NO X Reductions Established Under the NO X SIP Call and CAIR

June 1, 2010

Page 1 of 2 

### TENNESSEE DEPARTMENT OF ENVIRONMENT AND CONSERVATION

DIVISION OF AIR POLLUTION CONTROL

NASHVILLE, TENNESSEE 37243

- 1531



### Memorandum

To : Public Depository, Knoxville Ozone Redesignation Request

From : Travis Blake

Date: June 1, 2010 (Revised and Corrected July 16, 2010 )

Subject : NO X R eductions Established Under the NO X SIP Call and CAIR

Due to the remand of the Clean Air Interstate Rule (CAIR) NO X Ozone Season Trading Program and other CAIR rules, questions

have arisen as to whether or not Tennessee’s use of CAIR constitutes a “perma nent and enforceable” measure for ozone

attainment in the Knoxville area. Review of these issues indicates that, while CAIR will ultimately be replaced by a new

interstate transport rule, the NO X reductions established under the NO X SIP Call remain in eff ect, regardless of whether CAIR,

the NO X Budget Trading Program, or other applicable requirements are used to attain those reductions. Tennessee also notes

that most future NO X reductions in the Knoxville area occur in the mobile source sector, and these emission reductions are

expected to contribute to additional reductions in ambient ozone concentrations.

The NO X SIP Call requires States to make significant, specific emissions reductions. It also provided a mechanism, the NO X Budget Trading Program, whi ch States could use to achieve those reductions. When EPA promulgated CAIR, it discontinued

(starting in 2009) the NO X Budget Trading Program, (40 CFR §51.121(r)), but created another mechanism

— the CAIR NO X ozone season trading program

— which States could use to meet their SIP Call obligations.

EPA is not currently administering the NO X Budget Trading Program, but all States remain subject to all of the requirements in

the NO X SIP Call, even if the existing CAIR ozone season trading program is withdrawn o r altered. In addition, the anti

backsliding provisions of 40 CFR §51.905(f) specifically provide that the provisions of the NO X SIP Call, including the statewide

NO X emission budgets, continue to apply after revocation of the 1

- hour standard.

EPA has not ed in other rulemaking actions that all NO X SIP Call States have SIPs that currently satisfy their obligations under

the SIP Call, and that the SIP Call reduction requirements are being met. EPA has also indicated that the Agency will contin ue

to enforce the requirements of the NO X SIP Call after any response to the CAIR remand. R egardless of the status of the CAIR

program, the NO X SIP call requirements can be relied upon in demonstrating maintenance.

Tennessee has reviewed the projected changes in NO X emissions for the greater Knoxville area between 2007 and 2024.

Summary of NO X Emissions (tons/day)

Year Point Area Onroad Nonroad

(excluding

MLA) Nonroad

(MLA) Total Safety

Margin Change

from

2007

2007 42.69 2.07 71.84 13.16 5.44 135.2

2010 42.65 2.14 63.09 12.17 5.03 125.08 10.12

- 7.5%

2013 42.94 2.29 54.35 10.51 4.34 114.43 20.77

- 15.4%

2016 43.56 2.50 45.61 8.74 3.61 104.02 31.18

- 23.1%

2020 44.30 2.61 33.95 7.21 2.98 91.05 44.15

- 32.7%

2024 45.11 2.68 22.29 6.37 2.63 79.08 56.12

- 41.5%

Not e: Emissions are for Anderson, Blount, Jefferson, Knox, Loudon, Sevier and onroad emissions for Cocke County.

MLA = Commercial Marine Vessels, Locomotives and Aircraft.NO X Reductions Established Under the NO X SIP Call and CAIR

June 1, 2010

Page 2 of 2 NO X emissions from all categories are projected to decrease in the region by 56.1 ton s/day between 2007 and 2024 (41.5%

reduction). Total point source NO X emissions are projected to increase slightly (2.42 tons/day), while Electricity Generating

Unit (EGU) NO X emissions are projected to remain unchanged between 2007 and 2024.

Onroa d mobile sources, the largest emitting category in 2007, are expected to decrease from 71.84 tons/day to 22.29 tons/day

(69% decrease), and provide the bulk of NO X reductions in the emission inventory. Thus, in the absence of additional NO X

reductions fro m EGUs, total NO X emissions are projected to continually decrease throughout the maintenance period. Since

motor vehicle and non

- road emissions continue to decrease as the engine population is gradually replaced by newer engines,

it is reasonable to expec t that the projected decrease in NO X emissions from mobile and non

- road sources assure that ozone in

the Knoxville region will continue to decline.