Clean Air Act Approval and Promulgation of State Implementation Plan for Montana; Butte; PMINF10 Contingency Measures and Revisions to the Attainment and Maintenance Demonstrations

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[MT26-1-6692b; FRL-5163-9]

Clean Air Act Approval and Promulgation of State Implementation

Plan for Montana; Butte; PM10 Contingency Measures and Revisions

to the Attainment and Maintenance Demonstrations

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA proposes to approve the State implementation plan (SIP)

revisions submitted by the State of Montana with a letter dated August

26, 1994. This submittal addresses, for the Butte moderate PM10

nonattainment area, the Federal Clean Air Act requirement to submit

contingency measures for particulate matter with an aerodynamic

diameter less than or equal to a nominal 10 micrometers (PM10) for

areas designated as nonattainment for the PM10 National Ambient

Air Quality Standards (NAAQS). This submittal also includes revisions

to the attainment and maintenance demonstrations for the moderate

PM10 nonattainment area SIP for Butte due to the inclusion of new

emission limits in a revised air quality permit for Montana Resources,

Inc. Since the SIP adequately addresses the requirement for contingency

measures and, with the new emission limits for Montana Resources, Inc.,

still adequately demonstrates attainment and maintenance of the

PM10 NAAQS in Butte, EPA proposes to approve these revisions.

In the final rules section of this Federal Register, EPA is acting

on the State's SIP revisions as a direct final rule without prior

proposal because the Agency views this as a noncontroversial revision

amendment and anticipates no adverse comments. A detailed rationale for

EPA's actions is set forth in the direct final rule. If no adverse

comments are received in response to this proposed rule, no further

activity is contemplated and the direct final rule will become

effective. If EPA receives adverse comments, the direct final rule will

be withdrawn and all public comments received will be addressed in a

subsequent final rule based on this proposed rule. EPA will not

institute a second comment period on this action. Any parties

interested in commenting on this document should do so at this time.

DATES: Comments on this proposed rule must be received in writing by

April 21, 1995.

ADDRESSES: Written comments on this action should be addressed to Amy

Platt, 8ART-AP, at the EPA Regional Office listed below. Copies of the

State's submittal and documents relevant to this proposed rule are

available for inspection during normal business hours at the following

locations: Air Programs Branch, Environmental Protection Agency, Region

VIII; 999 18th Street, suite 500, Denver, Colorado 80202-2405; and

Montana Department of Health and Environmental Sciences, Air Quality

Bureau, Cogswell Building, Helena, Montana 59620-0901.

FOR FURTHER INFORMATION CONTACT: Amy Platt at (303) 293-1769.

SUPPLEMENTARY INFORMATION: See the information provided in the Direct

Final action which is located in the Rules Section of this Federal

Register.

Dated: February 17, 1995.

Jack McGraw,

Acting Regional Administrator.

[FR Doc. 95-7005 Filed 3-21-95; 8:45 am]

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