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Appendix IX

2008 Inventory and 2007/2008/2025 Inventory Comparison

A comparison of MARAMA’s v3.3 2007 and 2025 emission inventories and the USEPA’s 2008 

National Emissions Inventory (NEI) v2 was evaluated to show that the 2007 inventory is an 

appropriate and representative inventory to use as a surrogate attainment inventory for the 2008 

inventory for the Southern New Jersey-Philadelphia nonattainment area for the daily 35 μg/m3

PM2.5 standard. This comparison is included as Attachment 1. The 2008 NEI v2 emissions for 

New Jersey, Delaware, and Pennsylvania for the counties in the Southern New JerseyPhiladelphia Nonattainment Area were downloaded from the USEPA Emissions Inventory 

System (EIS) are also included in Attachment 1. The MARAMA technical support documents 

can be found in Appendices V and VI of this SIP. 

The New Jersey 2007 and 2025 MARAMA inventory portion was updated to include New 

Jersey’s latest inventory contained in this SIP, except for the PM2.5 emissions for point and 

area sources. The MARAMA v3.3 unadjusted fugitive dust emissions were used in this 

comparison in order to be consistent with the USEPA 2008 NEI which has unadjusted fugitive 

dust.

USEPA has updated their emissions methodology for paved roads, which is reflected in the

2007 and 2025 inventories, but not in the USEPA 2008 NEI. The new methodology results in 

much larger PM2.5 emissions for this category. New Jersey has updated the 2008 inventory 

emissions in the attached summary for New Jersey and Delaware based on the new 

methodology.

The inventory comparison in Attachment 1 excludes wildfires from the comparison. It would not 

be an accurate comparison of the 2007 and 2008 emissions inventories with the inclusion of 

wildfires. Wildfires are exceptional events, are not spread out over the entire year, and are 

unpredictable from year to year. For this reason, the USEPA has changed the way wildfires are 

reported in their US National Emissions Inventory (NEI). They are now required to be reported 

as events. Therefore, the exclusion of wildfires from this analysis provides a more reliable and 

accurate data comparison. Wildfires have been included in the SIP inventories, as discussed in 

Appendices V and VI and VIII. 

The data shows that the 2007 inventory is comparable to the 2008 inventory for both the New 

Jersey portion of the Southern New Jersey-Philadelphia (SNJ-Phila.) nonattainment area, and 

the SNJ-Phila. nonattainment area as a whole. A comparison of the MARAMA 2007 inventory to

the MARAMA 2025 inventory shows a decrease in PM2.5, NOx and SO2 emissions from 2007 to 

2025. A comparison of the USEPA 2008 NEI to MARAMA’s 2025 inventory also shows a 

decrease in PM2.5, NOx and SO2 emissions from 2008 and 2025.

Discrepancies in the two inventories (2007 and 2008) are noted due to methodology 

discrepancies. For some categories the USEPA uses their own data and calculations, not New 

Jersey’s state specific data and calculations, either because New Jersey did not submit 

emissions, because methodologies have recently changed or for certain categories they prefer 

to use their own data. Specifically, some discrepancies include:
IX-2

• USEPA does their own on-road MOVES model runs for the NEI. While some decreases 

are anticipated due to fleet turnover of new vehicles, discrepancies are also due to 

differences in model runs and inputs. Increases in SO2 from 2007 to 2008 are a 

reflection of methodology differences, not actual emissions. New Jersey’s inputs for 

2007 were based on actual New Jersey fuel survey data of gasoline and diesel fuel 

sulfur levels; while the 2008 fuel inputs used to generate the 2008 EPA NEI emissions 

did not use actual local fuel sulfur levels.

• 2008 USEPA NEI emissions for air and railroad emissions were calculated by USEPA, 

and may vary from New Jersey’s state specific calculations.

• As discussed above, USEPA has updated their emissions methodology for paved roads, 

which is reflected in the 2007 and 2025 inventories, but not in the USEPA 2008 NEI. 

The new methodology results in much larger PM2.5 emissions for this category. New 

Jersey has updated the 2008 inventory emissions in the attached summary for New 

Jersey and Delaware.

Despite the inventory methodology discrepancies, the inventory analysis shows that a 

decreasing trend in emissions is anticipated out to 2025 from a 2007 inventory base year and 

from a 2008 inventory base year. Both the 2007 and 2008 inventories satisfy the requirement 

that a state may demonstrate maintenance of a NAAQS by showing that future projected 

missions are less than or equal to the attainment year inventory.1

 

 1 USEPA memorandum dated September 4, 1992, entitled Procedures for Processing Requests to 

Redesignate Areas to Attainment, from John Calcagni, Director, Air Quality Management Division, to 

Regional Air Directors, page 9.
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Comparison of USEPA 2008 NEI with MARAMA 2007 and 2025 Emission Inventories 

New Jersey-Delaware-Pennsylvania PM2.5 Nonattainment Area

June 14, 2012

2007 2007 2007 2007 2007 2007 2007 2007 2007 2007 2007 2007

MARAMA 2007 Inv. v3.3 1/17/12 (1) NOx PM2.5 SO2 NOx PM2.5 SO2 NOx PM2.5 SO2 NOx PM2.5 SO2

Point 31,832 4,573 35,047 4,453 794 2,034 6,635 1,335 13,380 20,744 2,444 19,633

Area 17,639 15,153 16,763 3,422 3,061 1,129 1,293 1,207 630 12,924 10,885 15,004

Onroad 107,532 3,794 773 26,992 1,055 161 10,577 324 100 69,963 2,415 512

Nonroad and MAR 30,890 2,344 6,078 6,790 560 1,642 4,580 327 1,118 19,521 1,457 3,318

2007 Wildfire Emissions (2810001000) 62 415 0 61 413 0 0 0 0 0 1 0

2007 TOTAL including Wildfires 187,955 26,279 58,661 41,718 5,884 4,965 23,084 3,193 15,228 123,153 17,202 38,467

2007 TOTAL excluding Wildfires 187,893 25,864 58,661 41,657 5,470 4,965 23,084 3,193 15,228 123,153 17,201 38,467

2008 2008 2008 2008 2008 2008 2008 2008 2008 2008 2008 2008

EPA NEI 2008 v2 NOx PM2.5 SO2 NOx PM2.5 SO2 NOx PM2.5 SO2 NOx PM2.5 SO2

Point 31,233 4,790 29,340 4,131 733 2,321 5,596 1,145 10,577 21,506 2,911 16,443

Area 22,148 12,830 17,011 6,877 2,706 1,036 1,276 1,159 399 13,995 8,964 15,576

Onroad 71,510 2,724 1,140 19,471 782 332 8,889 299 129 43,151 1,643 678

Nonroad and MAR 27,246 2,250 5,330 5,787 507 1,467 4,464 319 1,159 16,995 1,425 2,704

2008 Wildfires (281001000) 50 338 0 50 338 0

2008 TOTAL including Wildfires 152,187 22,931 52,821 36,316 5,066 5,156 20,224 2,922 12,264 95,646 14,943 35,401

2008 TOTAL excluding Wildfires 152,137 22,594 52,821 36,266 4,729 5,156 20,224 2,922 12,264 95,646 14,943 35,401

2025 2025 2025 2025 2025 2025 2025 2025 2025 2025 2025 2025

MARAMA 2025 Inv. v3.3 1/17/12 (1) NOx PM2.5 SO2 NOx PM2.5 SO2 NOx PM2.5 SO2 NOx PM2.5 SO2

Point 19,862 3,870 13,565 4,433 853 1,355 4,113 1,208 6,352 11,316 1,808 5,858

Area 17,336 14,836 9,756 3,366 2,932 101 1,295 1,308 469 12,674 10,595 9,186

Onroad 27,316 1,460 423 6,095 278 124 2,591 113 89 18,630 1,069 210

Nonroad and MAR 17,296 1,315 712 3,915 315 141 2,116 148 40 11,265 852 531

2025 Wildfire Emissions (2810001000) 62 415 0 61 413 0 0 0 0 0 1 0

2025 TOTAL including Wildfires 81,871 21,895 24,456 17,870 4,792 1,721 10,115 2,777 6,949 53,886 14,326 15,785

2025 TOTAL excluding Wildfires 81,810 21,480 24,455 17,809 4,378 1,721 10115 2777 6949 53,886 14,325 15,785

Difference Between 2007 and 2008 -35,757 -3,270 -5,840 -5,390 -742 191 -2,860 -270 -2,964 -27,507 -2,258 -3,067

% Difference Between 2007 and 2008 -19% -13% -10% -13% -14% 4% -12% -8% -19% -22% -13% -8%

Difference Between 2007 and 2025 -106,084 -4,383 -34,205 -23,847 -1,092 -3,244 -12,969 -416 -8,279 -69,267 -2,876 -22,682

% Difference Between 2007 and 2025 -56% -17% -58% -57% -20% -65% -56% -13% -54% -56% -17% -59%

Difference Between 2008 and 2025 -70,327 -1,114 -28,366 -18,457 -350 -3,435 -10,109 -146 -5,315 -41,760 -618 -19,616

% Difference Between 2008 and 2025 -46% -5% -54% -51% -7% -67% -50% -5% -43% -44% -4% -55%

Notes:

1. MARAMA 2007 and 2025 Inventories v3.3 dated 1/17/2012 for DE and PA.

 NJ's inventory has been updated in accordance with final updates in this SIP, exept for Area and Point PM2.5.

 Area and Point PM2.5 emissions are from MARAMA v3.3 unadjusted for fugitive dust.

 Currently adopted Sulfur in Fuels Rule was used for SO2 Projections for Area Sources and NonEGU Point Sources

2. NJ and DE Area Source Paved Roads in 2008 Inventory have been updated with the new EPA methodology to be consistent with the 2007 inventory.

 PA 2008 paved roads have not been updated.

Delaware

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Pennsylvania

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New Jersey

 Emissions tpy

Nonattainment Area Total 

Emissions tpy