A Type III floating turbidity curtain can be used in conditions with less than what flow speed?

A Type III floating turbidity curtain is specifically designed for use in environments with moderate flow velocities. The correct answer, which indicates a flow speed of less than 5 feet per second, aligns with the engineering considerations for this type of curtain. Turbidity curtains are employed to control sediment dispersion in water, particularly during construction activities, and are designed to effectively contain suspended solids in conditions characterized by lower currents.

When flow speeds exceed 5 feet per second, the effectiveness of the turbidity curtain is compromised. High flow rates can lead to increased water velocities that can disrupt the curtain's deployment and functionality, potentially resulting in sediment escape. Therefore, the design specifications of a Type III curtain ensure that it maintains its structural integrity and operational efficiency in flow conditions below this threshold. This makes it a suitable choice for environments where sediment control is essential without the risk of inundation or failure due to excessive water flow.