UN ITED STATES ENVIRONMENTAL PROTECTION'AGENCY
 

WASHINGTON, D.C. 20400
 

JAN 2 8 1993 

OFFICE OF 

AIR AND RAOIATlON 

MEMORANDUM 

SUBJECT:	 Automatic or Blanket Exemptions for Excess Emissions 

During Startup' and Shutdowns Under _ 

FP.OM:	 John B. Rasnic, Direct~ Stationary Source Compl~ance Division 

Office of Air Quality Planning and Standards 

TO:	 Linda M. Murphy, Director 

Air, Pesticides and Toxics Management Division 

Region ::: 

This is in response to your memorandum dated June 15, 1992, 

asking that we advise Region I on whether you are correct in 

telling States and applicants that Prevention of Significant 

Deterioration (PSD) permits ,cannot contain automat~c exemptions 

which allow excess emissions during startup and shutdown. You 

also requested ~ha~ the Stationary Source Compliance Division 

(SSCD) issue a memo which outlines the Environmental Protection 

Agency's (EPA's) policy on excess emissions during startup and 

sh~tdown (especially as it per:tains to Best Available Control 

Tec~no~ogy (BACT) determinations) and on automatic exemptions that 

are gran~ed in PSD permits. I understand that my staff has 

discussed this issue and the tesponse with your staff by phone. 

However, we regret the delay in providing a written response. 

The two memoranda you mention, entitled "Policy on Excess 

Emissions During Startup, Shutdown, Maintenance, and Malfunction" 

from Kathleen M. Bennett (dated February 15, 1983 and September 

28, 1982), address automatic exemptions under the State 

Imp'lementation Plan (SIP). The memoranda state that the rationale 

for establishing these emissions as violations, as opposed to 

granting automatic exemptions, is that SIPs are ambient-based 

standards and any emissions above the allowable may cause or 

, ntribute to violations of the national ambient air quality 

andards. This rationale applies to the PSD program not only 

ecause PSD is ambient-based but also because generally, the PSD 

rogram is	 part of the SIP. Even in States where the PSD program 

is not SIP approved, the emissions limits are established to 

protect increments and the national ambient air quality standards 

(NAAQS) . 
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Another 1977 memorandum, entitled "Contingency Plan for FGD 

Systems During Downtime as a Function of PSD" from Edward E. 

Reich, states that PSD and SIP regulations require the 

establishment of emission 'limitations which will be sufficient to 

ensure nondegradation of air quality and attainment and 

maintenance, of the NAAQS. This memorandum specifically refers to 

the April 27, 1977 Federal Register notice (42 FR 21472) that is 

also mentioned in the EPA policy attached to the Bennett 

memoranda. 

Although we concur with Region I that PSD permits cannot 

contain automatic exemptions which allow excess emissions during 

startup and shutdown, we do not believe, that EPA's policy 

concerning this issue under PSD is some,what vague. The exemptions 

gr.anted under some New Source Performance Standards (NSPS) are not 

applicable to this issue under PSD. The NSPS are technology based 

standards that are not directly required for meeting ambient 

standards. 

Likewise, we do not concur at this time with the approach as 

outlined in the foo~note. You suggest setting a specific emission 

rate that would apply during startup and/or shutdown that is 

demonstrated to not cause a violation of any short-term increments 

or standards. While this may protect the ambient standards, this 

cannot be easily de=ermined if, as is suggested, the emission rate 

would reflect a longer averaging time. Further, as the 1982 

memoranda states, without clear definition and limitations, these 

automatic exemptions or even secondary limits could effectively 

shield excess emissions arising from poor operation and 

maintenance or design, thus precluding attainment. 

However, the States retain enforcement discretion, as 

discussed in the memoranda; to address the. occurrence of excess 

emissions. The at~achments to the memoranda provide that 

infrequent periods of excess emissions during startup and shutdown 

need not be treated as violations where 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. Startup and shutdown of 

process equipment are part, of the normal operation ofa 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. If excess emissions occur during 

routine startup and shutdown que to a malfunction, then those 

instances should be treated as other malfunctions which are 

subject to the malfunction provisions of the policy (attached) 
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If you have any questions regarding this matter, please 

contact Clara Poffenberger at 703 308-8709. 

Attachments