Empowerment of States and Tribes Under the Clean Water Act Section 401 On January 13, the EPA proposed revisions to its regulations implementing  Section 401 of the Clean Water Act , which governs how states and tribes review federally permitted projects that may affect local water quality. Section 401 is a key tool that allows states and tribes to ensure that projects such as pipelines, dams, and energy infrastructure do not degrade drinking watersources or waterways. The pr