Storm drains are completely separate from sanitary sewer systems:
- Storm Drains: Carry untreated rainwater and surface runoff straight into nature.
- Sanitary Sewers: Carry wastewater from indoor plumbing (toilets, sinks, and washing machines) to a treatment plant to be cleaned before release.
Because stormwater is generally not treated before it reaches local bodies of water, trash, pet waste, motor oil, and fertilizers that enter the system can severely pollute aquatic life and the environment.