figure 5-2: Washington DC-MD-VA Annual PM2.5 Trend Chart

1 5

2 5

3 5

4 5

5 5

6 5

7 5

1999-2001 2000-2002 2001-2003 2002-2004 2003-2005 2004-2006 2005-2007 2006-2008 2007-2009 2008-2010 2009-2011 PM2.5 Concentrations in ug/m3

3 year period

24-Hour PM2.5 Design Value Trend

Washington, DC-MD-VA PM2.5 Nonattainment Area

110010041

110010042

110010043

240313001

240330025

240330030

240338003

510130020

510590030

511071005

Series12

2006 24-hour Standard = 35 μg/m3

1997 24-hour Standard = 65 μg/m3

9.0

10.0

11.0

12.0

13.0

14.0

15.0

16.0

17.0

1999-2001 2000-2002 2001-2003 2002-2004 2003-2005 2004-2006 2005-2007 2006-2008 2007-2009 2008-2010 PM2.5 Concentrations in ug/m3

3 year period

Annual PM2.5 Design Value Trend

Washington, DC-MD-VA PM2.5 Nonattainment Area

110010041

110010042

110010043

240313001

240330025

240330030

240338003

510130020

510590030

511071005

1997 Annual Standard = 15.0 μg/m3
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 11

As required by the transportation conformity rule, this maintenance plan establishes onroad mobile source emissions budgets for NOX and PM2.5. These budgets represent the level of 

mobile source emissions that can be emitted in the area while supporting the air quality plan. 

The mobile source budgets established by this plan are presented in Table 5-4 and Table 5-5. 

Table 5-4: Washington DC-MD-VA Maintenance Plan Tier 1 On-Road Mobile Source Emissions Budgets

Year NOX On-Road 

Emissions (tpy)

PM2.5 On-Road 

Emissions (tpy)

2007 Attainment Year 91,639 3,452

2017 Interim Budget 41,709 1,787

2025 Predicted Emissions 27,400 1,322

Transportation Buffer --- 28

2025 Final Budget 27,400 1,350

Table 5-5: Washington DC-MD-VA Maintenance Plan Tier 2 On-Road Mobile Source Emissions Budgets

Year NOX On-Road 

Emissions (tpy)

PM2.5 On-Road 

Emissions (tpy)

2007 Attainment Year 91,639 3,452

2017 Predicted Emissions 41,709 1,787

Transportation Buffer 8,342 357

2017 Interim Budget 50,051 2,144

2025 Predicted Emissions 27,400 1,322

Transportation Buffer 5,480 264

2025 Final Budget 32,880 1,586

This maintenance plan provides a two-tiered approach for the motor vehicle emissions 

budgets (MVEBs). This approach will be applied in future conformity analyses supporting the 

1997 annual PM2.5 standard and uses transportation buffers1to accommodate future 

transportation conformity determinations.

The initial Tier 1 MVEBs for PM2.5 and the precursor NOX established for 2017 (interim 

year) and 2025 (out year) are based on mobile emissions inventory projections for 2017 and 

2025. One exception is the PM2.5 budget for 2025 which adds a transportation buffer of 28 tons 

per year (tpy) of PM2.5 emissions to the budget to accommodate current inventory projections for 

2040. The Tier 1 MVEBs will be in effect once the maintenance plan budgets are determined to 

be adequate.

 

1

Section 93.124(a) of the Code of Federal Regulations (CFR) allows for the use of conformity buffers (or safety 

margins) in setting motor vehicle emissions budgets.
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 12

The Tier 2 MVEBs have been developed by adding a 20 percent transportation buffer to 

the mobile emissions inventory projections for PM2.5 and NOX in 2017 and 2025. The buffers 

will add 357 tpy of PM2.5 and 8,342 tpy of NOX to the 2017 emission inventories, and 264 tpy of 

PM2.5 and 5,480 tpy of NOX to the 2025 emission inventories to develop the Tier 2 MVEBs. The 

overall emissions inventories even with these buffers remain below the maintenance year caps 

for both pollutants. In the near term, mobile source emissions are rapidly decreasing due to the 

implementation of the NLEV, and HDDV rules, even as Vehicle Miles Traveled (VMT)

continues to grow. Once these rules have sufficiently penetrated the fleet, growth in VMT 

begins to push mobile emissions back on an upward trend. The transportation buffers are 

provided to accommodate technical uncertainties primarily due to model changes and to vehicle 

fleet turnover that may affect future motor vehicle emissions inventories. Tier 2 MVEBs become 

effective if it is determined that one or more of these uncertainties lead to motor vehicle 

emissions estimates above the Tier 1 MVEBs. This determination will be made through the 

interagency consultation process and will be fully documented in the first conformity analysis 

that utilizes the Tier 2 budgets. Regulations related to the interagency consultation process

adopted by the District of Columbia, the State of Maryland, the Commonwealth of Virginia, and 

the Transportation Planning Board are identified below.

2

District of Columbia: Title 20 Environment, Chapter 20-15 General and Transportation Conformity, Rule 

Numbers 20-1503, 20-1504, 20-1505, 20-1506, 20-1507

Maryland: Title 26 Department of Environment, Subtitle 11 Air Quality, Chapter 26 Conformity, 

Regulation Numbers 26.11.26.04, 26.11.26.05, 26.11.26.06, 26.11.26.07, 26.11.26.08

Virginia: 9VAC5 Chapter 151 Regulation for Transportation Conformity Section 70 Consultation (9VAC5-

151-70)

Transportation Planning Board: Report titled “Transportation Planning Board Consultation Procedures 

with respect to Transportation Conformity Regulations Governing TPB Plans and Programs”, May 20, 

1998

 

Table 5-4 provides details of the Tier 1 MVEBs for PM2.5 and NOX for 2007, 2017, and 

2025. Table 5-5 provides details of the Tier 2 MVEBs for PM2.5 and NOx for 2007, 2017, and 

2025. The transportation buffers listed in these two tables use emission reductions achieved but 

not needed to maintain compliance with the standard after the attainment year.

Calculated as a percentage of total emissions, the transportation buffer for the 2017 Tier 2 

PM2.5 MVEB is 1.9% of the total PM2.5 inventory and for the 2017 Tier 2 NOx MVEB is 9.2% 

of the total NOx inventory. For 2025, the transportation buffer for the Tier 2 PM2.5 MVEB is 

1.5% of the total PM2.5 inventory and for NOx is 7.4% of the total NOx inventory.

The Washington DC-MD-VA area commits to evaluating and submitting, as a revision to 

the 1997 PM2.5 NAAQS maintenance plan, updated annual 2017 and 2025 MVEBs for NOx and 

PM2.5 by the end of 2015.3

 

2 District of Columbia: http://www.dcregs.dc.gov/Gateway/ChapterHome.aspx?ChapterNumber=20-15

 Maryland: http://www.dsd.state.md.us/comar/SubtitleSearch.aspx?search=26.11.26

 Virginia: http://leg1.state.va.us/000/reg/TOC09005.HTM#C0151 (9VAC5-151-70)

 Transportation Planning Board: http://www.mwcog.org/store/item.asp?PUBLICATION_ID=233

3 This is being pursued as part of an agreement between the District of Columbia, the State of Maryland, and the 

Commonwealth of Virginia. See Appendix D for details of the agreement. 
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 13

5.2.2 Control Measures for Maintenance of Good Air Quality

Point, non-road, and on-road emission projections for 2017 and 2025 include a variety of 

control strategies that will reduce emissions of PM2.5, NOX, and SO2 in the future years. The 

sections below describe the major control programs in each category. Many of these programs 

are federal programs that are enforced on a regional or national level. In cases where the 

programs are delegated programs or state programs, the District of Columbia, the State of 

Maryland, and the Commonwealth of Virginia commit to the continuation of each program, to 

include compliance and enforcement mechanisms as appropriate to ensure that reductions 

assumed in 2017 and 2025 will be achieved. 

5.2.2.1 Point Sector Controls

Point source emissions of PM2.5, SO2, and NOX are dominated in the Washington DCMD-VA region by the emissions from electrical generating units (EGU). The EGUs located in 

the Washington DC-MD-VA nonattainment area are the Possum Point Power Station in Fairfax, 

Virginia (ORIS43804); the Potomac River Power Station in Alexandria, Virginia (ORIS 3788); 

the Chalk Point Generating Plant, in Prince George's County, Maryland (ORIS 1571); the 

Dickerson Generating Plant, in Montgomery County, Maryland (ORIS 1572); the Morgantown 

Generating Plant, in Charles County, Maryland (ORIS 1573); and the Benning Road Generating 

Station in the District of Columbia (ORIS 603). These facilities are subject to a variety of 

federal and state-enforceable mechanisms that have reduced emissions at these units since 2007 

and will continue to reduce emissions into the future. The emission reduction measures 

applicable to the point sources are described in the following sections.

5.2.2.1.1 Maryland Healthy Air Act

The Maryland Health Air Act (HAA) regulations became effective on July 16, 2007

(approved into the State of Maryland SIP on 9/4/2008, 73 FR 51599) and required reductions in 

NOX, SO2, and mercury emissions from large coal burning power plants in Maryland. 

Specifically, this program limits emissions from the Chalk Point Generating Plant, the Dickerson 

Generating Plant, and the Morgantown Generating Plant, all of which are coal fired power plants 

located within the Maryland portion of the Washington DC-MD-VA nonattainment area. 

Emission reductions from the HAA are phased. The first phase required reductions in the 

2009/2010 timeframe. Compared against a 2002 emissions baseline, the first phase of the HAA 

reduced NOX emissions by almost 70 percent and SO2 emissions by 80 percent. The second 

phase of emission controls will occur in the 2012/2013 time frame. At full implementation, the 

HAA will reduce NOX emissions by approximately 75 percent from 2002 levels and SO2

emissions by approximately 85 percent from 2002 levels. The first phase of the HAA was 

successfully implemented, and the second phase of the program is expected to be implemented in 

a timely manner.

 

4 EGUs are assigned a 4-digit ORIS (Office of the Regulatory Information System) identifier by the Energy 

Information Agency (EIA) of the US Department of Energy.
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 14

Figure 5-3: Large EGUs in the Washington DC-MD-VA Area

5.2.2.1.2 District of Columbia Source Shutdown

As a condition of the operating permit for the Benning Road Generating Station, Pepco 

Energy Services, Inc., agreed to permanently cease operation of the facility’s two electric 

generating units by December 17, 2012. The permit condition became federally enforceable as 

part of a SIP revision that was approved by USEPA on February 2, 2012 (77 FR 22: 5191). 

Closure of the two large, uncontrolled oil-fired turbines will result in SO2 and NOx reductions. 

5.2.2.1.3 Virginia Permitting Requirements.

A federal settlement reduced emissions of NOX and SO2 significantly at the Possum Point 

Power Station, which is located in Fairfax County, Virginia. This consent decree, “United States 

v. Virginia Electric and Power Co.,” (No. 03-CV-517A, entered October 10, 2003), was signed 

April 17, 2003. The decree required the Possum Point Power Station to switch two coal-fired 

boilers to natural gas, thereby removing coal as a fuel at the facility. This requirement was also 

codified in a federally enforceable permit issued by the Virginia Department of Environmental 

Quality on October 5, 2001. This permit was issued under Article 8 and Article 9 of 9VAC5 

Chapter 80 (Permits for Stationary Sources). Article 8 was most recently approved into 

Virginia’s SIP on October 22, 2008 (73 FR 62897) and on September 2, 2011 (76 FR 54706). 

Article 9 was most recently approved into Virginia’s SIP on October 22, 2008 (73 FR 62893). 
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 15

The fuel switch from coal to natural gas was made in the 2003-2004 timeframe and resulted in 

large reductions in PM2.5, SO2, and NOX from these units.

Two other permitting actions affected the emissions of SO2 and NOX from the Potomac 

River Power Station, a coal-fired EGU located in Alexandria, Virginia. The first was a state 

operating permit issued on July 31, 2008 by the State Air Pollution Control Board to address 

modeled exceedances of the National Ambient Air Quality Standards and the Significant 

Ambient Air Concentrations. This permit limited the facility’s primary PM2.5 emissions to 207 

tpy, the SO2 emissions to 3,813 tpy, and the NOX emissions to 3,700 tpy. On July 29, 2010, a 

second state operating permit was issued, further limiting the facility to 890 tons of NOX per 

ozone season (May 1 through September 30). This permit supported the emissions reductions 

associated with the Washington DC-MD-VA 1997 ozone NAAQS nonattainment area’s 

attainment plan, "Plan to Improve Air Quality in the Washington, DC-MD-VA Region." These 

permits were issued under Article 5 of 9VAC5 Chapter 80 (Permits for Stationary Sources), 

which was most recently approved into Virginia’s SIP on June 27, 2003 (63 FR 38191).

5.2.2.1.4 Future Point Source Emission Reduction Programs

Three federal regulations may reduce emissions of SO2 even further than is already 

estimated by the 2017 and 2025 inventory shown in Table 5-2 for the Washington DC-MD-VA 

area. These rules were not finalized at the time of the development of this maintenance plan and 

therefore were not considered in the 2017 and 2025 estimates included in this document. As 

these regulations are finalized, each should instigate significant further reductions, both within 

and outside the Washington DC-MD-VA area.

 Mercury and Air Toxics Rule: On February 16, 2012 (77 FR 9304), USEPA published

the Mercury and Air Toxics Rule to reduce emissions of toxic air pollutants from new 

and existing coal and oil-fired EGUs. The rule establishes numerical emission limits for 

hydrogen chloride (HCl) as a surrogate for toxic acid gases or alternative standards for 

SO2. USEPA estimates that this rule would affect approximately 1,200 coal-fired units 

nationwide and would reduce SO2 emissions from power plants by 55 percent. Existing 

sources are required to demonstrate compliance with the standards by 2015.

 Industrial/Commercial/Institutional (ICI) Boiler Maximum Achievable Control 

Technology (MACT) Standard: USEPA issued a notice for the final ICI Boiler MACT 

rule on December 20, 2012. USEPA estimates that implementation of the revised 

rulemaking will reduce emissions nationwide from major source boilers and process 

heaters by 16,593 tpy of PM2.5, 570,000 tpy of SO2, and 2,400 tpy of VOCs.

5.2.2.2 Nonroad Diesel Emission Reduction Programs

Under 40 CFR Part 89, USEPA adopted standards for emissions of NOX, hydrocarbons, 

and carbon monoxide (CO) from several groups of nonroad engines, including industrial sparkignition engines and recreational nonroad vehicles (67 FR 68242). Industrial spark-ignition 

engines power commercial and industrial applications and include forklifts, electric generators, 

airport baggage transport vehicles, and a variety of farm and construction applications. Nonroad 
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 16

recreational vehicles include snowmobiles, off-highway motorcycles, and all-terrain vehicles. 

These rules were initially effective in 2004 and will be fully phased in by 2012.

The nonroad diesel rule set standards that reduced emissions by more than 90 percent

from nonroad diesel equipment and, beginning in 2007, the rule reduced fuel sulfur levels by 99

percent from previous levels. The reduction in fuel sulfur levels applied to most nonroad diesel 

fuel in 2010 and will apply to fuel used in locomotives and marine vessels in 2012 (69 FR 

38958). 

This program will continue to provide emission reductions of NOX as new equipment is 

purchased and older equipment is scrapped. Additionally, SO2 emissions from the combustion 

of nonroad diesel fuel and locomotive and marine diesel fuel will continue to be reduced through 

2012.5

5.2.2.3 On-Road Emission Reduction Programs

In the 2007 heavy-duty highway rule, which is codified in 40 CFR Part 86, Subpart P, 

USEPA set a PM emission standard for new heavy-duty engines of 0.01 grams per brake 

horsepower-hour (g/bhp-hr). This standard took full effect for diesel engines in the 2007 model 

year. This rule included standards for NOX and non-methane hydrocarbons (NMHC) of 0.20 

g/bhp-hr and 0.14 g/bhp-hr, respectively. These diesel engine NOX and NMHC standards were 

successfully phased in together between 2007 and 2010. The rule also required that sulfur in 

diesel fuel be reduced to facilitate the use of modern pollution control technology on these trucks 

and buses. USEPA required a 97 percent reduction in the sulfur content of highway diesel fuel --

from levels of 500 parts per million (ppm) for low sulfur diesel to 15 ppm for ultra-low sulfur 

diesel. The reductions in sulfur content engendered similar reductions in SO2 emissions. These 

requirements were successfully implemented on the timeline in the regulation.

The Tier 1 federal motor vehicle emission standards were published by USEPA on June 

5, 1991 and were phased in beginning with the model year 1994 (40 CFR Part 86 subpart A). 

The benefits of this program are reflected in the 2002 base year inventory and the 2007 

attainment year inventory. This federally implemented program affects light duty vehicles and 

light duty trucks. The regulations require more stringent exhaust emission standards as well as a 

uniform level of evaporative emission controls.

The Tier 2 vehicle and gasoline sulfur program, as codified in Subpart H of 40 CFR Part 

80, 40 CFR Part 85, and 40 CFR Part 86, became effective in the 2005 model year. This 

program for fleet averaging of on-road vehicles is modeled after the California LEV II standards. 

The Tier 2 program allows manufacturers to produce vehicles with emissions ranging from 

relatively dirty to very clean, but the mix of vehicles a manufacturer sells each year must have 

average NOX emissions below a specified value. Mobile emissions continue to benefit from this 

program as motorists replace older, more polluting vehicles with cleaner vehicles.6

 

5 Details of Nonroad engine and fuel rules are available at - http://www.epa.gov/otaq/standards/index.htm

6 Details of Onroad engine and fuel rules are available at - http://www.epa.gov/otaq/standards/index.htm
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 17

In additional to the federal Tier 2 program and the federal 2007 heavy duty highway rule, 

enhanced vehicle emissions inspection and maintenance (enhanced I/M) requirements have also 

been instituted by the District of Columbia (64 FR 31498, 06/11/1999), the State of Maryland 

(64 FR 58340, 10/29/1999), and the Commonwealth of Virginia (64 FR 47670, 09/01/99). The 

requirements involve mandating regional vehicle emission I/M programs that are stricter than 

basic programs, as required under §§ 182 and 202 of the CAA. Before 1994, basic automobile 

emissions testing checked only tailpipe emissions while idling and sometimes at 2,500 rpm. 

Enhanced I/M procedures include the use of On Board Diagnostic (OBD) system evaluations, a 

wider range of vehicles tested, and may include a dynamometer (treadmill) test that checks the 

car’s emissions under driving conditions. The OBD evaluations provide a more complete 

inspection, checking for excess evaporative emissions and other issues that might affect 

emissions from the vehicle. 

5.2.2.4 Future Control Strategies

The Washington DC-MD-VA area commits to begin planning to identify appropriate 

strategies to help the area achieve and maintain compliance with a potential bump-up of the 

region to a moderate classification for the 2008 ozone NAAQS, and with any future ozone 

NAAQS. This planning process will include, but is not limited to, the development of a 

preliminary 15% Rate of Progress Plan for the 2008 ozone NAAQS.

The Washington DC-MD-VA area will work with jurisdictions and USEPA to 

demonstrate the feasibility of (and get SIP credit for) achieving reductions across the entire 

region from market forces that will result in cleaner products being distributed across the entire 

region even when the regulations driving the cleaner products have only been adopted in a part 

of the region.

The State of Maryland and the District of Columbia will work to pursue at least five new 

regulations to insure that, to the extent the transportation buffers are needed, there is no 

degradation of environmental protection in the State of Maryland and the District of Columbia 

portion of the Washington DC-MD-VA 1997 PM2.5 NAAQS nonattainment area. These new 

measures will also begin the process of further reducing ozone and fine particle levels in the 

region to ensure that public health is protected. The State of Maryland and the District of 

Columbia agree with the scientific community who believe that more stringent ozone and fine 

particle standards are needed. The new regulatory programs include low sulfur home heating 

fuel, enhancements to current controls on consumer products and industrial adhesives, off-road 

idling, and tougher requirements for smaller diesel generators. The commitments made by The 

State of Maryland and the District of Columbia will not be construed to infringe upon any 

prerogative of the Commonwealth of Virginia.

Virginia will pursue measures that are necessary to attain and maintain current and future 

air quality standards as well as measures that may decrease the burden on regulated parties. For 

instance, Virginia is committed to pursue measures such as the on-road emissions program, 

which will ensure that up to 30 percent of all eligible registered vehicles in the Northern Virginia 

area have the option of remotely passing required biennial vehicle emissions inspections by 

2015. The increased level of on-road monitoring could also result in the early identification and 

repair of high emitting vehicles such that this program will maintain environmental protections 

as well as reduce the time required for station-based tests. Virginia is also committed to 
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 18

supporting voluntary efforts to reduce energy consumption through energy efficiency and 

renewable energy programs. Organizations, such as the nonprofit Local Energy Alliance 

Program (LEAP), operate residential and commercial programs in Northern Virginia that seek to 

reduce energy use by at least 20 percent, thereby saving consumers’ money, conserving 

resources, and decreasing air emissions.

6. Air Quality Monitoring Network

6.1 USEPA Requirements

Once an area has been redesignated, the states must continue to operate an appropriate air 

quality monitoring network in accordance with 40 CFR Part 58, to verify the area's attainment 

status. In cases where measured mobile source parameters (for example, vehicle miles traveled) 

have changed over time, the state may also need to perform a saturation monitoring study to 

determine the need for and location of additional permanent monitors.

6.2 Washington DC-MD-VA Approach

The District of Columbia, the State of Maryland, and the Commonwealth of Virginia 

operate a monitoring network that is significantly more robust than required by federal 

regulation.

Figure 6-1 provides a map showing the locations of the various PM2.5 monitoring sites in 

the current network.

The District of Columbia, the State of Maryland, and the Commonwealth of Virginia 

commit to operating and maintaining an air quality network for PM2.5 monitoring that meets all 

federal requirements. Should measured mobile source parameters change significantly over 

time, the states comprising the Washington DC-MD-VA nonattainment area will perform a 

saturation monitoring study to determine the need for and location of PM2.5 monitors.
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 19

Figure 6-1: Washington DC-MD-VA PM2.5 Monitoring Sites
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 20

7. Verify Continued Attainment

7.1 USEPA Requirements

States must ensure that they have the legal authority to implement and enforce all 

measures necessary to attain and maintain the NAAQS. Sections 110(a)(2)(B) and (F) of the 

CAA, and regulations promulgated in 40 CFR 51.110(k) suggest that one such measure is the 

acquisition of air quality and source emission data to demonstrate attainment and maintenance. 

The submittal must indicate how the states will track the progress of the maintenance plan. This 

is necessary due to the fact that the emission projections made for the maintenance 

demonstration depend on assumptions of point, area, and mobile source growth.

One option for tracking the progress of the maintenance demonstration would be for the 

states to periodically update the emissions inventory. In this case, the maintenance plan should 

specify the frequency of any planned inventory updates. Such an update could be based, in part, 

on the annual update of the USEPA Aerometric Information Retrieval System (AIRS) and could 

indicate new source growth and other changes from the attainment inventory (such as changes in 

vehicle miles traveled or in traffic patterns). As an alternative to a complete update of the 

inventory, states may choose to do a comprehensive review of the factors that were used in 

developing the attainment inventory to show no significant change. If this review does show a 

significant change, states should then perform an update of the inventory.

7.2 Washington DC-MD-VA Approach

The District of Columbia, the State of Maryland, and the Commonwealth of Virginia have

the legal authority to implement and enforce specified measures necessary to attain and maintain 

the NAAQS. Key regulatory elements that the respective state will keep in place to maintain 

attainment are as follows:

 Shutdown requirements, permitting requirements, and cap requirements, as described in 

Section 5.2.2.1.

 I/M program requirements, as described in Section 5.2.2.3.

In addition to maintaining key elements of its regulatory program, each state will acquire 

ambient and source emission data to track attainment and maintenance. Each state will track the 

progress of the maintenance demonstration by periodically updating the emissions inventory. 

This tracking will consist of annual and periodic evaluations. The annual evaluation will consist 

of checks on key emissions trend indicators such as the annual emissions update of stationary 

sources, the Highway Performance Monitoring System (HPMS) vehicle miles traveled data 

reported to the Federal Highway Administration, and other growth indicators. These indicators 

will be compared to the growth assumptions used in the plan to determine if the predicted versus 

the observed growth remains relatively constant. Each state will also develop and submit to 

USEPA comprehensive tracking inventories every three years or as required by federal 

regulation during the maintenance plan period. 
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 21

8. Contingency Measures

8.1 USEPA Requirements

The maintenance plan must include contingency measures, as necessary, to promptly 

correct two future situations. The first situation is an inventory estimate that indicates the 

Washington DC-MD-VA area had actual emissions of either SO2, NOX, or PM2.5 in any future 

year that were greater than that of the attainment year inventories listed in Table 4-1. The 

second situation is any NAAQS violation that occurs after redesignation of an area. The plan

should include measures to be adopted, a schedule and procedures for adoption and 

implementation, and a specific time limit for action. Specific triggers that would put the plan 

into motion must be identified. This plan is considered to be an enforceable part of the SIP and 

should ensure that the contingency measures are adopted expeditiously once they are triggered.

8.2 Washington DC-MD-VA Approach

The ability of the Washington DC-MD-VA nonattainment area to stay in compliance 

with the 1997 PM2.5 NAAQS depends at least partially on the level of NOX, SO2, and primary 

PM2.5 emissions in the region. Emissions are projected to stay well below the 2007 attainment 

year levels, through 2025. However, if emissions increase, the area may experience a PM2.5

violation. To address this unlikely situation, the District of Columbia, the State of Maryland, and 

the Commonwealth of Virginia have developed a contingency plan. The situations described 

below would trigger the implementation of the contingency measures as described in Section 

8.2.1, Section 8.2.2, or Section 8.2.3.

 Annual actual emissions of SO2, NOX, or PM2.5 exceeding the attainment year inventories 

in Table 4-1.

 Any annual exceedance (annual average for one year at any federal reference method 

monitor in the Washington DC-MD-VA maintenance area) of 15.0 μg/m3or greater.

 Any violation (three year average of the annual average at any federal reference method 

monitor in the Washington DC-MD-VA maintenance area) of 15.0 μg/m3or greater.

8.2.1 Exceedance of the Attainment Year Emissions Inventory

Should any future year emissions inventory data indicate that the Washington DC-MDVA area’s total emissions of SO2, NOX, or PM2.5 exceeded the levels in Table 4-1, the District of 

Columbia, the State of Maryland, and the Commonwealth of Virginia would first undertake an 

audit to determine whether inventory refinements were needed. This audit may include, but 

would not be limited to, a determination that appropriate models, control strategies, monitoring 

strategies, planning assumptions, industrial throughput, and production data were used in the 

attainment year and future year estimates. USEPA will be provided with the results of this audit. 

If this audit does not reconcile the originally estimated emissions exceedances, then the District 

of Columbia, the State of Maryland, and the Commonwealth of Virginia each commit to 

implementing one or more of the state-defined programs listed in Table 8-1, which applies to 
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 22

their individual jurisdictions, so that future total emission estimates for the Washington DC-MDVA area will not exceed those listed in Table 4-1.

8.2.2 Near Term Contingency Measures for Air Quality Exceedances

If an annual exceedance or violation of 15.0 μg/m3, as described in Section 8.2, occurs 

prior to January 1, 2013, the Maryland Healthy Air Act’s second phase will provide significant 

emissions reductions of precursors to PM2.5. This regulation, included in COMAR 26.11.27, 

requires additional SO2 reductions beginning January 1, 2013, for applicable coal-fired power 

plants in State of Maryland. These applicable units include coal-fired boilers located at the 

Morgantown Power Plant, the Dickerson Power Plant, and the Chalk Point Power Plant in the 

Washington DC-MD-VA nonattainment area. In 2013 the allowable tonnage cap for the units at 

these facilities will be reduced from 24,209 tpy of SO2 to 18,541 tpy of SO2, a reduction of 

almost 24 percent. This regulation has the added benefit of already being codified; these 

reductions will take place in January of 2013 without further action by the State of Maryland.

8.2.3 Long Term Contingency Measures

If an annual exceedance of 15.0 μg/m3, as described in Section 8.2, occurs after January 

1, 2013, the District of Columbia, the State of Maryland, and the Commonwealth of Virginia 

each commit to implementing one of the state-defined programs listed in Table 8-1, which 

applies to their individual jurisdictions, to garner additional emission reductions for air quality 

improvement. 

If an annual violation, as described in Section 8.2, occurs after January 1, 2013, the 

District of Columbia, the State of Maryland, and the Commonwealth of Virginia each commit to 

implementing two or more of the state-defined programs listed in Table 8-1, which apply to their 

individual jurisdictions, to garner additional emission reductions for air quality improvement.

Table 8-1: Contingency Control Measures

PM2.5 Reasonable Available Control Measure (RACM) Determination*

SO2 RACM Determination (DC & VA portions of the Washington DC-MD-VA area)*

NOX RACM Determination*

Non Road Diesel Emission Reduction Strategies

Low Sulfur Home Heating Oil Requirements (DC & MD portions of the Washington DC-MD-VA area)

Alternative Fuel and Diesel Retrofit Programs for Fleet Vehicle Operations

Concrete Manufacturing – Wet Suppression Upgrade Requirements

* If a RACM analysis determines that no controls are economically and technically feasible, then an alternate 

control measure from Table 8.1 will be implemented.
Washington, DC-MD-VA PM2.5 NAA Maintenance Plan, May 22, 2013 23

8.2.4 Contingency Measure Implementation Schedule

The District of Columbia, the State of Maryland, and the Commonwealth of Virginia 

commit to the implementation of any long term contingency measure on the following schedule:

 Schedule onset: Three months after quality assured data determines that an exceedance 

or violation occurred within the previous year, or three months after the conclusion of an 

audit that determines an emissions inventory exceedance of the levels noted in Table 4-1 

occurred.

 Applicable regulation or program to be adopted six months after this date.

 Applicable regulation to be implemented six months after adoption.

 Compliance with regulation, or full program implementation, to be achieved within 12 

months of adoption.