How To Prevent Sewer Backups in Your Home

Sewer backups are one of the most severe plumbing emergencies a homeowner can face. A blockage in the main sewage line or the city’s sewer network can prevent wastewater from being flushed out safely. This creates the risk of it backing up into your home through sinks, toilets, or drains.

The consequences of sewage damage can be devastating. Contaminated water can destroy floors, walls, furniture, and electrical systems, leading to costly repairs. Exposure to sewer water also creates severe health risks from harmful bacteria, mold growth, and foul odors that can linger long after cleanup.

Fortunately, sewer backups are often preventable with the right habits and maintenance. Learn how to prevent sewer backup and limit the dangers to your property and your family’s health.

Most Common Causes of Sewage Backup

Knowing what causes sewage backup can help determine if your home has potential sewage line problems and whether you’ll need a professional plumber’s services to address them.

• Fats, oils, and grease (FOG) buildup. Pouring fats, oils, grease, and food solids down the drain leads to hardened clogs, restricting flow and increasing the risk of plumbing being backed up.
• Tree root infiltration. Roots seek moisture, invading cracks in sewer lines and causing blockages or structural damage.
• Aging or poorly maintained pipes. Older clay, cast iron, or Orangeburg pipes deteriorate over time, making regular maintenance crucial.
• Flushing non-flushable items. Paper towels, feminine products, and diapers aren’t designed to break down in toilet water, leading to clogs. This also applies to “flushable” wipes; they don’t break down as easily as advertised.
• Ignoring early warning signs. Pay close attention to gurgling sounds, multiple drains draining slowly, or foul odors coming from drains or sinks. They could be early signs of a sewer line clog.
• Municipal sewer line issues. In some cases, city sewer line problems can be the cause of a sewage overflow. In California, it is common for homes to be at increased risk of backups after periods of heavy rainfall due to stormwater management being overwhelmed with rainwater.

How to Prevent Sewage Backups in Your House

Homeowners concerned with backup damage often ask themselves, “What is a sewage backup prevention method I can try?” or “How can I reduce backup risks in my home?” Adopting the right habits and measures can help prevent water and sewer backups, extend the life of your plumbing, and keep your family and belongings safe.

Avoid Pouring FOGs Down the Drain

FOGs—fats, oils, and grease—are one of the most common causes of sewage line clogs in houses. Pouring still-hot FOGs causes them to cool and harden inside the pipes, forming “fatbergs,” large masses of rock-hard material that stick to the sides of your pipes. Fatbergs restrict water flow, slow your drains, and increase the risk of backups.

A common sewer backup prevention method is to adopt better FOG disposal habits:

• Dispose of grease properly. Let cooking oils and grease cool down, then scrape them off your cooking gear into a garbage bag so you can dispose of them in the regular trash.
• Wipe before washing. Use paper towels to wipe greasy dishes and pans before rinsing, then dispose of them in a garbage bag.
• Install sink strainers. While they don’t prevent FOGs from going down the drain, they can catch greasy or oily food particles, preventing solids from entering your pipes and potentially worsening a fatberg.

Install Backwater Valves

A backwater valve is a device installed in your sewer line that prevents wastewater from flowing back into your home. It detects whether water or sewage is attempting to flow in the wrong direction and closes automatically before it reaches the inside of your home.

Backwater valves are designed to protect your home against sewer backups caused by municipal lines or stormwater management system issues. While California doesn’t require them statewide, local sanitation agencies, like the Los Angeles County Sanitation Districts (LACSD), may require them in specific areas.

A professional plumber can help you determine whether your home complies with local backwater valve ordinances and provide assistance with installation.

Manage Trees Near Sewer Lines

If you have trees planted on your property, their roots may seek moisture from the sewer lines. Tree roots can pass through cracks or holes in the sewer lines and grow inside the pipes, potentially causing blockages. To mitigate the risks, consider the following:

• Avoid planting trees with invasive roots near sewer lines. Species like willows, maples, and elms are particularly aggressive.
• If you already have trees planted on the property, schedule regular inspections to check for tree intrusions in the sewer lines. Early detection allows a professional to address the problem using augers or hydro-jetting.
• Ask a professional plumber about root barriers and their suitability for your property. These pipe covers can prevent tree roots from reaching and entering your sewer lines, reducing the risk of backup.

Only Flush Waste and Reasonable Amounts of Toilet Paper

Toilets aren’t designed to handle anything other than human waste and reasonable amounts of toilet paper. To limit the risk of toilet clogs and backups, avoid flushing the following:

• Excessive quantities of toilet paper
• Flushable wipes
• Paper towels and napkins
• Feminine hygiene products
• Cotton balls and swabs
• Diapers and baby wipes
• Toys and other plastic objects

Keep Your Plumbing Inspected and Maintained

While you can do many things to protect your home from sewage backups, scheduling regular plumbing inspections can help you address problems that cannot be solved with DIY.

Reputable plumbing professionals recommend scheduling inspections and routine maintenance at least once a year. In addition to knowing how to fix a sewage backup and other plumbing emergencies, a certified plumber can help address the following:

• Buildup removals. Regular inspections are a good opportunity to clean your sewage lines and remove debris, grease buildups, or tree roots before they can cause backups.
• Pipe maintenance and upgrades. Certified plumbers can inspect and assess the condition of your pipes, including the sewage lines. If you live in an older home with pipes made of outdated materials like cast iron or Orangeburg, your plumber can recommend pipe upgrades to reduce the risk of backups or pipe damage.
• Inspecting fixtures and equipment. Plumbing specialists can check the condition of your backwater valve and home fixtures, make necessary repairs, and offer maintenance tips.
• Sewer cleanout maintenance. The sewer cleanout is a capped pipe that provides direct access to your home’s sewer line. A professional may need access to the cleanout to clear a blockage during an emergency. If you don’t know where yours is, your local plumber can help you locate it and offer tips on how to keep it unobstructed.

When You Should Contact a Professional

While preventive measures help reduce backup risks, some situations require immediate attention from a licensed plumber:

• Multiple slow drains. While a single slow drain usually means only that drain is clogged, multiple slow drains often mean the sewer line may be clogged.
• Sewage odors. A persistent sewage smell inside or outside your home can mean sewage is stuck in your pipes and is at risk of backing up.
• Frequent plunging. Persistent or recurring clogs are a common symptom of sewer line clogs.
• Heavy rain or flooding. After major storms, many neighborhoods in the Los Angeles area, such as the San Fernando Valley, are vulnerable to heavy rainfall and flash floods. Contact a plumber to assess your sewage system and address any outstanding problems after the flooding event ends.

Protect Your Home From Sewer Backups

While sewage backups can be dangerous to your health and property, they can be prevented with good habits and proper maintenance.

Scheduling regular sewage line inspections with a local certified plumber is the best way to monitor the condition of your plumbing and lower the risk of sewage flowing back into your home. Professionals can also offer maintenance advice or suggest necessary repairs and upgrades to reduce the risk further, keeping your home and family safe from sewage exposure.