Final answer:
The storm sewer system carries rainwater and prevents flooding, whereas the sanitary sewer system carries wastewater from residential and industrial areas to be treated. The outdoor drain at a loading dock should be connected to the storm sewer to avoid overwhelming the sanitary system during heavy rain.
Step-by-step explanation:
The difference between the storm sewer system and the sanitary sewer system is in the type of water they each carry and their ultimate purpose. The storm sewer system is designed to carry rainwater and melted snow from urban areas to prevent flooding. It directs this water straight to water bodies like rivers and lakes without treatment. On the other hand, the sanitary sewer system carries wastewater from households and industries, which includes water from toilets, baths, showers, kitchens, sinks, and industrial processes. This wastewater is treated at a wastewater treatment plant before being released back into the environment.
The outdoor drain at a loading dock should be connected to the storm sewer system since it will primarily collect rainwater runoff. This prevents overloading the sanitary sewer system with large volumes of rainwater, which could cause untreated sewage to spill into the environment during heavy rainfall.