(a) (1) Except as provided in this section, this title does not limit the power of a political subdivision to adopt ordinances, rules, or regulations that set emission standards or ambient air quality standards. (2) A political subdivision may not adopt any ordinance, rule, or regulation that sets an emission standard or ambient air quality standard less stringent than the standards set by the Department under this title. (b) The governing body of any political subdivision may ask the Department to adopt rules and regulations that set more restrictive emission standards or ambient air quality standards in that political subdivision.
Maryland Legal Code