Tips on Ways to Avoid and Comply with NSPS OOOO
April 8, 2015
ALERT: Quad O Group 1 Tank Emission Controls Compliance Date

Group 1 storage vessels that emit 6 or more tpy VOC must reduce VOC emissions by 95.0% or greater by April 15, 2015.  This is a per storage tank emission limitation, but the 6 ton limitation includes any/all tanks that are manifolded together as one source, or “tank”. 

Group 1 storage vessels are those constructed after August 23, 2011, and on or before April 12, 2013. 

Control methods used include vapor recovery and vapor combustion units.

Note:  All Group 2 storage vessels that emit 6 tons or more per year (tpy) were required to reduce emissions by 95.0% or greater by April 15, 2014.   These include any storage vessels or tank batteries constructed or modified after April 12, 2013.


Easy ways to avoid and comply with NSPS OOOO 

Companies are always looking for the most efficient way to comply with the myriad of air quality rules like NSPS OOOO. Below are some tips that may help you. 



Storage Tanks

  1. Install a vapor recovery unit (VRU) and capture the vent gas. VRUs are considered process equipment by EPA and the gas recovered by the VRU does not count toward the VOC potential to emit (PTE) emissions for the storage tanks. VRUs lower overall emissions at the location unlike flares which have combustion emissions. VRUs should meet the EPA minimum definition of a VRU (proper compressor selection, etc), and should be specifically designed for high BTU, “wet” gas streams.
  2. Obtain an air permit for the facility that is “practically enforceable” from the air permitting agency such that the permit limits VOCs to less than 6 tons per year per tank.
  3. Use centralized batteries to process the crude oil/condensate which allow more efficient VRU systems. Centralized batteries receiving oil from several to many wells flowing can have a more constant flow of oil to storage tank which improves efficiency of a VRU system. VR Towers can also be used to effectively eliminate oxygen ingress.
  4. Ensure storage tank hatches and piping to the control device (flare/combustor) or VRU operate in a leak-free manner.
  5. Route storage tank vent gas to a combustion device such that per tank VOC emissions are less than 6 tons per year. Use of EPA pre-certified enclosed combustors reduce EPA Quad O reporting requirements to annual (versus monthly for open flares).


  1. Use dry seals for centrifugal compressors. Dry seals are exempt from emission controls.
  2. Track your hours of operation for you reciprocating compressors with a runtime meter.

 Natural Gas Pneumatic Controllers

  1. Use only low-bleed devices that the supplier certifies, in writing, vent natural gas at a rate less than or equal to 6 scfh.
  2. Convert pneumatic devices to compressed air.
  3. Use electric powered devices.
  4. Use Mizer No-Bleed Pilot Valve conversion packages that make existing devices to low devices.

Expect that  

HY-BON can help your company comply with NSPS OOOO and air quality permits using our IQR methodology and vent gas management (VGM) system. Contact us to find out ways to recover valulable vent gas and increase production sent to sales.