Q307. How do you report a unit in e-GGRT that uses Tier 2 or 3 for part of the year and CEMS for the remainder of the year?

A307.  You are required to add two configurations for the same unit. The first configuration represents when Tier 2 or 3 is used to calculate emissions and the second configuration represents the CEMS. You must specify the respective calculation methodology period for each configuration as appropriate. You also must identify the change in calculation methodology in the subpart A reporting module. (See §98.3(c)(6).)