Only certain facilities are required to rely upon a continuous emissions monitoring system (CEMS). The six conditions that must be met in order for Tier 4 methodology to be required using CEMS are described in Section 98.33 (b)(4)(ii). One of the six conditions is that the unit has installed CEMS that are required either by an applicable Federal or State regulation or the unit’s operating permit.
If a facility has a stationary combustion source and is required to report following Tier 4 methodology, the facility is required to begin reporting on January 1, 2010 using CEMS and the Tier 4 calculation methodology. If all of the monitors needed to measure CO2 mass emissions have not been installed and certified by January 1, 2010, the facility has until January 1, 2011 to begin using Tier 4 methodology. In this case, the facility may use Tier 2 or Tier 3 methods to report GHG emissions for 2010, and the facility is not required to receive prior approval from EPA.