The provisions of this section and sections 5-1.51—5-1.52 of this Subpart shall apply to all public water systems. The supplier of water of a public water system is responsible for completion of the monitoring requirements set forth in such sections and for performing all analyses in accordance with the analytical requirements set forth in Appendix 5-C of this Subpart. At the discretion of the State, analyses performed by the State may be used for monitoring purposes.