There are few things more alarming than walking downstairs and realizing your basement is filled with raw sewage. It’s messy, it’s stressful, and if you’re like most homeowners, you have no idea what to do first.
- Should you call someone?
- Try to clean it yourself?
- Is your insurance going to cover this?
Baethke’s licensed plumbers have been responding to emergency sewage backups in Chicago basements for over 30 years now, and we’ve seen exactly what causes them, from decades-old plumbing to homes sitting at the wrong elevation. We know what needs to happen in the first ten minutes and what needs to happen for good, long after the damage is done.
Today we’ll discuss the first steps in dealing with the flood, whether you can handle cleanup yourself, what’s really causing the backup, and how to help stop it from happening again.
If sewage is backing up into your basement, stop using water, stay out of the backed-up water, move valuables, and call a licensed plumber right away. Most Chicago basement backups come from a blocked main sewer line or the city’s combined sewer system overflowing during heavy rain. The best long-term protection is an overhead sewer or a check valve (backwater valve).
What Are the Absolute First Things I Should Do During a Sewage Backup?
- Stop using water. Every flush, shower, or load of laundry sends more water into a line that can’t drain.
- Stay out of the backed-up water, especially if it could reach outlets, appliances, or your electrical panel. Sewage is a health hazard, and standing water near electricity is a shock hazard.
- Call a plumber. This is not a wait-and-see situation. The longer sewage sits and spreads, the worse the damage gets and the more it costs to clean up and repair.
- Get anything valuable off the floor and away from the affected area. Yes, insurance may end up covering some of the damage, but that doesn’t mean you should let boxes, furniture, or anything irreplaceable sit in sewage water while you wait for help to arrive. Move what you can, and move it now.
This is one of those moments where the right move is picking up the phone, not trying to problem solve your way through it.
Can I Clean Up a Sewage Backup Myself, or Do I Need a Professional?
Call a professional. This isn’t a situation for a mop, a wet vac, and some determination.
Sewage backups typically require a remediation company, one that specializes in water and fire damage cleanup, in addition to a plumber who addresses the actual source of the problem. That’s because what’s sitting in your basement isn’t just water. It’s black water, meaning it’s hazardous and contaminated with waste, bacteria, and everything else that comes through a sewer line.
This matters more than people realize. Contact with sewage, especially around your mouth, eyes, or any open cut, can genuinely make you sick. This isn’t a “better safe than sorry” caution for the sake of caution. It’s a real health risk, and it’s the reason professionals handle it with the right equipment and protective gear instead of a homeowner with good intentions and a pair of latex gloves.
Most Common Causes of a Basement Sewer Backup in Chicago
Source: Chicago Metropolitan Agency for Planning
Most backups trace back to a sewer line that hasn’t been inspected or cleaned in years, allowing buildup, roots, or debris to create a blockage which eventually sends water back into your home instead of out to the city sewer.
That said, maintenance isn’t a guaranteed fix. In Chicago, a lot of the plumbing infrastructure was installed decades ago. City code and compliance standards have shifted drastically over the years, and your plumbing might not be up to speed. Even a well-maintained system can back up simply because of how and where it was originally built.
One of the biggest factors is elevation. Homes on higher ground are less likely to experience storm backups, because gravity works in their favor. Homes that sit lower than the street or neighboring properties are a different story. When heavy rain or snowmelt overloads the sewer system, that water needs somewhere to go, and a low-lying home can become the path of least resistance.
This is especially important if you’ve recently moved into a home. Previous owners aren’t always upfront about a property’s flooding history. If your home sits lower on the water table, it’s worth being proactive rather than waiting to find out the hard way.
Chicago’s combined sewer system is another major factor. The same underground pipes carry both sewage and stormwater, so heavy rain or fast snowmelt can overload them. When that happens, water can push back up through basement floor drains, even if your own sewer line is clear.
How Can I Prevent Sewage From Backing Up Into My Basement?
The most effective long-term solution is installing an overhead sewer.
Here’s why this works. Most older plumbing systems, particularly the city of Chicago, rely entirely on gravity. Everything below grade flows downhill into the city sewer system. The problem is that gravity works both ways. When the sewer system gets overwhelmed, water can just as easily flow back toward your home as it once flowed away from it.
Getting your sewer line inspected once a year is the single best thing you can do to catch problems before they turn into a flooded basement.
Overhead Sewer System
- An overhead sewer moves your home’s sewer connection up near the basement ceiling. Upstairs drains flow into a line that runs along the ceiling and exits high on the foundation wall, above the level where storm backups reach. Basement drains, such as floor drains, laundry, and any basement bathroom, empty into a sealed pit, where an ejector pump lifts the waste up into the overhead line. The old floor-level connection is capped, so a backed-up city sewer has no low opening to push through. It’s important to note that an ejector pump is different from a sump pump, which handles groundwater. An ejector pump handles sewage and wastewater from basement drains only.
Check Valve (Backwater Valve) System
- A check valve is a one-way valve installed on your main sewer line. Under normal conditions, its flap swings open and lets wastewater flow out to the city sewer. When heavy rain overloads Chicago’s combined sewer system and pressure reverses, the flap swings shut and seals the line, keeping sewage out of your basement. While the valve is closed, water from your own house can’t drain out either, so hold off on laundry, showers, and flushing until the storm passes. Have the valve inspected yearly so debris can’t hold the flap open.
The goal isn’t an impossible guarantee. It’s shifting the odds significantly in your favor and giving yourself a system that’s far more resilient than relying on gravity alone. The fact is, nothing is truly permanent. An overhead sewer with an ejector pump is a major upgrade and dramatically reduces your risk, but if that pump ever fails, you could end up dealing with backup from your own system instead of the city’s.
Does My Standard Homeowner’s Insurance Policy Cover Sewage Backup Damage?
This is genuinely a question best answered by your insurance company, not your plumber. Coverage for sewage backup varies significantly from policy to policy. Some standard homeowner’s policies exclude it entirely unless you’ve added a specific rider or endorsement for sewer and drain backup coverage. Others may include limited coverage as part of the base policy.
The honest answer is that this is a conversation to have directly with your insurance provider, ideally before you ever need to use it. Ask specifically whether sewer backup is covered, what the limits are, and whether an additional endorsement makes sense given your home’s elevation and plumbing history. It’s a case by case situation, and the only person who can give you a definitive answer is the one holding your policy.
Sewer Line Backups: Mitigating the Risks
Your sewage backup rarely comes out of nowhere. It’s the result of aging lines, tree roots, debris buildup, or a home sitting at the wrong elevation relative to the city sewer. And once it happens, it’s not a job for a mop and a wet vac. It calls for a remediation team and a plumber who can find and fix the actual source.
The good news is this isn’t a problem you have to just live with. An overhead sewer system with an ejector pump gives you the most protection by rerouting everything below grade and pumping it up and out. A check valve is another step that can still make a real difference, closing off the line the moment pressure starts pushing the wrong way.
If you’ve dealt with a backup before, or if your home sits low relative to the street, don’t wait for the next heavy rain to find out how your system holds up. Get your sewer line inspected, and talk through which option, overhead sewer or check valve, fits your home’s budget, layout and history.
Baethke Plumbing has dealt with thousands of these basement backups across the Chicagoland area, and we’re glad to share our experience with you to help navigate around this messy situation. Schedule an inspection with Baethke Plumbing before the next storm makes the decision for you. Call Baethke Plumbing at 773-276-5430, serving Chicago and the surrounding suburbs since 1993.
Sewage Backup FAQs For Chicago Homeowners
What causes a sewer backup in a Chicago home?
- Most sewer backups in Chicago come from one of two causes: a blockage in your home’s main sewer line, or the city sewer overflowing during heavy rain. Blockages usually come from tree roots, grease, flushed wipes or paper towels, or old cracked clay pipe, all common in Chicago’s older homes. Storm backups happen because Chicago has a combined sewer system that carries both rainwater and sewage. When it overloads, water can push back up through basement floor drains, even if your own line is clear.
How can I tell a sewer backup from a regular clog?
- A clog usually affects one fixture, while a sewer backup affects several drains at once. If your toilet, tub, and basement floor drain are all slow or backing up together, or you hear gurgling in one drain when you run water somewhere else, the problem is likely in your main sewer line. A backup that starts during or right after a heavy storm points to the city sewer instead.
What should I do if my basement has a sewer backup?
- Stop using water in the house, stay out of the backed-up water, and call a licensed plumber. Sewage is a health hazard, and standing water near outlets or appliances is an electrical hazard, so don’t wade in if the water may reach anything electrical. Baethke Plumbing uses a camera inspection to find the cause, then clears the line with an auger or hydro-jetting.
How can I prevent sewer backups in my basement?
- The two most effective ways to stop storm backups in a Chicago basement are a check valve and an overhead sewer conversion. A check valve closes automatically when the city sewer pushes water back toward your home. An overhead sewer reroutes your drains so they exit high on the basement wall, above the level where backups reach. Regular sewer rodding and keeping wipes, grease, and paper towels out of your drains help prevent blockages.
