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UNITED STATES 

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ENVIRONMEN' WASHINGTON, I 

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,L PROTECTION AGEN Y 7 :. 20460 ~ P. At =



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MEMORANDUM

SUBJECT: State Implementation Plai

Emissions During Malfunct

FROM: Steven- A. Herma 'K. ~

a A~ s-istant Admi ' CAssurance M C3

~ is: Policy Regarding EKcesin :ions, Startup, and Sh

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Robert Perciasepe Assistant Administrator ] or Air and Radiation

TO: Regional Administrators, Regions I - X

EPA's policy for state implemi excess emissions during malfunctioi maintenance is contained in memorai formerly Assistant Administrator f dated September 28, 1982 and Februi of SIPs'suggests that several conti be inconsistent with this policy, o inadvertently approved after EPA i: because they were part of the SIP i been.removed. In order to address consistent manner, today we are rei 1982-83 policy. In so doing, we a: clarify several issues of interprel that time. The attached updated p excess emissions provisions states that they can in turn provide grea community.

As EPA stated in its 1982,mem emissions ruight aggravate air qual: or interfere with maintenance of tl standards., EPA views all excess em: applicabie emission limitation. Ni ntation plans (SIPs) regarding s, startup, shutdown, and da from Kathleen Bennett, r Air, Noise and Radiation .I ry 15, 1983. A recent review in provisions that.appear to ither because they were sued the,1982-1983 guidance or t that time and have never. these provisions in a ffirming and supplementing the e taking this opportunit.y to, ation that have arisen since1 licy will clarify the types of may incorporate into SIPs sof er certainty to the regulated

randum, because excess ty so as to prevent attainmeit e ambient air quality ,ssions as violations of the !vertheless, EPA recognizes- 2

: that imposition of a penalty for sudden and unavoidable malfunctions caused by circumstances entirely beyond the control

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- the owner'or operator may not'be`'appropriate. Accordingly, a`

state or EPA can exercise its "enforcement.discretiori" to refrain from taking an enforcement action in these circumstances.

The main question of interpretation that has arisen regarding the old policy is whether a state may go beyond this "enforcement discretion" approach and include in its SIP a provision that would, in,the context of an enforcement action for excess emissions,. excuse a source from penalties if the source can demonstrate that it meets certain objective criteria (an "affirmative defense"). This policy clarifies that states have the discretion to provide'such a defense to actions for.penalties brought for excess emissions that arise during certain . malfunction, startup, and shutdown episodes,

In the context of malfunctions, EPA recognizes that even equipment that is properly designed and maintained can sometimes fail. At the same time, EPA has a fundamental responsibility under the Clean Air Act to ensure.that SIPs provide for attainment and maintenance of

- the national ambient air quality •standards ("NAAQS")and protection of PSD increments. Thus, EPA cannot approve an affirmative defense provision that would undermine the fundamental requirement of attainment and maintenance of the NAAQS, or any other.requirement of the Clean Air Act: See sections 110(a) and (1) of the Clean Air Act, 92. U.S.C. § 7910(a) and (1). 1 Accordingly, an acceptable affirmative defense provision.may only apply to actions for • penalties, but not to antions for injunctive relief. This restriction insures that both state and federal authorities remain able to'protect air quality standards and PSD increments.

Furthermore,' this approach is appropriate only when the respective cont.ributions of individual sources to pollutant concentrations in ambient air are such that:no single source or small -group•of•sources has the potential to cause an exceedance of th'e NAAQS or-PSD increments. Z Where a sirigle source or small

1 Pursuant to Section 110(1), EPA'may not approve a SIP revision if "the"'revision would interfere with any applicable requirement concerning attainment and reasonable further progress, or any other applicable requirement of this chapter." See also CAA'§ 193, 42 U.S:C. § 7515, and the definitions of "emission limitation" and "emission standard" contained in CAA § 302(k), 42

, U.S.C. § 7602(k).

. Z . In the case'of lead and sulfur dioxide, attainment problems usually are caused by one or a few sources and an ~ <S.. s

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group of sources has the potential NAAQS or PSD increments, EPA belie
, apprbath will not be adequate to p: environment, and the only appropri+ excess,emissions during malfunctioi episodes is through an enforcement

EPA is also taking this oppor not intend to approve SIP revision director's decision to bar EPA's o applicable requirements. Such an with the regulatory scheme establi Air Act. EPA is also adding conte notification criteria to make its events consistent with its enforce

Finally, EPA is clarifying ho during periods of startup and shutc general, because excess emissions I are reasonably foreseeable, they sl EPA recognizes that, for some sour available emissions control system:



### ~ effective during startup or shutdo respective contributions of indivir 0 4

_ concentrations in ambient air are : small group of sources has the potr of the NAAQS or PSD increments, th may be addressed in the underlying narrowly-tailored SIP revisions thi potential impacts on ambient air qi of these allowances. In these ins' justification of the SIP revision, to cause an exceedance of t es an affirmative defense otect public health and the te means of dealing with , startup, and shutdown discretion approach.'

unity to clarify that it does that would recognize a state citizens' ability to enforce pproach would be inconsistent hed in Tit1e I of the Clean j. poraneous record keeping and; olicy regarding these types of ent approach.

r excess emissions that occur lown should be addressed. In! :hat occur during these periods iould not be excused. However., :e categories,' even the best might not be.consistently rn periods. In areas where ttie lual sources to pollutant ;uch that no single source or mtial to cause an exceedance !se technological limitations standards themselves th-rough t take into account the ality caused by the inclusion :ances, as part of its the state should analyze the

affirmative defense is not appropr: particularly aggravated where a shr exceedances or violations are basec in place. Although this policy is NAAQS, enforcement

. discretion is,t] for dealing with excess emissions 

### ~ malfunction in a specific area whe: group of sources has the potential short-term NAAQS. ~

Late. This situation can be ; irt-term standard (e.g., where i on a few hour period) is also generally applicable for other ie only appropriate approach-I 3uring startup, shutdown, and :e a single source or a small to cause nonattainment of a

' In'American Trucking Association v. EPA, 175'F. 3d 1027



### ~ (D.C. Circ., 1999), the court remanded:the PM2.5 NAAQS to the EPA. The Agency has not determined whether this policy is appropriate for PM2.5 NAAQS.- 4 -

impact of

- the potential worst=case emissions that could occur• during startup and shutdown.',."



### , • _. ..... In addition to this approach,-states may address this problem through the use of enforcement discretion or they may include a general affirmative defense provision in their SIPs for short and infrequent startup and shutdown periods along the lines outlined in the attachment.:- As mentioned above, however; in those areas where:a:singLe source or small group of sources has the potential to cause•an"jexceedance of the NAAQS or PSD increments, issues relating to excess emissions arisi'ng during startup.and shutdown may only_•be addressed through an enforcement discretion approach'.

A11 Regions should review the-SIPs for their•states in light of this clarification and take steps to•insure that excess emissions provisions in these SIPs are consistent with the attached guidance..



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_ . Attach.ment . .



### ° States may account for such emissions by including them in their routine rule effectiveness estimates. Rule effectiveness estimates may be prepared in accordance with an EPA policy document entitled "Guidelines for Estimating and Applying Rule Effectiveness for Ozone/Carbon Monoxide State Implementation Plan Base Year Inventories." (EPA-452/R-92-010),November-1992.Attachment

POLICY ON EXCESS EMISSIONS DURIIG MALFUNCTIONS, STARTUP, AND SHUTDOWN Introduction

This policy specifies when a i nd'in what manner state 

### ~ implementation plans (SIPs) may provide for defenses to viol'ations caused by periods of eiccess emissions due to 

### ~ malfunctions,' startup, or shutdown. Generally, since SIPs must provide for attainment and maintenance of the national ambient ! air quality standards and the achi i evement of PSD increments, ali periods of excess emissions mus't be considered violations. Accordingly, any provision that allows for an 'automatic exemptionZ for'excess emissions is prohibited.

However, the imposition of a penalty for.excess emissions

, during malfunctions caused by circ'umstances entirely beyond the!

control of the owner or operator may not be appropriate. States may, therefore,- as an exercise of their inherent enforcement discretion, choose not to penalizela source that has produced excess emissions under such circumstances.

1 This policy provides an alternative approach to enforcement F discretion for areas and pollutants where the respective i contributions of individual sources to pollutant concentrationsl in ambient air are such that no single source or small group of: sources has the potential to causelan exceedance of the NAAQS or PSD increments. Where a single source or small group of sources has the potential to cause an exceedance of the NAAQS or PSD increments, as is often the case for sulfur dioxide and lead,' ' EPA believes approaches other thanlenforcement discretion are not appropriate. In such cases, any excess emissions may have a significant chance of causing an ezceedance or violation of the 

### ~ applicable standard or PSD increment.

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'The term excess emission means an air emission level which 

### ~ exceeds any applicable•emission limitation. Malfunction means a sudden and unavoidable breakdown of process or control.equipment.

z The terrti automatic exemotion means a generally applicable j provision in a SIP that would provide that if certain conditions existed during a period of excess emissions, then those exceedances would not be considere3 violations.
'This poli`cy also does not app,ly for purposes of PM2:5 NAAQS. In American Trucking Association v: EPA, 175 F. 3d 1027 (D.C. Circ., 1999), the court remanded the PM2.5 NAAQS to the EPA. The Agency has not determine3 whether this policy is appropriate for PM2.5 NAAQS.

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Except where a single source or small group of sources has the potential to cause an exceedance of the NAAQS or PSD

_-• -increments, states may include in:their-SIPs affirmative

defenses" for excess emissions, as long as the SIP establishes limitations consistent with those set out below. If approved into a SIP, an affirmative defense wquld be available to sources in an enfor-cement action seeking penalties brought by the state, EPA, or citizens: .However, a determination by t_he state not to take an enforcement action would not bar EPA or citizen action. s

. In addition, in certain limited circumstances,•it may be appropriate for the state to build into a source-specific,orsource-category-specific emission standard a provision statingthat the otherwise applicable emission limitations do, not apply during narrowly defined startup and shutdown periods.

.I. AUTOMATIC EXEMPTIONS AND ENFORCEMENT DISCRETION

If a SI_P contains a

. provision addressing excess emissions,. it cannot be the type that provides for automatic exemptions. Automatic exemptions might aggravate ambient air quality by excusing excess•emissions that cause or contribute to a,violation of an ambient•air quality standard. Additional grounds for disa rovin a SIP that includes the automatic exem tion a roach PP 4• P PP

. are discussed•in more detail at 42 Fed. Reg. 58171 (November 8, 1977) and,42-Fed. Reg. 21372 (Apri1.27, 1977). As a,result, EPA will not approve any ; SIP revisions that provide automatic exemptions.for periods of excess,emissions.

The best assurance that excess emi_ssions will.not interfere with NAAQS attainment, maintenance, or increments is to address excess emissions through enforcement discretion. This policy,, ' prodi des alternative means for addressing excess emissions of criteria pollutants. However, • this policy does not apply where a single source or small group of sources has the potential to cause an exceedance of the NAAQS or PSD increments. Moreover,

° The"term affirmative defense means, in the.context of an enforcement proceeding, a response or defense put forward by a defendant,.regarding which the defendant has the burden of proof, and the merits of;which are-independently and objectively evaluated in a judicial or administrative proceeding.

~ S Because all periods of excess emissions are violations and because affirmative defense provisions may not apply in actions for injunctive-relief, under no circumstances would EPA consider periods of excess emissions, even if covered by an affirmative=, defense, to be ;'federally permitted releases" under EPCRA or CERCLA.,

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nothing in this guidance should



### ~ to include affirmative defense be construed

ro i isions in as requiring stat

their SIPs.

II. AFFIRMATIVE DEFENSES FOR MALFUNCTIONS

EPA can approve a SIP revisiori that creates an affirmative 

### ~ defense to claims for penalties inlenforcement actions regarding excess emissions caused by malfunctions as long as the defense does not apply to SIP provisions that derive from federally I

. promulgated performance standards or emission limits, such as new

source performance standards (NSPS) and national emissions standards for hazardous air pollutants (NESHAPS). 6 In addition, affirmative defenses are not appropriate for areas and pollutants where a single source or small group of sources has the potential to cause an exceedance of the NAAQS or PSD increments. Furthermore, affirmative defenses to claims for injunctive relief are not allowed. To be approved, an affirmative defense provision must provide that the defendant has the burden of prolf of demonstrating that: I

1. The excess emissions were caused by a sudden, unavoidable breakdown of technology, •beyond the control of the owner or operator;

2. The excess emissions (a) did not stem from any activity or event that could have been foreseen and avoided, or planned { for, and (b) could not have been avoided by b.etter operation and maintenance practices; I

3. To the maximum extent practicable the air pollution i control equipment or processes were maintained and operated in a manner consistent with good practice for minimizing emissions;

4. Repairs were made in an expeditious fashion when the operator knew or should have known'that applicable emission limitations were being exceeded. Off-shift labor and overtime must have been utilized, to the extent practicable, to ensure i that such repairs were made as expedit.iously as practicable;
I 5. The amount and duration of the excess emissions (including any bypass) were minimized to the maximum extent practicable during periods of suchlemissions;

6 To the extent a state includes NSPS or NESHAPS in its SIP, the standards should not deviate f


### ~ rom those that were federally promulgated. Because EPA set these standards taking into account technological limitations, additional exemptions would be inappropriate.y

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6.° All possible steps were taken to minimize the impact

. of the excess emissions on ambient air quality;

7. A11 emission monitoring system_s were kept in operation if at all possible;

8. The owner or.operator's actions in response to the . excess emissions_were documented by properly signed,.
, contemporaneous operating logs, or other relevant evidence;

9. The-excess emissions were not part of a recurring pattern ihdicative of inadequate design, operation, or maintenance; and

10. The owner or operator properly and promptly notified the.appropriate regulatory authority..

EPA interprets these criteria narrowly. Only those malfunctions that are sudden, unavoidable, and unpredictable in nature qualify for the defense. For example, a single instance of a bur st pipe that meets the-above criteria may qualify under an affirmative defense. The defense would not be available, however, if the facility had a history of similar failures because 

### of improper design, improper maintenance, or poor operating practices. Furthermore, 

### a source must have taken all available measures to compensate for and,resolve the malfunction. If a

- -facility has a baghouse fire that leads to excess emissions, the affirmative defense would be appropriate only for the period of time necessary to modify or curtail operations to come into compliance. The fire should-not be used to excuse excess emissions generated during an'extended period of time while the operator orders and installs new bags, and relevant SIP language must limit applicability of the affirmative defense accordingly.

III. EXCESS.EMISSIONS DURING STARTUP AND SHUTDOWN
In general, startup-and.shutdown of proce'ss equipment,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. Accordingly, it is reasonable to expect,that careful and prudent planning,and design will eliminate violations of emission limitations during such periods.

A. SOURCE CATEGORY SPECIFIC RULES -FOR STARTUP AND SHUTDOWN

For some.source categories, given the types of control technologies available, there may exist short periods of : emissions during startup and shutdown when, despite best efforts regarding planning, design, and operating procedures, the- 5

otherwise applicable emission limitation cannot be met. Accordingly, except in the case where a single source or..small group of sources has the potentialito"cause'an excdedance'of'th NAAQS or PSD increments, it may be,appropriate, in consultation with EPA, to create narrowly-tailored SI P revisions that take these technological limitations into account and state that the otherwise applicable emissions limitations do not apply during narrowly defined startup and shutdown periods. To be approved, these revisions should meet the foilowing requirements:

1. The'revision must be limited to specific,.narrowlydefined source categories using specific control strategies (e.g., cogeneration facilities burning natural gas and using .selective catalytic reduction); "

2. . Use of.the control strategy for this source category must be technically infeasible during startup or shutdown periods;

3. The frequency and duration of operation in startup or shutdown mode must be minimized to!the maximum extent practicable; i

t ` rY 4. As part of its justification of the SIP revision, the state should analyze the potential worst-case emissions that could occur during startup and shutdown;

5. A11 possible steps must be taken to minimize the impac of emissions during startup and shutdown on ambient air quality

6. At all times, the facility must be operated in a manne consistent with good practice for minimizing emissions, and.the source must have used best efforts regarding planning, design, and operating procedures to meet the otherwise applicable emission limitation; and r -.

7. The owner or operator's actions during startup and shutdown periods must be documented by properly signed, contemporaneous operating logs, orio*_her relevant evidence.

B. GENERAL AFFIRMATIVE DEFENSE PROVISIONS RELATING TO STARTUP AND SHUTDOWN i

In addition to the approach outlined in Section II(A) abov states may address the problem of iexcess emissions occurring during startup and shutdown periods through an enforcement discretion approach. Further, except in the case where a singl source or small group of sources hlas the potential to cause an



# ~ -` exceedance of the NAAQS or PSD increments, states may also adop for their SIPs an affirmative defe i nse approach. Using this

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approach, all pe'riods of excess emissions arising during startup and shutdown must be treated as violations,- and the affirmative `'defe'n"'se' pro'vision' must not be available for claims 'for injunctive :s relief. Furthermore, to be approved, such a provision must provide that'the defendant has-

~ the burden of proof of. demonstrating that:'

1.
, The periods•of excess einissioins'that occurred during. startup andwshutdown were short and infrequent and.could not have been prevente.d through careful planning and design;

2.- The excess emissions were not part of a.recurring pattern indicative 4 of- inadequate.design, operation, or maintenance; f -

3: 'Sf the excess emissions•were caused by a bypass (an intentional diversion of control•equipment),.then .the bypass was unavoidable to prevent loss of life, personal injury, or severe property damage;

4. At all times,' the facility
, ivas operated in a manner consistent with good practice for minimizing emissions;

S: The'frequency and duration.of operation in startup or shutdown mode was

~ minimized to the maximum extent.practicable;

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6. All,possible steps were taken to minimize the impact of the excess emissions on ambierit air quality;-

7. A11 emission monitoring systems were kept in operation if at all possible;

•8. The owner or operator's actions during the p,eriod ofexcess emissions were documented by properly signed, contemporaneous operating logs, or other relevant evidence; and

9. The owner• or operator properly and.promptly notified the appropriate regulatory authority.

If excess emissions occur during routine startup or shutdown periods due to a malfunction, then those instances should be treated as other malfunctions that are subject to the malfunction provisions of this policy. (Reference Part I above)..

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