Daily Rules, Proposed Rules, and Notices of the Federal Government



Regional Haze Regulations; Availability of Guidance Documents

AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice of guidance availability.
SUMMARY: We are announcing today the availability of guidance to assist States and Tribes in implementing regulations governing regional haze which were published in theFederal Registeron July 1, 1999. These documents address the establishment of natural visibility conditions and the tracking of progress under the regional haze program.
ADDRESSES: Interested parties can download theGuidance for Estimating Natural Visibility Conditions Under the Regional Haze ProgramandGuidance for Tracking Progress Under the Regional Haze Programfrom EPA's Web site on the Internet under the followingaddress:
FOR FURTHER INFORMATION CONTACT: Neil Frank, U.S. Environmental Protection Agency (C304-01), Research Triangle Park, NC 27711;

In section 169A of the 1977 Amendments to the Clean Air Act, Congress established a national visibility goal as the “prevention of any future, and the remedying of any existing, impairment of visibility in mandatory Federal Class I areas which impairment results from manmade air pollution” (42 U.S.C. 7491). These provisions were further supplemented by section 169B of the Clean Air Act Amendments of 1990 (42 U.S.C. 7492). States are required to develop implementation plans that make “reasonable progress” toward this goal.

The EPA issued initial visibility regulations in 19801 that addressed visibility impairment in a specific mandatory Federal Class I area that is determined to be “reasonably attributable” to a single source or small group of sources. Regulations to address regional haze were deferred until improved techniques could be developed in monitoring, modeling, and in understanding the effects of specific pollutants on visibility impairment. The EPA issued regional haze regulations in 1999.2

1 See45 FR 80084 (December 2, 1980).

2 See64 FR 35713 (July 1, 1999).See also40 CFR 51.300-51.309.

The overall framework of the regional haze rule requires States to develop a State Implementation Plan that includes: (1) Reasonable progress goals for improving visibility in each mandatory Federal Class I area and (2) set of emission reduction measures to meet these goals. Specifically, States will set progress goals for each mandatory Federal Class I area to:

• Provide for an improvement in visibility for the 20 percent most impaired (i.e., worst visibility) days over the period of the implementation plan, and • Ensure no degradation in visibility for the 20 percent least impaired (i.e., best visibility) days over the same period. Baseline visibility conditions for the 20 percent worst and 20 percent best days are to be determined using monitoring data collected during calendar years 2000-2004. Baseline conditions for 2000-2004, progress goals, and tracking changes over time are to be expressed in terms of the deciview index.3

3The deciview is a haze index derived from calculated light extinction, such that uniform changes in haziness correspond to uniform incremental changes in visual perception across the entire range of conditions, from pristine to highly impaired. Deciview = 10 ln(b ext/10).

Most States (and Tribes as appropriate4 ) participating in regional planning organizations will submit regional haze implementation plans, including estimates of natural conditions and proposed progress goals in the 2007-2008 time frame. In developing any progress goal, the State will need to analyze and consider in its set of options the rate of improvement between 2004 (when 2000-2004 baseline conditions are set) and 2018 that, if maintained in subsequent implementation periods, would result in achieving estimated natural conditions in 2064.

4Under the Tribal Air Rule (63 FR 7254; February 12, 1998; 40 CFR part 49), Tribal governments may elect to implement air programs in much the same way as States, including development of Tribal implementation plans.

The purpose of the documents announced in today's notice is to provide guidance to the States and Tribes in implementing the regional haze program and to explain how EPA intends to exercise its discretion in implementing Clean Air Act provisions and EPA regulations concerning the estimation of natural visibility and tracking progress under the Regional Haze program. The guidance documents are designed to implement national policy on these issues. The guidance documents are designed to assist States and Tribes in implementing national policy on these issues. Sections 169A and 169B of the Clean Air Act and implementing regulations at 40 CFR 51.308 and 51.309 contain legally binding requirements. These guidance documents will not substitute for those provisions or regulations, nor will they constitute regulations themselves. Thus, they will not impose binding, enforceable requirements on any party, and may not apply to a particular situation based upon the circumstances. We and State decision makers retain the discretion to adopt approaches on a case-by-case basis that differ from this guidance where appropriate. Any decisions by us regarding a particular SIP demonstration will only be made based on the statute and regulations. Therefore, you are free to raise questions and objections about the appropriateness of the application of this guidance to a particular situation; we will, and States should, consider whether or not the recommendations in this guidance are appropriate in that situation. These guidance documents will be living documents and may be revised periodically without public notice. We welcome public comments on these documents at any time and will consider those comments in any future revision of these guidance documents.

Because these documents are not regulations and do not impose binding requirements, we are not required to solicit public comments on them. However, we chose to do so as a matter of discretion in order to improve the quality and responsiveness of the documents to the needs of the State and Tribal air quality management agencies. A summary of the comments we received and our responses to them will be available at the Web site identified above.

Dated: October 31, 2003. Henry C. Thomas, Jr., Acting Director, Office of Air Quality Planning and Standards.