The Public Water Systems Supervision Program (PWSSP) protects and regulates drinking water on the Navajo Nation. It ensures that the water that comes out of your tap is clean and safe to drink, by reviewing designs for public water systems (PWSs); regulating their construction and operation; and inspecting them for compliance with the Navajo Nation Safe Drinking Water Act (NNSDWA) and with the PWSSP regulations.

The PWSSP regulations set primary (health-based) and secondary (aesthetic) standards. In addition, the regulations prescribe water sampling requirements, water treatment techniques, operator certification requirements, and requirements for water system design and construction. All of these requirements are contained in the Navajo Nation Primary Drinking Water Regulations (NNPDWR).

 The U.S. Environmental Protection Program (USEPA) has approved the Navajo Nation’s PWSSP as meeting all the requirements to implement and enforce the federal Safe Drinking Water Act and federal regulatory requirements for PWSs. That approval means that the PWSSP has primary enforcement authority, or “primacy,” over all PWSs on the Navajo Nation, including on tribal trust lands outside the formal reservation boundaries.

The PWSSP also implements the Source Water Assessment Program (SWAP) and develops Source Water Protection Plans under that program.