Sewer Backup in NYC: Who Is Responsible and Who to Call

A sewer backup is unpleasant and urgent. Knowing who is responsible helps you decide who to call. The NYC Department of Environmental Protection (DEP) has guidance on sewer backups and the city sewer system.

Updated 2026-10-21

Public sewer vs private line

• DEP maintains the public sewer mains.
• The property owner is typically responsible for the private connection from the building to the main.
• If the problem is in the public main, report it to the city through 311 or DEP.

What to do right away

• Stop using water and drains in the affected area.
• Keep people and pets away from sewage water.
• Call a plumber to check the building line and identify where the blockage is.
• If the blockage is in the public main, report it to DEP and keep records.

What a plumber will do

• Clear the line.
• Use a camera to see where the problem is.
• Tell you whether it is in your private line or the public main.

Frequently asked questions

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