Signs Your Septic System Is Failing — And What To Do About It

Owning a home or managing a property with a septic system means taking responsibility for one of your most important underground assets. When working properly, a septic system safely and silently treats and disposes of household wastewater. But like any system, it requires maintenance—and when signs of failure appear, it’s critical to act quickly to avoid costly repairs or environmental damage.

In this guide, we’ll walk you through the top signs your septic system may be failing, explain the reasons behind these symptoms, and show you what to do to protect your property. If you recognize any of the issues below, don’t wait—take action with help from the professionals at A1 Tank Service.

1. Sewage Odors Around the Tank or Drainfield

Foul smells are one of the first and most obvious signs of septic problems. If you’re noticing a strong sewage odor in your yard, near your tank, or by your drainfield, it could be due to a tank that’s full, a leak in the system, or improper drainage. Odors might also travel back through household plumbing, particularly in basement areas or laundry rooms.

In many cases, these odors mean your tank is overdue for pumping. Septic pumping is a critical maintenance task that prevents solids from escaping the tank and clogging the drainfield. Waiting too long can result in irreversible system damage, so addressing odor issues immediately is key.

2. Slow Drains or Gurgling Sounds

If your sinks, tubs, or toilets are draining slowly or making strange gurgling sounds, your septic system might be clogged or full. While minor plumbing issues can cause similar symptoms, if multiple fixtures are affected—especially those on lower floors—it’s a strong sign of a system-wide septic backup.

Gurgling happens when air is trapped in the pipes due to restricted flow. It may also indicate rising wastewater levels in the tank or damage to internal baffles. Before using harsh drain cleaners that can harm the helpful bacteria in your tank, consider a professional inspection to assess what’s really going on.

3. Standing Water or Lush Grass Over the Drainfield

Your drainfield is designed to evenly disperse treated wastewater underground. If water is pooling on the surface or if one area of your yard looks unusually green and healthy, it may mean your system isn’t filtering properly. This often occurs when solid waste clogs the drainfield pipes or the soil becomes oversaturated.

In some cases, this can lead to sewage surfacing above ground—a serious health and environmental hazard. If you notice soggy soil or odors near the field, it’s time to schedule septic troubleshooting before the issue escalates into total drainfield failure.

4. Frequent Pumping or Unusual Tank Levels

Needing to pump your tank more often than recommended could signal a problem. Excessive water usage, leaks, or a failing tank can cause the tank to fill faster than normal. Alternatively, a low tank level may point to a cracked or leaking system that’s losing liquid into the surrounding soil.

Routine inspections can detect these issues before they become emergencies. With over two decades of experience, A1 Tank Service can provide a thorough diagnostic to measure scum and sludge levels and ensure your system is operating at peak performance.

5. Backup in the Home

One of the most dreaded signs of septic failure is sewage backing up into your home. This can happen in sinks, showers, and toilets, especially on lower floors. Besides being incredibly unpleasant and unsanitary, a backup poses health risks and can damage floors, walls, and fixtures.

Backups are often the result of a completely full tank, but they can also occur if the drainfield is no longer absorbing wastewater. If you notice slow drainage or strange smells before a backup, don’t delay—shut off your water and call A1 immediately to assess the situation and determine whether you need septic repair services.

6. Alarm Activation

Modern septic systems often include high-water alarms to alert homeowners of a potential overflow. If you hear your alarm beeping or see a red light on your control panel, it means wastewater levels are higher than normal—often due to a failing pump, clogged line, or system overload.

Do not ignore these alarms. Shutting off excess water use immediately and calling a professional could save you from a messy overflow and costly cleanup.

7. Unusual Noises or Odors Indoors

In addition to gurgling, you may notice unpleasant smells coming from your sinks or drains, especially after doing laundry or using the dishwasher. This could be a sign that sewer gases are entering the home due to a blockage or improper venting.

While this issue may be related to your home’s plumbing, it’s worth checking the septic system as a potential source—especially if you’re noticing other signs of stress or overcapacity.

8. Increased Insect or Rodent Activity

Rats, flies, and other pests are drawn to organic waste. If you’ve noticed a rise in insect or rodent activity near your tank or drainfield, it may be because your system is leaking untreated wastewater into the environment.

This creates both a public health concern and a property nuisance. A properly sealed and maintained septic system should not attract pests, so any increase in activity is worth investigating right away.

9. Your System Is Simply Old

Most septic systems are designed to last 20 to 40 years depending on their design, materials, and maintenance history. If your system is over two decades old and hasn’t received consistent maintenance, you may already be experiencing subtle signs of failure without realizing it.

Aging systems often suffer from corrosion, cracked tanks, collapsed pipes, or failing drainfields. If your system is nearing the end of its life expectancy, now is the time to have it evaluated for repair or replacement options.

What to Do If You See Signs of Septic Failure

Don’t wait until the signs become disasters. If you notice any of the above symptoms, schedule an inspection with A1 Tank Service right away. Our expert technicians will evaluate your tank, field, and plumbing system to pinpoint the cause of failure and help you take the next steps toward recovery.

In many cases, timely intervention—such as pumping, jetting, or replacing baffles—can restore function and extend the life of your system. The key is early action.

How A1 Tank Service Can Help

With over 20 years of experience serving California homeowners and businesses, A1 Tank Service provides:

We use the latest equipment, including hydro-jetting, camera inspections, and GPS-based locating to find and fix problems efficiently. Whether you’re dealing with a slow drain or a complete system failure, A1 is here to get your system back on track.

Schedule Your Septic Service Today

If your system is showing signs of failure, don’t wait. Call A1 Tank Service or contact us online to schedule your service. Our team is ready to provide honest advice, fast turnaround times, and solutions that protect your property and your peace of mind.

Stay proactive, stay protected—with A1.