a) A community water supply operating before July 26, 2019 is not required to modify or replace components to meet the requirements of this Part if:

1. 1) the requirements of 35 Ill. Adm. Code 611 are met;
2. 2) the requirements of Sections 604.205, 604.230 and 604.1210 are met;

3) water pressure meets the standards of Section 604.1415(a)(1); and

1. 4) the components were permitted or no permits were required at the time of construction.

2. b) Alternate Design, Maintenance and Operation Requirements

   1. 1) As specified in this Part, the Agency may approve design, maintenance, or operation requirements different from those contained in this Part so long as the alternative produces water meeting the requirements of 35 Ill. Adm. Code 601.101 and 35 Ill. Adm. Code 611.
   2. 2) When approving alternate design, maintenance or operation requirements, the Agency must issue a construction permit, operating permit or special exception permit.
   3. 3) The Agency must approve alternate design, maintenance or operation requirements when the community water supply demonstrates that compliance with this Part is economically unreasonable or technically impossible.