[Code of Federal Regulations] [Title 40, Volume 22] [Revised as of July 1, 2007] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR142.4] [Page 622-623] TITLE 40--PROTECTION OF ENVIRONMENT CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 142_NATIONAL PRIMARY DRINKING WATER REGULATIONS IMPLEMENTATION--Table of 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 [[Page 623]] shall relieve any person of any requirements otherwise applicable under this part.