Bea Aldrich

Oct 26, 2023 | wbznewsradio.iheart.com | Bea Aldrich |Chaiel Schaffel

Deer Island Wastewater Treatment Plant. Photo: Getty Images BOSTON (WBZ NewsRadio) — Boston is a historic city, right down to its sewer system. The area uses something called Combined Sewer Overflows (CSOs) — an invention that cropped up in the late 19th century. Those sewers were cutting edge around the turn of the century, but they're now starting to show their age. Combined Sewer Overflows are called "combined" because they let waste water and storm water flow into basically the same pipes.