National Ambient Air Quality Standards for Particulate Matter

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 50

[AD-FRL-5875-8]

National Ambient Air Quality Standards for Particulate Matter

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule; extension of supplemental public comment period.

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SUMMARY: EPA is announcing an extension of the supplemental comment

period that was first announced on July 18, 1997 for the limited

purpose of taking comment on certain laboratory and field test data and

related reports associated with the development of the reference method

(Appendix L of 40 CFR part 50) for measuring PM2.5 in the

ambient air.

DATES: Written comments must be received on or before September 8,

1997.

ADDRESSES: Submit written comments (duplicate copies preferred) to:

Office of Air and Radiation Docket and Information Center (6102), Attn:

Docket No. A-95-54, Environmental Protection Agency, 401 M St., SW.,

Washington, DC 20460.

FOR FURTHER INFORMATION CONTACT: John H. Haines, MD-15, Air Quality

Strategies and Standards Division, Office of Air Quality Planning and

Standards, Environmental Protection Agency, Research Triangle Park, NC

27711, telephone: (919) 541-5533, e-mail: [email protected]

or Neil H. Frank, MD-14, Emissions, Monitoring and Analysis Division,

Office of Air Quality Planning and Standards, Environmental Protection

Agency, Research Triangle Park, NC 27711, telephone: (919) 541-5560, e-

mail: [email protected].

SUPPLEMENTARY INFORMATION: On July 18, 1997 (62 FR 38652), EPA

published the final rule revising the national ambient air quality

standards for particulate matter. In Unit VI.B. (Appendix L--New

Reference Method for PM2.5), EPA concluded that the proposed

design and performance specifications for the reference sampler,

[[Page 43643]]

with modifications described in the final rule, will achieve the design

objectives set forth in the proposal. Accordingly, EPA has adopted the

sampler and other method requirements specified in the revised Appendix

L as the reference method for measuring PM2.5 in the ambient

air. As discussed in the preamble to the final rule, a series of field

tests were performed using prototype samplers manufactured in

accordance with the proposed design and performance specifications. The

results of these field tests confirmed that the prototype samplers

perform in accordance with design expectations. Operational experience

gained through these field tests did, however, identify the need for

minor modifications as discussed in the preamble to the final rule. As

explained in that preamble, EPA made other modifications to the

proposed design and performance specification in response to public

comment. As part of this process, EPA performed laboratory tests to

ensure that the modifications achieved the intended objective.

While the results of the field and laboratory tests were largely

confirmatory in nature and did not indicate a need to alter the basic

design and performance specifications, they did identify areas that

needed further refinement. Given that these tests were performed, by

necessity, during and after the close of the public comment period and

because the results were not available for placement in the docket

until late in the rulemaking process, the preamble to the final rule

announced that a supplemental comment period would be held for the

limited purpose of taking comments on these field and laboratory tests

results. The July 18, 1997 action announcing the supplemental comment

period (62 FR 38762), identified the following documents:

1. ``Adaptation of the Low-Flowrate, PM10, Dichotomous

Sampler Inlet to Fine Particle Collection.''

2. ``Filter Temperature Specification Report.''

3. ``Flow Rate Specification Report.''

4. ``Laboratory and Field Evaluation of FRM Sampler Report.''

5. ``Prototype PM2.5 Federal Reference Method Field

Studies Report.''

The July 18, 1997 action emphasized that the supplemental comment

period was for the limited purpose of taking comment on the documents

specified in the July 18, 1997 action only. Comments on the reference

method for PM2.5 that go beyond the scope of these specific

documents would not be considered. The July 18, 1997 action indicated

that upon close of the supplemental comment period, EPA would consider

the comments received and decide whether any further action is

appropriate.

Since the supplemental comment period was announced, EPA has

identified errors in the ``Prototype PM2.5 Federal Reference

Method Field Studies Report''. As a result, EPA has prepared three

correction pages and has entered them into Docket No. A-95-54 and they

are available for inspection and copying at the Office of Air and

Radiation Docket and Information Office at the address in ADDRESSES at

the beginning of this document. Copies may also be obtained by

contacting Neil H. Frank at the address in FOR FURTHER INFORMATION

CONTACT. In order to provide opportunity for the public to review and

comment on these corrected pages, and to permit additional time for

interested parties that could not immediately obtain copies of the five

documents, EPA is extending the supplemental comment period until

September 8, 1997.

List of Subjects in 40 CFR Part 50

Environmental protection, Air pollution control, Carbon monoxide,

Lead, Nitrogen dioxide, Ozone, Particulate matter, Sulfur oxides.

(Authority: Secs. 108 and 109, Clean Air Act, as amended (42 U.S.C.

7408, 7409)).

Dated: August 7, 1997.

Mary Nichols,

Assistant Administrator for Air and Radiation.

[FR Doc. 97-21697 Filed 8-14-97; 8:45 am]

BILLING CODE 6560-50-P