What is the typical regulatory limit for BOD in treated wastewater?

The typical regulatory limit for Biochemical Oxygen Demand (BOD) in treated wastewater is indeed less than 30 mg/L. This limit is crucial for maintaining ecological balance in receiving waters, as it ensures that the amount of organic matter discharged does not cause significant depletion of dissolved oxygen, which aquatic life relies upon. When BOD levels are kept low, it minimizes the impact on water quality and supports a healthier habitat for fish and other organisms.

The standard of less than 30 mg/L is often set for secondary treated wastewater and reflects common regulatory requirements across various jurisdictions. A lower limit, like less than 10 mg/L, might be required in more stringent situations, but typically, the less than 30 mg/L goal is a widely accepted benchmark. Maintaining BOD levels below this limit indicates effective treatment processes that reduce the organic load before the water is released back into the environment.