Which term refers to unusually strong wastewater discharge from a specific source?

• A. Shock Load
• B. BOD
• C. Infiltration/Inflow
• D. Anaerobic Decomposition

Answer: (A)

A sudden, unusually strong wastewater discharge from a single source is called a shock load. This describes a temporary spike in pollutant strength coming from one origin, such as a process batch release or a tank cleanup, which can push the treatment system beyond its normal operating conditions. Shock loads are important because they can overwhelm treatment units, disrupt stable biological processes, and lead to poor effluent quality or odors if not managed.

BOD is a measurement of how much oxygen is needed to break down organic matter, not the event itself. Infiltration/inflow refers to extra water entering the sewer from groundwater or surface water, increasing volume rather than the concentration of pollutants. Anaerobic decomposition is the microbial breakdown of organic matter without oxygen, a natural process inside the system, not the description of a discharge event.