[Federal Register Volume 82, Number 192 (Thursday, October 5, 2017)]
[Notices]
[Page 46490]
[FR Doc No: 2017-21245]

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ENVIRONMENTAL PROTECTION AGENCY

[FRL-9968-36-OCFO]

Draft FY 2018-2022 Environmental Protection Agency Strategic Plan

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of availability, request for public comments.

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SUMMARY: The U.S. Environmental Protection Agency (EPA) is announcing
the availability of the Draft FY 2018-2022 EPA Strategic Plan for
public review and comment, which is being revised as required by the
Government Performance and Results Act (GPRA) Modernization Act of
2010. The agency anticipates the final Strategic Plan will be submitted
to Congress in February 2018. For this notice, the EPA is seeking
comment from individual citizens, states, tribes, local governments,
industry, the academic community, non-governmental organizations, and
all other interested parties.

DATES: Comments must be received on or before October 31, 2017.

ADDRESSES: Submit your comments, identified by Docket ID No. [EPA-HQ-
OA-2017-0533] to the Federal eRulemaking Portal: http://www.regulations.gov. Follow the online instructions for submitting
comments. Once submitted, comments cannot be edited or withdrawn. The
EPA may publish any comment received to its public docket. Do not
submit electronically any information you consider to be Confidential
Business Information (CBI) or other information whose disclosure is
restricted by statute. Multimedia submissions (audio, video, etc.) must
be accompanied by a written comment. The written comment is considered
the official comment and should include discussion of all points you
wish to make. The EPA will generally not consider comments or comment
contents located outside of the primary submission (i.e. on the web,
cloud, or other file sharing system). For additional submission
methods, the full EPA public comment policy, information about CBI or
multimedia submissions, and general guidance on making effective
comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Vivian Daub, Director, Planning
Division, Office of Planning, Analysis, and Accountability, Office of
the Chief Financial Officer<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

Background

    The GPRA Modernization Act of 2010 (Pub. L. 111-352), holds federal
agencies accountable for using resources wisely and achieving program
results. Specifically, the GPRA Modernization Act requires agencies to
develop: Strategic Plans, which include a mission statement, set out
long-term goals, objectives, and strategic measures, and describe
strategies to achieve them over a four-year time horizon; two-year
Agency Priority Goals to advance progress toward the highest
priorities; Annual Performance Plans, which provide annual performance
measures and activities toward the long-term Strategic Plan; and,
Annual Performance Reports, which evaluate an agency's success in
achieving the annual performance measures.
    The Strategic Plan reflects the Administrator's priorities for
advancing the Agency's mission to protect human health and the
environment by setting three strategic goals:
     Core Mission: Deliver real results to provide Americans
with clean air, land, and water.
     Cooperative Federalism: Rebalance the power between
Washington and the states to create tangible environmental results for
the American people.
     Rule of Law and Process: Administer the law, as Congress
intended, to refocus the Agency on its statutory obligations under the
law.
    This Strategic Plan includes objectives and strategies for
achieving the strategic goals, and establishes strategic measures and
FY 2018-2019 Agency Priority Goals by which EPA will hold itself
accountable to monitor progress in improving significantly the way EPA
does business and environmental benefits, engaging closely with public
sector partners at all levels and the regulated community.

    Dated: September 19, 2017.
David A. Bloom,
Acting Chief Financial Officer, Office of the Chief Financial Officer.
[FR Doc. 2017-21245 Filed 10-4-17; 8:45 am]
BILLING CODE 6560-50-P


[Federal Register Volume 78, Number 23 (Monday, February 4, 2013)]
[Notices]
[Page 7774]
[FR Doc No: 2013-02247]

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DEPARTMENT OF ENERGY

Federal Energy Regulatory Commission

[Docket No. ER13-779-000]

SmartEnergy Holdings, LLC; Supplemental Notice That Initial
Market-Based Rate Filing Includes Request for Blanket Section 204
Authorization

    This is a supplemental notice in the above-referenced proceeding,
of SmartEnergy Holdings, LLC's application for market-based rate
authority, with an accompanying rate schedule, noting that such
application includes a request for blanket authorization, under 18 CFR
part 34, of future issuances of securities and assumptions of
liability.
    Any person desiring to intervene or to protest should file with the
Federal Energy Regulatory Commission, 888 First Street NE., Washington,
DC 20426, in accordance with Rules 211 and 214 of the Commission's
Rules of Practice and Procedure (18 CFR 385.211 and 385.214). Anyone
filing a motion to intervene or protest must serve a copy of that
document on the Applicant.
    Notice is hereby given that the deadline for filing protests with
regard to the applicant's request for blanket authorization, under 18
CFR part 34, of future issuances of securities and assumptions of
liability is February 13, 2013.
    The Commission encourages electronic submission of protests and
interventions in lieu of paper, using the FERC Online links at http://www.ferc.gov. To facilitate electronic service, persons with Internet
access who will eFile a document and/or be listed as a contact for an
intervenor must create and validate an eRegistration account using the
eRegistration link. Select the eFiling link to log on and submit the
intervention or protests.
    Persons unable to file electronically should submit an original and
14 copies of the intervention or protest to the Federal Energy
Regulatory Commission, 888 First Street NE., Washington, DC 20426.
    The filings in the above-referenced proceeding(s) are accessible in
the Commission's eLibrary system by clicking on the appropriate link in
the above list. They are also available for review in the Commission's
Public Reference Room in Washington, DC. There is an eSubscription link
on the web site that enables subscribers to receive email notification
when a document is added to a subscribed docket(s). For assistance with
any FERC Online service, please email<EMAIL_ADDRESS>or
call<PHONE_NUMBER> (toll free). For TTY, call<PHONE_NUMBER>.

    Dated: January 24, 2013.
 Kimberly D. Bose,
 Secretary.
[FR Doc. 2013-02247 Filed 2-1-13; 8:45 am]
BILLING CODE 6717-01-P


[Federal Register: September 7, 2007 (Volume 72, Number 173)]
[Notices]
[Page 51442-51443]
[DOCID:fr07se07-68]

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ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OPP-2007-0191; FRL-8146-4]

Pesticide Program Dialogue Committee, Pesticide Registration
Improvement Act Process Improvement Workgroup; Notice of Public Meeting

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

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SUMMARY: EPA's Pesticide Program Dialogue Committee (PPDC), Pesticide
Registration Improvement Act (PRIA) Process Improvement Workgroup will
hold its ninth public meeting on September 27, 2007. An agenda for this
meeting is being developed, and will be posted on EPA's website. The
workgroup is developing advice and recommendations on topics related to
EPA's registration process.

DATES: The meeting will be held on Thursday, September 27, 2007 from 1
p.m. to 4 p.m. To request accommodation of a disability, please contact
the person listed under FOR FURTHER INFORMATON CONTACT, preferably at
least 10 days prior to the meeting, to give EPA as much time as
possible to process your request.

ADDRESSES: The meeting will be held at Conference Center, Lobby Level,
One Potomac Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA.

FOR FURTHER INFORMATION CONTACT: Elizabeth Leovey, Immediate Office,
7501P, Office of Pesticide Programs, Environmental Protection Agency,
1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone
number:<PHONE_NUMBER>; fax number:<PHONE_NUMBER>; e-mail address:
<EMAIL_ADDRESS>

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

    This action is directed to the public in general, and may be of
particular interest to persons who are concerned about implementation
of the Pesticide Registration Improvement Act (PRIA), the Federal
Insecticide, Fungicide, and Rodenticide Act (FIFRA), and the Federal
Food, Drug, and Cosmetic Act (FFDCA). Other potentially affected
entities may include but are not limited to agricultural workers and
farmers; pesticide industry trade associations; environmental, consumer
and farmworker groups; pesticide users and growers; pest consultants;
State, local and tribal governments; academia; public health
organizations; food processors; and the public. Since other entities
may also be interested, the Agency has not attempted to describe all
specific entities that may be affected by this action. If you have any
questions regarding the applicability of this action to a particular
entity, consult the person listed under FOR FURTHER INFORMATION
CONTACT.

B. How Can I Get Copies of this Document and Other Related Information?

    1. Docket. EPA has established a docket for this action under
docket identification (ID) number EPA-HQ-OPPT-2007-0191. Publicly
available docket materials are available either in the electronic
docket at http://www.regulations.gov, or, if only available in hard

copy, at the Office of Pesticide Programs (OPP) Regulatory Public
Docket in Rm. S-4400, One Potomac Yard (South Bldg.), 2777 S. Crystal
Dr., Arlington, VA. The hours of operation of this Docket Facility are
from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal
holidays. The Docket Facility telephone number is<PHONE_NUMBER>.
    2. Electronic access. You may access this Federal Register document
electronically through the EPA Internet under the ``Federal Register''
listings at http://www.epa.gov/fedrgstr.

II. Background

    The Office of Pesticide Programs (OPP) is entrusted with the
responsibility of ensuring the safety of the American food supply,
protection and education of those who apply or are exposed to
pesticides occupationally or through use of products, and the general
protection of the environment and special ecosystems from potential
risks posed by pesticides. The PPDC was established under the Federal
Advisory Committee Act (FACA), Public Law 92-463, in September 1995 for
a 2-year term and has been renewed every 2 years since that time. The
PPDC provides advice and recommendations to OPP on a broad range of
pesticide regulatory, policy, and program implementation issues that
are associated with evaluating and reducing risks from the use of
pesticides. The following sectors are represented on the PPDC:
Pesticide industry and trade associations; environmental/public
interest and consumer groups; farm worker organizations; pesticide
user, grower and commodity groups; Federal and State/local/Tribal
governments; the general public; academia; and public health
organizations. Copies of the PPDC charter are filed with appropriate
committees of Congress and the Library of Congress and are available
upon request. Copies of the minutes of past meetings of this workgroup
are available on the internet at http://www.epa.gov/pesticides/ppdc/pria/index.html
.

III. How Can I Request to Participate in this Meeting?

    This meeting will be open to the public and seating is available on
a first-come basis. Persons interested in attending do not need to
register in advance of the meeting. Opportunity will be provided for
questions and comments by the public. Any person

who wishes to file a written statement may do so before or after the
meeting by giving a copy of the statement to the person listed under
FOR FURTHER INFORMATION CONTACT. These statements will become part of
the permanent record and will be available for public inspection at the
address listed under Unit 1.B.1. Do not submit any information in your
request that is considered CBI. To request accommodation of a
disability, please contact FOR FURTHER INFORMATION CONTACT, preferably
at least 10 days prior to the meeting, to give EPA as much time as
possible to process your request.

List of Subjects

    Environmental protection.

    Dated: August 27, 2007.
Debra Edwards,
Director, Office of Pesticide Programs.
[FR Doc. E7-17719 Filed 9-6-07; 8:45 am]

BILLING CODE 6560-50-S


 1 The core of the New Source Review program is its application to new sources. Congress specifically decided that the program generally should not apply to existing sources. These considerations are the starting point for understanding its application to " modifications" and the meaning we should give that term.

The NSR program's scope is closely related to the scope of the NSPS program, created seven years earlier in the Clean Air Act Amendments of 1970. In Section 111 of that Act, which sets forth the NSPS provisions, Congress applied the New Source Performance Standards to " new sources," secs. 111( b)( 1)( B),

111( b)( 4). Congress determined that as a general matter it would not impose the NSPS standards on existing sources, instead leaving to the State and local permitting authorities the decision of the extent to which to regulate those sources through " State Implementation Plans" designed to implement National Ambient Air Quality Standards ( NAAQS). See sec. 110.

Congress followed a similar approach in determining the scope of the major NSR program established by the 1977 Amendments to the Clean Air Act. As amended, the Act specifies that State Implementation Plans must contain provisions that require sources to obtain major NSR permits at the point of " construction" of a source. Secs. 172( c)( 5); 169( 2)( C). By contrast, the Act generally leaves to State and local permitting authorities in the 2 first instance the question of the extent, means and timetable for obtaining reductions from existing sources needed to comply with National Ambient Air Quality Standards. See secs.

172( c)( 1), 161.

NSR's applicability to existing sources to which a " modification" is made is an exception to this general rule.

This exception likewise finds its roots in the NSPS program's applicability to " modifications" of existing sources. The 1970 Act made the NSPS program applicable to modifications through its definition of a " new source," which it defined as " any stationary source, the construction or modification of which is commenced after the publication of regulations ... prescribing a[ n applicable] standard of performance . . . ." Section 111( a)( 2).

Section 111( a)( 4), in turn, defined a " modification" as " any physical change in, or change in the method of operation of, a stationary source which increases the amount of any air pollutant emitted from such source or which results in the emission of any air pollutant not previously emitted."

Congress did not further define the terms " physical change"

or " change in the method of operation" in the NSPS program.

Therefore we issued regulations to clarify their meaning. As early as our 1971 NSPS regulations, and since then, we have made clear that many activities that do not affect the contemplated operation of a unit in a manner consistent with its original 3 design are not physical or operational changes. Specifically, in our regulations to carry out the NSPS program, we determined that physical or operational changes do not include:

1) " Routine maintenance, repair and replacement" of equipment;

2) " An increase in the production rate, if such increase does not exceed the operating design capacity of the affected facility";

3) " An increase in the hours of operation"; and 4) " Use of an alternative fuel or raw material if ... the affected facility is designed to accommodate such alternative use."

36 Fed. Reg. At 24877 ( Dec. 23, 1971), codified at 40 C. F. R.

60.2( h). The premise behind characterizing these activities as not being " changes" is that they all contemplate that the plant will continue to be operated in a manner consistent with its original design.

The 1977 Amendments to the Clean Air Act likewise made the NSR program applicable to " modifications". The original 1977 Amendments did so explicitly only in their provisions dealing with the non attainment portion of the NSR program, see CAA sec.

171( 4). But in " technical and conforming" amendments to the 1977 Amendments, Congress clarified that it intended the same result with respect to the prevention of significant deterioration 4 provisions, see CAA sec. 169( 2)( C).

Notably, Congress did not enact a new definition of " modification" in either the original 1977 Amendments or the " technical and conforming amendments." Rather, it incorporated the NSPS definition of " modification" by cross reference. See CAA sec. 169( 2)( C); CAA sec. 171( 4). The Conference Report to the bill adding the technical and conforming amendments { check if that is what the citation refers to} indicates that this was a deliberate choice. As the conferees explained, Congress " intended to conform the meaning of the term ` modification' to usage in other parts of the Act." 123 Cong. Rec. H11956 ( daily ed.)( Nov. 1, 1977). We have understood this to be a reference to our preexisting rules interpreting the term " modification" in the NSPS context. 49 Fed. Reg. 43211, 43213 ( 1984) { not sure what the document being cited is}; see also 43 Fed. Reg. 26388, 26394,

26397 ( June 19, 1978).

The original 1978 NSR rules concerning modifications that we promulgated after enactment of the 1977 Amendments tracked the NSPS approach on all fronts: by specifying that " routine maintenance, repair and replacement" was not a change; by specifying that changes in hours of operation and rates of production were not a " change"; and by using the same approach NSPS used to the question of what constitutes an " increase"

( increase to a source's potential to emit). 43 Fed. Reg. 26388 5 ( June 19, 1978). Even after the D. C. Circuit struck down other portions of our 1978 NSR rules in its original per curiam decision in Alabama Power Co. v. Costle, 606 F. 2d 1068 ( D. C. Cir.

1979), we continued to propose to retain the RMR& R provision and the " potential to emit" approach to emissions increases in our revised rules, although to drop the " hours of operation and rate of production" provisions because the " potential to emit"

provision made them unnecessary. 44 Fed. Reg. 51924, 51937 ( September 5, 1979). In our final 1980 NSR rules, however,

issued after the D. C. Circuit's final Alabama Power decision, 635 F. 2d 323 ( 1980), we changed our approach to the definition of " increase" in the NSR context to specify that a change would trigger NSR if it would result in an increase over " actual annual emissions." 45 Fed. Reg. 52676 ( August 7, 1980). At the same time, and notably, we restored the provisions stating that increases in hours of operation or production rate were not " changes." Id. at 52704.

It is important to understand what we did   and did not   decide in those final 1980 NSR rules. What we did decide was that as a general proposition, we would better serve the purposes of the NSR program if we used " actual" rather than " potential"

emissions as a baseline for determining whether an activity at a new source results in an emissions increase. What we did not decide was that the purposes of the NSR program never allow us to 6 exclude from the definition of " change" any activity at a plant that may increase its actual emissions but does not increase its " potential" emissions. In particular, for example, we decided to retain the " hours of operation" and " rate of production"

exclusions even though such changes might result in increases in " actual" emissions because not having the provisions " would severely and unduly hamper the ability of any company to take advantage of favorable market conditions." Id. Similarly, we retained the exclusion for " routine maintenance, repair and replacement" even though it too can have a similar effect. Yet there is little doubt that increases in hours of operation and rates of production and RMR& R arguably could be understood to fall within the statutory definition of modification, since increases in hours of operation and rates of production certainly may be argued to be changes in the " method of operation" of a plant, and RMR& R certainly may be argued to be a " physical change" to a plant. On balance, however, we rejected that interpretation and determined that the definition of modification should not be read so broadly as to encompass hours of operation or production rate increases.

In the revisions to the NSR program we announced last December, we reiterated our adherence to the view that as a general matter we should continue to use " actual" rather than " potential" emissions in determining what activities constitute 7 " modifications" under NSR. We continue to believe that is correct, but we also believe we should amplify our reasons for holding this view and why that view is entirely consistent with the rule we are promulgating today. In determining the scope to give to " modification," we believe it is important to give weight to both aspects of what Congress decided in 1977. Congress decided that generally speaking, existing plants would not be subject to NSR, but that they would be subject to NSR when they made " modifications." It is also important to understand why Congress chose this point at which to impose NSR on existing plants: to avoid the need to impose costly retrofits, but require placement of new control technology at a time when it makes the most sense for it to be installed. See H. R. Rep. No. 294, 95th Cong., 1st Sess. 185, reprinted in 1977 U. S. Code Cong. & Admin.

News at 1254; 116 Cong. Rec. 32,918 ( remarks of Sen. Cooper) { add quotation if useful}. See also WEPCO, 893 F. 2d at 909 910;

National Southwire Aluminum Co. v. EPA, 838 F. 2d 835, 843 ( 6th Cir., Boggs, J., dissenting), cert. denied, 488 U. S. 955 ( 1988).{ add quotation if useful} A wholesale exclusion of any activity that restores a plant to its potential to emit from the definition of modification is not consistent with this balance,

since there are many activities that might have that effect but the conduct of which would be an extremely effective time for the placement for new control technology. 8 At the same time, we believe it is also important to give equal weight to the converse proposition, at the heart of Congress's decision not to subject existing plants to NSR. That proposition is that existing plants should not have to install new control technology in the ordinary course of their operations. To do so would subject these plants and the consumers who rely on them to enormous dislocation and expense.

That is why we believe we have rightly excluded increases in hours of operation and rates of production from the definition of " change." That is also why we believe we have rightly excluded " routine maintenance, repair and replacement" of existing plants from that definition.

For similar reasons, we believe today's rule draws an appropriate line of demarcation between replacements that should not be treated as changes, and those as to which further consideration of the question is appropriate. Our rule states categorically that the replacement of parts or components with identical or functionally equivalent parts or components that does not exceed 20% of the replacement value of the process unit and does not change its basic design parameters is not a change and is within the RMR& R exclusion. On the other hand, the rule contemplates case by case evaluation of identical or functionally equivalent equipment replacements that do not have these characteristics. 9 We believe this approach is consistent with the intended scope of " modification" under the NSR program. The record of this rulemaking demonstrates that there are substantial categories of replacement activities undertaken in order to assure the safety, reliability and efficiency of existing plants that, if conducted at the same time, meet the 20% replacement cost threshold. It also demonstrates that there are sound business reasons why an owner or operator may find it makes sense to conduct some of these activities at the same time.

On the other hand, given the costs associated with installing state of the art pollution controls, we do not believe it plausible that, if faced with the choice of replacing equipment that has a value less than 20% of a process unit and having to install those controls, or coming up with another solution   such as repairing the existing equipment or limiting hours of operation so as to be confident that the activity will not trigger NSR   the owner of a source would elect to replace the equipment if he also has to install the state of the art controls. Rather, we believe he will repair the existing equipment or artificially constrain production. Therefore the replacement of that equipment is not, in fact, an opportune time for the installation of such controls. It follows that treating such replacements as an NSR trigger will not lead to the installation of controls. Rather, it will merely create 10 incentives to make a plant less productive than its design capacity would allow it to be.

We do not believe it is the policy of the Act to seek to promote emissions reductions by forcing new limits on hours of operation or rates of production of existing plants. We made that point clear in 1980 when we determined that we should retain the hours of operation and rate of production exclusions in the NSR context. To the contrary, as we said in promulgating the 1980 rules, Congress's decision to exclude existing sources because of the dislocation that covering them would cause can reasonably be understood as allowing those sources to increase hours of operation or production up to permitted levels as market conditions dictate. We note that this does not leave such increases outside the scope of the CAA: if a State concludes that resulting air quality considerations warrant revision to its SIP to add further limitations to a permit, it may exercise its authority to impose them, even in the absence of anything that constitutes a " change" to an existing plant. But we believe that our 1980 conclusion that increases in hours of operation or production at existing plants should not trigger NSR remains the better construction of the Act. That being the case, we see no reason why the fact that such increases may occur after replacement of equipment that does not present an opportune time for the installation of controls should change that conclusion. 11 To summarize: With respect to existing sources, the purpose of the NSR provisions is simply to require the installation of controls at the appropriate and opportune time. The kind of replacements that automatically fall within the equipment replacement provision established today do not represent such an appropriate and opportune time. Accordingly, and given that it is consistent with the meaning of " change" to treat this kind of replacement as not being a " change," we believe excluding them on that basis from the definition of " modification" as used in the NSR program is well calculated to serve all of the policies of the NSR provisions of the Clean Air Act, and is therefore a legitimate exercise of our discretion under Chevron to construe an ambiguous term. Likewise, we believe this approach is consistent with the holding in the WEPCO case, and with some though not all of that case's reasoning.

Today's rule treats the activities excluded from the definition of " change" as a category of " routine maintenance,

repair and replacement." In our proposed rule, we inquired whether if we were to adopt the equipment replacement provision,

we should do so as a form of elaboration on this longstanding exclusion, or whether it would better be viewed as a new exclusion. We believe there are legitimate arguments both ways.

The phrase " routine maintenance, repair and replacement" could be read as limited to the day to day maintenance and repair of 12 equipment and the replacement of relatively small parts of a plant that frequently require replacement. That is the reading of the phrase we have adopted since the mid 1990s in the enforcement context, and it is a reading suggested in a number of applicability determinations as well. { is this accurate?} That reading is more plausible when the phrase is considered standing alone, without full consideration of the purpose it serves in the NSR program. On the other hand, as explained above, our efforts to understand the term " modification" in light of Congress's decision to exclude existing plants from NSR as a general proposition, but to include them when an activity at a plant presents a good opportunity for the installation of controls, are highly relevant to how this exclusion is best understood. We believe these considerations lie behind the view, also suggested in a number of Agency documents, most notably the preamble to our 1992 WEPCO rule, that the RMR& R exclusion should also include less common replacements that are nevertheless important for the continued safe, reliable and efficient operation of a plant, and that are to be expected with respect to a source category, such as the replacement of an important part that happens to be defective ( a rare occurrence) or once in a plant lifetime replacement of a large component that nevertheless can be expected to be replaced that one time. Viewing the exclusion for " routine maintenance, repair and replacement" in the context of 13 the policies of the Act, therefore, we also believe it may properly be understood, and indeed all things considered is properly best understood, to encompass those replacement activities within the latter category that today's rule determines to be within its scope. Accordingly that is the view we adopt today.

{ insert re: bright line rules}

We believe it is appropriate to add one final note regarding the fact that this approach represents a change from the approach we have taken in the recent past. As the Supreme Court explained in Chevron, where it upheld a considerably more significant shift in the Agency's understanding of Title I of the CAA, to wit, the scope of the term " stationary source," there is nothing inherently suspect about a change of approach of this type by an expert Agency seeking to interpret a technical statutory term so as best to accommodate competing interests that Congress has charged the Agency with reconciling.

In section 101 of the Clean Air Act, Congress stated that Title I of the Act has a dual purpose: " to protect and enhance the quality of the Nation's air resources so as to promote the public health and welfare and the productive capacity of its population" ( emphasis added). This duality is reiterated in the statement of purpose of the PSD provisions and in the House Report accompanying the 1977 Amendments in connection with the 14 non attainment provisions. See sec. 160( 1) ( purposes of the PSD program are, inter alia, " to protect public health and welfare from any actual or potential adverse effect" of air pollution and " to insure that economic growth will continue to occur consistent with the preservation of existing clean air resources"); H. R.

Rep. No. 95 294, p. 211 ( The " two main purposes" of the nonattainment permitting program are "( 1) to allow reasonable economic growth to continue in an area while making reasonable further progress to assure attainment of the standards by a fixed date; and ( 2) to allow States greater flexibility for the former purpose than EPA's present interpretative regulations afford").

More specifically, with regard to the question at issue here, Congress directed EPA not to apply NSR preconstruction permitting requirements to existing plants as a general matter,

but to apply them to " modifications." Both directives are entitled to receive appropriate weight.

In these circumstances, changes in an Agency's understanding informed by greater experience are not only not surprising, they are to be expected. Effectuating these underlying Congressional commands requires a careful weighing and accommodation of the competing considerations underlying them. Sensitivity to unintended consequences, and a willingness to adjust policies in a manner informed by a better understanding of those consequences, are a central element of the responsibilities of an 15 Agency given such a charge. As the Chevron Court explained:

Our review of the EPA's varying interpretations of the word " source"  both before and after the 1977 Amendments

convinces us that the agency primarily responsible for administering this important legislation has consistently interpreted it flexibly  not in a sterile textual vacuum,

but in the context of implementing policy decisions in a technical and complex arena. The fact that the agency has from time to time changed its interpretation of the term " source" does not, as respondents argue, lead us to conclude that no deference should be accorded the agency's interpretation of the statute. An initial agency interpretation is not instantly carved in stone. On the contrary, the agency, to engage in informed rulemaking, must consider varying interpretations and the wisdom of its policy on a continuing basis. Moreover, the fact that the agency has adopted different definitions in different contexts adds force to the argument that the definition itself is flexible, particularly since Congress has never indicated any disapproval of a flexible reading of the statute.

467 U. S. at 863 64.

The Court went on to point out: 16 In these cases the Administrator's interpretation represents a reasonable accommodation of manifestly competing interests and is entitled to deference: the regulatory scheme is technical and complex, the agency considered the matter in a detailed and reasoned fashion, and the decision involves reconciling conflicting policies. Congress intended to accommodate both interests, but did not do so itself on the level of specificity presented by these cases. . . .

[ A] n agency to which Congress has delegated policymaking responsibilities may, within the limits of that delegation, properly rely upon the incumbent administration's views of wise policy to inform its judgments. While agencies are not directly accountable to the people, the Chief Executive is, and it is entirely appropriate for this political branch of the Government to make such policy choices  resolving the competing interests which Congress itself either inadvertently did not resolve, or intentionally left to be resolved by the agency charged with the administration of the statute in light of everyday realities. . . .

We hold that the EPA's definition of the term " source"

is a permissible construction of the statute which seeks to accommodate progress in reducing air pollution with economic growth. ` The Regulations which the Administrator has adopted 17 provide what the agency could allowably view as . . . [ an]

effective reconciliation of these twofold ends. . . .'

Id. at 865 66 ( citations and footnotes omitted). We believe the same reasoning applies here, and makes it entirely appropriate for us to adopt the equipment replacement provision today.