Active monitoring area

Active monitoring area is the area that will be monitored over a specific time interval from the first year of the period to the last year in the period (t). The boundary of the active monitoring area is established by superimposing two areas:
(1) The area projected to contain the free phase CO2 plume at the end of year t, plus an all around buffer zone of one-half mile or greater if known leakage pathways extend laterally more than one-half mile.
(2) The area projected to contain the free phase CO2 plume at the end of year t + 5.

Source

40 CFR § 98.449


Scoping language

Except as provided below, all terms used in this subpart have the same meaning given in the Clean Air Act and subpart A of this part.

Is this correct? or