38762 Federal Register / Vol. 62, No. 138 / Friday, July 18, 1997 / Rules and Regulations

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.

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, email: haines.john@epamail.epa.gov 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, email: frank.neil@epamail.epa.gov.

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