(a)  Meter Readings. - Bills rendered periodically shall show the reading of the water meter at the beginning and end of the time for which bill is rendered, the dates on which the readings were taken, and the amount of water supplied.

(b)  Mechanical Billing. - Utilities desiring to adopt mechanical billing of such nature as to render compliance with all the terms of subsection (a) impracticable, may make application to the Commission for relief from part of these terms. After consideration of the reasons given when asking for relief, the Commission may allow the omission of part of these requirements.

(c)  Billing. - Meters will be read as nearly as possible at regular intervals. This interval may be monthly, or quarterly, however no change shall be made in the billing interval except on approval of the Commission.