Which statement best describes when receiving water monitoring is required for Risk Level 3 sites?

Which statement best describes when receiving water monitoring is required for Risk Level 3 sites?

• A. It is required only if there is a direct discharge
• B. It is required only when pH outside 6.0-9.0
• C. It is required when there is direct discharge to receiving waters and the effluent is outside the pH range 6.0-9.0 or turbidity exceeds 500 NTU
• D. It is never required

Answer: (C)

For Risk Level 3 sites, receiving water monitoring is triggered only when there is a direct discharge to a receiving water and the discharge shows water-quality exceedances: either the effluent pH is outside the 6.0–9.0 range or turbidity exceeds 500 NTU. This combination ensures you’re collecting data to verify actual potential impact on the receiving water, and only then. If there’s no direct discharge, no monitoring is needed, and if the discharge stays within the pH and turbidity limits, monitoring isn’t required either. That’s why the statement stating monitoring is required under both conditions—direct discharge plus an exceedance in pH or turbidity—is the correct one. The other ideas miss one of these essential elements: monitoring isn’t automatic with any direct discharge, nor is it needed solely because pH is out of range or solely because turbidity is high; both conditions together determine the requirement.

For Risk Level 3 sites, receiving water monitoring is triggered only when there is a direct discharge to a receiving water and the discharge shows water-quality exceedances: either the effluent pH is outside the 6.0–9.0 range or turbidity exceeds 500 NTU. This combination ensures you’re collecting data to verify actual potential impact on the receiving water, and only then. If there’s no direct discharge, no monitoring is needed, and if the discharge stays within the pH and turbidity limits, monitoring isn’t required either. That’s why the statement stating monitoring is required under both conditions—direct discharge plus an exceedance in pH or turbidity—is the correct one. The other ideas miss one of these essential elements: monitoring isn’t automatic with any direct discharge, nor is it needed solely because pH is out of range or solely because turbidity is high; both conditions together determine the requirement.