A major sewer pipe collapse has dumped hundreds of millions of gallons of sewage into the Potomac River, highlighting a nationwide problem involving failing infrastructure. The Potomac spill was a huge, but rare event that led to an emergency declaration and federal help. But across the country, sewer overflows happen tens of thousands of times each year. Baltimore shows how bad persistent problems can be. People regularly experience sewage backups into their homes, ruining property and bringing in harmful bacteria. The EPA says there is more than $600 billion is needed for flooding and clean water needs over the next two decades. The Trump administration has cut some funding for the work.