[Code of Federal Regulations] [Title 40, Volume 20] [Revised as of July 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR142.4] [Page 569] TITLE 40--PROTECTION OF ENVIRONMENT CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 142_NATIONAL PRIMARY DRINKING WATER REGULATIONS IMPLEMENTATION--Table of Contents Subpart A_General Provisions Sec. 142.4 State and local authority. Nothing in this part shall diminish any authority of a State or political subdivision to adopt or enforce any law or regulation respecting drinking water regulations or public water systems, but no such law or regulation shall relieve any person of any requirements otherwise applicable under this part.