83 Ill. Adm. Code 600.300
Testing Facilities
Section 600
Section 600.300 Testing
Facilities
Each utility furnishing water
service to any of its customers on a metered basis shall, unless specifically
excused by the Commission, make provision for a suitable meter testing
laboratory and equipment or apparatus as may be necessary to make the tests required
by this Part and other orders of this Commission. Meter testing equipment
shall, at all reasonable hours, be accessible for inspection and use by
authorized representatives of the Commission.