Section 141.900 - General requirements(a) The requirements of this subpart constitute the national primary drinking water regulations for PFAS. Each community water system (CWS) and non-transient, non-community water system (NTNCWS) must meet the requirements of this subpart including the maximum contaminant levels for the PFAS identified in § 141.61(c) .(b) The deadlines for complying with the provisions of this subpart are as follows: (1) Each system must meet the analytical requirements in § 141.901 by June 25, 2024.(2) Each system must report the results of initial monitoring, as described in § 141.902(b)(1) , to the State by April 26, 2027.(3) Each system must meet the compliance monitoring requirements in § 141.902(b)(2) by April 26, 2027.(4) Each system must meet the MCL compliance requirements in § 141.903 by April 26, 2029.(5) Each system must meet the reporting and recordkeeping requirements in § 141.904 by April 26, 2027.(6) Violations described in § 141.905 include monitoring and reporting violations and violations of MCLs. Monitoring and reporting violations may be assessed beginning on April 26, 2027. MCL violations may be assessed beginning on April 26, 2029.