Relating to the environment; limiting mercury emissions from electric generation facilities; specifying certain emissions calculation +duties of the public utilities commission and regulating the issuance of permits; +specifying certain emissions reduction credits purchasing requirements of +electric generation facilities seeking to exceed the emissions limit; +requiring registration of mercury emissions reductions with the PUC, requiring +the PUC to establish criteria for registration; specifying certain emissions +reduction requirements, mandatory reductions not to be eligible for +registration (mk)