Q85. Is the use of Subpart C tiers required after 2010 and is it acceptable to use the best available monitoring provisions under Subpart A beyond 2010?

A85. Yes, the use of Subpart C Tiers is required after 2010.  The use of best available monitoring methods as described in Subpart A may not be extended beyond the end of 2010 except for units subject to subpart P (Hydrogen Production), subpart X (Petrochemical Production), or subpart Y (Petroleum Refineries).  Note that there may be subpart specific BAMM requirements not included in subpart A.  Note, however, that this timing does not apply to subpart-specific BAMM requirements. (See §98.3(d)(2)(iii) and §98.3(j).)