The January collapse of a pipe as wide as a car dumped so much sewage into the Potomac River that officials tracked a spike of gut-wrenching bacteria drifting slowly past Washington for weeks, prompting an emergency declaration and federal assistance.
It was a disaster of historic scale — 244 million gallons (924 million liters) spilled — spotlighting the severe consequences of old, failing infrastructure. But smaller sewer overflows that draw far less notice are common. Tens of thousands occur every year across the U.S., contaminating rivers, flooding streets and sometimes causing backups into homes that threaten human health.
