·~

I p , ','

MEMORANDUM

lIT-- ......., ....

UNITED STATES ENVIRONMENTAL PROTECTION AGEN"CY"'''''<1·M'S BRANCH

Office of Air Quality Planning and Standards r "'"'l 1"1.

Research Triangle Park, North Carolina 27711 L\ AUG 19 f'l n

17 AUG 1993 uUt-J"__ '-'.J I

I..J

.. '~l"-JU

EPA-RJ.I:CH01v 1.V

ATLANi'Jl, GA.

(CO)

Technical Support Documents (TSD's) for

Redesignation Ozone and Carbon Monoxide

Nonattainment Areas

. /-yv--- G. T. Helms, Ch1ef /Iti

ozone/Carbon Monoxide Programs Branch (MD-15)

FROM:

SUBJECT:

TO: Air Branch Chief, Regions I-X

The purpose of this memorandum is to request your help in

trying to upgrade the TSD's prepared by the Regional Offices

which support Federal Register notices of proposed and final

rUlemaking actions on ozone and CO redesignations.

To make the review process flow more efficiently as we

reduce Headquarters review time and move state implementation

plan (SIP) actions from Table 1 to Table 2, it is important for

Headquarters to quickly process redesignation packages. To do

this, we will rely heavily on the Regional Offices to review the

State submittals and present the results of their reviews in the

TSD. 1 Therefore, it is important that the Regional Offices

present documentation in the TSD to support the Environmental

Protection Agency's (EPA's) evaluation of the submittals along

with the complete technical basis for EPA's rulemaking action.

For redesignations, the TSD should answer basic questions

such as:

-What years are the supporting air quality data covering?

Where are the monitors located? What are the relevant

concentrations?

- For what years were emissions inventories prepared and how

were they developed? In the interim, what are the total

{: l~

:: ~~

INote that a TSD should be prepared for the proposed rulemaking

action or a direct final action. If EPA's position changes prior

to final rulemaking, the reasons for the changes are normally

addressed in the notice of final rulemaking rather than redrafting

the TSD. General information on TSD's is in the document entitled,

"Processing Procedures For SIP Revisions For Part 52, Part 62

111(d) Plans," and Part 81 Redesignations."
-

2

season-day and/or annual emissions by pollutant for point,

area, and mobile sources for the attainment and maintenance

years?

- What transportation, emission, and/or dispersion models

were used? What were the significant input parameters,

including air quality data and assumptions used in the

demonstration? What are the model results?

- What are the maintenance plan triggers, commitments, and

contingency measures? What is the process for tracking the

plan and reporting results to EPA? What are the adoption

and implementation schedules for the contingency measures?

How is maintenance demonstrated in the interim years? Are

additional controls to be adopted and implemented in the

future to offset emission increases, and what is the impact

of these controls on emissions inventory planning cap(s)?

- When was the public hearing and what are the results of

any comments received by the state? What is the status of

an outstanding SIP call or findings letter, if any?

- What is EPA's evaluation of the State's supporting

materials that accompanied the submittal, such as the

technical data and commitment letters, and how do these

materials conform to EPA policy, guidance, and the Clean Air

Act?

Hopefully, you are checking the emissions inventories

submitted for redesignations and they are of the same quality as

those submitted to meet nonattainment area requirements. If this

is not the case, you should start transitioning to better

inventories. You may use the relevant portions of the document

entitled, "Quality Review Guidelines For Base Year 1990 Emission

Inventories," as a guide to summarizing the inventories in the

TSD.

If you have any questions, please contact Sharon Reinders at

(919) 541-5284.