Alternate operating scenario (AOS) for engines

To report an engine replacement (if authorized by your permit)

First, complete an Applicability Report for your replacement engine. 

  • The Applicability Report is your explanation of the regulatory requirements that apply to the replacement engine

Next, submit the Applicability Report with a revised APEN:

Additional guidance:

  • PS Memo 98-06
    Permit conditions for natural gas-fired engine AOS.
  • PS Memo 11-04
    Permit conditions for diesel engine AOS.
  • PS Memo 11-05
    Adoption of AOS for natural gas-fired engine permits not containing an AOS provision.