Air Plan Approval; California; Eastern Kern Air Pollution Control District; Portland Cement Kilns

The Environmental Protection Agency (EPA) is proposing to approve a revision to the Eastern Kern Air Pollution Control District (EKAPCD or “District”) portion of the California State Implementation Plan (SIP). This revision concerns emissions of oxides of nitrogen (NOx) from Portland cement kilns. We are proposing to approve Rule 425.3 to regulate these emission sources under the Clean Air Act (CAA or “Act”). We are taking comments on this proposal and plan to follow with a final action.