; (2) prevent accidental releases; or (3) protect the health of the communities most exposed to the emissions of hazardous air pollutants from such stationary sources to the greatest extent possible. (g) Determination regarding emission factors Not later than 3 months before the program under subsection (a) terminates, the Administrator shall complete an evaluation and promulgate a determination whether any existing emission factors must be updated to better reflect or account for the results of fenceline monitoring data collected pursuant to Method 325A or 325B or the program under subsection (a). (h) Authorization of appropriations There is authorized to be appropriated to carry out this section $73,000,000 for fiscal year 2021. 3. Community air toxics monitoring (a) Regulations Not later than one year after the date of enactment of this Act, the Administrator shall promulgate regulations pursuant to section 112(d) of the Clean Air Act ( 42 U.S.C. 7412(d) ) for each source category described in subsection (b), that— (1) require all sources in such source category to implement the best available form of continuous emissions monitoring and fenceline monitoring to assure compliance with the emission standards for hazardous air pollutants; (2) for facilities in such source category that are required to submit risk management plans under section 112(r) of the Clean Air Act, to prevent accidental releases and provide for effective emergency response; (3) establish a corrective action level at the fenceline for at least the top 3 hazardous air pollutants that drive the cancer, chronic non-cancer, or acute risk for the source category; and (4) require a root cause analysis and consequences if such corrective action level is exceeded. (b) Source categories The source categories described in this subsection shall include each category or subcategory of major sources or area sources containing— (1) at least one of the stationary sources of hazardous air pollutants that are on the list developed under section 2(c)