EPA is considering this action to propose limited amendments to the Standards of Performance for Volatile Organic Liquid Storage Vessels (Including Petroleum Liquid Storage Vessels) for Which Construction, Reconstruction, or Modification Commenced After July 23, 1984 (40 CFR part 60, subpart Kb). This proposed action would amend NSPS Kb by incorporating a voluntary alternative standard to allow certain sources subject to NSPS Kb to comply with the National Emission Standards for Storage Vessels (Tanks) - Control Level 2 found at 40 CFR part 63, subpart WW. The primary benefit anticipated from allowing this voluntary alternative is that some NSPS Kb sources can conduct top-side internal floating roof inspections without the need for emptying and degassing storage tanks, which is a costly process that releases emissions of VOC.