Q77. For a unit that has an O2 monitor and doesn't meet the conditions required to use Tier 4, but elects to use Tier 4, what are the monitoring requirements?

A77. A Tier 4 unit is required to report CO₂ mass emissions beginning on January 1, 2010, if all of the monitors needed to measure CO₂ mass emissions have been installed and certified by that date.  If all of the monitors needed to measure CO₂ mass emissions have not been installed and certified by January 1, 2010, the unit is required to report CO₂ mass emissions using Tier 4 no later than January 1, 2011 and use Tier 2 or Tier 3 to report emissions for 2010.

If your facility meets the applicability requirements of 98.3(d)(3),  you may submit an abbreviated report in 2011, for your 2010 emissions. If your facility qualifies to use the abbreviated report, you may use any Tier for quantifying emissions from stationary combustion in 2010.