Approval and Promulgation of State Implementation Plans; Colorado; Revisions to Opacity and Sulfur Dioxide Requirements

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[CO-001-0031; FRL-6432-7]

Approval and Promulgation of State Implementation Plans;

Colorado; Revisions to Opacity and Sulfur Dioxide Requirements

AGENCY: Environmental Protection Agency (EPA).2

ACTION: Proposed rule.

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

SUMMARY: On May 27, 1998, the Governor of Colorado submitted revisions

to the State Implementation Plan (SIP). Specifically, the State

submitted revisions to Colorado Regulation No. 1 to provide coal-fired

electric utility boilers with certain exemptions from the State's pre-

existing limitations on opacity and sulfur dioxide (SO2)

emissions during periods of startup, shutdown, and upset. The EPA is

proposing to disapprove these revisions to the Colorado SIP because the

revisions are not consistent with the Clean Air Act (Act) and

applicable Federal requirements. The effect of this disapproval will be

that the previous version of Colorado Regulation No. 1 (which did not

contain any exemptions from the SO2 emission limitations and

which generally provided for a 30% opacity limit during periods of

startup, as well as fire building, cleaning of fire boxes, soot

blowing, process modification, or adjustment of control equipment) will

remain part of the Federally enforceable SIP.2

DATES: Written comments must be received on or before October 4, 1999.2

ADDRESSES: Written comments may be mailed to Richard R. Long, Director,

Air and Radiation Program, Mailcode 8P-AR, Environmental Protection

Agency (EPA), Region VIII, 999 18th Street, Suite 500, Denver, Colorado

80202-2466. Copies of the documents relevant to this action are

available for public inspection during normal business hours at the Air

and Radiation Program, Environmental Protection Agency, Region VIII,

999 18th Street, Suite 500, Denver, Colorado 80202-2466. Copies of the

State documents relevant to this action are available for public

inspection at the Air Pollution Control Division, Colorado Department

of Public Health and Environment, 4300 Cherry Creek Drive South,

Denver, Colorado 80222-1530.2

FOR FURTHER INFORMATION CONTACT: Vicki Stamper, EPA Region VIII, (303)

312-6445.2

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Background of Submittal

A. Revisions to Opacity Standards

B. Revisions to SO2 Emission Limitations

II. EPA's Analysis of State's Submittal

A. Procedural Background

B. Analysis of State's Submittal

1. It Does Not Appear the State Has Adequately Addressed the

Requirements of Section 193 of the Act

2. It Does Not Appear the State Has Adequately Addressed the

Requirements of Section 110(l) of the Act

3. It Does Not Appear the State Has Addressed the Requirements

of 40 CFR 51.166(a)(2)

4. The SIP Revision Does Not Appear to Meet the Act's

Requirements That SIP Measures Be Enforceable

5. The SIP Revision Appears To Be Inconsistent With the

Requirements of the Act Regarding Continuous Compliance

6. EPA Invites Comment on Whether the SIP Revision Conflicts

With EPA's Any Credible Evidence Rule

III. Proposed Action

IV. Administrative Requirements

A. Executive Order 12866

B. Executive Order 12875

C. Executive Order 13045

D. Executive Order 13084

E. Regulatory Flexibility Act

F. Unfunded Mandates

I. Background of State Submittal

On May 27, 1998, the Governor of Colorado submitted revisions to

the Colorado SIP. The SIP submittal consisted of revisions to Colorado

Regulation No. 1 to provide exemptions from the existing limitations on

opacity and SO2 emissions for coal-fired electric utility

boilers during periods of startup, shutdown, and upset.

These revisions were adopted by the Colorado Air Quality Control

Commission (AQCC) on December 23, 1996. The revisions became effective

at the State level on March 2, 1997 for most sources. However, for

coal-fired electric utility boilers located within the Denver Metro PM-

10 non-attainment area, the AQCC specified that the provisions will not

become State-effective until EPA issues a final rule adopting the

revisions to Regulation No. 1 as a permanent part of the SIP.

The following explains in detail the revisions to Regulation No. 1

that the Governor submitted on May 27, 1998:

A. Revisions to Opacity Standards

Prior to these revisions to Regulation No. 1, sections II.A.1. and

4. of Regulation No. 1 generally required all sources to meet a 20%

opacity limit, except during periods of fire building, cleaning of fire

boxes, soot blowing, startup, process modification, or adjustment of

control equipment. During these periods, a 30% opacity limit applied,

except the regulation allowed one 6-minute period in excess of 30%

opacity in any sixty consecutive minutes. (In both the revised

Regulation No. 1 and the pre-existing Regulation No. 1, compliance with

the opacity limits is based on a six-minute average.) The revisions to

Regulation No. 1 that the Governor submitted on May 27, 1998 amended

these opacity requirements for coal-fired electric utility boilers.

Specifically, the State

[[Page 48128]]

added a provision in section II.A.10. of Regulation No. 1 governing

opacity at coal-fired electric utility boilers during startup,

shutdown, and upset. (Colorado defines ``upset conditions'' in its

Common Provisions Regulation as ``an unpredictable failure of air

pollution control or process equipment which results in the violation

of emission control regulations and which is not due to poor

maintenance, improper or careless operations, or is otherwise

preventable through exercise of reasonable care.'') Section II.A.10.

provides that, during periods of startup, shutdown, and upset, owners

and operators of coal-fired electric utility boilers must, to the

extent practicable, maintain and operate each such source including

associated air pollution control equipment in a manner consistent with

good air pollution control practice for minimizing emissions. This

provision also states that determination of whether acceptable

operating and maintenance procedures are being used will be based on

information available to the State, including monitoring results,

opacity observations, review of operating and maintenance procedures,

operator training, and inspection of the source.

Another provision in section II.A.10.c. of Regulation No. 1 states

that a source is not being maintained and operated in accordance with

good air pollution control practice for minimizing emissions if the

source's exceedance time (excluding exceedance time related to (1)

significant planned maintenance outage (PMO) startups, and (2)

emissions associated with periods that the unit is not ``on line,''

where ``on line'' is defined as fuel being fed to the boilers and the

fans are on) expressed as a percentage of total operating time,

calculated on a quarterly basis, exceeds the following ``exceedance

percentage time allowance:'' (1) for sources using baghouses for the

control of particulate matter, 0.8%; and (2) for sources using

electrostatic precipitators (ESPs) for the control of particulate

matter, 2% through March 31, 2000 and 1.5% beginning April 1, 2000. In

enforcing this exceedance percentage time allowance, section II.A.10.e.

of Regulation No. 1 provides that the State may consider each day on

which one or more excess emission periods occur during the remainder of

a given quarter, following the day on which the exceedance percentage

time allowance is exceeded in that quarter, to be a separate day of

violation for the purposes of assessing any penalties that may be

allowed.

Last, a provision was added in section II.A.10.d. of Regulation No.

3 stating that no specific opacity limits shall be in effect for coal-

fired electric utility boilers for the startup period following a

significant PMO, provided the following conditions are met:

1. Written notification is provided to the State no less than 30

days prior to shutting the unit down for the PMO. The notification must

include a plan for minimizing emissions during the startup and an

estimation of the period that the control equipment will not be

operated while the boiler is started up;

2. Throughout the startup following the PMO, the operator shall, to

the extent practicable, maintain and operate each source including the

associated air pollution control equipment in a manner consistent with

good air pollution control practice for minimizing emissions; and

3. During any PMO startup, the source shall place any air pollution

control equipment in service no later than the manufacturer's

specifications allow.

Section II.A.10.d. also provides that significant PMO startups

shall not exceed one event in any two consecutive years, and that a PMO

startup shall ``not normally exceed 14 days in duration,'' although the

State may extend this time period for good cause. Last, this provision

defines startup for the purposes of significant PMOs to be the period

of time beginning with the point of setting the unit into operation and

ending with the points when: (1) the generator is synchronized and is

operating at or greater than a specific unit's minimum load; (2)

primary fuel is being burned and the burners are in service without

stabilizing fuel being burned in the boiler; and (3) any air pollution

control equipment has reached minimum normal operating design

conditions consistent with manufacturer's specifications (as defined by

temperature, on a unit-by-unit basis).

B. Revisions to SO2 Emission Limitations

Section VI. of Regulation No. 1 contains SO2 emission limitations

for various source categories which vary depending on whether the

source was issued an emission permit before August 1, 1977 (i.e.,

defined as an ``existing source'') or issued an emissions permit on or

after August 1, 1977 (i.e., defined as a ``new source''). Before the

revisions to Regulation No. 1 that the Governor submitted on May 27,

1998, section VI.B.4.a. of Regulation No. 1 required new coal-fired

operations, including coal-fired steam generators, to meet the

following SO2 emission limits:

(1) 1.2 pounds (lbs) SO2 per million British Thermal Units (BTU) of

coal heat input for units converted from other fuels to coal and for

units with a coal heat input of less than 250 million BTU per hour; and

(2) 0.4 lbs SO2 per million BTU coal heat input for units with a

coal heat input of 250 million BTU per hour or greater.

There were no exemptions from these SO2 emission limits.

In the May 27, 1998 submittal, the State revised section VI.B.4.a.

to add a new subsection (iv), which states that, during periods of

startup, shutdown, and upset, owners and operators of coal-fired

electric utility boilers must, to the extent practicable, maintain and

operate each such source including associated air pollution control

equipment in a manner consistent with good air pollution practice for

minimizing emissions. This provision also states that determination of

whether acceptable operating and maintenance procedures are being used

will be based on information available to the State, including

monitoring results, opacity observations, review of operating and

maintenance procedures, operator training and inspection of the source.

The State also added a provision stating that, for those coal-fired

electric utility boilers subject to 40 CFR part 60, subpart Da (i.e.,

those coal-fired electric utility boilers for which construction or

modification commenced after September 18, 1978), the source is not

being maintained and operated in accordance with good air pollution

control practice for minimizing emissions if the source's exceedance

time expressed as a percentage of total operating time, calculated on a

quarterly basis, exceeds 1%.

Last, the State revised section VI.B.2. of Regulation No. 1.

Section VI.B.2. of Regulation No. 1 previously specified a 3-hour

averaging time for all new source emission standards for SO2. This

section further stated that any 3-hour rolling average of emission

rates which exceeded the emission standards in section VI.B. of

Regulation No. 1 would be a violation of the State's regulation. The

State added the phrase ``unless specified in a permit'' to the

beginning of this section, in order to allow the State to use the

permit process to specify an averaging time other than 3 hours for a

specific source.

II. EPA's Analysis of State's Submittal

A. Procedural Background

The Act requires States to observe certain procedural requirements

in developing implementation plans and plan revisions for submission to

EPA. Sections 110(a)(2) and 110(l) of the Act

[[Page 48129]]

provides that each revision to an implementation plan submitted by a

State must be adopted after reasonable notice and public hearing. The

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, April 16, 1992). The EPA's completeness criteria for SIP

submittals are set out at 40 CFR part 51, appendix V. The EPA attempts

to make completeness determinations within 60 days of receiving a

submission. However, a submittal is deemed complete by operation of law

under section 110(k)(1)(B) if a completeness determination is not made

by EPA within six months after receipt of the submission.

To entertain public comment on the revisions to Regulation No. 1

regarding coal-fired electric utility boilers, the Colorado AQCC held

public hearings on December 19, 20, and 23, 1996. Following the public

hearings, the regulation revisions were adopted by the AQCC. The

Governor initially submitted the revisions to EPA for approval on

October 31, 1997.

EPA found the initial SIP submittal incomplete and notified the

State of such finding in a January 12, 1998 letter. EPA requested

further information from the State pertaining to the AQCC's adoption of

the Regulation No. 1 revisions, due to the fact that the Sierra Club

and other plaintiffs had challenged the revisions in State court on the

grounds that the AQCC had failed to follow applicable State law

procedures in adopting the revisions. (See Cunningham v. Colorado Air

Quality Control Commission, Denver District Court, Case No. 97 CV

1808).

On May 27, 1998, the Governor of Colorado resubmitted the revisions

to Regulation No. 1 to EPA for approval. The resubmittal included a

letter from the Colorado Attorney General's Office opining that the

AQCC had followed applicable procedures in adopting the revisions. On

August 7, 1998, the Denver District Court issued an Order Affirming

Administrative Action that affirmed the AQCC's adoption of the

revisions.

EPA did not issue a completeness or an incompleteness finding for

the May 27, 1998 SIP submittal. Thus, pursuant to section 110(k)(1)(B),

the May 27, 1998 submittal was deemed complete by operation of law on

November 29, 1998 (i.e., six months from the date of receipt).

B. Analysis of State's Submittal

EPA has reviewed the State's May 1998 SIP submittal against the

relevant requirements of the Act, Federal regulations, and EPA policy

and guidance. EPA has identified several issues with the State's SIP

revision, as follows:

1. It Does Not Appear the State Has Adequately Addressed the

Requirements of Section 193 of the Act

For SIP provisions which EPA approved before November 15, 1990,

section 193 prohibits SIP modifications applicable within a

nonattainment area unless the modification insures equivalent or

greater emissions reductions of the pollutant for which the area is

nonattainment.

EPA approved the existing opacity and SO2 provisions in Regulation

No. 1 as part of the SIP prior to the enactment of the 1990 amendments

to the Act (i.e., prior to November 15, 1990). There are four coal-

fired power plants in the Denver metro PM-10 nonattainment area that

are affected by the State's revisions. The State's SIP revisions do not

impact any other nonattainment area in Colorado because there are no

affected coal-fired power plants in any of the State's other PM-10

nonattainment areas, and because the State does not have any SO2

nonattainment areas.

In the Denver metro PM-10 nonattainment area, SO2 emissions have

been determined to contribute significantly to PM-10 exceedances (see

section 189(e) of the Act and 58 FR 66331, December 20, 1993). However,

the revisions to the SO2 requirements in Regulation No. 1 only impact

coal-fired electric utility boilers which are subject to 40 CFR part

60, subpart Da, and there are no such coal-fired electric utility

boilers located within the Denver metro PM-10 nonattainment area. Thus,

the requirements of section 193 of the Act apply only to the State's

changes to the opacity requirements in Regulation No. 1, as they impact

the four coal-fired power plants in the Denver metro PM-10

nonattainment area.

The AQCC concluded that the revisions to Regulation No. 1 would

result in at least equivalent emissions reductions as the pre-existing

Regulation No. 1 provisions. In other words, the AQCC believed that the

revisions did not represent a relaxation of the existing rule.

Specifically, the AQCC's Statement of Basis states the following:

The regulatory change removing application of the 30% opacity

limit appears on first impression to relax requirements for these

units. However, by limiting the overall time during which the units

may exceed the 20% opacity limit, the Commission believes this

approach will result in at least the same levels of compliance with

the opacity standard and will likely result in lower overall

emissions.1

\1\ The State's Statement of Basis is somewhat unclear regarding

the reduced application of the 30% opacity standard and the baseline

for analyzing whether the rule change represents a relaxation. The

language of the revised Regulation No. 1 appears to be clear that

the 30% opacity limit continues to apply to fire building, cleaning

of fire boxes, soot blowing, process modification, or adjustment of

control equipment (unless these activities occur during a

significant PMO startup or a period when fuel is not being fed to

the boiler). In its discussion of section 193 of the Act, the State

does not draw this distinction. The State also fails to mention

that, under the provisions of Regulation No. 1, sources were

required to meet a 20% opacity limit during shutdown.

EPA does not believe the AQCC's conclusion is adequately supported.

The Statement of Basis explains that the State's enforcement discretion

has been exercised to effectively allow 5% noncompliance by electric

power plants. It also states that ``substantial regulatory ambiguity''

in the opacity limitations that previously applied during startup and

other periods led to lower compliance levels. Thus, the AQCC concluded

that the revisions to Regulation No. 1 are substantially equivalent or

better in their impact on emissions because a higher rate of compliance

is expected under the revised Regulation No. 1.2

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

\2\ In another part of the Statement of Basis, the AQCC

concluded that ``the changes made in this rulemaking will not lead

to increased emissions in amounts substantial enough to interfere

with the State's programs to attain and maintain the National

Ambient Air Quality Standards (NAAQS) or other federal

requirements.'' Here, the AQCC appears to concede that increased

emissions will result from the rule change.

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

EPA does not agree that the State's enforcement practices under the

previous version of Regulation No. 1 should be taken into account in

determining the stringency of the previous version of the rule or in

determining whether a SIP modification meets the requirements of

section 193 of the Act. The language of Regulation No. 1, on its face,

did not permit sources to exceed the applicable opacity limitations up

to 5% of the time. Thus, the fact that the State used enforcement

discretion in determining which types of violations to spend resources

and time pursuing has no impact on whether EPA or citizens could

enforce the requirements of Regulation No. 1 or whether sources were

obligated to comply with those requirements on a continuous basis. In

fact, a citizens group successfully enforced the opacity provisions of

Regulation No. 1 for violations at a coal-fired power plant that

complied with the opacity limitations of Regulation No. 1 more than 95%

of the time. See Sierra Club

[[Page 48130]]

v. Public Service Company of Colorado, 894 F. Supp. 1455 (D. Colo.

1995).

Application of the AQCC's rationale regarding enforcement

discretion would lead to an odd result: States with the least robust

enforcement programs could most easily meet section 193's equivalency

requirements. EPA does not believe Congress intended such a result when

it enacted section 193 of the Act.

Further, even though the revisions to Regulation No. 1 define when

a coal-fired electric utility boiler is not complying with good air

pollution control practices for minimizing emissions by specifying an

exceedance percentage time allowance, there is nothing in the revisions

that prevents the State from continuing to use enforcement discretion

in implementing the new provisions. Thus, there is no guarantee that

this new provision will be enforced any more stringently than the

previous version of Regulation No. 1. In fact, section II.A.10.e. of

Regulation No. 1 merely states that the State may assess penalties on a

violation-per-day basis.

EPA also disagrees with the AQCC's assertion that the prior version

of Regulation No. 1 was ambiguous. The AQCC does not explain what was

ambiguous about the prior version of the regulation. EPA believes the

previous version of Regulation No. 1 was clear in requiring a 20%

opacity limit to be met at all times, except for periods of fire

building, cleaning of fire boxes, soot blowing, startup, process

modification, or adjustment of control equipment. During those periods,

a 30% opacity limit applied, with one 6-minute period in excess of 30%

opacity allowed in any sixty consecutive minutes. The only provision in

the State's rules that explained when an exceedance would not be

considered to be a violation of the rules was the State's upset

provision in section II.E. of the Common Provisions Regulation, which

provided that upset conditions (as defined in the Common Provisions

Regulation) would not be considered to be a violation if certain

notification requirements were met (and, presumably, if the upset met

the State's definition--i.e., it was not due to poor maintenance,

improper or careless operation, or was otherwise preventable through

exercise of reasonable care).

EPA also believes the AQCC's analysis ignores critical features of

the proposed revisions to Regulation No. 1. Specifically, the AQCC

ignores the fact that, under the revisions to Regulation No. 1,

exceedances of the exceedance percentage time allowance during startup,

shutdown, or upset conditions would not be considered violations of the

opacity limitation and would not be penalized for each 6-minute

exceedance. Instead, exceedances of the exceedance percentage time

allowance during startup, shutdown, or upset conditions would only be

considered violations of the requirement for good air pollution control

practice for minimizing emissions and would only be penalized on a one-

violation-per-day basis. The prospect of fewer violations and lower

penalties would reduce sources' incentive to keep their emissions low

during startup, shutdown, and upset, and would likely lead to higher

emissions of PM-10 under the revised rule than under the Federally

approved rule.

Also, under the State's revisions, instead of being subject to a

20% opacity limit during shutdowns and a 30% opacity limit during

startups, sources may emit up to 100% opacity during startup, shutdown,

and upset conditions if, to the extent practicable, they exercised good

air pollution control practice for minimizing emissions. These sources

are potentially allowed up to 43.2 hours of 100% opacity in one

calendar quarter, if equipped with ESPs, and up to 17.3 hours of 100%

opacity in one calendar quarter, if equipped with baghouses, without

being considered in violation of the good air pollution control

practice standard.

In addition, the AQCC's analysis ignores the provision in the

revised regulation that exempts significant PMO startups from the

opacity limits. Under the revised Regulation No. 1, sources engaged in

a significant PMO startup could potentially emit at 100% opacity for

fourteen days or longer. Under the previous version of Regulation No.

1, emissions during a significant PMO startup would have been subject

to a 30%, and sometimes to a 20%, opacity limit. It appears that the

State's analysis fails to consider equivalency on a short-term basis,

such as 24 hours, that is directly relevant to the National Ambient Air

Quality Standards (NAAQS).

For the reasons stated, EPA does not believe the revisions to

Regulation No. 1 will insure equivalent or greater reductions of PM-10

as required by section 193 of the Act. Thus, EPA does not believe it

can approve the revisions.

2. It Does Not Appear the State Has Adequately Addressed the

Requirements of Section 110(l) of the Act

Section 110(l) of the Act provides that EPA cannot approve a

revision to a SIP if the revision would interfere with any applicable

requirement concerning attainment and reasonable further progress, or

any other applicable requirement of the Act. Section 110(l) applies to

SIP revisions affecting both attainment or unclassifiable areas, as

well as nonattainment areas. For attainment or unclassifiable areas,

analysis of proposed changes under this provision should, among other

things, focus on the 110(a)(1) requirement for maintenance of the

NAAQS.

As discussed above, the State does not consider the revisions to

Regulation No. 1 regarding coal-fired electric utility boilers to be a

relaxation of the SIP, a conclusion with which EPA disagrees. However,

the State's submittal did include a study commissioned by the Colorado

Utilities Coalition for Clean Air regarding the ambient impacts during

startup and shutdown at electric utility units, which the AQCC relied

upon in its rulemaking.3

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

\3\ The study analyzed impacts on PM-10 and PM-2.5. The recent

U.S. Court of Appeals decision in American Trucking Associations,

Inc. v. USEPA, Nos. 97-1440 and 97-1441 (D.C. Cir., May 14, 1999)

did not vacate the PM-2.5 standard promulgated on July 18, 1997. In

any event, EPA is not relying on potential adverse impacts on PM-2.5

as a basis to disapprove the revisions to Regulation No. 1. The D.C.

Circuit's decision had no impact on the pre-July 18, 1997 PM-10

standard. That standard remains in place in Colorado, and EPA has an

ongoing responsibility under the Act to ensure the standard is

attained and maintained.

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

EPA has reviewed the study included in the SIP submittal and has

found many flaws in the analysis. The study was based on startup and

shutdown data from four coal-fired electric utility boilers (out of

twenty-five in the entire State), but there was no information provided

to explain why these four units were chosen or how they were

representative of the potential ambient air issues from all of the

twenty-five coal-fired electric utility boilers in the State. The

modeling analysis projected ambient particulate matter impacts from

each of the four units, in addition to background PM concentrations,

that were less than the 24-hour PM-10 NAAQS. However, based on the

information submitted, it is apparent that the modeling analysis did

not follow the requirements contained in the EPA Guideline on Air

Quality Models. (See 40 CFR part 51, appendix W).

The emissions used in the modeling demonstration did not capture

the potentially most adverse emissions scenarios associated with

startup and shutdown. For example, it appears that the modeling

analysis was based on actual emissions from a sample start-up/shutdown

sequence that was simply repeated in the model throughout the year. The

EPA's Guideline on Air

[[Page 48131]]

Quality Models requires that, in testing for compliance with 24-hour

standards, worst case hourly emission rates (from the test sequence)

must be used in the model for every hour of the year. Also, the

meteorological data and selection of modeling input options was

problematic. It appears that only one year of National Weather Service

meteorology data was used in the modeling analysis, while the EPA

Modeling Guideline requires that five years of such data be used. If

the additional four years of meteorology data had been used in the

modeling, it is likely that more adverse dispersion situations and

higher ambient impacts would have been predicted. Further, the modeling

only analyzed whether emissions from one unit, considering background

concentrations, would cause a violation of the NAAQS. The modeling did

not analyze whether the emissions from one unit during startup or

shutdown would contribute to a violation, considering emissions from

other nearby sources in the area. (Each of the units modeled in the

study is collocated with two to four other coal-fired electric utility

boilers.)

In addition, the study only looked at particulate matter impacts,

and it did not address the revisions to the SO2 limits whatsoever.

Thus, EPA believes the modeling analysis included in the SIP

submittal cannot be relied upon because of its overall noncompliance

with the EPA Guideline on Air Quality Models, nor can the Agency rely

on it to conclude that the SIP revision will not interfere with

attainment or maintenance of the NAAQS.

3. It Does Not Appear the State Has Addressed the Requirements of 40

CFR 51.166(a)(2)

40 CFR 51.166(a)(2) requires that, if a SIP revision would result

in increased air quality deterioration over any baseline concentration,

the SIP revision must include a demonstration that it will not cause or

contribute to a violation of the applicable increment(s). The

demonstration does not need to be done for those section 107

attainment/unclassifiable areas (as identified in 40 CFR part 81) where

the minor source baseline date has not been triggered prior to

submittal of the SIP revision, although the State is still required

under 40 CFR 51.166(a)(4) to periodically review the adequacy of its

plan to prevent significant deterioration of air quality.

According to EPA's prevention of significant deterioration (PSD)

regulations, the ``baseline concentration'' represents the ambient

concentration that exists in the baseline area at the time of the

applicable minor source baseline date. The baseline concentration

includes the actual emissions of sources in existence on the minor

source baseline date, excluding (1) the actual emissions from any major

stationary source on which construction occurred after the ``major

source baseline date''--January 6, 1975 for sources of particulate

matter and SO2; and (2) the actual emissions increases and decreases at

any stationary source occurring after the minor source baseline date.

(See 40 CFR 51.166(b)(13).) Thus, once the minor source baseline date

is triggered for an area, any changes in emissions at any stationary

source impact the available maximum increase allowed over the baseline

concentration (i.e., the increment). In Colorado, the SO2 minor source

baseline date was triggered Statewide as of October 12, 1977 and the

particulate matter minor source baseline dates have been triggered for

a large part of the State (each ``air quality control region'' in the

State has a different minor source baseline date for particulate

matter).

As discussed above, EPA believes the changes to the opacity

provisions in Regulation No. 1 represent a relaxation from existing

requirements that will allow increased emissions into the air. EPA also

believes the revisions to the SO2 provisions are a relaxation that

would allow more SO2 emissions into the air. Thus, in those parts of

Colorado where the minor source baseline date has been triggered, this

SIP revision would potentially allow increased deterioration over

baseline concentration. As discussed above, the State did not consider

the revised Regulation No. 1 to be a relaxation of existing emission

limits. Thus, the State did not address the requirements of 40 CFR

51.166(a)(2). However, EPA believes this SIP revision would allow

increased deterioration of air quality over the baseline concentration

in some parts of the State and, therefore, a demonstration is required

to show that the SIP revision will not cause or contribute to a

violation of the applicable increment(s).

4. The SIP Revision Does Not Appear To Meet the Act's Requirements That

SIP Measures Be Enforceable

Section 110(a)(2)(A) of the Act requires the SIP to include, among

other things, ``enforceable emission limitations'' [emphasis added]. 40

CFR 51.281 further requires that SIPs must be ``adopted as rules and

regulations enforceable by the State agency.'' On September 23, 1987,

EPA issued a memorandum entitled ``Review of State Implementation Plans

and Revisions for Enforceability and Legal Sufficiency.'' This memo

provided guidance on how to determine whether a rule or regulation was

enforceable. This memo also directed the EPA Regional Offices to not

approve SIPs or SIP revisions which fail to satisfy the enforceability

criteria detailed in the September 23, 1987, memo. EPA has reviewed the

revised Regulation No. 1 and believes that the revised rule does not

meet the Act's requirement that SIP measures be enforceable as EPA has

interpreted that requirement. EPA's reasoning is as follows:

(a) EPA reads the revisions to Regulation No. 1 as substituting the

good air pollution control practice standard in section II.A.10. for

the opacity limits specified in sections II.A.1. and 4. during

startups, shutdowns, and upsets. In defining the ``exceedance

percentage time allowance'' in section II.A.10., the State does not

specify whether exceedances will be measured against the 20% opacity

limit of section II.A.1., the 30% opacity limit of section II.A.4., or

both. This lack of clarity undermines the enforceability of the

regulation.

(b) The State's Regulation No. 1 revisions either fail to specify a

test method for evaluating a source's performance against its

exceedance percentage time allowance, or specify an inadequate test

method. Section II.A.1. of Regulation No. 1 states that visible

emissions shall be measured by EPA Method 9 (40 CFR part 60, appendix

A) in all subsections of section II.A. and B. of Regulation No. 1,

unless otherwise specified. Section II.A.10. does not specify any other

method for measuring visible emissions for the purposes of determining

whether a source has exceeded the exceedance allowance. If, as EPA

suspects, the State intended continuous opacity monitoring (COM) data

to be used to evaluate a source's performance against the exceedance

percentage time allowance, the State needed to make this explicit in

the regulation to ensure enforceability. In the alternative, EPA

believes EPA Method 9 is inadequate to evaluate a source's performance

against the exceedance percentage time allowance because Method 9

observations cannot be made on a continuous basis. The revised SO2

provisions in section VI.A.2. also do not specify any test method for

determining whether or not a source has exceeded the SO2 exceedance

allowance.

(c) Regulation No. 1 specifies that section II.A.10. governs

opacity during startup, shutdown, and upset, but the

[[Page 48132]]

AQCC's Statement of Basis states that excess emissions due to fire

building, process modification, and adjustment of control equipment

will also be counted in determining compliance with the exceedance

allowance. It is not clear from the actual language of the rule whether

exceedances due to fire building, process modification, and adjustment

of control equipment are to be counted in determining the number of

exceedances in a given quarter. Thus, there is a potential

inconsistency between the language of the rule and the State's intent.

The enforceability of the State's intent, without clear rule language,

is questionable.

(d) EPA's September 23, 1987, guidance memo states that there must

be a clear, enforceable requirement that records be kept. While there

is no specific provision requiring recordkeeping and reporting in

section II.A.10. of Regulation No. 1, section IV.G. of Regulation No. 1

requires recordkeeping and reporting on a quarterly basis of periods of

excess emissions for sources required to operate continuous emission

monitoring systems for opacity and/or SO2 (which applies to most of the

coal-fired electric utility boilers). However, Regulation No. 1 does

not appear to require recordkeeping and reporting of total operating

time on a quarterly basis. Without such information, it is not clear

how the State could implement the exceedance percentage time allowance.

Further, section IV.G. of Regulation No. 1 does not require the

recordkeeping and reporting of the type of information that might be

needed to determine (1) whether a source is being maintained and

operated in accordance with good air pollution control practices for

minimizing emissions, or (2) whether or not a source is engaged in a

significant PMO startup.

(e) Significant PMO startups are not subject to an enforceable time

limit. Specifically, section II.A.10.d.iii. states that a significant

PMO startup ``shall not normally exceed 14 days in duration, but the

(Colorado Air Pollution Control) Division may extend this period for

good cause shown.'' This language constitutes a ``director's

discretion'' provision that undermines the enforceability of the time

limit and undercuts any benefit the time limit would have for

protecting the NAAQS.

(f) For significant PMO startups, section II.A.10.d.i requires the

source to submit to the Division a plan for minimizing emissions during

the startup, but the revisions do not require the source to follow the

plan. Thus, the plan is unenforceable.

(g) Section II.A.10.d.iii. describes the duration of significant

PMO startups. The duration is defined according to various events that

occur during the course of a startup, but it is not clear from the

language of the regulation that these events are adequately defined or

that the information needed to adequately define these events for

enforcement purposes is or will be available. For example, this section

of the regulation refers to a specific unit's minimum load. It is not

clear what this means or whether it is a constant and well-understood

value.

(h) In the Statement of Basis for the revisions to Regulation No.

1, the Commission states that the significant PMO startup exception

``is not intended to allow exclusion of excess emissions resulting from

routine maintenance outages, such as annual replacement of standard

equipment * * *.'' Instead, ``the Commission restricts the application

of the planned maintenance outage exception to events requiring

significant changes at the facility, such as replacement of major

facility components or installation of new processes * * *.'' However,

the language of the regulation does not restrict significant PMOs in

this way: Section II.A.10.d describes a significant PMO as ``a

scheduled, infrequent yet extended maintenance shutdown * * *.'' Thus,

it does not appear that the restriction the AQCC intended is

enforceable.

(i) The State revised section VI.B.2. of Regulation No. 1 to allow

a permit to specify a different averaging time for SO2 limits than the

3-hour averaging time contained in the regulation. This revision would

allow the State to change the Federally enforceable averaging time in

the SIP without EPA approval or Federal notice and comment rulemaking.

EPA is unwilling to approve such a director's discretion provision,

because it undermines the enforceability of the regulatory limit and

allows the State to change the SIP without meeting the Act's

requirements for SIP revisions. EPA believes it is impossible to judge

in advance whether the State's potential changes to averaging times

under such an open-ended provision would be consistent with maintenance

of the NAAQS. In addition, EPA generally cannot approve a SIP provision

that would be inconsistent with the averaging time of the NAAQS the SIP

provision is designed to protect. Thus, to ensure protection of the

secondary SO2 NAAQS, EPA believes the averaging time must not be longer

than three hours, and EPA cannot approve a discretionary provision in

the SIP that might allow averaging times longer than three hours.

(j) Section VI.B.4.a.(iv) of Regulation No. 1 states that, during

periods of startup, shutdown, and upset, owners and operators of coal-

fired electric utility boilers shall maintain and operate such sources

in accordance with good air pollution control practice for minimizing

emissions. However, the regulation does not state that such sources are

exempt from the SO2 emission limit during startup, shutdown, and upset.

Thus, the regulation reads as if both the SO2 emission limit and the

good air pollution control practice standard apply during startup,

shutdown, and upset at coal-fired electric utility boilers. However,

the AQCC's Statement of Basis strongly implies that the good air

pollution control practice standard applies in place of the SO2

emission limitation. This discrepancy between the Statement of Basis

and the regulation creates confusion and undermines the enforceability

of the regulation.

In addition to the above issues, section II.A.10.e. of Regulation

No. 1 states that, in enforcing the exceedance percentage time

allowance for opacity, the State may consider each day on which one or

more excess emission periods occur following the day on which the

exceedance percentage time allowance is exceeded for that quarter to be

a separate day of violation for the purposes of assessing any penalties

that may be allowed. This is much less stringent than considering each

six-minute average of excess emissions a separate violation, as was

previously required under the State's Regulation No. 1. Thus, the

compliance incentive during startup, shutdown, and upset will be

substantially reduced. This will, in turn, reduce the effectiveness of

the rule in controlling particulate emissions.

In summary, EPA does not believe that the revisions to Regulation

No. 1 meet the Act's requirements that SIP measures be enforceable.

5. The SIP Revision Appears To Be Inconsistent With the Requirements of

the Act Regarding Continuous Compliance

The Act requires continuous compliance with emission limitations to

ensure continuous protection of public health and the environment. The

exemptions the State has written into Regulation No. 1 eliminate the

requirement in the SIP that coal-fired electric utility boilers comply

with Regulation No. 1's opacity and SO2 limits on a continuous basis.

Under the

[[Page 48133]]

State's revisions to Regulation No. 1, emissions during startup,

shutdown, upset, significant PMO startups and certain other conditions

are automatically exempted from the otherwise applicable opacity and

SO2 limits, and are subject to no emission limit. Consistent with its

interpretation that emission limits must be met continuously, EPA has

interpreted the Act to not permit SIP revisions that automatically

exempt sources from emission limits.

More specifically, section 110(a)(1) of the Act requires SIPs to

provide for attainment and maintenance of the NAAQS. Because the NAAQS

are health and welfare-based standards, Congress intended that they

must be met continuously, not just intermittently. Accordingly, section

110(a)(2) of the Act requires SIPs to contain enforceable emission

limitations, and section 302(k) of the Act defines ``emission

limitations'' as a requirement ``which limits the quantity, rate, or

concentration of emissions of air pollutants on a continuous basis''

[emphasis added].

EPA explained its interpretation of the term ``continuous

compliance'' in a June 21, 1982 memorandum from Kathleen M. Bennett,

Assistant Administrator for Air, Noise, and Radiation, to the Regional

Air Division Directors. That guidance states that ``continuous

compliance is essentially the avoidance of preventable excess emissions

over time as a result of the proper design, operation, and maintenance

of an air pollution source.'' The guidance also emphasizes that excess

emissions resulting from malfunctions or other emergency situations

must be minimized and terminated quickly.

On September 28, 1982 and February 15, 1983, EPA issued policy

statements regarding exemptions from emission limitations during

startup, shutdown, and malfunction, based on EPA's interpretation of

the Act's requirements for continuous compliance and attainment and

maintenance of the NAAQS.4 For most situations, these

policies indicate that all excess emissions must be considered

violations, which may or may not be enforced based on the exercise of

enforcement discretion. These policies also indicate that events like

startup, shutdown, and maintenance are part of the normal operation of

a source and should be accounted for in the planning, design, and

implementation of operating procedures for the process and control

equipment.

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

\4\ See September 28, 1982 and February 15, 1983 Memorandums,

both entitled ``Policy on Excess Emissions During Startup, Shutdown,

and Malfunctions'', from Kathleen M. Bennett, Assistant

Administrator for Air, Noise, and Radiation, to the Regional

Administrators.

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

EPA realizes that a few sources cannot avoid short periods of

excess emissions during startup and shutdown, despite careful and

prudent planning and design. For these few sources, the February 15,

1983 policy states that excess emissions during these infrequent, short

periods need not be treated as violations provided that the source

adequately shows that the excess could not have been prevented through

careful planning and design and that bypassing of control equipment was

unavoidable to prevent loss of life, personal injury, or severe

property damage. Similarly, excess emissions during periods of

scheduled maintenance should be treated as a violation, unless a source

can demonstrate that such emissions could not have been avoided through

better scheduling for maintenance or through better operation and

maintenance practices.

These policy statements are consistent with EPA's view that SIP

limits must be met continuously because they are intended to protect

the NAAQS; any exceptions should be narrowly drawn and clearly place

the burden on the source to demonstrate that an exceedance was

unavoidable. EPA believes the revisions to Regulation No. 1 are

inconsistent with the Act's requirement for continuous compliance and

attainment and maintenance of the NAAQS, and believes the revisions

must be disapproved.

The revisions eliminate the requirement for coal-fired electric

utility boilers to meet any opacity limit during periods of startup,

shutdown, and upset. It appears the State intended to provide the same

exemption for SO2 limits. Instead, during these periods, coal-fired

electric utility boilers are only obligated to exercise good air

pollution control practice for minimizing emissions.

As noted in the Background section, above, the revisions establish

an ``exceedance percentage time allowance.'' The exceedance of this

exceedance percentage time allowance in a quarter is considered a

violation of the duty to exercise good air pollution control practice

for minimizing emissions. However, it is not considered a violation of

the underlying emission limit, and violations may only be penalized on

a per-day basis.

With respect to SO2 limits, Regulation No. 1 does not specify how

the State will treat exceedances of the exceedance allowance described

in section VI.B.4.a.(iv)(B) of Regulation No. 1, but it appears the

State intends to approach such exceedances in the same manner as

exceedances of the opacity exceedance percentage time allowance.

In order to ensure continuous compliance with the SIP's opacity and

SO2 limits, EPA believes it is essential that exceedances during

startup, shutdown, and upsets be considered violations of such limits,

that may only be excused in an enforcement action if the source

properly demonstrates that the exceedances were unavoidable.

EPA has the same objection to the SIP revision's exemption of

emissions during significant PMO startups and periods when fuel is not

being fed to the boiler. For significant PMO startups, revised

Regulation No. 1 requires sources to exercise good air pollution

control practices for minimizing emissions but states that no opacity

limit applies during these periods. As noted above, significant PMO

startups may last 14 days or longer. For emissions during periods when

fuel is not being fed to the boiler, the revisions do not appear to

impose any emission limit or requirement on sources. These exemptions

from the opacity limits are inconsistent with the Act's requirement for

continuous compliance and attainment and maintenance of the NAAQS.

EPA does not believe the requirement for the use of good air

pollution control practice for minimizing emissions during startups,

shutdowns, malfunctions, and significant PMO startups is an adequate

substitute for the opacity and SO2 limits. This provision in the

revisions to Regulation No. 1 is not adequate to ensure continuous

compliance as required by the Act.

First, the revisions to Regulation No. 1 do not require a source to

show that the exceedance during startup, shutdown, or upset was

unavoidable. In fact, the revisions do not even require a source to

demonstrate that it has exercised good air pollution control practice

for minimizing emissions. Instead, section II.A.10.b and section

VI.B.4.a.(iv) provide that a determination of whether acceptable

operating and maintenance procedures are being used will be based on

information available to the Division. This appears to put no burden on

the source to justify an exceedance and does not appear calculated to

determine whether or not the exceedance could have been prevented

through careful planning and design or whether bypassing of the control

equipment was unavoidable to prevent loss of life, personal injury, or

severe property damage.

[[Page 48134]]

Second, the State's requirement that the source exercise good air

pollution control practice only appears to apply during startup,

shutdown, and malfunction. Clearly, a problem could arise during

startup, shutdown, and malfunction that could have been prevented by

careful planning, design, or implementation before the startup,

shutdown or malfunction. Also, the Bennett memoranda describe good air

pollution control practice for minimizing emissions as only one

criterion to examine in evaluating exceedances, and indicate that good

air pollution control practice for minimizing emissions should be

exercised to the ``maximum extent practicable,'' not just to the

``extent practicable'' as the State provides.

Furthermore, according to the AQCC's Statement of Basis for this

Regulation No. 1 revision, the exceedance percentage time allowance was

adopted to provide more certainty for the State and for sources in

enforcing the good air pollution control practice standard. Thus, the

Statement of Basis and the language of the regulation itself

(``exceedance percentage time allowance'') strongly imply that excess

emissions during startup, shutdown, and upset will only be considered

to be violations if the exceedance percentage time allowance is

exceeded (although the Statement of Basis also states that the State is

not precluded from taking enforcement action when the exceedance

percentage time allowance has not been exceeded).

The State's rationale, in part, for revising the existing opacity

and SO2 provisions in Regulation No. 1 during periods of startup,

shutdown, and upset appears to have been to make the revised Regulation

No. 1 more consistent with the requirements in EPA's New Source

Performance Standards (NSPS) regarding startup, shutdown, and

malfunction (see 40 CFR part 60, subparts D and Da). However, emission

limitations and other control requirements of the NSPS were not

designed to ensure compliance with the NAAQS or to meet other SIP

requirements. Rather, the NSPS were designed to reflect best

demonstrated technology (taking into account costs) for the affected

sources. Further, because NSPS are based on the best system of emission

reduction which ``the Administrator determines has been adequately

demonstrated,'' EPA generally views the NSPS as the ``floor'' in

determining the emissions control technology that is feasible for a

source. Thus, the NSPS are intended to complement the SIP program, but

do not necessarily satisfy the requirements of section 110(a)(1) of the

Act, which requires control measures to provide for attainment and

maintenance of the NAAQS, or of other sections of the Act related to

SIP content.

In summary, EPA believes the revisions to Regulation No. 1 are not

consistent with the Act because the revisions allow less than

continuous compliance with SIP emission limits that are designed to

attain and maintain the NAAQS without requiring sources to demonstrate

that excess emissions could not have been prevented or avoided. The

revisions to Regulation No. 1 significantly reduce the incentive for

continuous compliance by sources.

6. EPA Invites Comment on Whether the SIP Revision Conflicts With EPA's

Any Credible Evidence Rule

On February 24, 1997, EPA promulgated changes to Federal

Regulations to clarify that any credible evidence can be used to

demonstrate compliance or noncompliance with emission standards (see 62

FR 8314-8328). In that rulemaking, EPA revised the SIP requirements in

40 CFR 51.212 to state that the SIP ``must not preclude the use,

including the exclusive use, of any credible evidence or information

relevant to whether a source would have been in compliance with

applicable requirements if the appropriate performance or compliance

test or procedure had been performed.''

As discussed above, section II.A.1. of Regulation No. 1 states that

visible emissions shall be measured by EPA Method 9 (40 CFR part 60,

appendix A) ``in all subsections of section II.A and B of this

regulation, unless otherwise specified.'' It is EPA's belief that this

language does not preclude the use of other credible evidence or

information to determine compliance with the opacity limits contained

in Regulation No. 1, or to determine whether a source has exceeded the

exceedance allowance specified in section II.A.10. of Regulation No. 1.

Recently, the United States District Court for the District of

Colorado held that the language of Regulation No. 1 does not preclude

the use of other credible evidence to show opacity violations, at least

in citizens suits. See Sierra Club v. Tri-State Generation and

Transmission Association, Inc., et al., Order and Memorandum of

Decision, Civil Action No. 96 N 2368, March 8, 1999, at 19, 20.

However, it is not clear from the Court's opinion whether the Court was

examining the language of the Regulation No. 1 revision or the

Federally-approved version of Regulation No. 1. The revision to

Regulation No. 1 adds the language ``unless otherwise specified'' to

the end of the language that specifies Method 9 for measuring opacity.

Also, it is not clear whether the Court would reach the same conclusion

in an enforcement action brought by EPA or the State.

Thus, EPA invites comment on whether the language of section

II.A.1. of Regulation No. 1 is consistent with the requirements of 40

CFR 51.212(c), and whether failure to comport with EPA's any credible

evidence rule should be an additional basis for disapproving the

revisions to Regulation No. 1.

For the reasons discussed above, EPA is proposing to disapprove

Colorado's May 27, 1998 SIP submittal of revisions to Regulation No. 1.

EPA is soliciting public comments on the issues discussed in this

document or on other relevant matters. These comments will be

considered before taking final action. Interested parties may

participate in the Federal rulemaking procedure by submitting written

comments to the EPA Regional office listed in the Addresses section of

this document.

III. Proposed Action

EPA is proposing to disapprove the revision to the Colorado SIP

pertaining to the opacity and SO2 provisions in Regulation No. 1, which

was submitted by the Governor of Colorado on May 27, 1998. The effect

of this action, once final, will be that the pre-existing version of

Regulation No. 1 will remain in effect as part of the Federally

enforceable SIP and will continue to apply to opacity and SO2 emissions

from coal-fired electric utility boilers.

IV. Administrative Requirements

A. Executive Order 12866

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

proposed regulatory action from Executive Order 12866, entitled

``Regulatory Planning and Review.''

B. Executive Order 12875

Under Executive Order 12875, EPA may not issue a regulation that is

not required by statute and that creates a mandate upon a state, local,

or tribal government, unless the Federal government provides the funds

necessary to pay the direct compliance costs incurred by those

governments. If the mandate is unfunded, EPA must provide to the Office

of Management and Budget a description of the extent of EPA's prior

consultation with representatives of affected state, local, and tribal

governments, the nature of their concerns, copies of written

communications from the governments, and a statement supporting the

need to issue the regulation.

[[Page 48135]]

In addition, Executive Order 12875 requires EPA to develop an

effective process permitting elected officials and other

representatives of state, local, and tribal governments ``to provide

meaningful and timely input in the development of regulatory proposals

containing significant unfunded mandates.'' Today's proposed rule would

not create a mandate on State, local or tribal governments. The rule

would not impose any enforceable duties on these entities. Accordingly,

the requirements of section 1(a) of Executive Order 12875 do not apply

to this rule.

C. Executive Order 13045

Executive Order 13045, Protection of Children from Environmental

Health Risks and Safety Risks (62 FR 19885, April 23, 1997), applies to

any rule that: (1) is determined to be ``economically significant'' as

defined under Executive Order 12866, and (2) concerns an environmental

health or safety risk that EPA has reason to believe may have a

disproportionate effect on children. If the regulatory action meets

both criteria, the Agency must evaluate the environmental health or

safety effects of the planned rule on children, and explain why the

planned regulation is preferable to other potentially effective and

reasonably feasible alternatives considered by the Agency.

This proposed rule is not subject to Executive Order 13045 because

it does not involve decisions intended to mitigate environmental health

or safety risks.

D. Executive Order 13084

Under Executive Order 13084, EPA may not issue a regulation that is

not required by statute, that significantly affects or uniquely affects

the communities of Indian tribal governments, and that imposes

substantial direct compliance costs on those communities, unless the

Federal government provides the funds necessary to pay the direct

compliance costs incurred by the tribal governments. If the mandate is

unfunded, EPA must provide to the Office of Management and Budget, in a

separately identified section of the preamble to the rule, a

description of the extent of EPA's prior consultation with

representatives of affected tribal governments, a summary of the nature

of their concerns, and a statement supporting the need to issue the

regulation.

In addition, Executive Order 13084 requires EPA to develop an

effective process permitting elected and other representatives of

Indian tribal governments ``to provide meaningful and timely input in

the development of regulatory policies on matters that significantly or

uniquely affect their communities.'' Today's proposed rule would not

significantly or uniquely affect the communities of Indian tribal

governments. EPA is proposing disapproval of a State rule revision,

which will have no impact on the communities of Indian tribal

governments. Accordingly, the requirements of section 3(b) of Executive

Order 13084 do not apply to this rule.

E. Regulatory Flexibility Act

The Regulatory Flexibility Act (RFA) generally requires an agency

to conduct a regulatory flexibility analysis of any rule subject to

notice and comment rulemaking requirements unless the agency certifies

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 small governmental

jurisdictions. This proposed rule would not have a significant impact

on a substantial number of small entities because EPA's proposed

disapproval of the State request under section 110 and subchapter I,

part D of the Clean Air Act, would not affect any existing requirements

applicable to small entities. Any pre-existing Federal requirements

would remain in place after this disapproval. Federal disapproval of

the State submittal would not affect State-enforceability. Moreover,

EPA's disapproval of the submittal would not impose any new Federal

requirements. Therefore, I certify that this action will not have a

significant economic impact on a substantial number of small entities.

F. 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 disapproval action being proposed 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. The proposed disapproval would

not change existing requirements and would include no Federal mandate.

If EPA were to disapprove the State's SIP submittal, pre-existing

requirements would remain in place and State enforceability of the

submittal would be unaffected. The action would impose no new

requirements. Accordingly, no additional costs to State, local, or

tribal governments, or to the private sector, would result from this

proposed action.

G. National Technology Transfer and Advancement Act

Section 12 of the National Technology Transfer and Advancement Act

(NTTAA) of 1995 requires Federal agencies to evaluate existing

technical standards when developing a new regulation. To comply with

NTTAA, EPA must consider and use ``voluntary consensus standards''

(VCS) if available and applicable when developing programs and policies

unless doing so would be inconsistent with applicable law or otherwise

impractical.

The EPA believes that VCS are inapplicable to this proposed action.

Today's proposed action does not require the public to perform

activities conducive to the use of VCS.

List of Subjects in 40 CFR Part 52

Environmental protection, Air pollution control, Incorporation by

reference, Intergovernmental relations, Particulate matter, Reporting

and recordkeeping requirements, and Sulfur oxides.

Dated: August 19, 1999.

Jack W. McGraw,

Acting Regional Administrator, Region VIII.

[FR Doc. 99-22937 Filed 9-1-99; 8:45 am]

BILLING CODE 6560-50-P