Aegis Regulatory Alert- October 2021

Aegis extends this Regulatory Alert:

Clean Air Act – Virginia Permit Exemptions
The following summarizes several air permit exemptions for internal combustion engines and replacement emissions units which have been a source of confusion for sources. This language is from Virginia regulations. Sources should review the requirements of other states to determine applicability.

Non-road Internal Combustion Engines (ICE):
• ICE is not subject to Federal New Source Performance Standards, e.g., 40 CFR Part 60 Subparts IIII for combustion ignition engines and JJJJ for spark ignition engines.
• ICE is not located at a source for more than 12 consecutive months. If this is a seasonal source, the unit is restricted to that time frame.• ICE replacement size must be equal to or less than the replaced unit and perform the same or similar function.
• The replaced unit must be removed or permanently shut down.

Emergency Engine/Generators:
• Exempted by size and fuel type. Example: diesel engines rated at aggregate 1,675 hp or less and diesel engines powering electrical generators rated at aggregate 1125 kW or less.
• Restricted to 500 hours or less each.
• If these requirements are exceeded, the units are functioning as non-emergency generators subject to more restrictive requirements.

Replacement Emissions Units:
• Replacement must be the same size or smaller and rated capacity equal to or less than the replaced unit.
• Replacement must be functionally equivalent to the existing unit and does not change the process design or operation.
• Potential emissions must be the same or less than emissions associated with the replaced unit.
• The replaced unit must be removed or permanently shut down.
• The DEQ must be notified 15 days prior to the change.

For more information on any of these updates, please contact Sandy Morse at, or call us at 804-378-6015.