What is a primary reason for not connecting blowdown directly to the sewer?

Connecting blowdown directly to the sewer can pose significant safety risks that justify avoiding this practice. Blowdown typically contains concentrated residuals from boiler water, which may include scale, chemicals, and other impurities. If this water were to flow directly into the sewer, it could lead to potential injuries for personnel due to the hazardous nature of the materials present. Additionally, high concentrations of certain chemicals can lead to reactions that could damage sewer infrastructure or cause blockages, posing both safety and maintenance challenges.

In contrast, while the other options might reflect valid concerns in specific contexts, they do not capture the primary issue associated with the safety implications of directly connecting blowdown to sewer systems. Therefore, the focus on injury to individuals and damage to the sewer emphasizes the critical need to manage blowdown properly to ensure safety and infrastructure integrity.