UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION III

1650 Arch Street

Philadelphia, Pennsylvania 19103

DATE: November 12, 2015

SUBJECT: Technical Support Document for the District of Columbia State Implementation 

Plan for the Interstate Pollution Transport Requirements for the 2010 Nitrogen 

Dioxide National Ambient Air Quality Standards

FROM: Emlyn Velez-Rosa, Environmental Engineer \s\

Office of Air Program Planning

TO: File for Docket ID Number EPA-R03-OAR-2015-0750

THRU: Cristina Fernandez, Associate Director \s\

Office of Air Program Planning 

A. INTRODUCTION

The Environmental Protection Agency (EPA) is taking action on a revision to the District of 

Columbia State Implementation Plan (SIP) submitted by the District Department of Energy and 

Environment (DDOEE) to satisfy the interstate pollution transport requirements under section 

110(a)(2)(D)(i)(I) for the 2010 nitrogen dioxide (NO2) national ambient air quality standards 

(NAAQS or standards).

B. BACKGROUND

On February 9, 2010 (75 FR 6474), EPA established a new 1-hour primary NAAQS for NO2 at a 

level of 100 parts per billion (ppb), based on a 3-year average of the 98th percentile of the yearly 

distribution of 1-hour daily maximum concentrations. See 40 CFR 50.11. NO2 is a subset, and 

often considered an indicator, of the broader pollutant nitrogen oxides (NOx).

Whenever new or revised NAAQS are promulgated, the CAA requires states to submit a plan for 

the implementation, maintenance, and enforcement of such NAAQS. The plan is required to 

address basic program elements, including, but not limited to, regulatory structure, monitoring, 

modeling, legal authority, and adequate resources necessary to assure attainment and 

maintenance of the standards. These elements are referred to as infrastructure requirements. 

Infrastructure SIP revisions should provide for the “implementation, maintenance, and 

enforcement” of such NAAQS. The statute directly imposes on states the duty to make these SIP 

submissions, and the requirement to make the submissions is not conditioned upon EPA’s taking 

any action other than promulgating a new or revised NAAQS. Section 110(a)(2) includes a list 

of specific elements that “[e]ach such plan” submission must address. 
2

One of the infrastructure requirements, section 110(a)(2)(D)(i)(I) of the CAA, or the “good 

neighbor” provision, requires states to address interstate transport of air pollution that affects 

downwind states’ ability to attain and maintain the NAAQS. Specifically, section 

110(a)(2)(D)(i)(I) requires state SIPs to address any emissions activity in one state that 

contributes significantly to nonattainment, or interferes with maintenance, of the NAAQS in any 

downwind state. EPA sometimes refers to these requirements as prong 1 (significant

contribution to nonattainment) and prong 2 (interference with maintenance), or conjointly, the 

interstate pollution transport requirements.

C. SUMMARY OF STATE SUBMITTAL

On June 6, 2014, the District submitted, through DDOEE, a revision to its SIP to satisfy the 

infrastructure requirements of section 110(a)(2) of the CAA for the 2010 NO2 NAAQS. The 

District’s infrastructure SIP revision addressed the applicable infrastructure requirements for the 

2010 NO2 NAAQS, including section 110(a)(2)(D)(i)(I) of the CAA. In its transport submittal, 

the District concludes that it does not contribute to nonattainment in, or interference with 

maintenance by, any other state with respect to the 2010 NO2 NAAQS, based on emissions and 

air quality data. Further discussion of the District’s justification provided in each submittal as 

well as EPA’s rationale for proposing approval of this SIP revision as meeting section 

110(a)(2)(D)(i)(I) of the CAA for the 2010 NO2 NAAQS is provided below.

D. EVALUATION OF STATE SUBMITTAL

NO2 is one component of NOx and is generally used as an indicator for the larger group of NOx.

The District evaluated actual emissions inventories for the District and concluded that there are 

currently no large stationary sources that can contribute significant NOx emissions to nearby 

states. EPA confirms that the District’s stationary point sources correspond to 7 percent of the 

total NOx emissions in 2011, while the nonpoint sources correspond to 17 percent. See Table 1 

below based for 2011 NEI data (version 2). 

Table 1. 2011 Actual Emission from the District by Source Category

Source 

Category

Annual Emissions 

(tons per year)

Point 692.33

Area 1621.35

Onroad 4739.47

Nonroad 2364.45

Total 9417.60

As indicated in the June 6, 2014 submittal, there are currently no electric generating units 

(EGUs) in the District. The District’s last remaining EGU, Benning Road Generating, was 

decommissioned in 2012, in part to meet other SIP requirements. See 77 FR 5191 (February 2, 

2012) (approving the District’s Regional Haze SIP revision). Additionally, the District indicates 
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that its two largest stationary sources of NOx, the U.S. General Services Administration’s 

Central Heating and Refrigeration Plant (GSA) and the U.S. Capital Power Plant (CPP), are 

subject to Federally-enforceable emissions limits that have already resulted in significant 

emissions reductions of NOx. The CPP is subject to NOx emissions for the two coal-fired 

boilers of 0.43 pounds per million British thermal units (lb/MMBtu) with slightly more stringent 

limits during the ozone season,1in addition to a recent plant-wide annual limit (PAL) of 248.1 

tons per year (tpy), effective since January 2013.2 EPA also notes that CPP has plans to 

construct combustion turbines to burn natural gas which will replace the coal-fired boilers and 

have significantly tighter NOx emission limits.3 

The GSA is subject to a Federally-enforceable PAL of NOx emissions of 268 tpy.4 In addition, 

the GSA has the only non-EGUs in the District that are subject to EPA’s NOx SIP Call5, which 

imposed NOx reduction requirements on large boilers and turbines over 250 million British 

thermal units per hour (MMBTU/hr) as well as imposing requirements on EGUs. Thus, to meet 

the NOx SIP Call requirements, as of May 2015, the GSA’s largest three emission units (i.e., 

over 250 MMBtu/hr) are subject to a combined stringent NOx emission limit of 25 tons per 

ozone season.6 The District explains in its SIP submittal that GSA does not have any other 

sufficiently large emissions units that could be controlled to significantly reduce NOx emissions. 

The District affirms that all other major stationary sources in the District have emitted less than 

30 tons per year of NOx since 2008.

On February 17, 2012 (77 FR 9532), EPA published its final designations for the 2010 NO2

NAAQS, based upon 2008-2010 design values. In this rulemaking, EPA determined that no area 

in the country was violating the standard, designating all the areas of the country as 

unclassifiable/attainment. The 2008-2010 design values reflect conditions at the time throughout

the country well below the 2010 NO2 NAAQS, including the District and nearby states. 

Currently available air quality monitoring data confirms that NO2 levels continue to be well 

below the 2010 NO2 NAAQS in the District and in any areas surrounding or bordering the 

District. The District’s June 6, 2014 submittal included historical NO2 air quality monitoring 

data for the District, as well as recent air quality monitoring data for the states surrounding or 

bordering the District within a 50 kilometer radius, the standard distance for modeling analysis in 

EPA’s Guideline on Air Quality Models (Appendix W to 40 CFR Part 51). Accordingly, the 

District provided NO2 air quality data from certain monitors in Maryland and Virginia which are

located within the 50 kilometer radius from the District, during 2008-2010, 2009-2011 and 2010-

2012, as presented in Table 2 below. See also attached the Air Quality System (AQS) reports 

(AMP480) with NO2 monitoring data reported by the states. Based on the air quality data 

provided, EPA confirms that NO2 air quality data for the District and for the surrounding states 

within the 50 kilometer radius from the District results in design values well below the 2010 NO2

 

1 See District’s Title V Permit Number 033, issued on April 14, 2000 and presently in effect.

2 See the EPA-approved permit EPA-R3-PAL-001, effective on January 23, 2013.

3 See District’s pre-construction permits 6663-C and 6664-C, effective on June 6, 2013.

4 See District’s Title V Permit Number 032, issued on July 28, 2000 and presently in effect.

5 63 FR 57371 (October 27, 1998)

6 This limit is required under 20 DCMR chapter 10, as amended by the District in May 2015. On June 26, 2015, the 

District submitted to EPA these amendments to 20 DCMR chapter 10 as a SIP revision, to address specific NOx SIP 

Call requirements. 
4

NAAQS, with the highest valid value being only 52 ppb (in Baltimore City, Maryland). 

Table 2. 1-Hour NO2 Design Values for the District, Maryland, and Virginia

State County Site

1-Hour Design Values (ppb) a

2008-

2010

2009-

2011

2010-

2012

2011-

2013

2012-

2014

DC District of Columbia 110010025 52 - - - -

DC District of Columbia 110010041 61 59 55 51 -

DC District of Columbia 110010043 59 57 53 50 48

MD Baltimore 240053001 52 50 48 44 44

MD Baltimore city 245100040 57 58 57 52 52

VA Arlington 510130020 50 49 47 - -

VA Charles City 510360002 57 55 52 47 43

VA Henrico 510870014 - 41 41 39 -

VA Loudoun 511071005 40 41 39 37 -

VA Prince William 511530009 30 28 28 28 28

VA Richmond city 517600024 54 52 51 - -

VA Roanoke 511611004 38 39 39 36 37

a Only valid design values are evaluated. 

The District affirms that improvements in air quality have been in part due to existing SIPapproved control measures for NOx emissions. The District’s SIP presently includes 

requirements for emissions limits on NOx including, but not limited to: 20 DCMR sections 802, 

804 and 805 and 20 DCMR chapter 10 for stationary sources. In addition, all major stationary 

sources of NO2 are subject to the Federal requirements for prevention of significant deterioration 

(PSD)7and the SIP-approved requirements of NSR in 20 DCMR section 204,8both which 

provide preconstruction review and permitting requirements in attainment and nonattainment 

areas. Further, as noted by the District and recognized by EPA, due to previous ozone 

designations, the District’s NSR program continues to apply to its major stationary sources of 

NOx with potential emissions of 25 tons per year, a much more rigorous threshold than currently 

applicable for major sources of NO2 under the PSD program.9 Additionally, the SIP-approved 

regulation of 20 DCMR section 209 contains the District’s minor NSR program, which regulates

“minor” new or modified stationary sources (with potential emissions exceeding certain lower 

thresholds) regardless of attainment status with respect the NAAQS. The District’s minor NSR 

program establishes permitting requirements for sources of NOx emissions with a level of 

control consistent with state-of-the-art technology. Altogether, these permitting requirements 

help ensure that no new or modified NO2 sources in the District will cause or contribute to 

nonattainment for the 2010 NO2 NAAQS. EPA finds the District’s SIP provisions are adequate 

 

7 The District is subject to a Federal Implementation Plan (FIP) containing the Federal PSD provisions in 40 CFR 

52.21, as incorporated by reference in the District SIP in 40 CFR 52.499. See August 7, 1980 (45 FR 52676, at 

52741); March 10, 2003 (68 FR 11316, at 11322); and December 24, 2003 (68 FR 74483, at 74488).

8 Since the District is part of the Washington, DC, MD, VA nonattainment area for the 2008 8-hour ozone NAAQS

and previous ozone standards, NO2 as a subset of NOx is regulated under the NSR program, as precursor of ozone. 

NO2 is also regulated under the PSD program, as the District is designated as unclassifiable/attainment under the 

2010 NO2 NAAQS.

9 See 20 DCMR 204 (69 FR 77647; December 28, 2004) and 20 DCMR chapter 1, section 199 (78 FR 24922; 

April 29, 2013). See also 40 CR 52.21(b)(1)(i). 
5

to prevent its NOx emission sources to interfere with maintenance, or contribute significantly to 

nonattainment, in another state with respect to the 2010 NO2 NAAQS. 

Based on and EPA’s review of air quality monitoring data and emission data, EPA does not 

expect NOx emissions in the District to increase significantly. EPA therefore does not expect 

monitors identified in Table 2 above, which all currently have design values well below the 2010 

NO2 NAAQS, to have difficulty maintaining attainment of the NAAQS. EPA concludes the 

District’s emission sources, which are subject to the SIP-approved provisions identified above, 

are not significantly contributing to nonattainment in another state with respect to the 2010 NO2

NAAQS and are not likely to interfere with maintenance of the 2010 NO2 NAAQS in another 

state.

E. EPA’s CONCLUSION

For all the reasons provided above, EPA is proposing to determine that the District’s SIP 

includes adequate provisions to ensure that NOx emissions sources within the District will not 

significantly contribute to nonattainment or interfere with maintenance in another state with 

respect to the 2010 NO2 NAAQS. Based upon EPA’s review of the air quality data and the 

District’s submittal, EPA proposes that the District has met its obligations pursuant to 

110(a)(2)(D)(i)(I) with respect to the 2010 NO2 NAAQS. 

Attachments:

Attachment A-1: EPA AQS Design Value Report (AMP480) dated November 5, 2015 for the 

District, Maryland, and Virginia.

Attachment A-2: EPA AQS Design Value Report (AMP480) dated November 5, 2015 for 

Virginia.