National Ambient Air Quality Standards for Particulate Matter

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 50

[AD-FRL-5725-4]

National Ambient Air Quality Standards for Particulate Matter

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule; availability of supplemental information and

request for comments.

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SUMMARY: EPA is announcing the availability of 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. Because these data were collected,

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

on the proposed revisions to the national ambient air quality standards

for particulate matter and thus, were not available for placement in

Docket No. A-95-54 until late in the rulemaking process, EPA is

announcing a supplemental comment period for the limited purpose of

taking comments on these field and laboratory test results only.

DATES: Written comments must be received on or before August 18, 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: Elsewhere in today's issue of the Federal

Register, EPA is publishing the final rule (FRL-5725-2) revising the

national ambient air quality standards for particulate matter. In Unit

VI.B. (Appendix L--New Reference Method for PM2.5) of the

preamble to the final rule, EPA concluded that the proposed design and

performance specifications for the reference sampler, 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

following documents present the results of the field and laboratory

tests and associated analyses that EPA considered, as discussed in Unit

VI.B. of the preamble to the final rule, in making minor modifications

or other refinements to the proposed reference method for measuring

PM2.5 in the ambient air. The documents are:

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.

These documents have been entered into Docket No. A-95-54 and 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.'' It

is emphasized that this supplemental comment period is for the limited

purpose of taking comment on the documents specified in this document

only. Comments on the reference method for PM2.5 that go

beyond the scope of these specific documents will not be considered.

Upon close of the supplemental comment period, EPA will consider the

comments received and decide whether any further action is appropriate.

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: July 16, 1997.

Carol M. Browner,

Administrator.

[FR Doc. 97-18578 Filed: 7-17-97; 8:45 am]

BILLING CODE 6560-50-F