### Question
How is the term stationary source defined?


### Answer
The term **stationary source** is defined in *40 CFR § 52.01* as the following:

> any building, structure, facility, or installation which emits or may emit an air pollutant for which a national standard is in effect.

#### Citation:
  - *40 CFR § 52.01*
  - Heading: **Title 40—Protection of Environment > PART 52—APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS > Subpart A—General Provisions > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)**

