Which statement best describes the Agency Primacy Rules?

• A. Regulations are enforced by state agencies.
• B. Recordkeeping and reporting are optional under the Primacy Rules.
• C. Regulations must be published in the Federal Register.
• D. Drinking water regulations are no less stringent than primary drinking water regulations.

Answer: (D)

Agency Primacy Rules require that when a state takes on the responsibility to enforce drinking water standards, its regulations must be at least as stringent as the federal primary drinking water regulations. This ensures that public health protections remain consistent across states, while also allowing states to go beyond federal standards if they choose. That direct requirement—no less stringent than the federal primary standards—best captures the purpose of primacy.

Note that while state agencies do enforce regulations under primacy, and states may publish their rules in state registers, the essential point of primacy is the stringency relationship to federal primary standards. Recordkeeping and reporting are not optional, and regulations themselves are not necessarily published in the Federal Register at the state level.