On May 2, 2002, EPA issued an AO to Respondent, after determining the Aguas Buenas Urbano public water system was in violation of the individual filter minitoring requirements of the SDWA. The AO required the Respondent's Aguas Buenas Urbano and Manillas filtration Plants to 1) install and operate continuous monitoring turbidimeters by October 31, 2002, and 2) provide certification to EPA and the PRDOH that compliance was achieved by November 22, 2002. On December 13, 2002, EPA issied a Complaint, Findings of Violation, Notice of Proposed Assessment of a Civil Penalty and Notice of Opportunity to Request a Hearing to Respondent for failure to comply with the AO.