How Long Does Waste In Septic Tanks Take To Decompose?

how to break down solids in your septic tank
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As homeowners with septic systems, understanding the decomposition process of waste in the septic tank is crucial for maintaining a healthy and functional system. In this guide, we'll dive into how long it takes for waste to decompose in a septic tank, and what you can put in your septic tank to break down solids.

On average, it takes anywhere from three to five years for waste to fully decompose in a septic tank. The decomposition time for waste in a septic tank can vary based on several factors, including the tank's size, the number of occupants in the household, and the types of waste introduced. This timeline can be influenced by variables like the presence of bacteria, the tank's maintenance, and the introduction of non-biodegradable materials.

how long for food to decompose in septic tanks

What Can I Put in My Septic Tank to Break Down Solids?

Here's what you can put in your septic tank to break down solids, and the most effective ways to keep your septic tank healthy:

  • Use Sepura: Sepura is designed to protect septic systems. It works like a garbage disposal but sends all food waste into an under-sink compost bin and only liquids go down your drain. No food waste enters your septic tank, allowing the bacteria to focus on breaking the human waste down and accelerating the process.

  • Use Bacterial Additives: Adding bacteria enhancers to your septic tank can help break down solids by accelerating the decomposition process. These additives introduce beneficial bacteria that aid in breaking down solids and waste.

  • Avoid Harsh Chemicals: Harsh chemicals, such as bleach and antibacterial cleaners, can disrupt the natural bacterial balance in the septic tank. Opt for septic-safe cleaning products to preserve the microbial ecosystem.

  • Regular Pumping: Regular septic tank pumping is essential to remove accumulated solids and prevent the tank from becoming overloaded. A professional should inspect and pump the tank every 3 to 5 years.

  • Conserve Water: Excessive water usage can hinder the decomposition process by flushing out beneficial bacteria. Practice water conservation to maintain a balanced septic system.

  • Septic-Safe Toilet Paper: Using septic-safe toilet paper that breaks down easily helps prevent clogs and ensures efficient waste breakdown.

Use Sepura

If you live on septic you can wash all your food waste down your sink with Sepura. Sepura filters all food scraps 3mm and larger into an odor-proof compost bin, only liquids enter your septic. This stops sludge buildup, eliminates the risk of your leach field clogging due to food waste sludge buildup, and reduces pumping frequency by up to 50%. This keeps your pipes clear and clog-free while effortlessly composting. By diverting food waste from entering your pipes and septic with Sepura, you can save $400+ by reducing septic pumps, and $200+ plumber visits to unclog pipes. Learn more about Sepura on septic.

help septic tanks break down waste by using sepura

Bacterial Additives

Bacterial additives are like the secret sauce for your septic system. These products contain a carefully selected blend of beneficial bacteria that thrive in septic environments. When introduced into the tank, these bacteria work to break down organic solids and waste, aiding in the decomposition process. They essentially provide a boost to the natural microbial population present in the tank. Bacterial additives can be found in various forms, including powders, liquids, and dissolvable packets. Regularly using these additives can significantly enhance the efficiency of waste breakdown and help maintain a balanced microbial ecosystem in your septic system.

Avoid Harsh Chemicals

While it's tempting to use strong and aggressive cleaning agents to maintain a clean home, it's best to avoid them when it comes to your septic system. Harsh chemicals like bleach, antibacterial cleaners, and strong solvents can disrupt the delicate balance of bacteria within the tank. These chemicals can kill off the beneficial bacteria responsible for breaking down solids. Without the necessary microbial activity, waste breakdown slows down, and solids can accumulate, leading to potential blockages and system inefficiencies. Opt for septic-safe cleaning products that are gentler on the bacterial ecosystem and kinder to your septic system's overall health.

what to put in septic tank to break down solids

Regular Pumping

Regular septic tank pumping is a fundamental maintenance task that directly impacts the breakdown of solids in your septic system. Over time, solid waste accumulates at the bottom of the tank, forming a layer of sludge. If not removed periodically, this sludge can reduce the available space for new waste, leading to backups and potential system failure. Professional septic tank pumping helps remove accumulated solids and prevents overloading of the system. The frequency of pumping depends on factors such as household size and water usage. A general rule of thumb is to have your septic tank inspected and pumped every 3 to 5 years to ensure optimal performance and waste breakdown.

Conserve Water

Water conservation isn't just about being eco-friendly; it also plays a crucial role in maintaining a healthy septic system. Excessive water usage can overwhelm the tank, flushing out essential bacteria responsible for breaking down solids. When the tank's microbial balance is disrupted, the decomposition process slows down, and solids may accumulate. To support efficient waste breakdown, practice water conservation measures such as fixing leaks promptly, installing low-flow fixtures, and spreading out water-intensive activities throughout the day. By using water wisely, you help maintain the ideal environment for bacterial activity and waste decomposition.

help septic tanks break down waste by using septic toilet paper

Septic-Safe Toilet Paper

Believe it or not, even your choice of toilet paper can impact your septic system's health. Septic-safe toilet paper is designed to break down quickly and easily in water. This is important because toilet paper that doesn't break down well can contribute to clogs and impede the flow of waste in the system. Using septic-safe toilet paper ensures that solids are properly broken down and can be more effectively processed by the septic tank's bacteria. Look for products labeled as septic-safe or biodegradable, and avoid using excessive amounts of toilet paper to further support efficient waste breakdown.

By following these guidelines and incorporating these practices into your routine, you can actively contribute to the optimal breakdown of solids in your septic tank. A well-maintained septic system not only ensures efficient waste processing but also extends the lifespan of your system, saving you money on potential repairs and replacements.


In conclusion, understanding the decomposition timeline of waste in a septic tank is vital for maintaining a healthy septic system. Factors such as bacterial activity, maintenance practices, and the types of waste introduced can influence this process. To support the breakdown of solids, adopt practices such as using Sepura so no food waste enters your septic, bacterial additives, avoiding harsh chemicals, regular tank pumping, conserving water, and opting for septic-safe products. By following these guidelines, you can ensure the longevity and optimal performance of your septic system.