Insignificance Determination for Tran sportation Conformity under the PM fine National Ambient Air Quality Standard (NAAQS) For Jackson County, Alabama Alabama Department of En vironmental Management

The following report shows that emissions of nitrogen oxides (NO x ) and direct fine particles (PM fine ) from mobile sources in the sma ll portion of Jackson County designated by EPA as nonattainment for the annual fine particle NAAQS, ar e an insignificant contributor to nonattainment of the PM fine NAAQS.

EPA designated a small portion of Jackson County, Alabama, as nonattainment for the annual PM fine NAAQS on December 17, 2004. Jackson County was designated as part of the Chattanooga, Tennessee, annual PM fine nonattainment area. According to EPA, the small portion of Jackson County which includes the Widows Creek Steam Plant was included in the Chattanooga nonattainment area because they believed that emissions from this utility contribute to nonattainme nt in Chattanooga. The technical support document for the December 17, 2004 designations states “Additionally we have included in our recommended nonattainment area Jack son County, AL, that is adjacent to the Chattanooga MSA, that is generally rural in character, and that contains an identifiable large emitting facility or facili ties (e.g., power plants) which we believe contribute to the nearby nonattainment problem.” Therefore, it should be noted that the small portion of Jackson County was included in the Chattanooga nonattainment area because of EPA concerns related to utility emissions and not b ecause of concerns related to mobile source emissions in the county.

According to 40 CFR 93.109(k), there are seve ral factors that are used to support a finding of insignificance for th ese transportation-related PM fine precursor pollutants. The first factor is the percentage of motor vehicle emissions in the context of the total SIP inventory. The second factor is the current state of the air quality in th e area. The third factor is the absence of SIP motor vehicle em ission control measures. Lastly, historical trends and future projections of the growth of motor vehicle emi ssions are reviewed. These factors are discussed in detail in the s ections to follow. Each section supports the insignificance of NO x and direct PM fine emissions from mobile sources in the Jackson County portion of the nonattainme nt area under the transportati on conformity rule for the PM fine NAAQS.

NO x : 1. Analysis of motor vehicle NO x emissions in the Jackson County portion of the Chattanooga nonattainment area.

Only a small portion of Jackson County, Al abama, was included in the Chattanooga PM fine non-attainment area. The small portion of the county designated nonattainment contains a limited number of roads. In order to determin e the on-road emissions of NO x from motor vehicles in that portion of Jackson County, the document titled “Chattanooga Non-Attainment Area Year 2030 Conformity Determination Re port for Particulate Matter(PM2.5)” was used to determine how emissions were calculated for Jackson County and the same methodology was applied in this analys is. In order to estimate on-road mobile source emissions for the nonattainment portion of Jackson County, a ra tio of the size of the nonattainment portion of Jackson County in square miles to th e size of the entire county in square miles was calculated. The nonattainment portion of Jackson County was determined to be only about one percent of the total area of the entire county. The same ratio was applied to obtain area and non-road mobile source emissions for the nonattainment portion of the county. The following table shows the small percentage of NO x emissions from on-road mobile sources as compared to NO x emissions from all other sources in the Jackson County portion of the nonattainment area. Emission data were obtained from the VISTAS 2002 Base G2 “best and final” emissions inventory.

Table 1: 2002 NO x (TPY) Emissions in the Nonattainment portion of Jackson County by Source Type

Area 3.1 <1% Point 26337.4 99.9% Non-Road Mobile 14.18 <1% On-Road Mobile 6.97 <1% Total 26361.65

As the above table demonstrates, NO x emissions from on-road mobile sources in the nonattainment portion of Jackson County are less than 1% of the total NO x emissions from all source categories in the same area.

In the table below, a comparison is made of the mobile source NO x emissions from the nonattainment portion of Jackson County to total mobile source NO x emissions for the entire Chattanooga nonattainment area.

Table 2: 2002 NO x (TPY) On-road Mobile Source Emissions in the Nonattainment Portion of Jackson County Compared to To tal On-road Mobile Source Emissions in the entire Chattanooga NAA

Jackson County NAA Portion 6.97 <1%

Chattanooga NAA 13977.73

As the table above demonstrates, NO x emissions from on-road mobile sources in the Jackson County portion of the nonattainment area are less than 1% of the total NO x emissions from on-road mobile sources in the entire Chattanooga non-attainment Area.

2. The current state of the air quality in Jackson County.

As stated earlier in this document, the small portion of Jackson County, Alabama, was included in the Chattanooga PM fine non-attainment area due to the fact that a power plant is located in that area and it was thought by EPA to contribute to the PM fine problem inChattanooga. There are no PM fine monitors located in Jackson County. The other monitors in Alabama near Jackson County have monitored values below the annual PM fine NAAQS. Other counties surrounding the c ounty are either in attainment or unclassifiable.

3. The absence of SIP motor vehicle controls for the area.

There are no SIP motor vehicl e controls for Jackson County.

4. Historical trends and futu re projections of the growth of motor vehicle emissions.

The “Chattanooga Non-Attain ment Area Year 2030 Conformity Determination Report for Particulate Matter (PM2.5)” was used to obtain past and future projections of the growth in NO x emissions from on-road mobile sources. As demonstrated in the table below, future emissions of NO x are expected to decrease.

Table 3: Historical a nd Future Projections of NO x emissions from On-Road Mobile Sources in Jackson County

2002 6.97 2010 3.40 2020 1.35 2030 0.96

Direct PM fine : 1. Analysis of motor vehicle NOx emissi ons in the Jackson County portion of the Chattanooga nonattainment area

Only a small portion of Jackson County, Al abama, was included in the Chattanooga PM fine non-attainment area. The portion desi gnated nonattainment contains a limited number of roads. In order to de termine the on-road emissions of PM fine from motor vehicles in that portion of Jackson County the document titled “Chattanooga NonAttainment Area Year 2030 C onformity Determination Report for Particulate Matter (PM2.5)” was used to determine how emissions were calculated for Jackson County and the same methodology was applied in this analys is. In order to estimate on-road mobile source emissions for the nonattainment portion of Jackson County, a ra tio of the size of the nonattainment portion of Jackson County in square miles to th e size of the entire county in square miles was calculated. The nonattainment portion of Jackson County was determined to be only about one percen t of the total area of Jackson County. The same ratio was applied to obtain area and non-road mobile source emissions for the nonattainment portion of the county. The following table shows the small percentage of PM fine emissions from on-road mobile sources as compared to PM fine emissions from all other sources in the nonattainment portion of Jackson County. Emission data were obtained from the VISTAS 2002 Base G2 “best and final” inventory.Table 4: 2002 Direct PM fine (TPY) Emissions in the Nonattainment Portion of Jackson County by Source Type

Area 12.09 <1% Point 932.51 98.6% Non-Road Mobile 0.882 <1% On-Road Mobile 0.145 <1% Total 945.63

As the above table demonstrates, direct PM fine emissions from on-road mobile sources in the nonattainment portion of Jackson County ar e less than 1% of the total direct PM fine emissions from all source categories in the same area.

In the table below, a comparison is made of the mobile source direct PMfine emissions from the nonattainment portion of Jacks on County to total mobile source PMfine emissions for the entire Ch attanooga nonattainment area.

Table 5: 2002 Direct PM fine (TPY) On-road Mobile Source Emissions in the Nonattainment Portion of Jackson Count y Compared to Total On-road Mobile Source Emissions in the entire Chattanooga NAA

Jackson County NAA Portion 0.145 <1%

Chattanooga NAA 264.97

As the table above demonstrates, direct PM fine emissions from on-road mobile sources in the Jackson County portion of the nonattainment area are less than 1% of the total direct PM fine emissions from on-road mobiles source s in the entire Chattanooga non-attainment

area.

2. The current state of the air quality in Jackson County.

The small portion of Jackson County, Al abama was included in the Chattanooga PM fine non-attainment area due to the f act that a power plan t is located in that area and it was thought by EPA to contribute to the PM fine problem in Chattanooga. There are no PM fine monitors located in Jackson County. The other mon itors in Alabama near Jackson County have monitored values below the annual PM fine NAAQS. Other counties surrounding the county are either in attainme nt or unclassifiable.

3. The absence of SIP motor vehicle controls for the area.

There are no SIP motor vehicl e controls for Jackson County.

4. Historical trends and futu re projections of the growth of motor vehicle emissions.The “Chattanooga Non-Attain ment Area Year 2030 Conformity Determination Report for Particulate Matter (PM2.5)” was used to obtain past and future projections of the growth in direct PM fine emissions from on-road mobile sources. As demonstrated in the table below, future emissions of direct PM fine are expected to decrease.

Table 6: Historical and Future Projections of PM fine emissions from On-Road Mobile Sources in Jackson County

2002 0.145 2010 0.072 2020 0.041 2030 0.039

Conclusion

Each of the factors set forth in 40 CFR 93.109( k) were reviewed for the transportationrelated PM fine precursor pollutants NO x and direct PM fine . These reviews support the conclusion that mobile source emissions of NOx and direct PM fine in the Jackson County portion of the Chattanooga, Tennessee fine part icle nonattainment area are insignificant under the transportation conformity rule for the PM fine NAAQS.