September 26, 1996

DRAFT PM Transition Principles

The EPA will use the following principles in crafting its transition policy for the implementation of particulate matter programs for the period between promulgation of any new or revised standard(s) and submittal/approval of SIP's for the new and/or revised standards.

If the current PM-10 standards are retained and new PM-2.5 standards are adopted:

There will be no transition issues. The PM-10 implementation programs will continue as required. Reclassifications of PM-10 nonattainment areas would still apply (i.e., moderate areas would still be subject to reclassification to serious). Implementation programs to attain any new PM-2.5 standard(s) would be addressed by the implementation strategy for the new NAAQS and not by the interim policy.

If the current PM-10 24-hour standard is revised or eliminated, the current PM-10 annual standard is revised or retained, and new PM-2.5 standards are adopted, then the following principles apply:

A.	The PM interim implementation policy becomes effective at the time the NAAQS are promulgated and remains effective until (. . . to be determined by EPA General Counsel).

B.	No backsliding is allowed.

1.	If the PM-10 24-hour NAAQS is revised:

a)	PM-10 requirements/control programs required prior to June 1997 remain in place.

-	5 initial serious areas are scheduled to submit their attainment demonstration on 2/18/97 and implement BACM measures;

-	13 additional moderate areas should continue to implement the RACM measures identified in their SIP;

-	5 moderate areas that failed to attain on 12/31/94 should proceed with their reclassification and develop and submit BACM and attainment demonstration SIP's and implement BACM measures. To date, only one of these areas has been reclassified to serious.

b)	Current nonattainment area boundaries remain in effect.

c)	Reclassifications will not occur for areas with attainment dates occurring during the interim period.

-	The 13 additional moderate areas were required to submit their SIP's on July 20, 1995 and are scheduled to attain the standard by January 20, 2000. These areas should continue implementing the measures identified in their SIP submittal.

-	The 5 initial moderate areas that were determined (spring 1995) to have failed to attain the NAAQS by the December 31, 1994 attainment date would still be subject to reclassification since it was a previous requirement (refer back to no backsliding provision). Those areas should also proceed with the development of their BACM & attainment demonstration SIP.

d)	PM-10 measures that have been adopted and/or implemented to address the 24-hour standard should be retained until the area demonstrates attainment of the revised PM-10 24-hour and annual NAAQS and demonstrates that the measures have no impact on PM-2.5.

2.	If the PM-10 24-hour NAAQS is eliminated:

a)	All existing PM-10 measures that affect PM- 2.5 concentrations must remain in place until the area can demonstrate that elimination of those measures will not affect the ability to attain and maintain the PM-10 annual and PM- 2.5 NAAQS.

b)	Those existing PM-10 measures that do not affect PM-2.5 concentrations may be candidates for elimination upon demonstration that removing the measure does not contribute to nonattainment in any area. The above could be reconsidered in the event there are regional reductions adopted prior to the availability of the demonstration.

C.	Additional PM-10 measures:

1.	No additional PM-10 requirements to address the 24-hour NAAQS, other than those measures required under the no backsliding section above, would apply in the interim.

2.	The above would be reconsidered if regional reductions are adopted during the interim period.

D.	PM-10 areas in nonattainment status with clean air quality data at the time of promulgation of new and/or revised PM standards cannot redesignate to attainment until an approved SIP is in place.

1.	If the PM-10 24-hour NAAQS is revised:

a)	Areas with a design value below or equivalent to the level of the revised PM-10 24-hour standard which have submitted a redesignation request and a maintenance plan which demonstrates they will remain below the level of the revised standard will be allowed to redesignate to attainment upon approval.

b)	Areas which have submitted a redesignation request and a maintenance plan that does not demonstrate that levels will be below the revised PM-10 24-hour standard should withdraw their request and resubmit a revised maintenance plan.

c)	Any area which has existing monitoring data which demonstrate attainment with a revised PM-10 24-hour standard would be eligible for redesignation to attainment and should submit a request for redesignation and a maintenance plan.

-	The EPA's 1995 review of data and attainment determinations indicated that 35 initial moderate areas had 3 years of clean data. These areas are currently candidates for redesignation to attainment and only require an approved PM-10 SIP and a maintenance plan. To date, only 4 areas have requested redesignation to attainment and developed/submitted maintenance plans.

-	13 of the initial moderate areas have been given 1 year extensions and must have clean data from 1994-96 and then request redesignation and submit a maintenance plan.

-	8 of the initial moderate areas were determined to have missing data and must have clean data from 1995-97 and then request redesignation and submit a maintenance plan.

2.	If the PM-10 24-hour standard is eliminated, there would be no need to discuss redesignations to attainment.

E.	Substitutions are not needed for PM at this time.

F.	The current attainment and unclassifiable areas would not be subject to additional requirements/controls except for those requirements in section 110 which may require immediate attention due to a revised NAAQS (e.g. monitoring plans, episode plans).

G.	The policy addressing "Areas Affected by PM-10 Natural Events" dated May 30, 1996, will remain in effect during the interim period and will be revised as appropriate for PM-2.5.

H.	Requirements to protect PM-10 increments will remain in place until/unless a revised increment for PM is established.

NOTE: An area will need actual PM-2.5 monitoring data before making a decision on attainment/nonattainment status for PM-2.5. This will serve as an incentive to initiate PM-2.5 monitoring on an accelerated basis. This will also encourage prompt submittals of PM-2.5 SIP's, as well as requests for redesignation of PM-10 nonattainment areas to attainment (where current data show attainment).