Which of the following is a common characteristic of a sanitary sewer overflow?

A common characteristic of a sanitary sewer overflow (SSO) is that they require immediate reporting and response. SSOs can pose serious health risks and environmental hazards, as they involve the discharge of untreated sewage into public areas, water bodies, or other environments. Since they may lead to contamination of drinking water sources, public beaches, and ecosystems, timely detection and response are crucial in mitigating potential risks.

The rapid reporting of an SSO allows for prompt remediation efforts to be enacted, which can include implementing temporary barriers, cleaning operations, and notifying the public or relevant authorities to avoid exposure. This swift action helps to minimize health risks and environmental impacts.

In contrast, the other choices do not accurately reflect the nature of SSOs. They can indeed occur during heavy rainfall but are not limited to such events—issues with infrastructure, blockages, or overflows in the system can lead to SSOs at any time. Furthermore, these overflows are typically harmful to the environment, and they are often complex situations that may not be easily contained or cleaned, requiring significant resources and planning to address properly.