What percent reduction is specified for vector attraction reduction?

What percent reduction is specified for vector attraction reduction?

• A. 25%
• B. 38%
• C. 60%
• D. 15%

Answer: (B)

Vector attraction reduction means stabilizing biosolids so they are less attractive to insects and other vectors by lowering the amount of readily degradable organics and reducing odors. The specified threshold is a 38 percent reduction, typically measured as the percent reduction in volatile solids from the raw sludge to the stabilized product. This reduction can be achieved through processes like anaerobic or aerobic digestion, lime stabilization, composting, or other approved stabilization methods. For example, if the raw sludge has a certain volatile solids fraction and stabilization brings that fraction down enough to yield about a 38% drop, that meets the requirement. The 38% figure is the standard value used in regulatory and exam contexts to demonstrate vector attraction reduction.

Vector attraction reduction means stabilizing biosolids so they are less attractive to insects and other vectors by lowering the amount of readily degradable organics and reducing odors. The specified threshold is a 38 percent reduction, typically measured as the percent reduction in volatile solids from the raw sludge to the stabilized product. This reduction can be achieved through processes like anaerobic or aerobic digestion, lime stabilization, composting, or other approved stabilization methods. For example, if the raw sludge has a certain volatile solids fraction and stabilization brings that fraction down enough to yield about a 38% drop, that meets the requirement. The 38% figure is the standard value used in regulatory and exam contexts to demonstrate vector attraction reduction.