CWEA Grade 1 Lab Analyst 2025 – 400 Free Practice Questions to Pass the Exam

BOD, or Biochemical Oxygen Demand, is a common measurement used to evaluate the organic "strength" of wastewater. This parameter indicates the amount of oxygen that microorganisms will consume while decomposing organic matter in water at a specified temperature over a set period, typically five days. A higher BOD value reflects a greater presence of biodegradable organic material, which suggests more pollution and a higher potential for oxygen depletion in receiving waters, potentially harming aquatic life.

Understanding BOD is crucial in the management and treatment of wastewater, as it helps facilities gauge how much organic material needs to be removed during treatment processes. This is a key factor in designing effective treatment systems and ensuring compliance with environmental regulations.

The other options relate to different parameters or measures that do not utilize BOD. For example, assessing the pH level of industrial water involves different methodologies focusing on acidity or alkalinity, while measuring salinity relates to the total dissolved salts in water. Evaluating drinking water purification efficiency might involve contaminants and microbial testing, but does not specifically use BOD measurements.