Report SSOS A Sanitary Sewer Overflow is an unintentional discharge of untreated sewage into the environment or onto property. If you encounter a sewer overflow, call BWSC 24 Hour Emergency Service Line 617-989-7000. BOSTON SEWER WE ARE ALL CONNECTED Let's Protect Boston's Waterways Boston Water and Sewer Commission BWSC.ORG Report SSOS A Sanitary Sewer Overflow is an unintentional discharge of untreated sewage into the environment or onto property. If you encounter a sewer overflow, call BWSC 24 Hour Emergency Service Line 617-989-7000. BOSTON SEWER WE ARE ALL CONNECTED Let's Protect Boston's Waterways Boston Water and Sewer Commission BWSC.ORG