Sewage backs up into a basement because the basement is usually the lowest point in the plumbing system. When the sewer line is blocked or the city sewer is full, wastewater looks for the easiest way out, which is often a basement floor drain, toilet, or shower.
A Blocked Sewer Line
The sewer line carries everything from your home to the city sewer. Grease, wipes, roots, or a damaged pipe can block it. When that happens, water from upstairs fixtures has nowhere to go and comes out of the lowest drain.
Heavy Rain and Full City Sewers
Much of New York City has combined sewers that carry rainwater and wastewater together. During intense storms, these sewers can fill up. When the sewer is full, water can push back up the line into homes, especially into basements and cellars.
No Backwater Valve
A backwater valve is a device on the sewer line that lets water leave the home but helps stop it from flowing back in. Many older Brooklyn homes do not have one. NYC Department of Environmental Protection encourages property owners to consider installing one, which should be done by a licensed plumber.
Signs to Watch For
Look for water or debris around the basement floor drain, gurgling toilets, and slow drains on the ground floor. A sewer smell in the basement is also a warning sign.
Stop using water in the home. Keep people and pets away from the sewage. Do not touch it without gloves and boots, and stay clear of any water near outlets or appliances. A plumber can find the cause and clear the sewer line.
If you have a backup and think the city sewer is involved, you can report it to 311.
When sewage is coming into your basement, call JPR Plumbing at (833) 603-1840. After the line is cleared, a look at the basement floor drain and nearby fixtures can help keep it from happening again.