Md. Code, Environment § 2–402

The Department may not require a permit or registration for:

(1) Any machinery or equipment that normally is used in a mobile manner;

(2) Any boiler used exclusively to operate steam engines for farm and domestic use;

(3) The construction of a generating station constructed by a person that is required to obtain a certificate of public convenience and necessity under §§ 7–207 and 7–208 of the Public Utilities Article and regulations adopted by the Public Service Commission;

(4) Actual construction of buildings, apart from any possible emission producing machinery housed in the buildings;

(5) Any parking garage; or

(6) Any parking lot.