(NewSection) 7.8 INTERSTATE TRANSPORT OF AIR POLLUTION

Section 110(a)(2)(D) (i) of the Federal Clean Air Act requires State Implementation Plans to contain adequate provisions prohibiting any source or other type of emissions activity within the State from emitting any air pollutant in amounts which will:

(1) Contribute significantly to nonattainment in, or interfere with maintenance by, any other State with respect to any such nationalprimary or secondaryambient air qualitystandard, or

(2) Interfere with measures required to be included ln the applicable implementationplan for any other state under Part C to prevent significant deterioration of air quality or to protect visibility.

In the reviewprocess for new or modified stationary sources,

or other types of emissions activities, the Department will assess the impact on neighboring states. When emissions are reasonably suspectedof contributing significantly to the ambient air quality concentration in neighboring states, receptors for any dispersion modeling analysis will be placed in the neighboring state and the compliance status with respect to the National Ambient Air Quality Standards and Prevention of Significant Deterioration incrementswill be determined. With respect to visibility, an assessment of the impact on PSD Class I area's visibility will be made when a significant impact is suspected. The analysis will be conducted in accordance with Chapters 33-15-14, 33-15-15, and 33-15-19 of the Air Pollution Control Rules.

7.8.1 Interstate Transport Relating to the 1997 8-hour Ozone and PM2.5 National Ambient Air Quality Standards.1 Section 7.8.1 Interstate Transport Relating to the 1997 8-hour Ozone and PM2.S National Ambient Air Quality Standards

A. Overview Section 110 (a) (2) (D) (I) of the CleanAirAct states that each State must submit a State Implementation Plan (SIP) that contains adequate provisions: (i) prohibiting, consistent with the provisions of this title, 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 such national primary or secondary ambient air**qual~ty** standard, or (II) interfere with measures required to be included in the applicable implementation plan under Part C to prevent significant deterioration of air quality or to protect visibility. B. Nonattainment and Maintenance Area Impact To demonstrate that emissions from North Dakota do not significantly contribute to nonattainment or interfere with maintenance of compliance with the National Ambient Air Quality Standards for ozone or particulate matter with an aerodynamic diameter of less than or equal to 2.5 micrometers (PM2.S)' North Dakota relies on the modeling conducted by the 

### u.S. Environmental ProtectionAgencyduring the development of the Clean Air Interstate Rule (CAIR) and on monitoring data andattainment status for theappropriateupwindanddownwind areas. Supporting data and analysis for PM2.S and ozone follows. NorthDakota, as reported in theMay 12, 2005 Federal Register Final Rule notice, was one of the 37 states that were evaluated for impact on nonattainment areas (70 CFR 25188, May 12, 2005). The results of EPA's modeling analysis, which determined the maximum contribution from each upwind state to downwind PM2.S nonattainment, indicate that the maximum North Dakota contribution to downwind states was well below the interstate transport thresholdof 0.2 Ug/mJ (70 FR 25247, Table VI-7, May 12, 2005).2 The closest nonattainment area for PM2.5 is at Libby, Montana, which is approximately 450 miles from the western most border of North Dakota. This nonattainment area is generally upwind of North Dakota and is influenced by local factors including topographyandmeteorology. Because thenonattainment area is generally upwind of North Dakota emission sources and the large distance between these sources and the nonattainment area, it is unlikely that North Dakota sources significantly contribute to nonattainment. To determine which of the initial 37 states contributed significantly to ozone interstate transport, in its Proposed and Final CAIR Federal Register notices EPA adopted modeling domains that excluded large parts of six states, one of which is North Dakota (69 FR 4584 and 4600, January 30, 2004; 70 FR 25246, May 15, 2005). North Dakota uses available monitoring and nonattainment information to demonstrate that it is unlikely that the State contributes significantly to ozone nonattainmentor interfereswithozonemaintenance indownwind states. The closest nonattainment area for the 8-hour ozone standard is located in Colorado (Fort Collins, Boulder, Denver area)

. The northernborder of this area is located approximately 325 miles south-southwest of the southwestern most point of North Dakota. The next closest nonattainment area is located along the eastern edge of Wisconsin, approximately 400 miles from the eastern border of North Dakota. The Wisconsin area is generally located downwind of North Dakota emission sources while the Colorado area is not. Monitoringdata gatheredby the states andreportedby theEPA Air Quality System indicates that during the years 2004-2006 none of the monitors in the State of North Dakota showed exceedances for the 8-hour ozone standard. During the same three-year period the monitors in Iowa and Minnesota, the closest and most likely to be affected among the downwind states, measured 8-hour ozone exceedances on less than 0.5 percent of the days. Iowa monitors monitored 8-hour exceedances on two days, andMinnesotamonitors on three days. The absence of 8-hour ozone exceedances in North Dakota combined with the rare occurrence of exceedances in Iowa and Minnesota make it unlikely that the State of North Dakota contributes significantly to ozone transport affecting attainment or interferingwithmaintenance of NAAQS standards in downwind states.

# - 3 Based on the conclusions drawn above about the unlikely occurrence of significant interstate transport of ozone from North Dakota to Minnesota or Iowa, it would follow that such a transport wouldbe even less likely fromNorthDakota to the Wisconsinnonattainrnent area, whichlies significantlyfurther east than Minnesota. Based on the results of the EPA's modeling in the development of the CAIR rule, the relative distance of North Dakota to downwindnonattainrnent areas, andanalysis ofmonitoringdata, the State of North Dakota concludes that emissions from North Dakota do not significantly affect nonattainrnent or maintenance areas in other states. C. Impact on Prevention of Significant Deterioration (PSD) EPA guidance1 indicates that states with State Implementation Plans (SIP's) addressing Prevention of Significant Deterioration (PSD) andNonattainrnentNew SourceReview (NNSR) have adequately demonstrated that they do not affect PSD implementation in other states. EPA guidance1 states: 1 )**~For** 8-hour ozone, each state dnly needs to make a SIP submissionconfirming thatmajor sources inthe Stateare currently subject to PSD and NNSR permitting programs that implement the 8-hour ozone standard and that SIPapproved states are on track to meet the June 15, 2007 deadline for SIP submissions adoptingtherequirements of the Phase II ozone implementation rule." 2 ) "For PM2.s, states need only provide a SIP submission confirming thatmajor sources in the state are subject to PSD and NNSR permitting programs implemented in accordancewithEPA's interimguidance calling for use of PM10 as a surrogate for PM2.s in the PSD and NNSR programs." North Dakota has a SIP approved PSD program. Since North Dakota has no nonattainrnent areas, there is no NNSR program. NorthDakota's PSD SIPwas updatedeffectiveFebruary 1, 2005,

lEPA, August 15, 2006. Guidance for State Implementation Plan Submissions to Meet Current Outstanding Obligations Under Section 110(a)(2)(D) (I) for the 8-Hour Ozone and PM2.S National Ambient Air Quality Standards. (page 8)4 to conform with the federal NSR Reform rules. These changes have been submitted to EPA and were approved effective August 20, 2007. North Dakota will implement the current rules in accordance with EPA's interim guidance using PM10 as a surrogate for PM25 in the PSD program. The 8-hour ozone standardis applied to all major sources inthe state that are subject to PSD review. Based on the conclusions stated by EPA in their August 15, 2006 guidance1

, the State of North Dakota concludes that its implementation of its PSD SIP ensures that North Dakota emission sources do not interfere with PSD implementation in other states. D. Protection of Visibility The August 15, 2006 guidanceJ states: "At this point in time, EPA has made no determination that emissions from any State interfere with measures required to be included in a plan to address reasonably attributable visibility impairment. Further, EPA is not aware of any certification of existing reasonably attributable impairment of visibility by a Federal Land Manager that has not already been resolved. The EPA accordingly believes that States should be able to make a relatively simple SIP submission verifying that no source within the State emits pollutants that interfere with measures included in the visibility SIPs under the 1980 regulations." Based on the conclusions stated by EPA, the State of North Dakota concludes there are no North Dakota sources of emissions that interferewith implementationofvisibilitySIP under the 1980 regulations. The StateofNorthDakota is workingwith theWesternRegional AirPartnership, includingassociatedStatesandstakeholders, to prepare a SIP to address the EPA Regional Haze regulation (40 CFR 51.308). Until regional haze SIPs are submitted and approved, North Dakota believes it is not possible at this

IEPA, August 15, 2006. Guidance for State Implementation Plan Submissions to Meet Current Outstanding Obligations Under Section 110(a) (2)(D) (I) for the 8-Hour Ozone and PM2.5 National Ambient Air Quality Standards. (page 8)

2Ibid. (page 9)5 time to assess whether there is any interferencewithmeasures in the applicable SIP for another state for regional haze.