42088 Federal Register / Vol. 62, No. 150 / Tuesday, August 5, 1997 / Proposed Rules

Air and Radiation Docket and

Information Center (Air Docket 6102),

U.S. Environmental Protection

Agency, 401 M Street, SW,

Washington, DC 20460.

Environmental Protection Agency,

Region 4 Air Planning Branch, 61

Forsyth Street, SW, Atlanta, Georgia

30303. Benjamin Franco, (404) 562–

9039.

Tennessee Department of Environment

and Conservation, Division of Air

Pollution Control, L & C Annex, 9th

Floor, 401 Church Street, Nashville,

Tennessee 37243–1531. Telephone:

(615)-532–0554.

Knox County Department of Air

Pollution Control, City-County

Building, Suite 339, 400 West Main

Street, Knoxville, Tennessee, 37902.

Telephone: (615) 521–2488.

FOR FURTHER INFORMATION CONTACT:

Benjamin Franco at 404/562–9039.

SUPPLEMENTARY INFORMATION: For

additional information see the direct

final rule which is published in the

rules section of this Federal Register.

Dated: July 9, 1997.

Michael V. Payton,

Acting Regional Administrator.

[FR Doc. 97–20577 Filed 8–4–97; 8:45 am]

BILLING CODE 6560–50–P

ENVIRONMENTAL PROTECTTION

AGENCY

40 CFR Part 52

[CO–001–0017 and CO–001–0018; FRL–

5869–4]

Clean Air Act Approval and

Promulgation of the Denver, Colorado

Mobile Source Emissions Budgets for

PM10 and NOX

AGENCY: Evironmental Protection

Agency (EPA).

ACTION: Proposed rule.

SUMMARY: EPA is requesting additional

comments on certain aspects of the State

Implementation Plan (SIP) revisions for

the Denver PM10 and NOX mobile

source emissions budgets that were

submitted by the Governor of Colorado.

EPA initially proposed approval of the

SIP revisions on October 3, 1996 (61 FR

51631). During that rulemaking’s public

comment period, EPA received several

comments. Due to the complexity of the

issues, EPA is asking interested parties

to submit additional information on two

issues. This information may help EPA

make a more informed decision on the

appropriateness of approving both the

PM10 and NOX emissions budget SIPs.

DATES: Comments on this request for

additional information must be received

in writing on or before September 4,

1997.

ADDRESSES: Copies of the State’s

original PM10 and NOX emissions

budget SIPs, comments received during

the public comment period, and other

information are available for inspection

during normal business hours at the

Environmental Protection Agency,

Region VIII, Air Program, 999 18th

Street, 3rd Floor, South Terrace, Denver,

Colorado 80202–2466.

FOR FURTHER INFORMATION CONTACT:

Callie Videtich at (303) 312–6434.

SUPPLEMENTARY INFORMATION:

I. Background

On July 18, 1995, and April 22, 1996,

the Colorado Governor submitted

revisions to the Denver PM10 SIP which

establish mobile source emissions

budgets for PM10 and NOX respectively.

These budgets are used under EPA

regulations for making transportation

related conformity determinations as

required by section 176(c) of the Act.

EPA’s transportation conformity rule

provides that these budgets establish a

cap on motor vehicle-related emissions

which cannot be exceeded by the

predicted transportation system

emissions in the future unless the cap

is amended by the State and approved

by EPA as a SIP revision and attainment

and maintenance of the standard can be

demonstrated.

EPA proposed approval of both

emissions budgets on October 3, 1996

(61 FR 51631) along with the Denver

PM10 SIP. Following a 60 day public

comment period, EPA finalized

approval of the Denver PM10 SIP on

April 17, 1997 (62 FR 18716). EPA did

not take final action on the emissions

budget submittals in order to more

thoroughly consider comments received

on the proposals during the public

comment period.

II. This Action

Based upon a thorough review, EPA

has concluded that additional

information is needed in order for EPA

to make an informed decision about

certain aspects of the SIPs based upon

public comments responding to our

proposed approval of the PM10 and NOX

emissions budgets. EPA is seeking

additional information on the two issues

outlined below.

1. It appears to EPA that the Colorado

legislature, through Senate Bill 95–110

(codified at section 25–7–105(1)(a)(III),

C.R.S.), changed the PM10 emissions

budgets that the Colorado Air Quality

Control Commission (AQCC) had

adopted on February 16, 1995. EPA

wishes to take comment on whether the

PM10 budgets that were ultimately

submitted to EPA for approval were

adopted after reasonable notice and

public hearing as required by section

110 of the Clean Air Act (CAA). Section

110(a)(2) of the CAA provides that

‘‘[e]ach implementation plan submitted

by a State under this Act shall be

adopted by the State after reasonable

notice and public hearing.’’ Robert

Yuhnke, on behalf of COPIRG, Colorado

Environmental Coalition, Citizens for

Balanced Transportation, American

Lung Association of Colorado,

Environmental Defense Fund, and Ms.

Stephanie Mines, and Frank Johnson, on

behalf of the Colorado Attorney

General’s Office, have submitted

information that touches on this

question. Their letters may be examined

at the address listed above. EPA wishes

to obtain further comment on this issue.

In particular, EPA is concerned that the

legislative action did not meet the

CAA’s requirements for notice and

public hearing and that no subsequent

public hearing was held before the

AQCC. The Colorado Attorney General’s

Office has suggested that hearings held

before the AQCC in September and

October 1994, and in February 1995,

were adequate to satisfy the CAA’s

hearing requirement, and that there is

no requirement that a hearing be held at

every step in the State review process.

It has also indicated that the State

legislative process is an open and public

process and that the legislators are

accountable to the electorate.

2. Commentors were concerned that

the budgets do not demonstrate

attainment considering growth in nonmobile sources, and that the adopted

NOX budget of 119.4 tons per day was

not consistent with the NOX inventory

of 102.7 tons per day used in the

maintenance demonstration. (In the

following discussion, EPA uses the

terms ‘‘mobile source’’ and ‘‘mobile

source emissions’’ to mean ‘‘motor

vehicle’’ and ‘‘motor vehicle

emissions,’’ consistent with the State’s

submittal. Neither the State’s budget

submittal nor EPA’s conformity rule

regulate emissions from non-road

mobile sources.)

The Regional Air Quality

Council’s(RAQC’s) proposal to the

AQCC to increase the emissions budget

was based on an analysis showing that

the Denver modeling region could

tolerate mobile source PM10 emissions

of 221 tons per day in 2015 before a

violation of the PM10 standard would

occur. (This analysis was not submitted

at the time the budgets were submitted

to EPA, but was referenced in
Federal Register / Vol. 62, No. 150 / Tuesday, August 5, 1997 / Proposed Rules 42089

proceedings before the RAQC and the

AQCC in 1994 and was provided by the

RAQC on April 23, 1997.) By contrast,

the attainment and maintenance

demonstrations are based on emissions

levels of 41 and 44 tons per day,

respectively. The RAQC defined the

difference between 44 tons per day and

221 tons per day (i.e., 177 tons) as a

‘‘safety margin’’ in emissions and

assigned 16 tons of this safety margin to

mobile source PM10 (i.e., raised the SIP’s

budget to 60 tons per day) in order to

facilitate future conformity

determinations by the Denver Regional

Council of Governments (DRCOG). The

RAQC and the State justified the

increase of the budget from 44 to 60 tons

by noting that this increase represented

only a small portion of the available

safety margin. The RAQC’s analysis

assumed 2015 emissions levels of all

non-mobile sources, and assumed zero

NOX emissions from mobile sources

(i.e., that all emissions were direct PM10

emissions).

The RAQC’s analysis is strictly a

mathematical analysis of the maximum

level of emissions that could

theoretically be accommodated in each

grid in the modeling domain; it is not

an analysis of any particular projected

growth scenario for Denver. The

analysis assumes equal levels of

emissions in each grid of the modeling

domain, from downtown Denver to rural

outlying portions of the domain.

Although the safety margin provision in

Section 93.132(b) of the conformity rule

applies only to existing adopted SIPs

which contained a built-in safety

margin, section 93.132(a) clearly

envisions cases in which a SIP

quantifies a safety margin and explicitly

assigns some or all of it to the mobile

source budget. This general provision

applies to situations where a state

reanalyzes a SIP to quantify and assign

the safety margin.

As noted above, the RAQC’s analysis

accounts for growth in non-mobile

sources of emissions to 2015 levels but

does not account for mobile source NOX

(all mobile source emissions are treated

as PM10 emissions). To quantify the

impact of this omission, EPA reviewed

documents related to the attainment

demonstration and found that an

increase of 10.4 tons per day of NOX

would lead to a 1.0μg/m3 increase in

PM10 concentrations (source: July 7,

1994 and February 8, 1995 Kevin Briggs

memoranda). Thus, the adopted budget

of 119.4 tons per day of NOX would

equate to approximately 22 tons per day

of PM10. Subtracting this 22 tons from

the RAQC’s original 221 ton budget, a

199 ton PM10 budget along with a 119.4

ton NOX budget would still provide for

attainment of the NAAQS. However, the

State has only revised the SIP to

establish a 60 ton PM10 budget and a

119.4 ton NOX budget. Thus, NOX

emissions of 119.4 tons per day can be

easily by accommodated within the 177

ton PM10 safety margin identified by the

RAQC and the State.

The fact that the 119.4 ton per day

NOX budget can be accommodated

within the safety margin identified by

the RAQC is one reason that EPA is not

concerned that this budget is

inconsistent with the SIP’s 1998

maintenance demonstration budget of

102.7 tons per day. The other reason is

the SIP’s requirement that each

conformity determination must include

a modeling analysis demonstrating

attainment of the PM10 NAAQS

(discussed below). Even though the

adopted NOX budget is higher than the

inventory used in the maintenance

demonstration, DRCOG’s transportation

plans and transportation improvement

programs (TIPs) must still pass a

modeling analysis showing attainment

of the NAAQS, incorporating the

impacts of the 119.4 ton NOX budget, or

the plans and TIPs cannot be found to

conform.

EPA believes that the NAAQS are

protected by the SIP’s requirement for

dispersion modeling each time a

conformity analysis is conducted. The

SIP requires that DRCOG support each

conformity determination with a

dispersion modeling analysis that shows

that each grid in the modeling domain

will be in attainment, considering the

emissions expected from

implementation of the transportation

plan or TIP. If the modeling analysis

shows that emissions reductions are

needed in any locations in order to

provide for attainment of the NAAQS, it

is incumbent upon DRCOG to identify

and ensure implementation of any

measures needed to provide those

reductions. Thus, DRCOG must satisfy

two types of tests to demonstrate

conformity: compliance with the 60 ton

PM10 budget and the 119.4 ton NOX

budget, and a dispersion modeling

analysis showing no violations.

The commentors quote the preamble

to EPA’s November 24, 1993

transportation conformity regulation in

objecting to the use of dispersion

modeling in conformity determinations.

EPA believes that the Act precludes the

use of dispersion modeling as a

substitute for an emissions budget test.

However, EPA’s conformity rule did not

anticipate situations where a state

would wish to require a regional

dispersion modeling analysis in

addition to an emissions budget test.

EPA does not believe that such an

application of dispersion modeling is

precluded by either the Act or the

conformity rule. One commentor

suggested that the State adopt

subregional emissions budgets in lieu of

requiring dispersion modeling;

however, as a practical matter, the

requirement for dispersion modeling

has the same effect as establishing

subregional budgets because in either

case a certain target level of emissions

has to be met in each grid in order for

each grid to show attainment.

In fact, the requirement for dispersion

modeling in addition to a budget test is

arguably more protective of the NAAQS

than the budget-only process envisioned

by the conformity rule. First, a

supplemental requirement for

dispersion modeling is certainly more

protective than a region-wide budget

alone. The commentors argue that

subregional budgets for problem grids

could be identified. However,

establishing fixed subregional budgets

through the SIP process would not

provide the flexibility to consider future

growth patterns. Due to changes in the

geographic distribution of growth,

NAAQS problems could emerge in areas

of the city outside of the area for which

subregional budgets had been

established, in the geographic area

covered only by the region-wide budget.

A requirement for dispersion modeling

each time a conformity determination is

made ensures that these new ‘‘hotspots’’

are identified and addressed. A onetime effort to establish subregional

budgets would not.

EPA notes that the SIP does not

require growth in non-mobile sources to

be considered in conducting dispersion

modeling for the purposes of conformity

determinations. However, the RAQC

factored in the future year contribution

of non-mobile source emissions

(estimated at 23.8 tons per day in 2015

in the February 8, 1995 Briggs

memorandum, or 29 tons per day in the

April 23, 1997 RAQC memorandum) in

defining the region’s 177 ton per day

safety margin (and thus, in setting the

60 ton budget). More importantly, this

aspect of the conformity modeling

methodology (that is, not considering

growth in non-mobile sources each time

a conformity determination is made) is

consistent with the way conformity is

applied in the other nonattainment

areas throughout the country which rely

solely on their SIP emission budgets.

Growth in non-mobile sources must be

considered when budgets are set

through the SIP process; however, there

is no requirement for future conformity

determinations to continually reevaluate the adequacy of these budgets

given growth in non-mobile sources.
42090 Federal Register / Vol. 62, No. 150 / Tuesday, August 5, 1997 / Proposed Rules

In summary, EPA believes that the

fact that only a small portion of the

SIP’s safety margin has been allocated to

the mobile source emissions budget,

along with the requirement for

dispersion modeling each time a

conformity determination is conducted,

are adequate to ensure that the NAAQS

are protected by the emissions budgets

adopted by the State and submitted to

EPA. EPA is requesting further comment

in support of or opposed to this

rationale for approving the budget

submittals.

III. Proposed Action

EPA is seeking additional information

from interested parties on two issues

related to the Denver PM10 and NOX

mobile source emissions budget SIPs.

EPA initially proposed approval of the

SIP revisions on October 3, 1996 (61 FR

51631).

As indicated elsewhere in this

document, EPA will consider any

comments received by September 4,

1997 relating to the two issues described

above relating to the two SIPs.

IV. Executive Order 12866

The Office of Management and Budget

(OMB) has exempted this regulatory

action from E.O. 12866 review.

V. Regulatory Flexibility

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-forprofit enterprises, and government

entities with jurisdiction over

populations of less than 50,000.

SIP approvals under sections 110 and

subchapter I, part D of the CAA do not

create any new requirements but simply

approve requirements that the State is

already imposing. Therefore, because

this proposed Federal SIP approval does

not impose any new requirements, I

certify that it does not have a significant

impact on any small entities affected.

Moreover, due to the nature of the

Federal-State relationship under the

CAA, preparation of a flexibility

analysis would constitute Federal

inquiry into the economic

reasonableness of state action. The CAA

forbids EPA to base its actions

concerning SIPs on such grounds.

Union Electric Co. v. U.S. E.P.A., 427

U.S. 246, 256–66 (1976); 42 U.S.C.

7410(a)(2).

VI. 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 costeffective 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 also determined that this

proposed action does not include a

Federal mandate that may result in

estimated costs of $100 million or more

to State, local, or tribal governments in

the aggregate, or to the private sector.

This Federal action would approve preexisting requirements under State or

local law, and would impose no new

Federal requirements. Accordingly, no

additional costs to State, local, or tribal

governments, or to the private sector

would result form this action.

List of Subjects in 40 CFR Part 52

Environmental protection, Air

pollution control, Hydrocarbons,

Intergovernmental relations, Nitrogen

dioxide, Particulate matter, Reporting

and recordkeeping requirements, Sulfur

dioxide, Volatile organic compounds.

Authority: 42 U.S.C. 7401–7671q.

Dated: July 14, 1997.

Jack W. McGraw,

Acting Regional Administrator.

[FR Doc. 97–20582 Filed 8–4–97; 8:45 am]

BILLING CODE 6560–50–P

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 721

[OPPTS–50625A; FRL–5734–1]

Proposed Revocation of Significant

New Use Rules For Certain Acrylate

Substances; Extension of Comment

Period

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Extension of comment period.

SUMMARY: EPA is extending the

comment period for the proposed

significant new use rule (SNUR) for

certain acrylate esters. As initially

published in the Federal Register of

June 2, 1997 (62 FR 29688) (FRL–5595–

1), the comments were to be received on

or before July 2, 1997. One commenter

requested additional time to research

and submit more detailed comments

concerning these proposed revocations.

EPA is therefore extending the comment

period in order to give all interested

persons the opportunity to comment

fully.

DATES: Written comments must be

submitted to EPA by August 14, 1997.

ADDRESSES: Each comment must bear

the appropriate docket control number

OPPTS–50625, etc. All comments

should be sent in triplicate to: OPPT

Document Control Officer (7407), Office

of Pollution Prevention and Toxics,

Environmental Protection Agency, 401

M Street, SW., Room G–099, East

Tower, Washington, DC 20460.

Comments and data may also be

submitted electronically by sending

electronic mail (e-mail) to: opptncic@epamail.epa.gov. Electronic

comments must be submitted as an

ASCII file avoiding the use of special

characters and any form of encryption.

Comments and data will also be

accepted on disks in WordPerfect 5.1

file format or ASCII file format. All

comments and data in electronic form

must be identified by (OPPTS–50625,

etc.). No confidential business

information (CBI) should be submitted

through e-mail. Electronic comment on

this notice may be filed online at many

Federal Depository Libraries.

All comments which are claimed

confidential must be clearly marked as

such. Three additional sanitized copies

of any comments containing CBI must

also be submitted. Nonconfidential

versions of comments on this rule will

be placed in the rulemaking record and

will be available for public inspection.

FOR FURTHER INFORMATION CONTACT:

Susan Hazen, Director, Environmental

Assistance Division (7408), Office of

Pollution Prevention and Toxics,

Environmental Protection Agency, Rm.

E–543B, 401 M St., SW., Washington,

DC 20460; telephone: (202) 260–3949;

TDD: (202) 554–0551; e-mail: TSCAHotline@epamail.epa.gov.

SUPPLEMENTARY INFORMATION: This

extension of the comment period will

allow interested parties who intend to

comment on the proposed rule

additional time to consider their

response.

List of Subjects in 40 CFR Part 721

Environmental protection, Chemicals,

Hazardous materials, Recordkeeping

and reporting requirements.