Which regulation is not federally enforceable but is intended as a guideline for the States?

• A. Title XIV
• B. Primary Drinking Water Regulations
• C. Secondary Drinking Water Regulations
• D. 40 CFR Part 3

Answer: (C)

The main idea is the difference between enforceable health-based standards and non-enforceable guidelines used to guide states. Primary drinking water regulations are the enforceable health-based standards that water systems must meet or face federal or state enforcement actions. Secondary drinking water regulations, on the other hand, are non-enforceable guidelines designed to address taste, odor, color, and other aesthetic or corrosivity concerns. They help utilities and states anticipate consumer acceptance issues and plan treatment, but they aren’t federal requirements with penalties for noncompliance. States may adopt them as enforceable standards if they choose, but at the federal level they remain advisory. The other options don’t fit because they either refer to enforceable health-based standards (which are enforceable) or pertain to parts of the regulations that aren’t guidelines for state enforcement.