September 24, 1997

This draft addresses comments from the September 19, 1997 Coordination Group call and the September 24, 1997 BPAP work group call.

BPAP Work Group Recommendations on Classifications

Classifications for PM2.5

The BPAP work group members generally agree that designing a PM2.5 classification scheme is premature until the outcome of the standard review is known and more PM2.5 data are available. This does not mean that areas should wait until after the standard review process has been completed to analyze their PM2.5 data; areas should examine their PM2.5 data as it becomes available.

Classifications for Ozone

The BPAP work group recommends no additional ozone classifications for the 8-hour standard beyond the transitional classification established by the Presidential directive. The Presidential directive establishes transitional classifications for areas that 1) are attaining the 1-hour standard or will attain the 1-hour standard by 2000 and 2) participate in the regional NOx strategy or achieve emissions reductions on the same schedule as the regional strategy.

Classifications to establish attainment dates

The BPAP work group recommends that classification should not be used to facilitate the establishment of attainment dates for the 8-hour ozone standard. Work group members generally agree that the attainment date should be established based on the complexity of an area's air pollution problem (e.g., overwhelmingly by transport, transport plus local, or local) and the area's success at planning and implementing a control strategy. {Attainment dates are addresssed in the Attainment Dates issue paper.}

Classifications to differentiate planning and control requirements

The BPAP work group recommends that classification not be used to differentiate planning and control requirements from one area to another. Work group members generally agree that states and local air quality agencies should be given the maximum flexibility to develop control strategies that make sense for their area. A classification scheme designed to prescribe planning and control requirements would limit flexibility. [Backstops and contingency plans are addressed in the Control Strategies, Reasonable Further Progress, and Contingency Measures issue papers.]

Classifications to inform the public of unhealthy levels of air pollution

The BPAP work group generally agrees that classification is not an effective mechanism for communicating health risks associated with air pollution to the public. Reasons why using classification as a communication tool would be difficult or confusing to the public include:

1)	Since the transitional classification is not based on air quality, the "transitional" label would have to be overlaid with an additional classification label that indicates air quality.

2)	Some areas will be violating both the 1-hour and 8-hour ozone standards.

3)	The ozone standard is based on a three-year average, and the PM2.5 standard is based on a spatial average. These averages would be difficult to communicate.

In addition, classifications are established once -- they do not represent real-time air quality data. The work group agreed that the Pollutant Standards Index (PSI) and programs such as ozone action days more effectively communicate risk levels to the public.