What are ground storage tanks required to have for proper operation?

Ground storage tanks are essential components in water distribution systems, and various operational requirements ensure their effective management and safety. The inclusion of features like screened vents and an overflow pipe is crucial because these elements prevent contamination and manage excess water safely, respectively. Screened vents allow for air exchange while keeping debris and contaminants out, which helps maintain water quality.

An approved locking roof hatch is important for access while ensuring security and preventing unauthorized entry, further protecting the stored water from potential contamination. Regular annual inspection is vital for identifying and addressing any structural or operational issues before they lead to significant problems.

Having an overflow pipe with a hinged flap device is necessary not only to manage overflow but also to prevent backflow and maintain system pressure. Regular maintenance of these components is critical to ensuring they function effectively when needed.

Given these explanations, it's clear that a comprehensive approach combining all these features is required for the proper operation of ground storage tanks, making the option that includes all components the correct choice.