Approval and Promulgation of State Implementation Plans: Idaho

I. Background

On September 22, 1994, EPA issued a proposed rulemaking action on the State Implementation Plan (SIP) for the Northern Ada County PM10 nonattainment area. See 59 FR 48582, Sept. 22, 1994. The plan was submitted for the purpose of satisfying the moderate area planning requirements for PM10 nonattainment areas, as set forth in subparts 1 and 4 of Title I of the Clean Air Act (CAA or Act). In that proposed rulemaking, EPA proposed to grant full approval of the emissions inventory and PM10 precursor exclusion elements, limited approval of the control measures submitted by the State for the limited purpose of making them Federally enforceable, and disapproval of the control measures, attainment demonstration and quantitative milestones, and reasonable further progress elements of the SIP. Disapproval of these elements was based on the State's failure to adopt into the SIP and submit to EPA the wood smoke control ordinances for the cities of Garden City, Meridian, and Eagle, and for unincorporated Ada County, which the State had relied on to implement the residential wood burning program identified in the SIP. In addition, the State had failed to adequately address in the SIP the enforceability of its control measures. EPA received no comments on its proposal. On December 30, 1994, the State of Idaho, Department of Health and Welfare, Division of Environmental Quality (IDEQ or State) submitted to EPA additional information which included the wood smoke control ordinances for these areas; an explanation of the enforcement procedures, responsibilities, and sources of funding for each of the adopted ordinances; and the State's assurance of responsibility for adequate implementation of the local control measures. As described in more detail below, EPA believes the Northern Ada County PM10 SIP is now fully approvable and therefore fully approves the State's plan.

II. Analysis of State Submission

A detailed analysis of the SIP is contained in the September 22, 1994, Federal Register document proposing action on the Northern Ada County PM10 SIP. (59 FR 48582) That analysis evaluated each of the SIP elements, and concluded that certain elements were approvable and that certain elements had deficiencies requiring resolution. A summary of the analysis, and additional analysis of information contained in the December 30, 1994, submittal follows.

1. Procedural Background

IDEQ conducted public hearings and adopted the SIP consistent with Section 110 of Clean Air Act. The initial public hearing was held on October 11, 1990, and a second public hearing was held on November 14, 1991, on a plan modification. The additional information submitted on December 30, 1994, included four implementing ordinances that had each been adopted by the responsible agency after having gone through the public hearing process required by State and local law. EPA has determined that notice and public hearing, meeting the requirements of 40 CFR 51.102, is not required for the December 30, 1994, submittal because the ordinances and other information submitted by the State do not differ materially from the control measures outlined in the SIP that went through notice and public hearing.

2. Accurate Emissions Inventory

The September 22, 1994 Federal Register document discussed the emissions inventory contained in the November 15, 1991, SIP and concluded it was consistent with the requirements of Sections 172(c)(3) and 110(a)(2)(K) of the Act. The additional information submitted on December 30, 1994, did not change the emissions inventory. Thus, for the reasons set forth in the September 22, 1994 Federal Register document, EPA is fully approving the emission inventory.

3. Control Measures

In the September 22, 1994 Federal Register document, EPA determined that the November 14, 1991, SIP did not provide for the timely implementation of reasonably available control measures (RACM), including reasonably available control technology (RACT). To achieve required emission reductions, the SIP relied upon a residential wood burning program, which consisted of four elements: an episodic wood burning curtailment program, a wood smoke public education/awareness program, a wood stove certification program, and a wood stove change- out program. The principal element of the residential wood burning program was the episodic wood burning curtailment program. The SIP stated that this program would be implemented at the local level through the adoption of local ordinances by Ada County, and by the cities of Boise, Garden City, Eagle, and Meridian. However, as noted in the September 22, 1994, Federal Register document, the State had not adopted and submitted all of these ordinances as part of the SIP submittal and the SIP therefore did not satisfy the RACM/RACT requirement. The additional information submitted to EPA on December 30, 1994, included the required ordinances for Ada County, and for the cities of Garden City, Eagle, and Meridian. Each ordinance describes the procedures for instituting a wood stove curtailment program, including the monitored level at which an ``alert'' is called (100 g/m \3\), and provisions for exemptions from the program. The additional information also included a description of the procedures by which each local agency in the nonattainment area which has passed a wood smoke control ordinance will issue wood stove permits, determine exemptions from the curtailment program, enforce the program, and fund implementation. EPA believes that the State's December 30, 1994, submittal addresses the deficiencies identified in the September 22, 1994, Federal Register document, with one exception which does not bar full approval of the State's control measures as meeting the RACM/RACT requirement. The State's initial SIP submittal stated that all cities in the nonattainment area and the unincorporated areas of Ada County had ordinances prohibiting the sale and installation of uncertified wood stoves. The initial SIP submittal, however, only included the ordinance for the City of Boise, and EPA proposed limited approval of that control measure. As stated above, the additional information

submitted on December 30, 1994, included wood smoke control ordinances for Garden City, Eagle, Meridian, and unincorporated Ada County. Only the Garden City and Ada County ordinances, however, have prohibitions on the sale and installation of non-certified wood stoves. EPA does not believe that the failure of the Cities of Meridian and Eagle to prohibit the sale and installation of uncertified wood stoves poses a bar to full approval of the control measures identified in the SIP as meeting the RACM/RACT requirement. As stated in the September 22, 1994, Federal Register document, the State did not take any emission reduction credit for the wood stove certification program. See 59 FR 48585. RACM/RACT does not require the implementation of all available control measures where an area demonstrates timely attainment of the NAAQS and implementation of additional control measures would not expedite attainment. See 57 FR 13498, 13540-13544 (April 10, 1992). The September 22, 1994 document discussed whether, assuming the implementation of control measures on wood smoke as identified in the SIP, RACM/RACT required the imposition of controls on emissions of other sources of PM10 in the nonattainment area, such as road dust, prescribed silvicultural and agricultural burning, and stationary sources. See 59 FR 48585. EPA preliminarily concluded that additional controls on these sources would not be necessary, assuming implementation of the proposed wood smoke controls, either because emissions from such sources were insignificant or because additional controls on such sources were not necessary for and would not expedite attainment. Now that the State has fully implemented the wood smoke controls discussed in the SIP and demonstrated that such controls result in timely attainment of the PM10 standard, EPA concludes that RACM/RACT does not require additional controls on sources other than wood smoke.1 Accordingly, for the reasons set forth in the September 22, 1994, Federal Register document and the reasons set forth herein, EPA is approving the State's control measures as meeting the RACM/RACT requirement. ---------------------------------------------------------------------------

\1\ As discussed in Section II.6 below, the State has recently identified in the nonattainment area two major sources of NOX, which is a precursor to particulate formation under certain meteorological conditions. Whether RACM requires the implementation of additional controls on these major sources of NOX is discussed in Section II.6 below. ---------------------------------------------------------------------------

4. Attainment Demonstration

As discussed in the September 22, 1994, Federal Register document, IDEQ conducted modeling which demonstrated the nonattainment area will be in attainment of the 24-hour PM10 NAAQS during the period of 1993 through 2000. However, because IDEQ had not demonstrated to EPA that it had adopted the wood smoke control measures necessary to achieve the emission reductions identified in the SIP, EPA proposed to disapprove the attainment demonstration. See 59 FR 48586. Now that IDEQ has demonstrated that the necessary control measures have been adopted and implemented and EPA is approving those measures as meeting the RACM/RACT requirement, EPA is giving full approval to the State's attainment demonstration. A review of monitored data in the Northern Ada County NAA indicates that no exceedences of the standard have occurred since January 7, 1991. Over time, the expected exceedence rate for the 24-hour standard has been steadily decreasing, from a high of 4.5 during the three-year period 1986-1988 to 0.0 for the period 1992-1994. Based on the monitored data, it appears the nonattainment area has attained the 24- hour PM10 standard.

5. Quantitative Milestones and Reasonable Further Progress

The State's initial SIP submittal also met the requirements for quantitative milestones and Reasonable Further Progress (RFP). In the September 22, 1994, Federal Register document, however, EPA proposed disapproving these requirements because attainment and maintenance of the standard was predicated on control measures that had not been incorporated into the SIP. See 59 FR 48586-48587. Now that this deficiency has been corrected by the December 31, 1994, submittal, EPA is fully approving State's plan as meeting the quantitative milestones and RFP requirements.

6. PM10 Precursors

The September 22, 1994, Federal Register document proposed to grant the exclusion from controls authorized under Section 189(e) of the Act for major stationary sources of PM10 precursors in the nonattainment area. See 59 FR 48587. EPA proposed a finding that major stationary sources of PM10 precursors did not contribute significantly to PM10 levels in excess of the NAAQS in the nonattainment area. IDEQ has subsequently submitted information identifying in the nonattainment area two major stationary sources of NOx, a PM10 precursor under certain meteorological conditions. Northwest Pipeline has a potential to emit 314 tons of NOx per year and St. Alphonsus Hospital has the potential to emit 116 tons of NOx per year. The SIP provides an adequate demonstration that implementation of RACT will be sufficient to attain the PM10 by the applicable attainment date. In addition, EPA reviewed the ambient air quality data from 1992, 1993, and 1994 and determined that the area attained the NAAQS by December 31, 1994. Thus, although there are two major stationary sources of PM10 precursors in the nonattainment area, EPA believes these sources do not contribute significantly to PM10 levels in excess of the NAAQS in the nonattainment area. Therefore, Section 189(e) of the Clean Air Act does not require the imposition of control requirements on major stationary sources of PM10 precursors in the nonattainment area.

7. Enforceability of Control Measures

In the September 22, 1994, Federal Register document, EPA reserved judgment on the enforceability of the identified control measures because several of the control measures relied on by the State in its SIP submittal had not been submitted to EPA. See 59 FR 48587. As discussed in Section II.3 above, IDEQ has now submitted those control measures to EPA, and EPA has determined the control measures meet the RACM/RACT requirement. The December 31, 1994, submittal includes a description of each implementing ordinance, the agency responsible for enforcement, enforcement procedures and penalties, and the steps the State of Idaho would take should an agency fail to implement or enforce its respective ordinance, as required by Section 110(a)(2)(E) of the Clean Air Act. Specifically, IDEQ has committed to impose Tier II operating permits on all owners and operators of wood stoves within the nonattainment area should a local agency fail to implement its ordinance, and IDEQ has demonstrated its authority to do so. In summary, EPA believes that IDEQ has satisfied the enforceability requirements of Title I of the Act, including the requirements of Section 110(a)(2)(E), and is therefore fully approving the State's SIP as meeting these requirement.

8. Contingency Measures

Section 172(c)(9) of the Act requires that contingency measures be included in each moderate area PM10 nonattainment plan. These measures must take effect without further action by the State or EPA upon a

determination that the area has failed to make Reasonable Further Progress (RFP) or attain the PM10 NAAQS by the applicable statutory deadline, and should result in emission reductions approximately equal to the emissions reductions necessary to demonstrate RFP. See generally 57 FR 13510-13512 and 13543-13544. For a moderate PM10 nonattainment area, such as Northern Ada County, with a three to four year period between SIP development and the attainment date, this would mean that contingency measures should result in emission reductions equal to at least 25 percent of the emission reductions in the total control strategy. 57 FR 13544. A State may rely on ``over control'' as a contingency measure, that is, rely on control measures that are part of the core control strategy in the SIP, if such control measures result in emission reductions greater than those required to achieve the 24-hour NAAQS standard of 150 g/ m3. On July 13, 1995, IDEQ submitted contingency measures to EPA for approval which were a combination of over control from the wood smoke control measures and new controls on fugitive road dust. Modeling of the core control measures in the SIP for the Northern Ada County nonattainment area indicates a 17 g/m\3\ reduction in the 24- hour standard (from 164 g/m\3\ to 147 g/m\3\). This means that the core control measures in the SIP result in over control of 18 percent (ratio of the difference between 147 g/m\3\ and 150 g/m\3\ to 17 g/m\3\). To obtain the additional 7 percent of emission reductions needed for 25 percent reduction of emissions through contingency measures, the State has adopted a program for the reduction of fugitive road dust. The State's submittal includes a signed agreement between the Idaho Transportation Department, Ada County Highway District, and IDEQ, which details a road sweeping program designed to reduce particulate emissions by prioritizing road sanding such that streets with the highest potential to emit PM10, in the form of re-entrained dust, are swept first, and more frequently. IDEQ retains the authority to review and approve any changes to the plan. The State anticipates that this road dust program will result in an additional 9 percent reduction in PM10 emissions. Together with the 18 percent in emission reductions achieved through over control, the State's contingency measures are predicted to result in more than 25 percent of the total reductions necessary for attainment. EPA therefore approves the contingency measures submitted by the State on July 13, 1995.

9. New Source Review

States with initial moderate PM10 nonattainment areas were required to submit a permit program for the construction and operation of new and modified stationary sources of PM10 by June 30, 1992. See Section 189(a) of the Clean Air Act. This permit program element, known as the New Source Review (NSR) program, was submitted by the State of Idaho on May 17, 1994. EPA notified the State on June 10, 1994, that its NSR program submittal was complete. EPA is currently reviewing Idaho's NSR program submittal to determine if the program meets the requirements of the Act. EPA intends to take action on Idaho's NSR program in another rulemaking after EPA has completed its review.

III. This Action

EPA is granting full approval to the November 14, 1991, Northern Ada County PM10 SIP, as supplemented by additional information which IDEQ has submitted since that time. IDEQ has demonstrated that the SIP meets the applicable requirements of the Act.

IV. Administrative Review

Under the Regulatory Flexibility Act, 5 U.S.C. 600 et seq., EPA must prepare a regulatory flexibility analysis assessing the impact of any proposed or final rule on small entities. 5 U.S.C. 603 and 604. Alternatively, EPA may certify that the rule will not have a significant impact on a substantial number of small entities. Small entities include small businesses, small not-for-profit enterprises, and government entities with jurisdiction over populations of less than 50,000. SIP approvals under Section 110 and Subchapter I, Part D, of the CAA do not create any new requirements, but simply approve requirements that the State is already imposing. Therefore, because the Federal SIP- approval process does not impose any new requirements, I certify that it does not have a significant impact on any small entities affected. Moreover, due to the nature of the Federal-State relationship under the CAA, preparation of a regulatory flexibility analysis would constitute Federal inquiry into the economic reasonableness of State action. The CAA forbids EPA to base its actions concerning SIPs on such grounds. Union Electric Co. v. U.S.E.P.A., 427 U.S. 246, 256-66 (S.Ct. 1976); 42 U.S.C. 7410(a)(2). Under Section 202 of the Unfunded Mandates Reform Act of 1995, signed into law on March 22, 1995, EPA must prepare a budgetary impact statement to accompany any proposed or final rule that includes a Federal mandate that may result in estimated costs to State, local, or tribal governments in the aggregate; or to the private sector, of $100 million or more. Under Section 205, EPA must select the most cost- effective and least burdensome alternative that achieves the objectives of the rule and is consistent with statutory requirements. Section 203 requires EPA to establish a plan for informing and advising any small governments that may be significantly or uniquely affected by the rule. EPA has determined that the approval action promulgated does not include a Federal mandate that may result in estimated costs of $100 million or more to State, local, or tribal governments in the aggregate, or to the private sector. This Federal action approves pre- existing requirements under State or local law, and imposes no new Federal requirements. Accordingly, no additional costs to State, local, or tribal governments, or to the private sector, result from this action. EPA has reviewed this request for revision of the Federally- approved SIP for conformance with the provisions of the 1990 Clean Air Act Amendments enacted on November 15, 1990. The EPA has determined that this action conforms with those requirements. Nothing in this action should be construed as permitting or allowing or establishing a precedent for any future request for revision to any SIP. Each request for revision to the SIP shall be considered separately in light of specific technical, economic, and environmental factors, and in relation to relevant statutory and regulatory requirements. This action has been classified as a Table 3 action for signature by the Regional Administrator under the procedures published in the Federal Register on January 19, 1989 (54 FR 2214-2225), as revised by a July 10, 1995, memorandum from Mary Nichols, EPA Assistant Administrator for Air and Radiation. The Office of Management and Budget has exempted this regulatory action from Executive Order 12866 review. EPA is publishing this action without prior proposal because the Agency views this as a noncontroversial amendment and anticipates no adverse comments. However, in a separate document in this Federal Register publication, EPA is proposing to approve the SIP revision should adverse or critical comments be filed. This action will be effective July 29, 1996

unless, by July 1, 1996 adverse or critical comments are received. If EPA receives such comments, this action will be withdrawn before the effective date by publishing a subsequent document that will withdraw the final action. All public comments received will be addressed in a subsequent final rule based on this action serving as a proposed rule. EPA will not institute a second comment period on this action. Any parties interested in commenting on this action should do so at this time. If no such comments are received, the public is advised that this action will be effective July 29, 1996. Under Section 307(b)(1) of the Clean Air Act, petitions for judicial review of this action must be filed in the United States Court of Appeals for the appropriate circuit by July 29, 1996. Filing a petition for reconsideration by the Administrator of this final rule does not affect the finality of this rule for the purposes of judicial review nor does it extend the time within which a petition for judicial review may be filed and shall not postpone the effectiveness of such rule or action. This action may not be challenged later in proceedings to enforce its requirements. (See Section 307(b)(2), 42 U.S.C. 7607(b)(2)).

List of Subjects in 40 CFR Part 52

Environmental protection, Air pollution control, Incorporation by reference, Intergovernmental relations, Particulate matter.

Note: Incorporation by reference of the Implementation Plan for the State of Idaho was approved by the Director of the Office of Federal Register on July 1, 1982.

Dated: March 20, 1996. Chuck Clarke, Regional Administrator. Part 52, chapter I, title 40 of the Code of Federal Regulations is amended as follows:

PART 52--[AMENDED]

1. The authority citation for Part 52 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart N--Idaho

2. Section 52.670 is amended by adding paragraph (c)(31) to read as follows:

Sec. 52.670 Identification of plan.

* * * * * (c) * * * (31) On November 14, 1991, and on December 30, 1994, the Idaho Department of Health and Welfare (IDHW) submitted revisions to the Idaho State Implementation Plan (SIP) for the Northern Ada County/Boise Particulate (PM10) Air Quality Improvement Plan. (i) Incorporation by reference. (A) November 14, 1991, letter from the IDHW Administrator to the EPA Region 10 Regional Administrator submitting a revision to the Idaho SIP for the Northern Ada County/Boise Particulate Air Quality Improvement Plan; The Northern Ada County Boise Particulate (PM10) Air Quality Improvement Plan adopted on November 14, 1991. (B) December 30, 1994, letter from the IDHW Administrator to the EPA Region 10 Regional Administrator including a revision to the Idaho SIP for the Northern Ada County/Boise PM10 Air Quality Improvement Plan; Appendix C-1, Supplemental Control Strategy Documentation, Northern Ada County/Boise PM10 Air Quality Improvement Plan, adopted December 30, 1994, with the following attachments: Garden City Ordinances #514 (May 14, 1987), #533 (January 10, 1989) and #624 (September 13, 1994); Meridian Ordinance #667 (August 16, 1994); Eagle Ordinance #245 (April 26, 1994); Ada County Ordinance #254 (November 3, 1992); and Table Ordinance-1 (December 30, 1994). [FR Doc. 96-12888 Filed 5-29-96; 8:45 am] BILLING CODE 6560-50-P