The purpose of the proposed rule development (OGC No. 16-0106) is to amend Rule 62-210.300(3)(a), F.A.C., to update provisions for fossil fuel steam generators, hot water generators, and other external combustion heating units with heat input capacity less than 100 million Btu per hour. The rule revision will allow units that meet the requirements of 40 CFR 63 Subpart JJJJJJ to maintain the existing permit exemption. This rule development also proposes to amend Rule 62-210.310, F.A.C. to address the circumstances under which temporary and relocatable sources, including emissions units operating under an Air General Permit (AGP), may collocate at an otherwise permitted facility, as well as revisions to the AGP for Chromium Electroplaters to reflect updates to 40 CFR 63 Subpart N. Clarifying and corrective revisions to existing rule language in Rules 62-210.200, .300 and .310, F.A.C., will also be considered.