(a)  Each utility shall make a sufficient number of pressure measurements on its mains and at the customer's meter so that it will have a substantially accurate knowledge of the pressures in the low, intermediate and high pressure systems in each district, division, or community served by its distribution mains.

(b)  All pressure records obtained under this rule shall be retained by the utility for at least 2 years and shall be available for inspection by the Commission's representatives. Notations on each record shall indicate the following:

(1)           The location where the pressure check was made.

(2)           The time and date of the check.