### Question
How does PART 52—APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS define commenced?


### Answer
Under *40 CFR § 52.01*, **commenced** is defined as:

> that an owner or operator has undertaken a continuous program of construction or modification.

#### 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)**

