Why is My Main Sewer Line Backed Up?

Executive Summary

• Main sewer line backups can usually be traced back to blockages caused by household waste buildup, tree root intrusion, damaged pipes, heavy rain, or the improper flushing of items.
• If your sinks, showers, or appliances are draining slowly, emitting foul odors, making gurgling noises, or causing water to back up, you should schedule a sewer inspection to rule out blockages.
• When left unchecked, sewer line blockages can contaminate water, cause structural damage, fuel mold growth, and jeopardize personal property.
• Keep sewer line blockages at bay through preventative care by building careful flushing habits and scheduling regular inspections and maintenance services with professionals.

Understanding Sewer Line Backups

When everything in your home is draining correctly, it is easy to forget about the main sewer line, a crucial piece of infrastructure that carries wastewater from your home’s sinks, tubs, toilets, and appliances to the municipal sewer system. However, when sewer line blockages occur, the results can be messy, disruptive, and expensive.

Without anywhere else to go, wastewater may reverse its course when faced with sewer line blockages. In turn, the wastewater may bubble up through drains, accumulate in toilets, or appear in the basement. Unfortunately, backed-up wastewater can contain harmful bacteria, viruses, and other contaminants, making it essential to address even the most minor clogs before they become a household emergency.

By reading through the information below, you can better understand what causes sewer line blockages, learn about potential warning signs, and educate yourself on health- and property-related consequences that may arise. This guide also features helpful preventative strategies and advice on when it is best to call an environmental professional.

Common Causes of Sewer Line Backups

Most homeowners are surprised to learn about the myriad of issues that can contribute to sewer line blockages. Understanding the frequent causes that are outlined below can help you stay proactive.

Clogs from Household Waste

The improper disposal of everyday waste is one of the most common culprits of sewer line blockages. Unlike toilet paper, grease, food scraps, paper towels, and “flushable” wipes do not break down as easily. Therefore, flushing or putting unsuitable items down drains can cause the waste to cling to pipe walls and accumulate until wastewater flow is restricted.

Tree Root Intrusion

If there are trees or shrubs near your piping, they may naturally grow toward the moisture. If the sewer lines are made from old clay or concrete, there may be small cracks that allow roots to penetrate inside, where they can expand and eventually cause blockages.

Aging or Damaged Pipes

Some factors that can cause sewer lines to break are:

• Corrosion
• Shifting soil
• General wear

So, as pipes age, cracks, collapses, or misalignments can appear, which can ultimately reduce water flow and make sewer line blockages more likely.

Heavy Rain or Flooding

During severe storms, municipal sewer systems may become overwhelmed with excess water. In some cases, the added pressure from heavy rain can force sewage back into residential lines, causing backups that make property owners think the issue started inside their home.

Warning Signs of a Clogged Sewer Line

Thankfully, sewer line blockages usually provide warning signs before they result in a sewage backup, giving you time to act. Being able to recognize the early indicators can save you from a major household disaster. 

Some signs indicating that you need a sewer inspection are:

• Slow drains throughout the house – If multiple sinks, showers, or toilets are simultaneously draining sluggishly, it’s likely a sign of a sewer line blockage rather than a coincidence.
• Gurgling noises – Bubbling or gurgling sounds coming from drains or toilets usually mean that there is air trapped in the pipes, which may signify that wastewater cannot flow freely.
• Unpleasant odors – Persistent sewage smells inside or outside your home may be traced back to sewer line blockages pushing foul gases back up through the plumbing system.
• Water backup – A toilet that overflows when the washing machine drains, or a sink that backs up when another appliance is in use, is usually a red flag for sewer line issues.
• Unusual yard changes – Wet spots, sinkholes, or patches with especially lush grass may mean there are leaks or sewer line blockages underground.

Health and Property Risks of Sewer Backups

Sewer backups may seem like just a messy inconvenience, but they have the potential to cause other problems throughout your property. Historically, sewer backups have presented the following health and property risks.

Contaminated Water Exposure

Backed-up sewage can carry harmful pathogens that can cause illness, including Campylobacteriosis and Escherichia coli Diarrhea. If the issue is not handled promptly, inhabitants may be at risk of being exposed to bacteria, viruses, or parasites due to direct contact or the inhalation of lingering vapors from backed-up sewage.

Structural Damage

When water seeps into flooring, walls, or foundations, it has the potential to warp, crumble, or weaken building materials, especially if it sits long enough to spur the growth of xylophagous or “wood-decay” fungus. 

Even if the backup does not hinder other aspects of your home, your pipes may be permanently damaged and require sewer repair to fix their structure and restore function.

Mold Growth

The excess moisture from backed-up sewer lines can create an ideal environment for mold growth. This fungus is known to spread throughout homes and compromise indoor air quality; however, scheduling mold services in a timely manner can help limit its spread.

Personal Property Loss

Some personal belongings that are exposed to sewage may be unsalvageable, such as:

• Furniture
• Carpets
• Electronics
• Mattresses and bedding
• Clothing and shoes
• Books and important documents
• Children’s toys and stuffed animals

Unfortunately, even items that can be cleaned may require a time-consuming and expensive restoration process, making it vital to prevent backups in the first place.

Prevention Strategies

Sewer line blockages can be disruptive, but fear not, you can drastically reduce your risk of experiencing one by adopting the smart habits and maintenance procedures detailed below.

Be Careful What You Flush

When contemplating what to put down the toilet, stick to the basics—only human waste and toilet paper should be flushed. Some examples of items that do not belong in the toilet and should go in the trash instead are:

• Wipes, including “flushable” ones
• Paper towels
• Feminine hygiene products
• Cotton swabs
• Diapers
• Cat litter
• Medication or chemicals

Dispose of Grease Properly

Pouring cooking oil or grease down the drain or flushing it down the toilet can lead to clogged sewer lines, because it can congeal and sit in your pipes. Instead, you should collect cooled grease in a container and safely dispose of it in a trash can.

Install a Backwater Valve

A backwater valve is a simple tool designed to prevent sewage from flowing back into your home during heavy rains or municipal-wide overloads. This tool allows wastewater to flow out of your home like normal, but if there is a blockage or flood, it automatically closes to stop sewage from backing up into your pipes.

Maintain Your Pipes

Scheduling regular inspections and professional sewer cleaning services is the best way to detect minor issues before they become major sewer line blockages. For example, a professional can hydro-jet the sewer line to clear out buildup and small intrusions.

Address Trees and Landscaping

You should avoid planting vegetation near sewer lines, especially trees with aggressive root systems. If you already have them on your property, consult a professional about installing root barriers and prioritize regular pipe maintenance.

When to Call a Professional

Since there are many factors at play, sewer line blockages can occur even if the property owner is extremely diligent and practices the preventive strategies below. If that happens, there are some do-it-yourself ways to unclog your drain that may work for minor blockages; however, knowing when to bring in a licensed plumber or environmental professional can spare your time, mental state, and wallet. 

Some examples of scenarios that warrant contacting an environmental professional are:

• Recurring blockages – If backups keep happening even after you have cleared your drains, your sewer system should be inspected by a professional because the problem may be deeper in the sewer line.
• Persistent warning signs – If you have multiple slow drains, strong sewage-like odors coming from your pipes, or persistent gurgling noises coming from your sink or tub, have a professional come out promptly.
• After flooding or storms – Extreme weather may overload sewage systems and damage pipes. Proactively scheduling an inspection can give you peace of mind that your system can withstand adverse weather conditions.

In addition to the scenarios above, sewer line inspections should be part of your due diligence before making property-related decisions, such as buying or renovating a home. These thorough inspections use advanced tools like specialized cameras to reveal hidden issues that might otherwise go unnoticed until after you invest in the property.

Clearing the Way for a Healthy Home

Even though sewer line blockages are disruptive, you can safeguard your household by using the knowledge and preventive care tips shared in this article, from disposing of grease properly to managing root systems that may interfere with your pipes. Still, for the most optimal results, it is crucial to rely on professional help; doing so can keep your plumbing system flowing smoothly for as long as possible.

If your Portland-based property faces a backup, Alpha Environmental can help in a timely manner. Our team has been tackling environmental concerns for residential and commercial properties in Oregon for over two decades, so our trained professionals are sure to have the skill and tools needed to clear your blockage and restore proper function to your sewer line. 

However, you shouldn’t wait for an issue to arise before taking action. Our team can help you prevent sewer line blockages altogether through preventive services, such as sewer inspections and cleanings, which are essential for maintaining and preserving your plumbing system.

Regardless of the state of your sewer line, you should contact Alpha Environmental for expert-level, individualized support.