There is no gentle way to describe it. When sewage backs up into your home, raw waste comes up through floor drains, toilets, and shower drains. It floods your basement, soaks into your carpet, saturates your drywall, and fills your home with a smell that clings to everything it touches.

This can be one of the most unpleasant things a Michigan homeowner can experience. It is also one of the most dangerous. Sewage carries bacteria, viruses, and parasites that can cause serious illness. The cleanup process is not something you can handle with a mop and a bottle of bleach. And the insurance picture is more complicated than most homeowners expect.

If you are dealing with a sewage backup right now, get your family and pets out of the affected area and call a professional. If you are reading this to prepare for the possibility, here is what every Michigan homeowner should understand.

Why Sewage Backups Happen

A sewage backup occurs when wastewater that should be flowing away from your home reverses direction and comes back inside. Several things can cause this.

Tree root intrusion. Tree roots naturally seek out moisture. Over time, they can grow into small cracks or joints in your sewer lateral, which is the pipe that connects your home to the municipal sewer main. Once inside, roots expand and trap debris until the line is partially or fully blocked. Michigan’s mature trees, particularly silver maples, willows, and elms, are notorious for this.

Aging sewer infrastructure. Many Michigan communities, especially in the metro Detroit area, the older neighborhoods of Grand Rapids, Flint, Lansing, and smaller towns across the state, have sewer systems that are decades old. Aging pipes crack, sag, and deteriorate. When the municipal main is compromised, backups can affect homes connected to that section of the system.

Heavy rainfall and combined sewers. Some older Michigan municipalities still operate combined sewer systems, which carry both stormwater and sanitary sewage in the same pipe. During heavy rain events, these systems can become overwhelmed. When the volume of water exceeds what the pipes can handle, sewage backs up into the lowest connected drains, which are usually basement floor drains.

Blockages from household waste. Grease poured down kitchen drains, so-called flushable wipes that do not actually break down, paper towels, and other materials accumulate in your home’s drain lines over time. Eventually, they create a blockage that forces wastewater back into the house.

Sump pump failure. If your home relies on a sump pump to manage groundwater and it fails during a storm or power outage, water can enter the basement and mix with sewer connections, creating a contaminated mess.

The Health Risks Are Serious

Sewage is not dirty water. It is biologically hazardous material.

The restoration industry classifies water damage into three categories based on contamination level, following the IICRC S500 Standard set by the Institute of Inspection, Cleaning and Restoration Certification. Sewage backup is automatically classified as Category 3, also called “black water.” This is the most severe classification.

Category 3 water contains pathogenic bacteria, viruses, parasites, and other harmful agents that can cause serious illness through skin contact, ingestion, or inhalation. The Centers for Disease Control and Prevention has identified organisms commonly found in raw sewage, including E. coli, Salmonella, Hepatitis A, Giardia, and Cryptosporidium.

Exposure can cause gastrointestinal illness, skin infections, respiratory problems, and in severe cases, hospitalization. Children, elderly family members, pregnant women, and anyone with a compromised immune system face elevated risk.

There is also an airborne hazard that most homeowners do not consider. When sewage-soaked materials are disturbed during cleanup, bacteria and other pathogens can become aerosolized. Breathing in these particles, called bioaerosols, can lead to respiratory infections. This is one of the key reasons professional remediation teams use personal protective equipment and negative air pressure containment during Category 3 cleanup.

The health risk does not end when the visible sewage is gone. Moisture left behind in walls, flooring, and subfloor cavities can promote aggressive mold growth within 24 to 48 hours. In Michigan, where many homes have basements that are already prone to humidity, this timeline is even tighter during warmer months.

What You Should Do Immediately

If sewage has backed up into your home, there are a few things to do right away and several things to avoid.

Stay out of the affected area. Do not walk through standing sewage, especially without protective gear. If the water level has reached electrical outlets, appliances, or your electrical panel, do not enter the area until a qualified electrician has confirmed it is safe.

Turn off the water supply if the backup is still active. If sewage is coming up through drains and you can safely reach the main shutoff valve, closing it can limit the volume of waste entering your home.

Do not use household drains. Running sinks, flushing toilets, or using the washing machine while a backup is active pushes more water into an already overwhelmed system.

Do not attempt to clean it yourself. This is not a situation where household cleaning products will make things safe. Bleach does not penetrate porous materials. It will not eliminate bacteria trapped inside drywall, carpet padding, insulation, or wood framing. Consumer-grade disinfectants are not rated for Category 3 contamination. Attempting a DIY cleanup puts your health at risk and can spread contamination to areas that were not initially affected.

Document everything before cleanup begins. Take photos and video of the affected areas, damaged belongings, and the water level. This documentation is critical for your insurance claim. Do not throw anything away until it has been recorded.

Call your insurance company promptly. Report the loss as soon as possible. Ask specifically whether your policy includes water and sewer backup coverage. More on this below.

The Professional Cleanup Process

Restoring a home after a sewage backup is a structured process. It follows strict protocols because of the biohazard classification. Here is what a qualified restoration team will do.

Safety setup. Technicians arrive in full personal protective equipment. They establish containment around the affected area and set up negative air pressure with HEPA-filtered air scrubbers to prevent contaminated particles from spreading to clean areas of the home.

Sewage extraction. Standing sewage and contaminated water are removed using commercial-grade pumps and extraction equipment. Every minute the sewage sits increases the damage to your home and the difficulty of remediation.

Removal of contaminated materials. Here is where most homeowners are surprised by the scope of the work. Under IICRC S500 standards, porous materials that have absorbed sewage cannot be disinfected. They must be removed and disposed of. That includes carpet, carpet padding, drywall (typically cut at least 12 to 24 inches above the visible water line to account for wicking), insulation, particleboard, and any other absorbent materials the sewage contacted. There is no way to safely clean sewage out of these materials. They have to go.

Cleaning and disinfection of salvageable surfaces. Hard, non-porous surfaces like concrete floors, metal framing, and sealed wood can be cleaned using professional-grade, EPA-registered disinfectants. Technicians scrub and treat these surfaces multiple times to ensure decontamination.

Structural drying. Once contaminated materials are removed and surfaces are disinfected, industrial dehumidifiers and air movers are placed to thoroughly dry the remaining structure. Moisture meters and thermal imaging confirm that hidden moisture in wall cavities, subfloor areas, and concrete has been addressed. This step is essential to preventing mold growth.

Odor treatment. Sewage odor lingers long after the visible waste is gone. Professional deodorization using thermal fogging, ozone generators, or hydroxyl generators neutralizes the smell at a molecular level rather than simply masking it.

Reconstruction. After the space is clean, dry, and verified safe, the rebuilding begins. New drywall, insulation, flooring, and trim are installed. Depending on the scope of damage, this may also include electrical work, plumbing repairs, and replacement of damaged fixtures or appliances.

What Michigan Homeowners Need to Know About Insurance

This is the section that catches most people off guard.

Standard homeowners insurance policies in Michigan do not cover sewage or water backup damage. The Michigan Department of Insurance and Financial Services (DIFS) has published guidance making this clear. Water and sewer backup is not automatically included in your homeowners or renters policy. It is a separate endorsement that must be added.

If you have not added this endorsement, you are likely responsible for the full cost of cleanup and restoration out of pocket. Professional sewage remediation typically costs several thousand dollars, and complex cases involving finished basements or extensive contamination can exceed $10,000 or more.

If you do have the endorsement, coverage varies. Some Michigan insurers offer water and sewer backup coverage up to a specified dollar limit. Others calculate coverage as a percentage of your dwelling coverage. The limits range widely, with common amounts between $5,000 and $25,000. For a finished basement with flooring, drywall, furniture, and electronics, $5,000 may not come close to covering the actual loss.

There are also important exclusions to be aware of. Water and sewer backup coverage typically does not cover damage caused by external flooding, such as a river overflowing. It also generally does not cover the cost of repairing or replacing a broken sump pump, or damage resulting from a lack of maintenance or wear and tear on your plumbing. Flood damage requires a separate flood insurance policy, which is an entirely different product.

DIFS recommends that Michigan homeowners talk to their insurance agent about adding water and sewer backup coverage if they do not already have it. If your current insurer does not offer the level of coverage you need, DIFS suggests consulting with a different insurer. You can contact DIFS with insurance questions at 1-877-999-6442 or visit michigan.gov/DIFS.

When the City May Be Responsible

If the sewage backup was caused by a defect in the municipal sewer system rather than a problem on your property, Michigan law provides a process for seeking compensation from the local government.

Public Act 222 of 2001 amended Michigan’s governmental immunity act to create a narrow exception for sewage disposal system events. Under this law, a municipality may be liable if all of the following are true: a defect existed in the sewage disposal system, the governmental agency knew or should have known about the defect, it failed to correct the defect within a reasonable time, and that failure was the substantial proximate cause of the backup. “Substantial proximate cause” means the government’s fault must account for 50 percent or more of what caused the event.

Critically, the backup must not have been primarily caused by something on your property, such as your own service lateral, a sump pump connection, or a private drain line. If the problem originated on your side of the connection, the municipality is not responsible.

If you believe the city’s sewer system caused your backup, you must file a written notice of claim with the appropriate governmental agency within 45 days of discovering the backup. Missing this deadline can prevent you from recovering any damages. Keep records of everything: photos, receipts, cleanup invoices, and any communication with the municipality.

Preventing Future Backups

No prevention method is foolproof, but several steps can reduce your risk.

Have your sewer lateral inspected. A plumber can run a camera through your line to check for root intrusion, cracks, bellies, or other problems. This is especially important if your home is more than 30 years old.

Install a backwater prevention valve. This device allows sewage to flow out of your home but prevents it from coming back in during a system overload. A licensed plumber can install one in your basement drain line.

Keep a battery backup on your sump pump. Power outages and heavy storms often happen at the same time. A battery backup keeps your sump pump running when the electricity goes out.

Be careful what goes down your drains. Grease, cooking oil, wipes (even those labeled “flushable”), paper towels, and feminine hygiene products do not belong in your sewer line. They are among the most common causes of residential blockages.

Review your insurance annually. Check whether you have water and sewer backup coverage, confirm the coverage limits, and make sure they reflect the actual value of what is in your basement.

Call EzDry

At EzDry, we handle water & fire restoration services  across Michigan. Our IICRC-certified technicians respond 24/7 with the equipment, training, and protocols required for Category 3 water damage. We extract the sewage, remove contaminated materials, disinfect and dry your home, and manage the restoration from start to finish. We also work directly with your insurance company to document the damage and coordinate the claims process.

If sewage has backed up into your home, do not wait. Every hour increases the health risk and the scope of the damage. Call us at (248) 788-6422 and we will get a team to your home as fast as possible.