Understanding Septic System Components and How They Work
Many homeowners don’t feel as comfortable with their septic system as they’d like. If you’re a rural homeowner, understanding and maintaining your septic system is an important part of caring for your property. Which is why we want to share some basic, easily digestible information on the common parts of a septic system and their function.
This is the primary sewer pipe that carries all the wastewater from your household plumbing (toilets, showers, sinks, washing machine, dishwasher) to the septic tank.
This is a watertight container, usually buried underground, made of concrete, or polyethylene. It’s the primary treatment stage where the separation of solids and liquids occurs. Most modern tanks in Ontario have two compartments.
This is a series of shallow, covered trenches in the unsaturated soil, usually arranged in the shape of a fork, with one outlet leading to a few prongs. The trenches typically contain perforated pvc pipes surrounded by gravel. The partially treated wastewater (effluent) from the septic tank flows into these pipes and slowly filters through the gravel and then into the soil. Arc Chambers are increasing in popularity as a method of decreasing the size of your leach field.
The soil beneath the drain field is a critical component. It provides the final stage of treatment as the effluent percolates through its layers. Microbes in the soil help to remove harmful bacteria, viruses, and nutrients.
How a Septic System Works: A Step-by-Step Process
- Wastewater goes down your drains and flows through the main drain line into the septic tank.
- Inside the septic tank, the wastewater is held long enough for gravity to separate the solids from the liquids, usually classified into three groups.
- Sludge: Heavier solids settle to the bottom of the tank, forming a layer called sludge. Anaerobic bacteria (bacteria that don’t need oxygen) begin to decompose some of this sludge.
- Scum: Lighter materials, such as fats, oils, and grease, float to the top, forming a layer called scum.
- Effluent: The liquid wastewater in the middle layer, now partially treated, is called effluent.
- Before leaving the tank, the effluent passes through a filter designed to prevent suspended solids from flowing into the drain field. Effluent filters have been a requirement for new septic tank installations in Ontario since 2006.
- Flow to the Drain Field: The effluent then exits the septic tank through an outlet pipe and flows to the drain field.
- The effluent is discharged through the perforated pipes into the gravel-filled trenches. From there, it slowly seeps into the unsaturated soil.
- Filtration: The soil acts as a natural filter, trapping any remaining solid particles.
- Biological Treatment: Aerobic bacteria (bacteria that need oxygen), along with other microorganisms in the soil, further break down and digest organic matter and pollutants in the effluent.
- Absorption: Nutrients like phosphorus are adsorbed or chemically bonded to the soil particles.
- Return to the Water Cycle: As the treated wastewater percolates through the soil, it eventually reaches the groundwater, having been naturally purified.
Understanding these components and how they work is the first step in properly caring for your septic system and ensuring its long-term, effective operation. You can find more about our septic tanks and their components online or in store. Whether you’re a homeowner looking for advice, or a septic tank installer looking for a supplier, we’re here to help. If you have questions, our team is always available via phone at (905) 386-1744 or email at sales@ontarioagra.ca to help with your research and make customized recommendations.
