In continuous ATS monitoring, what interval is required at minimum?

• A. 5 minutes
• B. 15 minutes
• C. 30 minutes
• D. 60 minutes

Answer: (B)

Continuous monitoring relies on capturing data frequently enough to detect short-term changes and ensure accurate compliance reporting. The minimum interval for ATS monitoring is fifteen minutes. This interval provides sufficient resolution to catch spikes or excursions without creating an overwhelming amount of data, and it aligns with common regulatory practices that use 15-minute blocks for evaluating permit limits.

A shorter interval, like five minutes, would add data handling complexity without a corresponding change in regulatory expectation. A longer interval, such as thirty or sixty minutes, could miss transient events and permit violations, reducing the ability to protect water quality or air quality and to report accurately.