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###### Environmental Protection Agency

          - 40 CFR Part 52
          - [CO-001-0055; FRL-6972-1]

# AGENCY:

Environmental Protection Agency (EPA).

# ACTION:

Proposed rule.

# SUMMARY:

EPA is proposing to approve a proposed revision to the long-term strategy portion of Colorado's State Implementation Plan (SIP) for Class I Visibility Protection, contained in section III of the document entitled “Colorado's State Implementation Plan for Class I Visibility Protection: Craig Station Units 1 and 2 Requirements,” as submitted by the Governor with a letter dated February 20, 2001. The proposed revision will incorporate into the SIP emissions reduction requirements for the Craig Station (a coal-fired steam generating plant located near the town of Craig, Colorado). EPA proposes to approve the proposed SIP revision, which is expected to remedy Craig Station's contribution to visibility impairment in the Mt. Zirkel Wilderness Area and, therefore, make reasonable progress toward the Clean Air Act National visibility goal with respect to such contribution. EPA makes this proposal based on its understanding that the State will make two minor changes to the proposed SIP revision before final adoption, as described in this proposed rule.

# DATES:

Comments on this proposed action must be received in writing by May 31, 2001.

# ADDRESSES:

Comments should be addressed to Richard Long, Director, Air and Radiation Programs, 8P-AR, Environmental Protection Agency, Region VIII, 999 18th Street, Suite 300, Denver, Colorado 80202-2405.

Copies of the State's submittal and other information are available for inspection during normal business hours at the following locations: Air and Radiation Programs, Environmental Protection Agency, Region VIII, 999 18th Street, Suite 300, Denver, Colorado 80202-2405; and Colorado Department of Public Health and Environment, Air Pollution Control Division, 4300 Cherry Creek Drive South, Denver, Colorado 80222-1530.

# FOR FURTHER INFORMATION CONTACT:

Amy Platt, Air and Radiation Programs, Environmental Protection Agency, Region VIII, (303) 312-6449.

# SUPPLEMENTARY INFORMATION:

Throughout this document, wherever “we,” “us,” or “our” are used it means the Environmental Protection Agency.

## I. Background

                    Section 169A of the Clean Air Act (CAA),[1] 42 U.S.C. 7491, establishes as a National goal the prevention of any future, and the remedying of any existing, anthropogenic visibility impairment in mandatory Class I Federal areas [2]                                          (referred to herein as the “National goal” or “National visibility goal”). Section 169A called for EPA to, among other things, issue regulations to assure reasonable progress toward meeting the National visibility goal, including requiring each State with a mandatory Class I Federal area to revise its State Implementation Plan (SIP) to contain such emission limits, schedules of compliance and other measures as may be necessary to make reasonable progress toward meeting the National goal. CAA section 169A(b)(2). Section 110(a)(2)(J) of the CAA, 42 U.S.C. 7410(a)(2)(J), similarly requires SIPs to meet the visibility protection requirements of the CAA.                

                    We promulgated regulations that required affected States to, among other things, (1) coordinate development of SIPs with appropriate Federal Land Managers (FLMs); (2) develop a program to assess and remedy visibility impairment from new and existing sources; and (3) develop a long-term (10-15 years) strategy to assure reasonable progress toward the National visibility goal. See 45 FR 80084, December 2, 1980 (codified at 40 CFR 51.300-307). The regulations provide for the remedying of visibility impairment that is reasonably attributable to a single existing stationary facility or small group of existing stationary facilities. These regulations require that the SIPs provide for periodic review, and revision as appropriate, of the long-term strategy not less frequently than every three years, that the review process include consultation with the appropriate FLMs,                           ( print page 21722)                        and that the State provide a report to the public and EPA that includes an assessment of the State's progress toward the National visibility goal. See 40 CFR 51.306(c).                

On July 12, 1985 (50 FR 28544) and November 24, 1987 (52 FR 45132), we disapproved the SIPs of states, including Colorado, that failed to comply with the requirements of the provisions of 40 CFR 51.302 (visibility general plan requirements), 51.305 (visibility monitoring), and 51.306 (visibility long-term strategy). We also incorporated corresponding Federal plans and regulations into the SIPs of these states pursuant to section 110(c)(1) of the CAA, 42 U.S.C. 7410(c)(1).

                    The Governor of Colorado submitted a SIP revision for visibility protection on December 21, 1987, which met the criteria of 40 CFR 51.302, 51.305, and 51.306 for general plan requirements, monitoring strategy, and long-term strategies. We approved this SIP revision in an August 12, 1988                     **Federal Register**                     document (53 FR 30428), and this revision replaced the Federal plans and regulations in the Colorado Visibility SIP.                

The Governor of Colorado submitted subsequent SIP revisions for visibility protection with letters dated November 18, 1992, August 23, 1996, and August 19, 1998. These revisions were made to fulfill the requirements to periodically review and, as appropriate, revise the long-term strategy for visibility protection. We approved the first two long-term strategy revisions on October 11, 1994 (59 FR 51376), and January 16, 1997 (62 FR 2305), respectively. The 1998 revisions will be addressed at a later date.

After Colorado's 1992 long-term strategy review, the U.S. Forest Service (USFS) certified visibility impairment in Mt. Zirkel Wilderness Area (MZWA) and named the Hayden and Craig generating stations in the Yampa Valley of Northwest Colorado as suspected sources. The USFS is the FLM for MZWA. This certification was issued on July 14, 1993. Hayden Station was addressed in the State's 1996 long-term strategy review and revision (see 62 FR 2305, January 16, 1997).

                    Craig Station, which is the focus of this SIP revision, is located 40 miles upwind from MZWA. The facility consists of three units, but only Units 1 and 2 are subject to this action. Unit 1 is a 428 megawatt steam generating unit that commenced commercial operation in 1980 and Unit 2 is a 428 megawatt steam generating unit that commenced commercial operation in 1979. The existing emission control equipment on Units 1 and 2 consists of the following: wet scrubbers to control sulfur dioxide (SO2) (currently achieve 65% SO2                     removal), electro-static precipitators to control particulate pollution, and low nitrogen oxides (NOX) burners to control  NOX                     emissions. The 1999 emissions inventory for Craig Station Units 1 and 2, as reported to EPA's Acid Rain database, indicated that these units emitted 9,216 tons of SO2                     and 12,501 tons of  NOX. Particulate emissions have been more difficult to estimate since continuous emissions rate data is not available.                

                    On October 9, 1996, Sierra Club, Inc. (“Sierra Club”) sued the owners of the Craig Station in United States District Court, alleging numerous violations of State and Federal opacity standards from 1991-1996. In the Fall of 1996, the State, Craig Station owners, and EPA initiated a joint study to develop information on SO2                     emission reduction options and associated costs for Craig Station Units 1 and 2. This joint study, referred to as the “Craig Flue Gas Desulfurization Study (Craig FGD Study),” was viewed as a means to move the parties to a negotiated resolution of Craig Station's contribution to visibility impairment in MZWA, and if negotiations failed, as a possible basis for a Best Available Retrofit Technology (BART) determination under State and EPA visibility regulations. The Craig FGD Study was completed on August 31, 1999.                

The Craig FGD Study identified several options, at reasonable costs, for addressing Craig Station's contribution to visibility impairment at MZWA. This information and the results of other technical analyses led us, on September 22, 1999, to call for a revision to the Colorado Visibility SIP to resolve the long outstanding certification of visibility impairment for MZWA with respect to Craig Station (see 64 FR 54010, October 5, 1999). The State was given 12 months to revise the SIP accordingly.

In October 1999, the Sierra Club, the Colorado Air Pollution Control Division (APCD), EPA, USFS, and the Craig Station owners entered into negotiations to try to reach a “global settlement” of the various issues facing the power plant. These issues included the Sierra Club lawsuit and the USFS certification of impairment in MZWA.

On October 17, 2000, the Sierra Club and owners of Craig Station reached an agreement in principle to resolve the Sierra Club lawsuit. Sierra Club and the Craig Station owners subsequently negotiated and signed a consent decree that they filed with the United States District Court for the District of Colorado on January 10, 2001 (Civil Action No. 96-N-2368) (referred to hereafter as “Craig Consent Decree” or “Consent Decree.”)

                    The Consent Decree resolves the Sierra Club complaint regarding opacity violations and also requires substantial reductions in air pollutants that are intended to resolve Craig Station's contribution to visibility impairment in MZWA. The Consent Decree contemplates that its requirements will be incorporated into the Colorado SIP. Although we were not involved in the direct negotiations between Sierra Club and the Craig Station owners regarding the terms of the Consent Decree, during negotiations Sierra Club and the Craig Station owners sought, and we provided, our input regarding terms of the settlement. In particular, in a December 20, 2000 letter, we commented on a final draft of the Consent Decree and gave our preliminary views of the settlement with respect to the SO2                     limits for Craig Station. We made clear that only through our public rulemaking process would we reach final judgment regarding a Visibility SIP revision based on the Consent Decree. This proposed rulemaking is the first step in that public rulemaking process. The Sierra Club and Craig Station owners also asked the State, USFS, and National Park Service to provide input on the Consent Decree during the negotiations of the final agreement.                

## II. Colorado's February 1, 2001, Proposed Revision

                    With a letter dated February 20, 2001, the Governor of Colorado submitted a proposed revision to the long-term strategy portion of Colorado's SIP for Visibility Protection, entitled “Revision of Colorado's State Implementation Plan for Class I Visibility Protection: Craig Station Units 1 and 2 Requirements.” The proposed revision is being made to fulfill, with respect to Craig Station's contribution to visibility impairment in MZWA, the Federal and Colorado requirements to revise the long-term strategy to include emission limitations and schedules for compliance necessary to demonstrate reasonable progress toward the National visibility goal.[3] 

                    Among other things, the proposed SIP revision incorporates provisions of the Craig Consent Decree that require the                           ( print page 21723)                        owners of Craig Station to install control equipment and meet stringent emission limitations for particulates (including opacity),  NOX                     and SO2.                

### A. Analysis of State's Proposed Revision

#### 1. Procedural Background

The CAA requires States to observe certain procedural requirements in developing implementation plans and plan revisions for submission to EPA. Section 110(a)(2) of the CAA provides that each implementation plan submitted by a State must be adopted after reasonable notice and public hearing. Section 110(l) of the CAA similarly provides that each revision to an implementation plan submitted by a State under the CAA must be adopted by such State after reasonable notice and public hearing.

On January 11, 2001, the Colorado Air Pollution Control Division requested that the Colorado Air Quality Control Commission (AQCC), after providing adequate notice, hold a public hearing on April 19, 2001 to consider the proposed revision to the Long-term Strategy of the Visibility SIP. This request was granted. In a February 20, 2001 letter to EPA from Governor Bill Owens, the State requested that we “parallel process” the proposed revision.

Parallel processing allows us to propose rulemaking on a proposed SIP revision at the same time the State is soliciting public comment on the proposed SIP revision. If the Colorado Air Quality Control Commission (AQCC) adopts the proposed SIP revision without significant changes (except for the two minor changes we believe are necessary, as described below), and the Governor submits the final revision to us for approval, we will consider any comments received and proceed with a final rulemaking action. However, should the State substantially change the proposed SIP revision before submitting the final version to us, we will re-propose and again solicit public comment on the State amended SIP revision before we take final rulemaking action. For further information regarding parallel processing, please see 40 CFR part 51, appendix V, section 2.3.1.

We have reviewed the proposed SIP revision incorporating requirements for Craig Units 1 and 2 to determine adequacy should the State's proposal be finalized. We believe the State's proposed revision would adequately address Craig Station's contribution to visibility impairment in MZWA, thereby resolving the USFS's certification of impairment and making reasonable progress toward the National visibility goal. In addition, should the State's proposed revision be finalized and submitted to EPA, with the two minor changes described below in section II.A.2.b., Analysis of Reasonable Progress, it will adequately satisfy EPA's September 22, 1999, Visibility SIP Call.

#### 2. Content of Proposed SIP Revision

The proposed SIP revision is contained in section III of the submittal entitled “Revision of Colorado's State Implementation Plan for Class I Visibility Protection: Craig Station Units 1 and 2 Requirements,” dated February 1, 2001. Only section III contains provisions that are enforceable against the Craig Station owners. Part III incorporates relevant portions of the Craig Consent Decree into the long-term strategy. The remainder of the proposed SIP revision contains provisions that are explanatory and analyses that are required by section 169A of the CAA, Federal visibility regulations (40 CFR 51.300 to 51.307), and/or the Colorado Visibility SIP.

#### a. Section III: Enforceable Portion of the Proposed SIP Revision: Craig Station Units 1 and 2 Requirements

The State incorporated into its proposed Visibility SIP revision provisions of the Craig Consent Decree including Definitions, Emission Controls and Limitations, Continuous Emission Monitors, Construction Schedule, Emission Limitation Compliance Deadlines, and Reporting. Such provisions must be met by the Craig Station owners and are enforceable. The Consent Decree numbering scheme was retained to avoid confusion between the SIP and the Consent Decree, but only the Consent Decree's emission controls and limitations, construction schedule, and sections necessary to ensure enforceability of these requirements were included in the proposed SIP. Some changes were made to Consent Decree language to conform to a SIP framework. Finally, changes were made to the force majeure provisions of the Consent Decree to ensure that a demonstration of reasonable progress could be made at this time. Provisions of particular interest incorporated from the Craig Consent Decree are summarized below.

*SO*2*Emission Limitations*                    —Craig Units 1 and 2 will be designed to meet at least a 93.7% SO2                     removal rate. The Craig Station owners must design, construct and operate FGD upgrades and related equipment to reliably treat 100% of the flue gas and to meet the following emissions limitations:                

                    —No more than 0.160 lbs SO2                     per million Btu heat input on a 30 boiler operating day rolling average basis;                

                    —No more than 0.130 lbs SO2                     per million Btu heat input on a 90 boiler operating day rolling average basis;                

                    —At least a 90% reduction of SO2                     on a 90 boiler operating day rolling average basis, unless Craig Station owners show this limit cannot be met, in which case an alternative limit shall be established, not to be less than an 85% reduction of SO2                     on a 30 boiler operating day average or 86% on a 90 boiler operating day average [4]                                         ; and                

                    —A unit cannot operate for more than 72 consecutive hours without any SO2                     emissions reductions; that is, it must shut down if the control equipment is not working at all for three days.                

*Particulate Emission Limitations*                    —The Craig Station owners must install and operate a Fabric Filter Dust Collector (known as a baghouse or FFDC) on Craig Units 1 and 2. Particulate emission limitations for each unit are:                

—No more than 0.03 lbs of particulate matter per million Btu heat input; and

—No more than 20.0% opacity, with certain limited exceptions, as averaged over each separate 6-minute period within an hour as measured by continuous opacity monitors.

*NO*X*Emissions Limitations*                    —NOX                     reductions are to be achieved through the requirement to install “state-of-the-art” low-NOX                     burners utilizing two-stage combustion with supplemental over-fire air systems. The emissions limitations on each of Craig Station Units 1 and 2 are:                

—No more than 0.30 lbs per million Btu heat input on a calendar year annual average basis.

*Compliance with Emissions Limits*                    —All required controls must be designed to meet enforceable emission limits. Compliance with the emission limits shall be determined by continuous emission monitors. Compliance with the percentage reduction requirement for SO2                     shall be determined by comparing SO2                     emissions from the stack (measured by continuous emissions monitors—“CEMs”) to potential SO2                     emissions from coal combusted (determined through coal sampling and analysis).                

*Construction Schedule*                    —The final deadlines for constructing control equipment are as follows: Unit 1—                          ( print page 21724)                        Completion of construction and initiation of start-up of all upgrades by 12/31/03. Unit 2—Completion of construction and initiation of start-up of all upgrades by 6/30/04.                

The schedule for commencement of compliance with the emissions limitations is as follows:

####                     SO2

                    —For Unit 1, within 180 days after completion of construction of the additional SO2                     control equipment, or by June 30, 2004, whichever date is earlier, except for 90% SO2                     reduction, which must be achieved within 270 days of the above compliance date, but no later than March 31, 2005.                

                    —For Unit 2, within 180 days after completion of construction of the additional SO2                     control equipment, or by December 31, 2004, whichever date is earlier, except for 90% SO2                     reduction, which must be achieved within 270 days of the above compliance date, but no later than September 30, 2005.                

#### Particulates

—For Unit 1, within 180 days after completion of construction of baghouse system, or by April 30, 2004, whichever date is earlier.

—For Unit 2, within 180 days after completion of construction of baghouse system, or by October 31, 2004, whichever date is earlier.

####                     NOX

—June 30, 2004 for Unit 1 and December 31, 2004 for Unit 2.

These construction deadlines and emission limitation compliance deadlines are subject to the “force majeure” provisions of the Consent Decree, which have been included in the proposed SIP revision. A force majeure event refers to an excused delay in meeting construction deadlines or in meeting emission limitation compliance deadlines due to certain limited circumstances wholly beyond the control of the Craig Station owners.

To help ensure that reasonable progress continues to be made, the State commits in the proposed SIP revision to reopen the SIP (with public notice and hearing) after it is determined that a construction schedule or an emission limitation schedule has been, or will be, delayed by more than 12 months as a result of a force majeure determination or determinations. The State will re-evaluate the SIP at that time to determine whether revisions are necessary to continue to demonstrate reasonable progress, and to ensure that the emission limitations are met. In addition, the proposed SIP revision also contains a clarification that the force majeure provisions are not to be construed to authorize or create any preemption or waiver of the requirements of State or Federal air quality laws, or of the requirements contained in the SIP or Consent Decree.

EPA believes that the language of the proposed SIP revision should assure reasonable progress toward the National visibility goal. If deadlines extend more than twelve months, we expect the State to revise the SIP.

#### b. Analysis of Reasonable Progress

Congress established as a National goal “the prevention of any future, and the remedying of any existing” anthropogenic visibility impairment in mandatory Class I Federal areas. The statute does not mandate that the national visibility goal be achieved by a specific date but instead calls for “reasonable progress” toward the goal. Section 169A(b)(2) of the CAA requires EPA to issue implementing regulations requiring visibility SIPs to contain such “emission limits, schedules of compliance and other measures as may be necessary to make reasonable progress toward the National goal.”

EPA's implementing regulations provided for an initial round of visibility SIP planning which included a long-term strategy to make reasonable progress toward the National goal. See 40 CFR 51.302(c)(2)(i) and 51.306. Section 169A(g)(1) of the CAA specifies factors that must be considered in determining reasonable progress including: (1) the costs of compliance; (2) the time necessary for compliance; (3) the energy and non-air quality environmental impacts of compliance; and (4) the remaining useful life of the source. Protection of visibility in a mandatory Class I Federal area is the objective.

In this unique case, the Craig Station owners have agreed in the context of a judicially-enforceable Consent Decree to meet emissions limitations that are expected to reduce Craig Station's contribution to visibility impairment in MZWA to below perceptible levels. The State has analyzed the emission reductions provided for in the Consent Decree in light of the statutory factors for determining reasonable progress and the ultimate objective of protecting visibility. The State has proposed that the measures assure reasonable progress by remedying Craig Station's contribution to perceptible visibility impairment in MZWA and has proposed a Visibility SIP revision containing these measures.

Further, in a December 14, 2000 letter from Tom Thompson, USFS, Rocky Mountain Region, to Margie Perkins, APCD, the USFS concluded that “the proposed reductions of both sulfur dioxide and nitrogen oxides will resolve all Forest Service issues relative to the Craig Station and our 1993 Certification of Impairment.” Based in part on this letter, the State has proposed that the pertinent provisions of the Craig Consent Decree, as embodied in the proposed SIP revision, effectively resolve the USFS certification of impairment in MZWA in relation to Craig Station.

We have reviewed the State's proposed SIP revision and supporting information in light of the statutory and regulatory requirements and propose to approve it based on the understanding that the State will make two minor changes. First, in section III, Enforceable Portion of the SIP Revision: Craig Station Units 1 and 2 Requirements, the following language should be added to section II.2.(m) (definition of “Craig Owners”) to ensure that successor owners are covered by the SIP revision: “and successor owners of Craig Station.” Second, also in section III, the following language should be removed from section IX.26., to clarify that reporting requirements continue indefinitely after the Consent Decree is terminated: “and continuing until the Decree is terminated.” We believe these changes are necessary to ensure enforceability of the SIP revision and consistency with the Hayden SIP revision. Our proposed approval is based on our anticipation that these changes will be made in the final SIP revision adopted by the AQCC.

We believe the State has reasonably proposed that the emission reduction measures at Craig Station required by the Consent Decree and contained in the proposed Visibility SIP revision will remedy Craig Station's contribution to perceptible visibility impairment at MZWA, with reasonable costs, an expeditious compliance schedule, and no significant adverse energy or non-air quality environmental impacts. The State's February 1, 2001 proposed SIP revision and accompanying information, available at the addresses listed at the beginning of this document, provides a detailed analysis of each of the “reasonable progress” considerations. We have reviewed these “reasonable progress” considerations and a summary of the State's analysis follows.

#### (i) Factor (1) Cost of Compliance

                    By signing the Consent Decree, the Craig Station owners have demonstrated their willingness to bear the cost to upgrade Craig Station Units 1 and 2. Therefore, this factor is not particularly relevant to this action. However, the                           ( print page 21725)                        State proposes that the costs are reasonable given that the cost of the combined Craig Units 1 and 2 SO2                     removal upgrades (approximately $27.5 million total or $4.49 million/year and $659/ton of SO2                     removed—in January 1998 dollars) at the facility are within the range of retrofit costs at other facilities. It should be noted that included in these cost estimates are credits that represent a portion of the control costs that the Craig Station owners will be able to recoup by the sale of marketable allowances of SO2                     received under the allowance trading program of the Clean Air Act's Acid Rain Program (approximately $100/ton).                

                    The State also compared costs with the results of an EPA modelling study [5]                                          which estimated the retrofit costs for SO2                     control at 200 coal-fired electric utilities (630 boilers). This study indicated that the 50th percentile cost (in 1998 dollars) was more than the estimated cost of the Craig Units 1 and 2 upgrade.                

                    The State believes that estimated costs for SO2                     emission reductions at Craig Station Units 1 and 2 appear to be lower or similar to estimates for other projects and therefore, that the cost of these SO2                     emission reductions is reasonable. For a more detailed discussion of the cost of compliance, please refer to the proposed SIP revision.                

#### (ii) Factor (2) Time Necessary for Compliance

                    The time necessary for compliance is reasonable. Under the terms of the Craig Consent Decree, approximately three to four years will elapse between the filing of the Decree and operation of the control equipment on Units 1 and 2, respectively.[6]                                          By comparison, if the State went through a complete regulatory process with the Craig Station to make a reasonable attribution decision and BART determination, the State estimates that the time until installation of controls could be 5                    1/2                     years. We note that the Hayden Consent Decree allowed approximately 3                    1/2                     years time between the filing of the Consent Decree and operation of the required control equipment. See 62 FR 2305 (January 16, 1997).                

#### (iii) Factor (3) Energy and Non-Air Quality Environmental Impacts of Compliance

Any negative impacts are minimal, as discussed below.

(a) Energy Impacts. It will be necessary to divert additional power (estimated at 1.5 MW/unit) to in-house use to operate the upgrade equipment, resulting in a percent decrease in plant output of 0.2%. By comparison, the retrofit at Hayden Station resulted in a decrease in plant output of 1.1%. See 62 FR 2305 (January 16, 1997).

                    (b) Water Impacts. An increase in water consumption will be needed to support the SO2                     upgrades. However, it is uncertain at this time how large this increase will be. It is possible that the increase can be met entirely through increased internal efficiencies in water use at the facility. If not, then Craig Station will need to increase its consumptive use of existing water rights in the Yampa River. Craig Station is a “zero discharge facility” and does not have a river water discharge. Overall, the State believes that the upgrades to current control equipment should have only a minimal impact on water usage at Craig Station.                

                    (c) Solid Waste Impacts. Craig Station's solid waste will increase, although no major changes to current disposal methods will be required. However, the increase in scrubber waste solids due to the increase in SO2                     removal may require the acquisition of two new transport trucks for landfill disposal of the wastes.                

                    (d) Other Environmental Benefits. In a December 14, 2000 letter from Tom Thompson, USFS, Rocky Mountain Region (                    *i.e.*                    , the Federal land manager for Mt. Zirkel Wilderness Area), to Margie Perkins, APCD, the USFS indicated that it believes the proposed reductions in SO2                     and  NOX                     emissions required under the Consent Decree will “significantly benefit” the aquatic ecosystems in MZWA. The State concurs that the emission reductions should reduce acid accumulations in the snowpack.                

Overall, the State believes that any energy and non-air quality related impacts that will result from this proposed revision are acceptable.

#### (iv) Factor (4) Remaining Useful Life of Source

The owners of the Craig Station assume that Craig Station Units 1 and 2 have a remaining useful life of 20 years. In its technical judgment, the State believes 20 years is an accurate estimate and therefore, the upgrade required in this proposed SIP revision is reasonable.

#### (v) Visibility Benefits

                    Any contribution to visibility impairment in MZWA caused or contributed to by the Craig Station Units 1 and 2 come from their SO2                     emissions converted to sulfate haze in the atmosphere. The enhanced FGD control systems will lower Craig Station Units 1 and 2's combined SO2                     emissions to a total of approximately 2,600 tons per year from the current level of over 9,300 tons per year. In the State's technical judgment, this will effectively address visibility problems in MZWA caused by SO2                     from Craig Units 1 and 2 and will lower the threshold of SO2                     emissions from the units to below perceptible levels in MZWA. We believe these conclusions are reasonable. It should be noted that the State recognizes that regional haze from outside Colorado and emissions from other Colorado sources could also be contributing to visibility impairment at MZWA.                

#### (vi) Reasonable Progress and BART

                    The State believes that its proposed SIP revision assures reasonable progress toward meeting the National visibility goal as it relates to Craig Station and MZWA. First, the proposed SIP revisions embody emission reductions of visibility impairing pollutants at Craig Station Units 1 and 2 at a reasonable cost, within the same timeframe or earlier than similar reductions would likely occur through reasonable attribution and BART determinations. Second, the emission limitations for Craig Station Units 1 and 2 for SO2, particulate, and  NOX                     reached through a negotiation process are similar to or more stringent than those imposed on some units subject to Prevention of Significant Deterioration (PSD) regulations (                    *e.g.*                    , Craig Station Unit 3 and Rawhide Energy Station). Third, although there have been no BART determinations made nationally under the mandatory Class I Federal visibility protection program since 1977, there have been several “BART-like” decisions made in settlement of FLM certifications of impairment that have resulted in SO2                     limitations that are similar or less stringent than those in the Craig Consent Decree.                

                    The State believes that the Craig Consent Decree, as embodied in the proposed SIP revision, expeditiously remedies Craig Station's contribution to visibility impairment in MZWA, at a reasonable cost and without undue non-air environmental or energy impacts. Although a formal BART analysis has not been performed for Craig Station Units 1 and 2, the State also expects that the Consent Decree's 90% control                           ( print page 21726)                        requirement on a 90-day rolling average for SO2                     would be at least as good as BART had such an analysis been performed.                

Finally, as noted above, the USFS has concluded that the emissions reductions reflected in this proposed SIP revision should effectively address concerns of visibility impairment in MZWA associated with Craig Station.

In our opinion, the State's belief is reasonable that the proposed SIP revision will assure reasonable progress in remedying Craig Station's contribution to visibility impairment in MZWA. However, as described above, we believe that two minor changes to the proposed SIP revision are necessary.

#### c. Six Factors Considered in Developing the Long-Term Strategy

The State considered the six factors contained in 40 CFR 51.306(e) when developing this proposed revision to its long-term strategy. These six factors are as follows: (1) Eemission reductions due to ongoing air pollution control programs; (2) additional emission limitations and schedules for compliance; (3) measures to mitigate the impacts of construction activities; (4) source retirement and replacement schedules; (5) smoke management techniques for agricultural and forestry management purposes including such plans as currently exist within the State for these purposes; and (6) enforceability of emission limitations and control measures. Because this long-term strategy SIP revision is focused entirely on the Craig Station Units 1 and 2 requirements that resulted from a negotiated settlement, the State concluded that factors (1), (4), and (5) are not applicable. These factors will be considered when the State conducts its next full long-term strategy review process in September 2001. For a detailed discussion of the remaining factors as they relate to Craig Station Units 1 and 2, please refer to Colorado's proposed long-term strategy revision, which is available at the addresses listed in the beginning of this document.

#### 3. Additional Requirements

#### a. FLM Consultation

As required under State and Federal regulations (Colorado Air Quality Control Commission Regulation No. 3, section XV.F.; 40 CFR 51.306(c)), the State prepared and distributed a FLM Comment Draft of its long-term strategy review/revision to the USFS and the National Park Service. These agencies are the FLMs of all of Colorado's Class I areas.

#### b. SIP Enforceability

                    All measures and other elements in the SIP must be enforceable by the State and EPA (see sections 172(c)(6), 110(a)(2)(A) and 57 FR 13556). Our criteria addressing the enforceability of SIPs and SIP revisions were stated in a September 23, 1987 memorandum (with attachments) from J. Craig Potter, Assistant Administrator for Air and Radiation,                     *et al.*                     (see 57 FR 13541).                

                    The specific emissions limitations contained in this February 1, 2001 proposed revision to the SIP are addressed above in section II.A.2.a., “Section III: Enforceable Portion of the SIP Revision: Craig Station Requirements.” By adopting emission limitations for Craig Station into the Visibility SIP, the limitations will become enforceable by the State. C.R.S. 25-7-115. Enforceability of emission limitations will be ensured by the inclusion in this proposed SIP revision of Consent Decree sections VI., Continuous Emission Monitors (for SO2                     and opacity), and IX., Reporting, to ensure determination of compliance through reliable and valid measurements and to ensure accurate and adequate data reporting. As described above, we believe that two minor changes to the proposed SIP revision are needed to ensure enforceability. Should EPA finalize this proposed approval of the proposed SIP revision, the emission limitations will be federally enforceable.                

Consistent with section 110(a)(2)(A) of the CAA, the State of Colorado has a program that will ensure that the measures contained in the SIP are adequately enforced. The Colorado APCD has the authority to implement and enforce all control measures adopted by the AQCC. C.R.S. 25-7-111. In addition, Colorado statute provides that the APCD shall enforce against any “person” who violates the emission control regulations of the AQCC, the requirements of the SIP, or the requirements of any permit. C.R.S. 25-7-115. Civil penalties of up to $15,000 per day per violation are provided for in the State statute for any person in violation of these requirements (C.R.S. 25-7-122), and criminal penalties are also provided for in the State statute. C.R.S. 25-7-122.1.

Thus, we believe that the control measures contained in the proposed revision to Colorado's State Implementation Plan for Class I Visibility Protection: Craig Station Units 1 and 2 Requirements, will be enforceable and that the APCD has adequate enforcement capabilities to ensure compliance with those control measures.

## III. Proposed Action

We have reviewed the adequacy of the State's proposed revision to the long-term strategy portion of Colorado's SIP for Class I Visibility Protection, contained in section III of the document entitled “Revision of Colorado's State Implementation Plan for Class I Visibility Protection: Craig Station Units 1 and 2 Requirements,” as submitted by the Governor with a letter dated February 20, 2001. We are proposing to approve the proposed revision, which includes the incorporation of certain requirements from the Craig Consent Decree, provided that the State makes two minor changes to the proposed SIP revision, as described in the body of this document.

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 a SIP shall be considered separately in light of specific technical, economic, and environmental factors and in relation to relevant statutory and regulatory requirements.

## IV. Request for Public Comments

We are requesting comments on all aspects of this proposal. As indicated at the outset of this document, we will consider any comments received by May 31, 2001.

## V. Administrative Requirements

                    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this proposed action is not a “significant regulatory action” and therefore is not subject to review by the Office of Management and Budget. This proposed action merely approves state law as meeting federal requirements and imposes no additional requirements beyond those imposed by state law. Accordingly, the Administrator certifies that this proposed rule will not have a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601*et seq.*). Because this rule proposes to approve pre-existing requirements under state law and does not impose any additional enforceable duty beyond that required by state law, it does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4). This proposed rule also does not have a substantial direct effect on one or more Indian tribes, on the relationship between the Federal Government and Indian tribes, or on the                           ( print page 21727)                        distribution of power and responsibilities between the Federal Government and Indian tribes, as specified by Executive Order 13175 (65 FR 67249, November 9, 2000), nor will it have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government, as specified in Executive Order 13132 (64 FR 43255, August 10, 1999), because it merely approves a state rule implementing a federal standard, and does not alter the relationship or the distribution of power and responsibilities established in the Clean Air Act. This proposed rule also is not subject to Executive Order 13045 (62 FR 19885, April 23, 1997), because it is not economically significant.                

                    In reviewing SIP submissions, EPA's role is to approve state choices, provided that they meet the criteria of the Clean Air Act. In this context, in the absence of a prior existing requirement for the State to use voluntary consensus standards (VCS), EPA has no authority to disapprove a SIP submission for failure to use VCS. It would thus be inconsistent with applicable law for EPA, when it reviews a SIP submission, to use VCS in place of a SIP submission that otherwise satisfies the provisions of the Clean Air Act. Thus, the requirements of section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) do not apply. As required by section 3 of Executive Order 12988 (61 FR 4729, February 7, 1996), in issuing this proposed rule, EPA has taken the necessary steps to eliminate drafting errors and ambiguity, minimize potential litigation, and provide a clear legal standard for affected conduct. EPA has complied with Executive Order 12630 (53 FR 8859, March 15, 1988) by examining the takings implications of the rule in accordance with the “Attorney General's Supplemental Guidelines for the Evaluation of Risk and Avoidance of Unanticipated Takings' issued under the executive order. This rule does not impose an information collection burden under the provisions of the Paperwork Reduction Act of 1995 (44 U.S.C. 3501*et seq.*).                

# List of Subjects in 40 CFR Part 52

      - Environmental protection
      - Air pollution control
      - Intergovernmental relations
      - Nitrogen dioxide
      - Particulate matter
      - Reporting and recordkeeping requirements
      - Sulfur oxides

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

Dated: April 19, 2001.

Patricia D. Hull,

Acting Regional Administrator, Region 8.

# Footnotes

1.                             The Clean Air Act is codified, as amended, in the U.S. Code at 42 U.S.C. 7401,                         *et seq.*
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2.                             Mandatory class I Federal areas include international parks, national wilderness areas, and national memorial parks greater than five thousand acres in size, and national parks greater than six thousand acres in size, as described in section 162(a) of the Act (42 U.S.C. 7472(a)). Each mandatory Class I Federal area is the responsibility of a “Federal land manager” (FLM), the Secretary of the department with authority over such lands. See section 302(i) of the Act, 42 U.S.C. 7602(i).                    
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3.                             This proposed revision is specific to requirements for Craig Station and does not constitute the State's three year review of the components of the Long-term Strategy, as required by 40 CFR 51.306(c). That review and report are not due from the State until September 2001, at which time the public will be able to review and comment on the State's full Long-term Strategy.                    
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4.                             Any changes made to the percentage reduction requirement will be made pursuant to the requirements of the Consent Decree, and if the ultimate percentage reduction requirement changes from 90%, the State has indicated that it would report the changes in its next long-term strategy review. We would provide an information notice on any such changes as well.                    
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5.                             “Project Summary: Retrofit Costs for SO2                         and NOX                         Control Options at 200 Coal-Fired Plants,” EPA/600/S7-90-021, March 1991.                    
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6.                             EPA notes that should this proposed approval be finalized, the time period between SIP approval and operation of control equipment would be even shorter.                    
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[FR Doc. 01-10806 Filed 4-30-01; 8:45 am]

BILLING CODE 6560-50-P