How Long Will an Aerobic Septic System Last?

The anaerobic septic system is one of the most common waste treatment systems in areas without centralized sewage systems. Its widespread popularity is due to its simplicity, effectiveness, and affordability. However, one question that many homeowners have is: how long will an anaerobic septic system last? In this article, we’ll explore the typical lifespan of these systems and the factors that influence their longevity.

I always hate having to start an answer with, “It depends…” but that’s often the way it just has to be. So, here we go…

Anaerobic Septic System: A Brief Overview

Before diving into lifespans, it’s crucial to understand how an anaerobic septic system functions. The term “anaerobic” refers to processes that occur without the presence of oxygen. In this system, wastewater from households flows into a septic tank, where anaerobic bacteria break down organic materials. The byproducts are mainly gases, solids (known as sludge), and a clarified liquid effluent that exits the tank and is distributed into a drain field.

Typical Lifespan of an Anaerobic Septic System

This might be the main answer you’re looking for…

On average, an anaerobic septic system can last between 20 to 40 years, with the septic tank itself often lasting longer if well-maintained. The drain field, on the other hand, generally has a shorter lifespan, ranging from 15 to 25 years.

Now, let’s look at the factors that affect the longevity of aerobic septic systems.

Factors Influencing the Lifespan

1. System Installation: The initial installation plays a crucial role. If the system is correctly installed following all guidelines and regulations, it is likely to last longer. On the flip side, poorly installed systems can present problems early on.
2. Usage and Overloading: Regular overloading of the system, either by sending more water into the tank than it’s designed to handle or introducing non-biodegradable items, can reduce its lifespan.
3. Maintenance: Regular maintenance, including periodic pumping of the septic tank to remove inorganic materials (wipes, toys, plastics, tampons…), sludge, and floating scum, can significantly extend the system’s life. Neglecting this vital service can lead to system failures. Keeping the organic solids cleared out with Drain Field Cleaner to keep your tank and drain field clean also extends the life of your total system.
4. Soil Conditions: The type of soil in the drain field affects the system’s efficiency and lifespan. Permeable soils that drain well are ideal, while clay or compacted soils might reduce the system’s effectiveness.
5. Chemicals and Additives: Introducing harsh chemicals or “home remedy” additives (roadkill, yeast, horse manure, we’ve heard ’em all) can kill the essential anaerobic bacteria in the septic tank or give the healthy bacteria in the system more work to do, affecting the system’s efficiency and reducing its lifespan.
6. Physical Damage: Damage to the tank or drain field, such as from vehicular traffic or landscaping activities, can lead to premature system failures.

Prolonging the Lifespan

1. Regular Inspections: Have a professional inspect the system every 1 to 3 years to identify potential issues.
2. Pump Periodically: Depending on usage, pump the tank every 3 to 5 years to remove accumulated sludge and scum.
3. Mind What You Flush: Be cautious about what goes down the drain. Avoid flushing non-biodegradable items, oils, fats, and harsh chemicals.
4. Conserve Water: Reduce water usage and avoid overloading the system.
5. Protect the Drain Field: Avoid planting large trees near the drain field, and never drive or park vehicles on it.

Conclusion: Take care of your system and it will last longer

While the lifespan of an anaerobic septic system can vary based on numerous factors, with proper care and maintenance, homeowners can expect a service life of several decades. By understanding how the system works and the factors that influence its longevity, you can take steps to ensure that your anaerobic septic system remains functional for years to come.