Sewerage is the system of pipes, pumps, and treatment plants that carries wastewater and human waste away from buildings to places where it can be safely cleaned and disposed of. When you flush a toilet or water goes down a drain, it flows through your home's plumbing into the sewerage system beneath your streets.

Before modern sewerage, people dumped waste into streets or rivers, causing terrible diseases like cholera and typhoid. Cities smelled awful, and epidemics killed thousands. In the mid-1800s, engineers began building underground sewerage networks that revolutionized city life. London's sewerage system, completed in 1865, helped end deadly cholera outbreaks. Today, sewerage systems are essential infrastructure in every modern city.

The word sewerage refers specifically to the system itself: the network of pipes and facilities. Don't confuse it with sewage, which is the actual wastewater and refuse flowing through the system. You might read about a city upgrading its sewerage, meaning they're improving the pipes and treatment plants, not the waste itself.

Sewerage engineers design these systems to handle millions of gallons daily, ensuring waste moves downhill through increasingly larger pipes until reaching treatment plants, where the water is cleaned before returning to rivers or oceans.