Clean Air Act Approval and Promulgation of PMINF10/INF Implementation Plan for Colorado; Designation of Areas for Air Quality Planning Purposes; Steamboat Springs

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[CO-001-0006a & CO-001-0021a; FRL-5934-2]

Clean Air Act Approval and Promulgation of PM10

Implementation Plan for Colorado; Designation of Areas for Air Quality

Planning Purposes; Steamboat Springs

AGENCY: Environmental Protection Agency (EPA).

ACTION: Direct final rule.

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SUMMARY: EPA approves the State implementation plan (SIP) submitted by

the State of Colorado to achieve attainment and maintenance of the

National Ambient Air Quality Standards (NAAQS) for particulate matter

with an aerodynamic diameter less than or equal to a nominal 10

micrometers (PM10), including among other things, control

measures, technical analyses, quantitative milestones and contingency

measures. The SIP was submitted by the Governor of Colorado with a

letter dated September 16, 1997 to satisfy certain Federal requirements

for an approvable SIP for the Steamboat Springs, Colorado moderate

PM10 nonattainment area, as designated effective January 20,

1994. In addition, EPA approves the Steamboat Springs emergency episode

plan. EPA also amends the boundary for the Steamboat Springs

nonattainment area to clarify the original description.

DATES: This action is effective on March 2, 1998 unless adverse

comments are received by January 30, 1998. If the effective date is

delayed, timely notice will be published in the Federal Register.

ADDRESSES: Comments should be addressed to: Richard R. Long, Director,

Air Program, EPA Region VIII at the address listed below. Copies of the

State's submittal and other information are available for inspection

during normal business hours at the following locations: Air Program,

Environmental Protection Agency, Region VIII, 999 18th Street, suite

500, 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, 8P2-A, Environmental

Protection Agency, Region VIII, 999 18th Street, suite 500, Denver,

Colorado 80202-2466, (303) 312-6449.

SUPPLEMENTARY INFORMATION:

I. Background

The Steamboat Springs, Colorado area was designated nonattainment

for PM10 and classified as moderate under section 107(d)(3)

of the Clean Air Act, on December 21, 1993. 1 See 57 FR

43846 (September 22, 1992), 58 FR 67334 (December 21, 1993) and 40 CFR

81.306 (Routt County (part)). The Steamboat Springs designation became

effective on January 20, 1994. The air quality planning requirements

for moderate PM10 nonattainment areas 2 are set

out in Subparts 1 and 4 of Title I of the Act.3

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\1\ The 1990 Amendments to the Clean Air Act made significant

changes to the Act. See Pub. L. 101-549, 104 Stat. 2399. References

herein are to the Clean Air Act, as amended (``the Act''). The Clean

Air Act is codified, as amended, in the U.S. Code at 42 U.S.C. 7401,

et seq.

\2\ The requirements which are the subject of this document

arise under the pre-existing PM NAAQS. EPA promulgated a new PM

NAAQS on July 18, 1997, which became effective on September 16,

1997.

\3\ Subpart 1 contains provisions applicable to nonattainment

areas generally and Subpart 4 contains provisions specifically

applicable to PM10 nonattainment areas. At times, Subpart

1 and Subpart 4 overlap or conflict. EPA has attempted to clarify

the relationship among these provisions in the ``General Preamble''

and, as appropriate, in today's notice and supporting information.

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EPA has issued a ``General Preamble'' describing EPA's preliminary

views on how EPA intends to review SIPs and SIP revisions submitted

under Title I of the Act, including those State submittals containing

moderate PM10 nonattainment area SIP requirements (see

generally 57 FR 13498 (April 16, 1992) and 57 FR 18070 (April 28,

1992)). Because EPA is describing its interpretations here only in

broad terms, the reader should refer to the General Preamble for a more

detailed discussion of the interpretations of title I advanced in this

document and the supporting rationale. In this document and supporting

rationale, EPA is applying its interpretations considering the specific

factual issues presented.

A State containing a moderate PM10 nonattainment area

designated after the 1990 Amendments is required to submit, among other

things, the following provisions within 18 months of the effective date

of the designation (i.e., these provisions were due for the Steamboat

Springs area by July 20, 1995):

1. Provisions to assure that reasonably available control measures

(RACM) (including such reductions in emissions

[[Page 68189]]

from existing sources in the area as may be obtained through the

adoption, at a minimum, of reasonably available control technology

(RACT)) shall be implemented no later than four years after designation

(i.e., January 20, 1998 for Steamboat Springs);

2. Either a demonstration (including air quality modelling) that

the plan will provide for attainment as expeditiously as practicable

but no later than the end of the sixth calendar year after the

effective date of designation (i.e., December 31, 1999 for Steamboat

Springs), or a demonstration that attainment by that date is

impracticable;

3. Quantitative milestones which demonstrate reasonable further

progress (RFP) toward the attainment date (i.e., December 31, 1999 for

Steamboat Springs). Since the SIP for a new nonattainment area is due

18 months after the area is designated as nonattainment, the first 3-

year milestone is to be achieved 4 \1/2\ years after nonattainment

designation (i.e., July 20, 1998 for Steamboat Springs) and the second

milestone must be achieved three years after the first milestone or 7

\1/2\ years after nonattainment designation (i.e., July 20, 2001 for

Steamboat Springs);

4. Provisions to assure that the control requirements applicable to

major stationary sources of PM10 also apply to major

stationary sources of PM10 precursors except where the

Administrator determines that such sources do not contribute

significantly to PM10 levels which exceed the NAAQS in the

area. See sections 172(c), 188, and 189 of the Act; and

5. Contingency measures which consist of other available measures

that are not part of the area's control strategy. These measures must

take effect without further action by the State or EPA, upon EPA's

determination that the area has failed to make RFP or attain the

PM10 NAAQS by the applicable deadline. See section 172(c)(9)

of the Act.

II. This Action

Section 110(k) of the Act sets out provisions governing EPA's

review of SIP submittals (see 57 FR 13565-13566). The Governor of

Colorado submitted the Steamboat Springs PM10 SIP with a

letter dated September 16, 1997. The Steamboat Springs moderate

nonattainment area plan includes, among other things, technical

analyses, control measures to satisfy the RACM requirement, a

demonstration (including air quality modelling) that attainment and

maintenance of the PM10 NAAQS will be achieved by the

required dates, and enforceability documentation. In this final

rulemaking, EPA announces its approval of those elements of the

Steamboat Springs PM10 SIP which were due on July 20, 1995

and submitted on September 16, 1997.

In addition, EPA has determined that major sources of precursors of

PM10 do not contribute significantly to PM10

levels in excess of the NAAQS in Steamboat Springs.4

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\4\ The consequences of this finding are to exclude these

sources from the applicability of PM10 nonattainment area

control requirements. Note that EPA's finding is based on the

current character of the area including, for example, the existing

mix of sources in the area. It is possible, therefore, that future

growth could change the significance of precursors in the area.

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Finally, EPA is amending the nonattainment area boundary

description for Steamboat Springs in order to clarify the original

description.

A. Analysis of State Submission

1. Procedural Background

The Act requires States to observe certain procedural requirements

in developing implementation plans and plan revisions for submission to

EPA. Section 110(a)(2) of the Act provides that each implementation

plan submitted by a State must be adopted after reasonable notice and

public hearing. 5 Section 110(l) of the Act similarly

provides that each revision to an implementation plan submitted by a

State under the Act must be adopted by such State after reasonable

notice and public hearing.

EPA also must determine whether a submittal is complete and

therefore warrants further EPA review and action (see section 110(k)(1)

and 57 FR 13565). EPA's completeness criteria for SIP submittals are

set out at 40 CFR part 51, appendix V. EPA attempts to make

completeness determinations within 60 days of receiving a submission.

However, a submittal is deemed complete by operation of law if a

completeness determination is not made by EPA six months after receipt

of the submission.

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\5\ Also Section 172(c)(7) of the Act requires that plan

provisions for nonattainment areas meet the applicable provisions of

Section 110(a)(2).

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To entertain public comment on the PM10 implementation

plan for Steamboat Springs, the Steamboat Springs City Council and the

Routt County Commission held public hearings on June 6, 1995 and June

12, 1995, respectively. The State of Colorado, after providing adequate

public notice, held a public hearing on September 21, 1995. After

considering all public comments and following the public hearing, the

Steamboat Springs PM10 SIP was adopted by the Colorado Air

Quality Control Commission (AQCC). The Steamboat Springs

PM10 SIP was submitted by the Governor in a letter dated

August 7, 1996. The Steamboat Springs PM10 SIP was reviewed

by EPA to determine completeness in accordance with the completeness

criteria set out at 40 CFR part 51, appendix V. The submittal was found

to be complete and a letter dated August 29, 1996 was forwarded to the

Governor indicating the completeness of the submittal and the next

steps in the review process.

Subsequently, the Steamboat Springs City Council and the Routt

County Commission held public hearings on extensive revisions to the

Steamboat Springs PM10 SIP on September 17, 1996 and

approved the revisions. The Colorado AQCC conducted a public hearing on

the revised SIP on October 17, 1996 and adopted the revisions. In a

January 31, 1997 letter from Margie Perkins, Air Pollution Control

Division (APCD), to Richard Long, EPA, the State requested that EPA

Region VIII delay processing of the original Steamboat Springs SIP

submitted with the August 7, 1996 Governor's letter. The reason

provided for the request was that the substantial revisions adopted on

October 17, 1996 made the original SIP and regulations obsolete. These

revisions were submitted by the Governor with a letter dated September

16, 1997, and the State requested that this documentation completely

replace the August 7, 1996 submittal.

The September 16, 1997 Steamboat Springs PM10 SIP

submittal was reviewed by EPA to determine completeness in accordance

with the completeness criteria set out at 40 CFR part 51, appendix V.

The submittal was found to be complete and an October 20, 1997 letter

was forwarded to the Governor indicating the completeness of the

submittal and the next steps in the review process.

As requested by the State, this rulemaking action is specific to

the September 16, 1997 submittal.

2. Accurate Emission Inventory

Section 172(c)(3) of the Act requires that nonattainment plan

provisions include a comprehensive, accurate, current inventory of

actual emissions from all sources of relevant pollutants in the

nonattainment area. The emission inventory also should include a

comprehensive, accurate, and current inventory of allowable emissions

in the area. See, for example, section 110(a)(2)(K). Because the

submission of such inventories is a necessary adjunct to an area's

attainment demonstration (or demonstration that the area cannot

practicably attain), the emission

[[Page 68190]]

inventories must be received with the submission (see 57 FR 13539).

The Colorado APCD chose 1991 as the Steamboat Springs base year

emissions inventory of PM10 emissions. The results indicate

that area sources contribute approximately 99% of the total emissions

for the area, of which re-entrained road dust (including paved and

unpaved roads) contributes approximately 94% and woodburning

contributes approximately 5%. Stationary sources accounted for less

than 1% of the emission inventory. 6

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\6\ Although emissions from the Craig and Hayden power stations

were not included in the inventory because these sources are outside

the inventory domain, the emissions were included in the modelling

analyses for the SIP to determine impacts on the nonattainment area.

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EPA is approving the emission inventory because it is accurate and

comprehensive, and provides a sufficient basis for determining the

adequacy of the attainment demonstration for this area consistent with

the requirements of sections 172(c)(3) and 110(a)(2)(K) of the Act.

7 For further details see the Steamboat Springs

PM10 SIP Technical Support Document (TSD) for this action.

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\7\ EPA issued guidance on PM-10 emissions inventories prior to

the enactment of the Clean Air Act Amendments in the form of the

1987 PM-10 SIP Development Guideline. The guidance provided in this

document appears to be consistent with the revised Act.

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The September 16, 1997 submittal also establishes an emission

budget for the Steamboat Springs nonattainment area, which is to be

used for Federal conformity purposes. The PM10 mobile source

emission budget for 1999 is 16,661 pounds/day and for 2002 is 20,682

pounds/day for the modelling domain. These budgets are the 1999 and

2002 mobile source PM10 emissions presented in Section G. of

the SIP, which include emissions from vehicle exhaust, brake, and tire

wear, controlled emissions from paved roads, and unpaved road

emissions. These budgets are calculated for the emission inventory/

modelling domain, which is somewhat larger than the nonattainment area.

3. RACM (Including RACT)

As noted, the moderate PM10 nonattainment areas,

designated after the 1990 Amendments, must submit provisions to assure

that RACM (including RACT) are implemented no later than January 20,

1998 (see sections 172(c)(1) and 189(a)(1)(C)). The General Preamble

contains a detailed discussion of EPA's interpretation of the RACM

(including RACT) requirement (see 57 FR 13539-13545 and 13560-13561).

In broad terms, the State should identify available control

measures and evaluate them for their reasonableness in light of the

feasibility of the controls and the attainment needs of the area. See

57 FR 13540-13544. A State may reject an available control measure if

the measure is technologically infeasible or the cost of the control is

unreasonable. In addition, RACM does not require controls on emissions

from sources that are insignificant (i.e., de minimis) and does not

require the implementation of all available control measures where an

area demonstrates timely attainment and the implementation of

additional controls would not expedite attainment.

Colorado's SIP revision for Steamboat Springs contains control

measures for sources of re-entrained fugitive dust (including paved and

unpaved roads) and woodburning (including fireplaces and woodstoves).

In the following table, an outline is presented on these sources, their

control measures, associated emissions reduction credit, and effective

dates.

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Effective

Source category Control measure PM10 emissions reduction date

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Colorado Air Quality Control ......................... 12/30/96

Commission State Implementation

Plan-Specific Regulations for

Nonattainment Areas, Steamboat

Springs PM10 Nonattainment Area.

Re-entrained fugitive dust........ Sections VIII.B, C. & D. Require 720 kg/day or

compliance with specifications for approximately 1588 lbs/

street sanding materials, reduction day fewer PM10 emissions

in the amount of street sand than base year.

applied, and street sweeping.

Woodburning....................... Section VIII.E.--Requires continued Existing local programs

implementation of local programs to were given emission

restrict the number and type of new reduction credits in the

solid fuel burning devices in the base and attainment year

nonattainment area. emissions inventories.

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RACM does not require additional controls on other area sources

since the plan demonstrates attainment of the NAAQS and implementation

of additional controls would not further expedite attainment. Further,

RACT does not require additional controls for the stationary sources in

the Steamboat Springs nonattainment area because point source emissions

in the area are de minimis and control of such sources would not

expedite attainment of the PM10 NAAQS.

There are also other Statewide control measures that already apply

in the Steamboat Springs area, which will help curb PM10

emissions in the Steamboat Springs nonattainment area. Specifically,

Colorado Regulation No. 4 requires new wood stoves to meet the emission

requirements of EPA's Standards of Performance for New Residential Wood

Heaters in 40 CFR 60.532(b), and Colorado Regulation No. 3 regulates

the construction and modification of stationary sources of

PM10. These measures will help to

[[Page 68191]]

reduce emissions from new stationary source growth and residential wood

combustion. However, EPA is not acting on Regulation Nos. 3 and 4 at

this time because EPA has previously approved these regulations. For

further information, see the TSD accompanying this document.

A more detailed discussion of the source category contributions,

associated control measures (including available control technology),

and an explanation of why certain available control measures were not

implemented can be found in the TSD. EPA has reviewed the State's

documentation and concluded that it adequately justifies the control

measures to be implemented. The implementation of Colorado's

PM10 nonattainment plan for Steamboat Springs will result in

the attainment of the PM10 NAAQS by December 31, 1999, and

maintenance of the PM10 NAAQS through 2002. EPA is approving

the Steamboat Springs PM10 plan's control strategy as

satisfying the RACM (including RACT) requirement.

4. Demonstration

As noted, moderate PM10 nonattainment areas designated

subsequent to enactment of the 1990 Amendments must submit a

demonstration (including air quality modelling) showing that the plan

will provide for attainment as expeditiously as practicable, but no

later than the end of the sixth calendar year after an area's

designation to attainment (see section 188(c)(1) of the Act). In the

case of Steamboat Springs, this attainment deadline is December 31,

1999, or the State must show that attainment by December 31, 1999, is

impracticable.

The attainment demonstration presented in the September 16, 1997

submittal indicated that the PM10 NAAQS will be attained by

1999 in the Steamboat Springs area. The 24-hour PM10 NAAQS

is 150 micrograms/cubic meter (g/m3), and the

standard is attained when the expected number of days per calendar year

with a 24-hour average concentration above 150 g/m3

is equal to or less than one (see 40 CFR 50.6). The annual

PM10 NAAQS is 50 g/m3, and the standard

is attained when the expected annual arithmetic mean concentration is

less than or equal to 50 g/m3 (id.).

EPA regulations provide that attainment be demonstrated by means of

a proportional model or dispersion model or other procedure shown to be

adequate and appropriate for such purposes. See 40 CFR 51.112(a). In

general, EPA policy provides that the preferred approach for estimating

the air quality impacts of emissions of PM10 is to use

receptor modelling in combination with dispersion modelling.

The State utilized the monitoring and emissions data and control

measure efficiencies presented in the Steamboat Springs PM10

SIP as inputs in a dispersion modelling-based attainment demonstration.

The dispersion model was used to predict concentrations of

PM10 for the Steamboat Springs nonattainment area. The model

was first calibrated to accurately predict worst-case PM10

levels for 1991, for which monitoring data is available. Based upon

these accurate predictions for 1991, the State is confident that the

model's predictive capabilities are very good, and also confident that

the modelling results generated for the attainment year of 1999 are

reliable.

The dispersion modelling for Steamboat Springs, submitted with the

SIP on September 16, 1997, demonstrates attainment of the 24-hour

PM10 NAAQS by December 31, 1999 since the highest modelled

concentration for that year is 115 g/m3 at the

downtown Steamboat Springs receptor. Because no exceedances of the

PM10 annual NAAQS have been recorded in the Steamboat

Springs area and because the attainment demonstration submitted with

the Steamboat Springs SIP shows attainment of the 24-hour

PM10 NAAQS, EPA believes it is reasonable and adequate to

assume that protection of the 24-hour standard will be sufficient to

protect the annual standard as well. The dispersion modelling also

demonstrates maintenance of the 24-hour PM10 NAAQS by

December 31, 2002, since the highest modelled concentration for that

year is 123 g/m3. The control strategies relied on

to demonstrate timely attainment and maintenance are summarized in the

section above entitled ``RACM (including RACT).'' For a more detailed

description of the attainment and maintenance demonstrations and the

control strategies used, see the TSD accompanying this document.

5. PM10 Precursors

The control requirements that are applicable to major stationary

sources of PM10 also apply to major stationary sources of

PM10 precursors, unless EPA determines such sources do not

contribute significantly to PM10 levels which exceed the

NAAQS in that area (see section 189(e) of the Act). The General

Preamble contains guidance addressing how EPA intends to implement

section 189(e) (57 FR 13539-13542). An analysis of air quality and

emissions data for the Steamboat Springs nonattainment area indicates

that exceedances of the NAAQS are attributable chiefly to direct

particulate emissions from re-entrained road dust and residential wood

burning (i.e., area sources). The emissions inventory for Steamboat

Springs did not reveal any major stationary sources of PM10

precursors within the inventory domain. The chemical mass balance

analysis of filters from high concentration days revealed insignificant

source apportionments to secondaries (approximately 1% to ammonium

nitrates and approximately 2% to ammonium sulfates). The dispersion

modelling for the SIP included a screening of major PM10

stationary sources outside of the nonattainment area, including the

Hayden and Craig power plants, to determine impacts to the

nonattainment area. These analyses revealed insignificant source

apportionments in the nonattainment area to the Hayden and Craig power

plants, which is logical given the distances that these plants are from

the nonattainment area. Craig is approximately 37 miles from downtown

Steamboat Springs and Hayden is approximately 18.5 miles from downtown

Steamboat Springs.

Based upon the emissions inventory, chemical mass balance analyses,

and dispersion modelling, EPA believes that the overall contribution of

PM10 precursors is insignificant. Therefore, EPA is making

the determination that major sources of PM10 precursors do

not contribute significantly to PM10 levels in excess of the

NAAQS in Steamboat Springs. The consequence of this finding is to

exclude any such sources from the applicability of PM10

nonattainment area control requirements. Note that EPA's finding is

based on the current character of the area including, for example, the

existing mix of sources in the area. It is possible, therefore, that

future growth could change the significance of precursors in the area.

Further discussion of the analyses and supporting rationale for EPA's

finding are contained in the TSD accompanying this document.

6. New Source Review

On August 18, 1994 (59 FR 42500-42506), EPA approved the State's

nonattainment new source review (NSR) permitting regulations for

sources of PM10 in the State's PM10 nonattainment

areas. In that notice, EPA stated that, because the Steamboat Springs

PM10 nonattainment area SIP was not due to be submitted

until July 20, 1995, EPA would determine the approvability of the

State's NSR provisions for that nonattainment area when EPA took action

on the State's SIP submittal for

[[Page 68192]]

Steamboat Springs. Since the State's NSR regulations meet all of the

Federal requirements for new and modified major stationary sources of

PM10 locating in moderate PM10 nonattainment

areas (as discussed in the August 18, 1994 Federal Register), EPA finds

that the State has met the nonattainment NSR permitting requirements

for sources of PM10 locating in the Steamboat moderate

PM10 nonattainment area. In addition, as discussed in

Section 5. above, EPA finds that major stationary sources of

PM10 precursors do not contribute significantly to

PM10 levels in excess of the NAAQS in Steamboat Springs. The

consequence of this finding is to exclude major stationary sources of

PM10 precursors in Steamboat Springs from the applicability

of PM10 nonattainment area control requirements, including

nonattainment NSR permitting requirements. Thus, the State's

nonattainment NSR regulations for Steamboat Springs are considered

fully approvable.

7. Quantitative Milestones and Reasonable Further Progress

The PM10 nonattainment area plans demonstrating

attainment must contain quantitative emission reduction milestones

which are to be achieved every three years until the area is

redesignated attainment and which demonstrate reasonable further

progress (RFP), as defined in section 171(1), toward timely attainment.

While section 189(c) plainly provides that quantitative milestones are

to be achieved until an area is redesignated attainment, it is silent

in indicating the starting point for counting the first three-year

period or how many milestones must be initially addressed. In the

General Preamble, EPA addressed the statutory gap in the starting point

for counting the three-year milestones, indicating that it would begin

from the due date for the applicable implementation plan revision

containing the control measures for the area (i.e., November 15, 1991

for initial moderate PM10 nonattainment areas). See 57 FR

13539. As to the number of milestones, EPA believes that at least two

milestones must be initially addressed.

States containing moderate nonattainment areas designated

subsequent to enactment of the 1990 Amendments are expected to

initially submit two milestones. States are required to submit SIP's

for these areas 18 months after their redesignation as nonattainment.

The attainment date for new PM10 nonattainment areas is ``as

expeditiously as practicable'' but no later than the end of the sixth

calendar year after an area's designation as nonattainment. Therefore,

the attainment date for Steamboat Springs is December 31, 1999.

Because the SIP revision, including the quantitative milestones

element, for a new nonattainment area is due 18 months after the area

is designated as nonattainment, the first 3-year milestone is to be

achieved 4\1/2\ years after the nonattainment redesignation. Since

Steamboat Springs redesignation became effective on January 20, 1994,

the first 3-year milestone must be achieved by July 20, 1998 (i.e.,

1\1/2\ years prior to the attainment deadline). The second quantitative

milestone must be achieved three years after the first milestone or

7\1/2\ years after the nonattainment designation. In Steamboat Springs,

the second quantitative milestone must be achieved by July 20, 2001

(i.e., 1\1/2\ years after the attainment deadline if the maximum of six

years is needed to attain the PM10 NAAQS). The second

quantitative milestone should provide for continued emission reduction

progress toward attainment and should provide for continued maintenance

of the NAAQS after the attainment date for the area.8

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\8\ Section 189(c) provides that quantitative milestones are to

be achieved ``until the area is redesignated attainment.'' However,

this endpoint for quantitative milestones is speculative because

redesignation of an area as attainment is contingent upon several

factors and future events. Therefore, EPA believes it is reasonable

for States to initially address the first two milestones. Addressing

two milestones will ensure that the State continues to maintain the

NAAQS beyond the attainment date for at least some period during

which an area could be redesignated attainment. Requiring that

additional milestones be addressed, at least initially, would place

a potentially unnecessary planning burden on States containing areas

that are redesignated attainment. However, in all instances,

additional milestones must be addressed if an area is not

redesignated attainment.

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Because all of the Steamboat Springs emission control measures will

go into effect in 1996, and because measures have been developed to

keep the area in attainment through 2002, the State believes, and EPA

agrees, that the quantitative milestone requirements for emission

reductions will be achieved.

8. Enforceability Issues

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). The EPA 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). Nonattainment area plan provisions

also must contain a program to provide for enforcement of control

measures and other elements in the SIP (see section 110(a)(2)(C)).

The specific control measures contained in the SIP are addressed

above in Section II.A.3., ``RACM (including RACT).'' The Colorado Air

Quality Control Commission State Implementation Plan-Specific

Regulation for Nonattainment Areas, Section VIII. Steamboat Springs

PM10 Nonattainment Area, became effective on December 30,

1996. This regulation requires the City of Steamboat Springs to

continue implementation and enforcement of Ordinance No. 1191 (1991),

Ordinance No. 1148 (1990), Ordinance No. 1045 (1988), and Ordinance No.

977 (1987). The State regulation also requires Routt County to continue

implementation and enforcement of Resolution No. 91-032 (1991). The

ordinance and resolutions will limit future growth in emissions from

solid fuel burning devices. The State regulation also includes record

keeping requirements. The City of Steamboat Springs and Routt County

must each submit to the APCD by May 31st of each year a report that

describes the tracking and enforcement of these local control

strategies. The report must include information on compliance and

enforcement activities that have occurred during the previous year so

that the APCD can verify that the ordinances and resolution have been

properly implemented.

The Colorado Air Quality Control Commission State Implementation

Plan-Specific Regulation for Nonattainment Areas, Section VIII.,

Steamboat Springs PM10 Nonattainment Area, also details

specifications for street sanding materials, requirements for the

reduction in the amount of street sand applied, and street sweeping

requirements for Lincoln Avenue. These requirements will limit re-

entrained road dust emissions in the area. To limit woodburning

emissions in the area, the State regulation also requires continued

implementation of local programs to restrict the number and type of new

solid fuel burning devices in the nonattainment area. Annual

recordkeeping and reporting requirements are detailed for each control

strategy, as follows.

Beginning November 1, 1996, each user of street sanding materials

must submit a report to the APCD which provides a copy of all

independent tests performed on sanding materials. The report must also

include the name and address of all suppliers of street sanding

material along with a description of the location of the supplier's

aggregate pit

[[Page 68193]]

from which all material was supplied. Files must be maintained for two

years.

No later than May 31 of each year, beginning in 1997, the Colorado

Department of Transportation must submit a report to the APCD which

demonstrates compliance with the provisions for the reduction of street

sand applied for the previous sanding season. Files must be maintained

for two years.

No later than February 28 and May 31 of each year, beginning in

1997, the City of Steamboat Springs must submit a report to the APCD

which demonstrates compliance with the street sweeping requirements for

Lincoln Avenue. The reports must contain information for the period

December 1--January 31 and February 1--March 31, respectively, as

follows: (1) Date of sweeping operation; (2) specific segments of

Lincoln Avenue swept; (3) type of equipment used; (4) equipment

malfunctions and downtime, if any; (5) conditions of traffic lanes

(dry, wet, snow packed, patchy ice, etc.); and (6) general weather

conditions at time of sweeping operations. Files must be maintained for

two years.

No later than May 31 of each year, beginning in 1997, the City of

Steamboat Springs and Routt County must submit to the APCD a report

containing information that describes the tracking and enforcement of

the local woodburning ordinances and resolution. The annual report must

include information on compliance and enforcement activities that have

occurred during the previous year.

EPA has reviewed the Colorado Air Quality Control Commission State

Implementation Plan-Specific Regulations for Nonattainment Areas,

Section VIII., Steamboat Springs PM10 Nonattainment Area,

for enforceability and has determined that it meets all of the criteria

included in the September 23, 1987 Potter Memorandum.

As discussed in Section II.A.3. above, there are also State-wide

regulations that will impact the emissions of PM10 in the

Steamboat Springs nonattainment area. These regulations include

Colorado Regulation No. 4, which requires all wood stoves sold after

July 1, 1991 to meet the emission requirements of EPA's Standards of

Performance for New Residential Wood Heaters in 40 CFR 60.532(b), and

Colorado Regulation No. 3, which requires construction permits for new

or modified stationary sources. EPA previously reviewed these

regulations, and determined that they met the enforceability criteria

of the September 23, 1987 Potter Memorandum and approved them as part

of the SIP (see the TSD for information on EPA approvals of these

regulations).

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 emission

limitations and control measures adopted by the AQCC. 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. The

definition of ``person'' includes any ``municipal corporation, county,

city and county or other political subdivision of the State,'' such as

the City of Steamboat Springs and Routt County. 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, and criminal

penalties are also provided for in the State statute.

Thus, EPA has determined that the control measures contained in the

SIP revision for Steamboat Springs are enforceable and that the APCD

has adequate enforcement capabilities to ensure compliance with those

control measures and the State regulations. The TSD contains further

information on the State-wide regulations, enforceability requirements,

and a discussion of the personnel and funding intended to support

effective implementation of the control measures.

9. Contingency Measures

As provided in section 172(c)(9) of the Act, all moderate

nonattainment area SIPs that demonstrate attainment must include

contingency measures. See generally 57 FR 13510-13512 and 13543-13544.

Contingency measures should consist of other available measures that

are not part of the area's control strategy. These measures must take

effect without further action by the State or EPA, upon EPA's

determination that the area has failed to make RFP or attain the

PM10 NAAQS by the applicable statutory deadline.

The Governor of Colorado submitted PM10 contingency

measures for the Steamboat Springs area with a September 16, 1997

letter. These measures, as discussed below, require additional street

sweeping for Lincoln Avenue and the downtown core area within two

months following EPA's determination that the Steamboat Springs

moderate PM10 nonattainment area failed to attain the

PM10 NAAQS or make reasonable further progress (RFP) in

reducing emissions.

The City of Steamboat Springs will expand the sweeping program to

include the traffic lanes of Lincoln Avenue from 13th Street west for

one mile, and Lincoln Avenue from Old Fish Creek Falls Road to Pine

Grove Road. These roadways must be swept within four days of the

roadways becoming free and clear of snow and ice following each sanding

deployment, as weather and street conditions permit. In addition, the

traffic lanes of all streets within the downtown core area of Steamboat

Springs, as bounded by 3rd Street, 12th Street, Yampa, and Oak. These

roadways must be swept within four days of the roadways becoming free

and clear of snow and ice following each sanding deployment, as weather

and street conditions permit.

The State believes, and EPA agrees, that these contingency measures

are adequate since the control measures implemented in the

PM10 SIP provide a safety margin by achieving more emissions

reductions than needed to demonstrate attainment of the PM10

NAAQS, as indicated by the State's predicted 24-hour attainment

concentration of 115 g/m\3\. For a detailed discussion of

these contingency measures, see the TSD accompanying this document.

10. Emergency Episode Plan

EPA believes the Steamboat Springs emergency episode plan, as

included in the September 16, 1997 submittal, is adequate. The plan

describes the actions to be taken when conditions exist that have

historically resulted in exceedances of the 24-hour PM10

standard. Voluntary and mandatory activities include suspension of open

burning, curtailment of wood/coal burning, and reduction of non-

essential motor vehicle operations. For details on the emergency

episode plan, please see the TSD.

11. Revisions to the Nonattainment Area Boundary

The Steamboat Springs nonattainment area boundary as codified in

the Federal Register notice published on December 21, 1993 (see 58 FR

67334) is currently defined as the Steamboat Springs area airshed. See

40 CFR 81.306. This boundary description was intended to be responsive

to comments received from the State of Colorado on EPA's September 22,

1992 proposed rulemaking to redesignate the area to nonattainment (see

57 FR 43846). In those comments, the State indicated that on June 20,

1991 the AQCC adopted a map which outlined the Steamboat Springs

PM10 nonattainment area. The map identified the

nonattainment area

[[Page 68194]]

as a portion of Routt County which included the City of Steamboat

Springs, as well as certain surrounding areas in Routt County. With its

PM10 SIP submittal dated August 12, 1996, the State provided

a clearer description of the boundary by providing a legal description

of the map outline. The following legal description of the

nonattainment area represents the map outline adopted by the AQCC and

used by APCD for SIP purposes:

On the East--The Routt National Forest.

On the South--The southern border of sections 19, 10, 21, T4N, R84W

of the 6th P.M. and the southern border of sections 23, 24, T4N, R85W

of the 6th P.M.

On the West--Beginning at the south western corner of section 23,

T4N, R85W of the 6th P.M. North along the western border of sections

23, 14, 11, T4N, R85W. Thence, along the ridge which bisects sections

35, 36, 25, 24, 13, 14, 11, 12, 1, T5N, R85W, and sections 36, 25, 24,

T6N, R85W. Thence heading northwest along the ridge which bisects

sections 23, 15, 10, 9,4, T6N, R85W of 6th P.M. Thence, heading

northeast along the ridge which bisects sections 33, 34, 35, 36, 25,

T7N, R85W and sections 30 and 10 of T7N, R84W. Thence, north along the

N 1/2 of the western edge of section 19, to the NW corner of section

18, T7N, R84W.

On the North--The northern boundary of sections 16, 17, 18, T7N,

R84W of 6th P.M.

The boundary was determined to be the reasonable Steamboat Springs

air shed by considering factors such as local topography, meteorology,

emissions sources, land use practices, and tourism. EPA is replacing

the boundary description currently in 40 CFR 81.306 with this revised

description to more clearly define the nonattainment area.

B. Update to Code of Federal Regulations

EPA is also updating 40 CFR 52.332, Moderate PM10

nonattainment area plans, to reflect the approved status of the

Telluride moderate PM10 nonattainment area plan. EPA

approved that SIP on October 4, 1996 (61 FR 51784), but neglected to

update 40 CFR 52.332 at that time.

III. Final Action

EPA is approving the elements of the PM10 SIP for the

Steamboat Springs, Colorado nonattainment area that were due on July

20, 1995 and submitted to EPA by the Colorado Governor with a letter

dated September 16, 1997, including among other things, control

measures, technical analyses, quantitative milestones and contingency

measures. Additionally, EPA is approving the Steamboat Springs

emergency episode plan. EPA is also amending the boundary description

for the Steamboat Springs nonattainment area to clarify the original

description.

Note that per an October 29, 1997 letter from the State, EPA is not

acting on revisions to the Ambient Air Quality Standards for the State

of Colorado which were included in the September 16, 1997 SIP submittal

for informational purposes only.

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 March 2, 1998 unless, by January 30, 1998 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 on March 2, 1998.

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. Administrative Requirements

A. Executive Order 12866

The Office of Management and Budget (OMB) has exempted this

regulatory action from E.O. 12866 review.

B. Regulatory Flexibility Act

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 economic 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

Clean Air Act do not create any new requirements but simply approve

requirements that the State is already imposing. Therefore, because the

Federal SIP approval does not impose any new requirements, the

Administrator certifies 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 Clean Air Act 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 (1976); 42 U.S.C. 7410(a)(2).

C. Unfunded Mandates

Under Section 202 of the Unfunded Mandates Reform Act of 1995

(``Unfunded Mandates Act''), 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 impacted 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 either State, local, or tribal governments in the

aggregate, or to the private sector. This Federal action proposes to

approve 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.

D. Submission to Congress and the General Accounting Office

Under 5 U.S.C. 801(a)(1)(A) as added by the Small Business

Regulatory Enforcement Fairness Act of 1996, EPA submitted a report

containing this rule and other required information to the U.S. Senate,

the U.S. House of

[[Page 68195]]

Representatives and the Comptroller General of the General Accounting

Office prior to publication of this rule in today's Federal Register.

This rule is not a ``major rule'' as defined by 5 U.S.C. 804(2).

E. Petitions for Judicial Review

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 March 2, 1998. 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).)

List of Subjects

40 CFR Part 52

Environmental protection, Air pollution control, Hydrocarbons,

Incorporation by reference, Intergovernmental relations, Nitrogen

dioxide, Particulate matter, Reporting and recordkeeping requirements,

Sulfur dioxide, and Volatile organic compounds.

40 CFR Part 81

Air pollution control, National parks, Wilderness areas.

Dated: November 4, 1997.

Jack W. McGraw

Acting Regional Administrator.

40 CFR Parts 52 and 81 are amended as follows:

PART 52--[AMENDED]

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

Authority: 42 U.S.C. 7401 et seq.

2. Section 52.320 is amended by adding paragraph (c)(76) to read as

follows:

Sec. 52.320 Identification of plan.

* * * * *

(c) * * *

(76) The Governor of Colorado submitted the moderate nonattainment

area PM10 State Implementation Plan (SIP) for Steamboat

Springs, Colorado with a letter dated September 16, 1997. The submittal

was made to satisfy those moderate PM10 nonattainment area

SIP requirements due for Steamboat Springs on July 20, 1995, including

among other things, control measures, technical analyses, quantitative

milestones, and contingency measures. The September 16, 1997 submittal

also included the Steamboat Springs emergency episode plan.

(i) Incorporation by reference.

(A) Colorado Air Quality Control Commission Nonattainment Areas, 5

CCR 1001-20, Section VIII., Steamboat Springs PM10

Nonattainment Area, adopted October 17, 1996 and effective on December

30, 1996.

(ii) Additional material.

(A) An October 29, 1997 letter from Margie M. Perkins, APCD, to

Richard R. Long, EPA, clarifying that the regulation entitled ``Ambient

Air Quality Standards for the State of Colorado'' was included in the

September 16, 1997 Steamboat Springs SIP submittal for informational

purposes only.

* * * * *

3. Section 52.329 is amended by revising paragraph (a) to read as

follows:

Sec. 52.329 Rules and regulations.

(a) On January 14, 1993, the Governor of Colorado submitted

revisions to the State's nonattainment new source review permitting

regulations to bring the State's regulations up to date with the 1990

Amendments to the Clean Air Act. With these revisions, the State's

regulations satisfy the part D new source review permitting

requirements for the following nonattainment areas: the Canon City,

Lamar, Pagosa Springs, Aspen, Telluride, and Steamboat Springs moderate

PM10 nonattainment areas, the Denver/Metro Boulder,

Longmont, Colorado Springs, and Fort Collins moderate carbon monoxide

nonattainment areas, the Greeley not classified carbon monoxide

nonattainment area, and the Denver transitional ozone nonattainment

area.

* * * * *

4. Section 52.332 is amended by adding paragraphs (g) and (h) to

read as follows:

Sec. 52.332 Moderate PM10 nonattainment area plans.

* * * * *

(g) On March 17, 1993, December 9, 1993, and April 22, 1996, the

Governor of Colorado submitted the moderate PM10

nonattainment area plan for Telluride. The submittals were made to

satisfy those moderate PM10 nonattainment area SIP

requirements which were due for Telluride on November 15, 1991. The

December 9, 1993 submittal was also made to satisfy the PM10

contingency measure requirements which were due for Telluride on

November 15, 1993.

(h) On September 16, 1997 the Governor of Colorado submitted the

moderate PM10 nonattainment area plan for Steamboat Springs.

The submittal was made to satisfy those moderate PM10

nonattainment area SIP requirements which were due for Steamboat

Springs on July 20, 1995.

PART 81--[AMENDED]

1. The authority citation for part 81 continues to read as follows:

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

2. In Sec. 81.306, the table for Colorado-PM10

Nonattainment Areas is amended under Routt County (part) by revising

the entry for ``The Steamboat Springs Area Airshed'' to read as

follows:

Sec. 81.306 Colorado.

* * * * *

Colorado--PM-10 Nonattainment Areas

----------------------------------------------------------------------------------------------------------------

Designation Classification

Designated area ----------------------------------------------------------------------------

Date Type Date Type

----------------------------------------------------------------------------------------------------------------

* * * * *

* *

Routt County (part)--Steamboat 1/20/94 Nonattainment.................. 1/20/94 Moderate.

Springs.

On the East--The Routt National

Forest.

On the South--The southern border

of sections 19, 10, 21, T4N, R84W

of the 6th P.M. and the southern

border of sections 23, 24, T4N,

R85W of the 6th P.M.

[[Page 68196]]

On the West--Beginning at the

southwestern corner of section 23,

T4N, R85W of the 6th P.M. North

along the western border of

sections 23, 14, 11, T4N, R85W.

Thence, along the ridge which

bisects sections 35, 36, 25, 24,

13, 14, 11, 12, 1, T5N, R85W, and

sections 36, 25, 24, T6N, R85W.

Thence heading northwest along the

ridge which bisects sections 23,

15, 10, 9,4, T6N, R85W of 6th P.M.

Thence, heading northeast along

the ridge which bisects sections

33, 34, 35, 36, 25, T7N, R85W and

sections 30 and 10 of T7N, R84W.

Thence, north along the N \1/2\ of

the western edge of section 19, to

the NW corner of section 18, T7N,

R84W.

On the North--The northern boundary

of sections 16, 17, 18, T7N, R84W

of 6th P.M.

* * * * *

* *

----------------------------------------------------------------------------------------------------------------

* * * * *

[FR Doc. 97-33958 Filed 12-30-97; 8:45 am]

BILLING CODE 6560-50-P