How should vapors be discharged during tank ventilation using an eductor-type air mover?

Discharging vapors at least 12 feet above the ground surface during tank ventilation with an eductor-type air mover is essential for safety and compliance reasons. This height helps to ensure that any potentially harmful vapors are released into the atmosphere where they can safely dissipate and reduce the risk of ignition. It also minimizes the potential for any vapors to accumulate at ground level, where they could pose a hazard to personnel and equipment.

The regulation surrounding vapor discharge typically takes into account both safety and environmental considerations. By having the discharge point elevated, it mitigates the risk of creating an explosive atmosphere close to the ground.

Additionally, ensuring a proper distance between the discharge point and any potential sources of ignition, as well as occupied spaces, is crucial. The practice aligns with best management practices in hazardous material management and is often stipulated in local safety codes and standards.

The other options either do not meet safety regulations or practical considerations associated with vapor discharge. For instance, discharging at ground level presents a significant safety risk by allowing vapors to accumulate, while containment vessels are generally used for collecting materials rather than venting vapors. Using carbon dioxide as a discharge mechanism does not fit the context of tank ventilation practices, which prioritize the safe release of vapors