2010 NO2 NAAQS (75 Fed. Reg. 6474)

District of Columbia Infrastructure SIP

May 2014

 

ATTACHMENT B

Section 110(a)(2)(D)(i): Interstate Transport Provisions, Part I

Include an explanation in support of the conclusion that no source will contribute significantly to 

nonattainment or interfere with maintenance of the SO2 NAAQS in another state. 

The District of Columbia (District) was designated as an unclassifiable/attainment area for the 2010 

nitrogen dioxide (NO2) national ambient air quality standards (NAAQS)1. This is at least in part 

because no source in the District contributes significantly to nonattainment or interferes with 

maintenance of the 2010 NO2 NAAQS in another state. No source in the District has ever caused a 

violation of the NO2 NAAQS and no source emits quantities that are potentially of concern. 

No NO2 NAAQS Violations

Currently, the District operates three ambient air monitors to measure NO2: one at the River Terrace

site, one at the McMillan NCore site, and one at a Takoma site2. None of the monitors have revealed a 

violation of the 2010 NO2 standard. Figure 1 shows that the District’s design values for NO2 have 

remained well below the annual and 1-hour NAAQS for years. 

Figure 1. Monitored NO2 Concentrations in the District Over Time (parts per billion)

 

1 Letter from the U.S. EPA to the Honorable Vincent C. Gray (June 29, 2011).

2 The NO2 monitor at the Takoma School site stopped operating in 2011 due to a building fire. NO2 monitoring resumed at a 

nearby Takoma Recreation Center site in January 2013.
CONTINUED: Monitored NO2 Concentrations in the District Over Time (parts per billion)

Insignificant Contribution (Prong 1)

NO2 is one component of oxides of nitrogen (NOx) and is generally used as an indicator for the larger 

group of NOx. Of all NOx emissions generated in the Washington DC-MD-VA nonattainment area, the 

District contributes a nominal portion – about nine percent (2011 NEI Version 1). This implies that in 

general, NO2 emissions are small.

o Currently, there are no EGUs or other large 

industrial sources of NOx emissions in the 

District.

o The District has only one “non-EGU” facility 

with units large enough (>250 mmBTU/hr in 

size) to be applicable under EPA’s NOx SIP 

Call: the U.S. General Services Administration 

(GSA).

o The only other source that comes anywhere 

close to emitting roughly 100 tons per year is 

the U.S. Capitol Power Plant (CPP).
Figure 2. Point Source NOx Emissions in the District (tons per year)

Facility 2008 2009 2010 2011 2012

GSA 193.5 215 214.6 195.5 185.9

CPP 107.1 137.7 106.1 105.5 94.7

All Major Sources 676.1 740.9 944.9 702.9 441.7

Both GSA and CPP have plant-wide emissions limits in their Title V permits that will continue to at 

least cap potential annual NOx emissions3, and thus NO2 emissions, into the future. Every other major 

source currently operating in the District has emitted less than 30 tons per year (tpy) of NOx since 2008. 

There is also evidence that emissions of NO2 will not increase significantly. Because the District was in 

serious nonattainment of the 1-hour ozone NAAQS, CAA anti-backsliding provisions mean that the 

major source permitting threshold for NOx remains at 25 tpy (20 DCMR § 399). The District’s new 

source review program (20 DCMR Chapter 2) and prevention of significant deterioration federal 

implementation plan (PSD FIP) will continue to sufficiently control emissions due to facility changes. 

Additional NOx controls in the District’s State Implementation Plan (SIP) include NOx RACT (20 

DCMR § 805), a high enhanced inspection and maintenance (I/M) program (see 40 C.F.R. § 52.470(c)), 

and numerous Federal NOx measures.

No Interference with Maintenance (Prong 2)

There are no nonattainment areas for NO2 within a 50-kilometer radius of the District, which is the 

standard distance generally considered by EPA for air dispersion modeling (Appendix W to 40 C.F.R. 

Part 51). The most recent design values (DVs) computed using quality-assured and certified ambient air 

modeling data, based on the Federal Reference Method or an equivalent monitoring measurement, and 

reported to EPA’s Air Quality System (AQS) in states bordering the District are in Figure 3:

Figure 3. Recent Design Values at Monitors in Maryland and Virginia 

State County Site 

2008-

2010

2009-

2011

2010-

2012 

ANNUAL (53 ppb)

MD Baltimore 240053001 13 13 12

MD Baltimore city 245100040 18 18 16

MD Prince George's 240330030 - - 9

VA Arlington 510130020 13 12 12

VA Charles City 510360002 5 6 5

VA Hampton city 516500008 - 5 5

VA Henrico 510870014 11 10 9

VA Loudoun 511071005 8 8 7

 

3 CPP’s recently approved Title V permit reduced the plant-wide emission limit from the equivalent of 925 tpy for NOx down 

to 197 tpy for NOx (see DDOE, “District Issues Air Quality Permits for Cogeneration Equipment at the U.S. Capitol Power 

Plant” (June 6, 2013), found at: http://ddoe.dc.gov/release/district-issues-air-quality-permits-cogeneration-equipment-uscapitol-power-plant). GSA’s existing Title V permit (as of July 28, 2000) includes annual plant-wide emissions limits for 

NOx of 268 tpy for the Central Heating and Refrigeration Plant (which no longer exists) and 256 tpy for the West Heating 

Plant.
State County Site 

2008-

2010

2009-

2011

2010-

2012 

VA Norfolk city 517100024 - 10 8

VA Prince William 511530009 5 6 5

VA Richmond city 517600024 12 10 10

VA Roanoke 511611004 8 7 7

VA Rockingham 511650003 10 9 9

1-HOUR (100 ppb)

MD Baltimore 240053001 52 50 48

MD Baltimore city 245100040 57 58 57

VA Arlington 510130020 50 49 47

VA Charles City 510360002 57 55 52

VA Henrico 510870014 - 41 41

VA Loudoun 511071005 40 41 39

VA Prince William 511530009 30 28 28

VA Richmond city 517600024 54 52 51

VA Roanoke 511611004 38 38 39

Source: “Design Values” on EPA website at: http://www.epa.gov/airtrends/values.html; 

only data with completeness determinations

All nearby DVs are well below the NAAQS for NO2 – none are close to half the annual NAAQS and all 

are hovering near or below half the 1-hour NAAQS. Since there are also no nearby areas violating the 

NO2 NAAQS, the District has no reason to believe that any monitors identified in the table above may 

have difficulty maintaining the NO2 standards, particularly as a result of emissions from the District.

Conclusion

The District does not have any substantial sources of NO2 within its borders, nor is not aware of any 

plans to establish any substantial new sources. Federally enforceable SIP provisions that limit NOx, and 

thus NO2, will prevent emissions from increasing to worrisome levels. Thus, it is reasonable to 

conclude that no source in the District will contribute significantly to nonattainment or interfere with 

maintenance of the NAAQS in any other state.