Which statement is true about Category 3 Smoke?

Which statement is true about Category 3 Smoke?

• A. Only 0900-1700 EST burning is allowed.
• B. All hours for daytime burning and nighttime burning are allowed regardless of dispersion.
• C. If dispersion is excellent, all hours for daytime burning and nighttime burning are allowed.
• D. Category 3 does not permit nighttime burning.

Answer: (C)

The key idea is that burn permissions for Category 3 smoke depend on atmospheric dispersion. Category 3 indicates higher potential for smoke impacts, so whether you can burn at certain times hinges on how well the smoke will disperse. When dispersion is excellent, the atmosphere can dilute and mix the smoke effectively, allowing you to burn at any hour—both daytime and nighttime—without exceeding air-quality concerns. That’s why the statement about all hours being allowed under excellent dispersion is the best choice. The other options impose fixed daytime windows, claim all hours are allowed regardless of dispersion, or state nighttime burning isn’t permitted for Category 3. These don’t reflect the role dispersion plays: if conditions are not excellent, nighttime burning may be restricted; but with excellent dispersion, nighttime burning can be permissible just like daytime burning.

The key idea is that burn permissions for Category 3 smoke depend on atmospheric dispersion. Category 3 indicates higher potential for smoke impacts, so whether you can burn at certain times hinges on how well the smoke will disperse. When dispersion is excellent, the atmosphere can dilute and mix the smoke effectively, allowing you to burn at any hour—both daytime and nighttime—without exceeding air-quality concerns. That’s why the statement about all hours being allowed under excellent dispersion is the best choice.

The other options impose fixed daytime windows, claim all hours are allowed regardless of dispersion, or state nighttime burning isn’t permitted for Category 3. These don’t reflect the role dispersion plays: if conditions are not excellent, nighttime burning may be restricted; but with excellent dispersion, nighttime burning can be permissible just like daytime burning.