How often does the Environmental Protection Agency publish a list of contaminants that may warrant regulation?

• A. Every year
• B. Every five years
• C. Every ten years
• D. Every two years

Answer: (B)

The main idea here is that the EPA follows a five-year cycle to update a list of contaminants that may need regulation. This list, called the Candidate Contaminant List, identifies substances that aren’t yet regulated but deserve further evaluation under the Safe Drinking Water Act. Updating it every five years allows the EPA to incorporate new health data, monitoring results, and advances in measurement or treatment options, guiding research and potential rulemaking. The five-year cadence is the established schedule, whereas annual or two-year updates would be more frequent than required, and a ten-year gap would let important newer contaminants go unassessed for too long.