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Plumbing services · Atlanta, GA

Main sewer line clog in Atlanta

When the main line clogs, every drain in the house shares the problem. Water used upstairs can come back up at a drain on the bottom floor.

Last reviewed November 13, 2026

Short answerStop using water, including the washer and dishwasher, so you don't push more into a blocked line. Call a plumber to clear it through the cleanout. If sewage is overflowing outside from a manhole, call the city.

Signs it's the main line

ATL311 lists not being able to flush toilet waste and waste seeping up around a shower drain, sink or basement drain as signs of a sewage backup inside the home (ATL311). Several fixtures acting up at once is the giveaway.

The cleanout

ATL311 says the cleanout is a direct access point to the sewer drain, usually near the front of the house where the drain exits, and sometimes outside under soil (ATL311). See main sewer cleanout.

Whose line is it?

In Atlanta, ATL311 says the entire sewer service lateral is the property owner's responsibility (ATL311). For an outside spill, such as waste overflowing from a manhole, call ATL311 at 404-546-0311 (ATL311).

Common causes

Atlanta Watershed Management says more than half of sanitary sewer spills in the city are caused by grease (Atlanta Watershed Management). The Insurance Information Institute points to tree roots entering cracks and joints, and to aging sewer systems (Insurance Information Institute). If your line is old cast iron, see cast iron sewer pipe.

Keeping it from happening again

The Insurance Information Institute describes a backwater valve as letting sewage out but not back in, and says to use a qualified plumber to install it (Insurance Information Institute). Gwinnett County says Georgia plumbing code requires one when a fixture on the bottom level sits below the next upstream manhole (Gwinnett County).

Checking the plumber

Georgia licenses plumbers through the Secretary of State. The state does not register plumbing companies, and only licensed master plumbers may run a plumbing business (Georgia Secretary of State). A Class I master plumber license covers single-family homes and one-level homes for up to two families; Class II has no restrictions (Georgia Secretary of State). Ask for the master plumber's name and check it in the state's licensee search.

Common questions

Sewage is already on the floor. Now what?

See sewage cleanup in Atlanta. Sewer backup coverage is often an add-on to a homeowners policy (Insurance Information Institute).

Sources

This guide is general information, not legal, insurance or plumbing advice.

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