PRASA failed to comply with a May 2, 2002 AO requiring Respondent's Mayaguez Miradero public water system to install and operate continuous monitoring turbidimeters at the Mayaguez Vieja Filtration Plant by Sept. 30, 2002. Respondent was to have certified to EPA that compliance with the Enhanced Interim Surface Water Treatment Rule was achieved by August 15, 2002. On Oct. 28, 2002, EPA issued an Administrative Complaint, Findings of Violation, Notice of Proposed Assessment of a Civil Penalty and Notice of Opportunity to Request a Hearing (the Complaint