Array Insights

3 Key A&WMA Takeaways

I attended an A&WMA webinar on TANKS 4.09D today; and among all the great information that was presented, here are the three most important takeaways:

  1. EPA enforcement has stated that reliance on TANKS 4.09D is not an effective defense even if a state agency has approved and/or required it. As such, EPA can over-file if they feel a state agency has made an incorrect determination in allowing the use of TANKS 4.09D.
  2. TANKS 4.09D is only good at estimating annual emissions for floating roof tanks in equilibrium with ambient temperatures where actual stock data (i.e., no defaults) are used with the actual guide pole status. If all of these conditions are met, the TANKS results can be relied upon.
  3. EPA is revising AP-42 Chapter 7.1 to include clarifications, corrections, adjustments to some of the equations; and emission calculations for additional scenarios (e.g., tank cleaning losses). Once the new version of AP-42 is out, any further use of TANKS 4.09D should cease.