UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

JAN 28 1993

OFFICE OF

AIR AND RADIATION

MEMORANDUM 

SUBJECT: Automatic or Blanket Exemptions for Excess Emissions

During Startup, and Shutdowns Under PSD

FROM: John B. Rasnic, Director

Stationary Source Compliance Division

Office of Air Quality Planning and Standards

TO: Linda M. Murphy, Director

Air, Pesticides and Toxics Management Division

Region 1

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 automatic exemptions which allow excess

emissions during startup and shutdown. You also requested that 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 shutdown (especially as it

pertains to Best Available Control Technology determinations) and on

automatic exemptions that are granted in PSD permits. I understand

that my staff has discussed this issue and the response 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 Implementation 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 contribute to violations of the national

ambient air quality standards. This rationale applies to the PSD

program not only because PSD is ambient-based but also because

generally, the PSD program 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).
2

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 somewhat vague. The exemptions granted 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 footnote. 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

determined 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

attachments 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 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. If excess emissions occur during routine startup

and shutdown due to a malfunction, then those instances should be

treated as other malfunctions which are subject to the malfunction

provisions of the policy (attached).
3

If you have any questions regarding this matter, please contact

Clara Poffenberger at 703 308-8709.

Attachments