EPA is promulgating a regulation to require monitoring and reporting of greenhouse gas emissions from magnesium production, underground coal mines, industrial wastewater treatment, and industrial waste landfills. This action adds these four source categories to the list of source categories already required to report greenhouse gas emissions. This action requires monitoring and reporting of greenhouse gases for these source categories only for sources with carbon dioxide equivalent emissions above certain threshold levels as described in this regulation. This action does not require control of greenhouse gases.