Proposal:

AQMD Comments Regarding U.S. EPA’s Proposed Ambient Air Quality Standards for Fine Particulates and Ozone

Synopsis:

On November 27, 1996, U.S. EPA proposed revised ambient air quality standards for fine particulates and ozone. The proposed standards have been published in the Federal Register, with public comments due by February 18, 1997. Staff is reviewing the proposed standards, interim transition policy, and new monitoring requirements for PM2.5. Staff is providing general principles for Board consideration, from which comment letters will be drafted and submitted to the U.S. EPA prior to the deadline.

Committeee:

None

Recommended Action:

Approve general principles regarding the proposed new federal ambient air quality standards for fine particulates and ozone, interim transition policy, and new monitoring requirements for PM2.5 and direct the Executive Officer to submit AQMD’s comments, consistent with the general principles, to the U.S. EPA prior to the February 18, 1997 deadline for public comments.

James M. Lents, Ph.D.
Executive Officer

Background

Under Section 109(d)(1) of the federal Clean Air Act, the U.S. Environmental Protection Agency (EPA) is required to complete a thorough review of the ambient air quality standards at five-year intervals beginning in 1980. The U.S. EPA has been reviewing the ozone national ambient air quality standards (NAAQS) since 1992 and is currently under court order to complete a review of the particulate NAAQS. Under court order, the U.S. EPA must complete the review and promulgate any proposed revisions by June 1997.

On November 27 1996, the U.S. EPA proposed revisions to both the ozone and particulate NAAQS. As part of the proposal, an interim implementation policy and new monitoring requirements were proposed. (These proposals are summarized in Attachments A and B.) These proposals were published in the Federal Register on December 13, 1996, and will undergo a public comment period which ends on February 18, 1997.

Staff has conducted a review of the 578-page document on the U.S. EPA’s proposals, and is providing general principles for the Board’s consideration and approval. Upon Board approval, the staff will continue to review these documents, and will develop comment letters to the U.S. EPA which will be consistent with the general principles approved by the Board. The letters will then be submitted to the U.S. EPA as part of the public records dockets prior to the close of the public comment period.

General Principles for Responding to the Proposed Revised Standards for Particulate Matter and Ozone

The following general principles and policy positions will form the basis for responding to the U.S. EPA’s proposals:

General Principle #1

The level and form of the revised standards should be protective of public health and based on the best medical/scientific information available.

Comment:

While there is considerable debate on the level and form of the proposed revised standards, staff believes that the U.S. EPA, with its expertise and charter to set such standards, should base its decisions on the best set of clinical, epidemiological, and other scientific data which demonstrates protection of public health from exposures to ozone and particulate matter. Costs associated with meeting new health standards should be considered only with respect to timelines and other implementation issues related to meeting the standards.

U.S.EPA’s Proposal Related to this Principle:

The proposed standards may fit these criteria. (It should be noted that the proposed standards are similar in effect to state standards which have stood for a decade or more.) However, some parties are pushing U.S.EPA to make the cost of meeting the standards a

key criterion of the standard setting process.

General Principle #2

The revised standards should be of such form as to be easily understood by the public, and should not mask local hotspots for ozone or particulate matter.

Comment:

The public, especially sensitive individuals, need to be able to understand an ambient air quality standard and relate it to their daily lives. Secondly, the success of air quality programs requires public support. The staff believes that an informed public is essential to such success, and accordingly, the public has an inherent right to clearly understand local air quality conditions. In this regard, the revised standards should be in forms which are easy to understand, and not of such complexity as to be confusing. Furthermore, the public should be entitled to an understanding of air quality conditions relative to their locales, and the existence of local hotspots should not be masked by conditions in other locales as a result of averaging.

U.S.EPA’s Proposal Related to this Principle:

EPA is proposing to average air quality over multiple years and, for particulates, multiple stations. This could leave an area declaring attainment of the federal standards, yet having high levels at individual locations, or in individual years.

General Principle #3

New particulate monitoring methods should be accurate and properly account for all species of particulates.

Comment:

It is imperative that monitoring instruments and air sampling programs be predicated on sound science and procedures to assure that accurate air quality data are collected and reported to the public. Accuracy should not be compromised, nor should monitoring complexity overwhelm resources needed to collect representative data.

U.S.EPA’s Proposal Related to this Principle:

New monitoring methods are being proposed for PM2.5, along with proposed requirements for daily sampling at some locations. Because the South Coast Air Basin is dominated by particulate nitrate as part of PM2.5, and because such particles tend to "evaporate" off the filters, monitors and procedures ultimately required by the U.S. EPA should assure the integrity of the samples without compromising any of the individual components. The requirements and guidance for sampling should be clear, so that resource requirements can be properly evaluated. Furthermore, the U.S. EPA should provide funding to meet new monitoring requirements.

General Principle #4

The U.S. EPA should provide adequate time and assistance to meet the revised standards and required SIP submittals, consistent with expeditious progress, future available technology, and economic viability.

Comment:

Once standards are set, the process to attain those standards begins. The U.S.EPA will issue policies and guidance from which the SIP process develops. Such policies need to recognize and account for costs, the potential for technology development, severity of nonattainment, and other factors which have bearing on the ability to attain standards expeditiously.

U.S.EPA’s Proposal Related to this Principle:

The proposed Interim Implementation Policy does not include proposals for attainment dates of the revised standards. However, in the policy the U.S. EPA would require an early modeling assessment of the new ozone standards within 90 days of promulgation. Public participation for this submittal could not be accomplished within such a short time period. U.S. EPA should appropriately recognize the need for public participation in this process, and should further recognize that the time frames for attainment should reflect the increased severity of the proposed standards. The U.S. EPA should also provide resource assistance to local agencies to meet the new requirements.

Additional Policy Positions

(a) The forms of the standards should be consistent with modeling capabilities to simulate them.

Comment:

Current modeling capabilities are limited by the number of days with detailed information. Special studies, such as the 1987 SCAQS and the upcoming 1997 SCOS, provide needed three-dimensional data which are not ordinarily available. This data helps to reduce model uncertainties, but also limits the number of days in which modeling can be applied. The form of the current standards is reasonably matched to current modeling protocols. More complex forms of the standards, as proposed by U.S. EPA, may not match current modeling protocols. This could lead to greater uncertainties for future modeling requirements. It should be incumbent upon U.S. EPA to assure that the forms of the standards are consistent with modeling capabilities to simulate those standards.

(b) Interim implementation policies should assure that future efforts by U.S. EPA and ARB provide their fair share of emission reductions from sources under their jurisdiction.

Comment:

The proposed Interim Implementation Policy would retain the existing standards until a demonstration of attainment is approved for the new standards. However, revisions to existing SIPs in the interim could be less stringent, including that for on- and off-road mobile sources, than current policy. The staff believes that the interim policy should assure that fair-share commitments by both the ARB and the U.S. EPA, as contained in the recently adopted 1997 AQMP, be maintained.

(c) The proposals for the rounding of data to determine compliance with the revised standards should be consistent with the previous standards.

Comment:

The U.S. EPA is proposing data rounding conventions similar to the conventions currently being used, but may consider extending the rounding requirements for ozone to an extra level of significance. The staff believes that the extension exceeds the accuracy of monitoring capabilities, and, therefore, the current methods, as proposed, should be retained.

Attachments

A. Comparison of Proposed Revised Federal Air Quality Standards with Current Air Quality Standards
B. Summary of Proposed Revised Ambient Air Quality Standards and Interim Implementation Policies

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