5 Common Reasons Septic Systems Fail
And the Warning Signs You Shouldn’t Ignore
Your septic system is one of those parts of your home that is easy to forget about when everything is working properly.
Until it isn’t.
Fortunately, septic problems rarely appear completely out of nowhere. Slow drains, unusual odors, wet spots in the yard, or a toilet that starts gurgling can all be early warning signs that something needs attention.
Whether your property has a mound system, conventional drainfield, pressure distribution system, or another approved septic treatment system, the basic warning signs are often similar.
Catching a problem early can mean the difference between a relatively simple repair and a much larger, more expensive septic system replacement.
Here are five of the most common reasons septic systems develop problems, what to watch for, and what you can do to help prevent them.
1. Too Much Water Going Into the System
What happens?
Your septic system is designed to handle a certain amount of wastewater. When too much water enters the system at once, it can overwhelm the tank and the treatment area.
Large amounts of water from showers, laundry, water softeners, dishwashers, leaking fixtures, or other sources can move wastewater through the system too quickly and reduce the time available for proper treatment and settling.
Excess water can be especially problematic during periods of heavy rain or when the soil around the treatment area is already saturated.
Warning signs
- Slow drains or recurring backups
- Gurgling toilets or drains
- Wet or unusually green areas near the treatment area
- Problems that appear after heavy laundry days or periods of heavy water use
- Problems that become worse after heavy rain
How can you prevent it?
- Repair leaking toilets and faucets promptly.
- Spread laundry and other high-water-use activities throughout the week rather than doing everything at once.
- Consider water-efficient fixtures and appliances.
- Avoid unnecessary water use.
- Make sure gutters and downspouts direct water away from the septic system and treatment area.
Remember: Your septic system is designed to treat wastewater, not stormwater.
2. Improper Use of the Septic System
What happens?
Your septic system relies on natural biological processes to treat wastewater. Introducing materials that don’t belong in the system can interfere with those processes, clog components, or cause damage.
Your toilet is not a trash can, and your septic system is not designed to dispose of everything that goes down a drain.
Never flush:
- Wipes, even those labeled “flushable”
- Paper towels
- Feminine hygiene products
- Diapers
- Cotton swabs
- Dental floss
- Cat litter
- Grease or cooking oil
- Household chemicals
- Paint or solvents
- Medications
What about septic additives?
Most properly functioning septic systems do not need special additives, treatments, or “septic boosters.” Adding products to a septic system without knowing whether they are appropriate can do more harm than good.
If you have questions about what is safe for your system, ask a septic professional.
How can you prevent it?
Think of your drains as a doorway into your septic system. If something shouldn’t be in the septic tank, don’t put it down the drain.
When in doubt, throw it out rather than flush it.
3. Lack of Regular Maintenance
What happens?
Over time, solids accumulate in the septic tank. If they aren’t removed, they can eventually move into the treatment and dispersal system, where they can clog components and interfere with proper wastewater treatment.
Regular inspection and pumping help keep the system working properly and give you an opportunity to catch problems before they become emergencies.
Warning signs
- Slow drains
- Recurring plumbing backups
- Sewage odors
- Gurgling toilets
- Problems returning shortly after pumping
- No record of the septic system ever being inspected or pumped
How can you prevent it?
Have your septic system inspected and pumped according to the needs of your household and system. (Commonly every 2-3 years)
The right maintenance schedule varies based on factors such as:
- Household size
- Water usage
- Tank size
- System design
- Amount of solids entering the tank
A septic professional can help determine an appropriate maintenance schedule for your property.
Don’t wait for a backup to remind you that your septic tank needs attention.
4. The Treatment Area Becomes Overloaded or Fails
What happens?
After wastewater leaves the septic tank, it enters the system’s treatment and dispersal area. Depending on the property, this may be a conventional drainfield, mound system, pressure distribution system, or another approved treatment method.
This part of the system relies on the soil, system components, and proper wastewater distribution to treat and disperse effluent.
When the treatment area becomes overloaded, saturated, compacted, clogged, damaged, or otherwise unable to properly treat and disperse wastewater, the system can begin to fail.
Warning signs
- Wet or soggy areas near the treatment area
- Standing water
- Unusually lush or fast-growing vegetation
- Sewage odors outside
- Sewage surfacing on the ground
- Slow drains or recurring backups
- Alarms or other system warnings
- Problems that continue even after the tank has been pumped
How can you prevent it?
Protect the area where your septic system treats and disperses wastewater.
Avoid placing:
- Vehicles or heavy equipment
- Buildings or sheds
- Swimming pools
- Large structures
- Excessive landscaping
- Other activities that could damage or compact the area
Do not intentionally direct roof runoff, sump pump discharge, or other sources of excess water toward the treatment area.
Important: The specific protection requirements vary depending on your septic system design. If you’re not sure what area needs to be protected, ask a septic professional.
5. Aging, Damaged, or Failing Components
What happens?
A septic system is more than just a tank. It can include tanks, pumps, distribution components, pipes, electrical components, alarms, controls, and other equipment depending on the system design.
Over time, components can wear out, become damaged, or stop functioning properly.
Sometimes a problem is relatively simple to repair. Other times, an aging system may need significant repairs, redesign, or replacement.
Warning signs
Watch for:
- Unusual noises from pumps or equipment
- Alarms going off
- Sewage odors
- Slow drains or backups
- Wet areas around components
- Repeated repairs
- Problems that keep returning
- A system that is approaching or beyond its expected service life
How can you prevent it?
Regular inspections can help identify aging or damaged components before they cause a larger system failure.
If your system has electrical components, pumps, alarms, or other mechanical equipment, make sure those components are inspected and maintained as recommended for your particular system.
A small problem is usually easier to address than a failed system.