ATTACHMENT B :

CLEAN AIR ACT § 110(a)(2)(D)(i) (I)

– Interstate Transport Provisions

“Each such plan shall [...] contain adequate provisions (i) Prohibiting, consistent with the provisions of this subchapter, any source or other type of emissions activity within the state from emitting any air pollutant in amounts which will: (I) Contribute significantly to nonattainment in, or interfere with maintenance by, any other State with respect to any suc h national primary or secondary ambient air quality standard, or

The District of Columbia (District) does not contribute to nonattainment in, or interference with maintenance by, any other state with respect to the 2008 8

- hour ozone national ambient air quality standards (NAAQS). As explained below, emissions of oxides of nitrogen ( NO x ) from sources in the District are small relative to those from other states. State Implementation Plan ( SIP )

- approved regulations to reduce emissions from sources that emit NO x and volatile organic compounds ( VOCs ) are in place as appropriate . The District ’s ozone air quality is significantly impacted by transported pollution from outside its boundaries and is heavily reliant on federal measures and r eductions from other states.

Ozone Trends

Ambient measurements for ground

- level ozone (O 3 ) are conducted at three air monitoring sites in the District. The 8

- hour O 3 concentrations have generally dropped over time at the District’s monitors. The chart in Figure 1 below shows the 8

- hour O3 design concentrations from the District’s lead monitor and demonstrates how, over time, O3 air quality has improved in the District

.Figure 1: Design Values at the McMillan Monitoring Station Over Time

The trend is similar to design value trends in the Washington DC

- MD

- VA ozone nonattainment area as a whole (shown in Figure 2 below)

.

Figure 2: Design Values in the Washington DC

- MD

- VA Area Over Time 0.060 0.065 0.070 0.075 0.080 0.085 0.090 0.095 0.100 0.105 

## 8

- Hour O 3 

## Design Values at McMillan

2008 8

- hr Ozone NAAQS: 0.075 ppm 1997 8

- hr Ozone NAAQS: 0.084 ppmThe District’s Contribution and SIP

- Approved Emissions Reduction Efforts

Emissions of NO x and efforts to control NO x are generally the primary focus of interstate transport related to O 3 precursor pollution. Of all NO x emissions generated in the Washington DC

- MD

- VA nonattainment area, the District contributes a nominal portion

– about nine percent (2011 NEI Version 1 )

.

EGUs: E lectric generating units (E GU ) are a significant source of NO x and this sector is a major contributor to interstate transport of O 3 precursor pollution

. Currently, there are no EGUs or other large industrial sources of NO x emissions in the District. The Dis trict’s last remaining EGUs were decommissioned in 2012, in part to meet permit requirements incorporated into the District’s Regional Haze State Implementation Plan (SIP) ( 77 Fed. Reg. 5191 ; codified at 40 C.F.R. § 52.470(e ) )

.

Non

- EGUs: The District has only one “ non

- EGU ” facility with an ozone season cap applicable under EPA’s NO x SIP Call : the United States General Services Administration (GSA). GSA’s three regulated units are required to meet a combined stringent NO x emissions limit of 25 tons
per ozone season

. None of the other stationary point sources regulated under the Clean Air Act Title V program in the District have units large en ough (over 250 mmBTU/hr in size) to require NO x controls specifically to address interstate transport

. In general , point sources in the District contribute a small amount of NO x compared to other
sectors , as illustrated in Figure 3

. Figure 3. NO x Emissions by Sector

I n the District, t he primary source of point and area source NO x emissions is fuel combustion, mainly from smaller boilers . Most fuel burning equipment in the District requires a permit; only fuel burning equipment with a capacity of five million British thermal units or less per ho ur of heat input is exempt from general permitting requirements at 20 DCMR Chapter 2 ( see § 200.12). Lowest Achievable Emission Rate ( LAER ) controls and emission offsets are required point 7%

area 17%

nonroad 24% onroad 52% 

### 2011 NOx Emissions in the Districton sources that trigger the District’s revised nonattainment NSR requirements (§ 204)

. (Revised

Chapter 2 regulations were proposed to EPA as a SIP revision on Apr il 5, 2013. ) Under new minor NSR requirements (§ 209), new or modified stationary sources with potential emissions exceeding certain thresholds must meet a minimal level of control consistent with state

- of

- the

- art technology for that type of equipment.

M obile Sources: T he District implement s an Enhanced Vehicle Inspection and Maintenance (I/M) program t o control emissions from onroad vehicles

. The District also does extensive outreach to educate tour bus drivers and others who may be impacted by the District’s strict engine idling time limits at 20 DCMR § 900.1. Otherwise, the District relies heavily on federal measures to reduce NO x emissions from onroad and n onroad engines.

Presented in Figure 4 below are the emission inventories for the District by source category based on official National Emissions Inventory (NEI) estimates by the U.S. Environmental Protection Agency (EPA).

Figure 4. NO x Emissions in the District by Source Sector Over Time.

The District’s emissions show a significant d ownward trend despite increases in population, employment, households, and VMT over time.

Contributions from Other States

EPA’s modeling analysis for the proposed Cross State Air Pollution Rule (CSAPR) 1 projected that in 2012, states outside of the Washington DC

- MD

- VA nonattainment area would account

1 On August 21, 2012, the U.S. Court of Appeals for the District of Columbia Circuit vacated CSAPR. EME Homer City Generation, L.P. v. EPA (696 F. 3d 7 (D.C. Cir. 2012)). On June 24, 2013, the U.S. Supreme Court granted EPA’s petition for certiorari. The Supreme Court heard arguments on December 10, 2013. 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000

1996 1999 2002 2005 2008 2011 

## NO x 

## Emissions By Sector

Point Area Nonroad Onroadfor 74 percent of the region’ s ozone pollution. A ctual monitored design values in 2012 at the

District’s three monitoring sites for ozone were higher than projected.

District of Columbia Monitor Site 2012 Base Case Average Values (ppb) 2012 Base Case

Maximum Values (ppb) Actual

DVs, 2010 (ppb) Actual

DVs, 2011 (ppb) Actual

DV s, 2012 (ppb) 110010043 (McMillan) 76.9 79.0 79 79 84 110010041 (River Terrace) 72.9 77.2 77 76 80
110010025 (Takoma) 72.7 73.9 75 75* N/A* * There was a fire at the Takoma monitoring station in 2011, so measurements ceased at that location.

In the CSAPR preamble, EPA suggested that the District d oes not have sources of NO x emissions within its boundaries t hat contribute to transported NO x pollution in other states. Hence, EPA did not propose to establish a NO x budget or finalize a FIP for the Distr ict upon conclusion that

, “there are no emissions reductions available for EGUs...at the cost threshold deemed sufficient to eliminate significant contribution to nonattainment and interference with maintenance of the NAAQS...” (76 Fed. Reg. 48262; August 8, 2 011). Since EPA’s analysis for the proposed CSPAR rule 2 , the District’s stationary point sector NO x emissions have actually reduced further because of the decommissioning of facilities.

I n its analysis regarding the District’s designation recommendation for the 2008 8

- hour ozone NAAQS, EPA noted that it “preliminarily agrees...that an appreciable part of the air quality problem within the District of Columbia is due to emissions outside its bo rders

. ” Reasons cited in EPA’s analysis include the fact that the District is surrounded by three of the “top five” counties for emissions in the Washington

- Baltimore

- Northern Virginia Combined Statistical Area (CSA) and the top three in the DC

- MD

- VA nona ttainment area: Fairfax County (VA), Montgomery County (MD), and Prince George’s County (MD). At the time of EPA’s analysis, the District’s VMT was only one

- twelfth that of the Washington DC

- MD

- VA nonattainment

area. A large percentage of the time , adjac ent and geographically close counties and cities in Virg inia a re upwind of the District. 3

Conclusion

The District of Columbia is a small jurisdiction with no significant sources of NO x and VOC emissions and little opportunity to reduce precursor emissions of ground

- level ozone

. A significant part of the air quality problem within the District is due to transported pollution from outside of its borders

. While the District does what it can to adopt new c ontrol measures, it historically has and will likely continue to rel y heavily on Federal measures particularly from the point and (on

- road and nonroad) mobile sectors , and measures in other states

.

2 U.S. EPA, “Air Quality Modeling Final Rule TSD: Contributions of 8

- hour ozone, ann ual PM2.5, and 24

- hour PM2.5 from each state to each monitoring site,” found at: http://www.epa.gov/crossstaterule/techinfo.html
3 U.S. EPA, “EPA Response” letter for the District of Columbia ( December 9, 2011 ) , found at: http://www.epa.gov/ozonedesignations/2008standards/rec/region3R.htm