Illinois Administrative Code
Title 83 - PUBLIC UTILITIES
Part 600 - STANDARDS OF SERVICE FOR WATER UTILITIES (GENERAL ORDER 24)
Subpart B - RECORDS
Section 600.130 - Pressure Record

a) Each utility furnishing service within a given contiguous service area to 300 or more customers or a population equivalent of 1,000 persons shall maintain a graphic pressure gauge located at its plant or at some central point in the distribution system where continuous records shall be made of the pressure in the mains at that point. All records or charts shall be identified, dated and filed chronologically and shall be open to inspection by the public.

b) Each utility shall furnish and place other recording pressure gauges at such locations and for such periods as may be determined by the Commission.