What is a septic system?

A septic system is underground infrastructure that relies on bacteria to clean and treat household wastewater (water that goes down the drain – sink, shower, toilet etc) when municipal water infrastructure is not available. These systems have two components the septic tank and the leaching field.

Septic tank:

After wastewater travels down drain pipes and out of residences it enters into a buried septic tank. This tank is usually made out of concrete, fiberglass or plastic, is in close proximity to residences and contains two chambers (all newer models are two chambers). Once wastewater enters the tank, heavy solids sink to the floor of the first chamber while lighter solids settle on the floor of the second chamber both forming a “sludge” layer on the bottom. Any lighter organic materials, like grease and oil, float to the top of the tank where they create a “scum” layer.

Inside each of the chambers, living anaerobic (do not need oxygen) bacteria work happily filtering, eating and breaking down organic matter (like human waste). However, tanks must still be emptied periodically to remove all the scum and excess sludge that the bacteria have been unable to breakdown.

Leaching field:

After the wastewater reaches the second tank, and the remaining solids have sunk to the bottom, the treated water, or effluent, passes through the effluent filter (on all systems from 2007) and is then dispersed into the leaching field through perforated pipes. Under these pipes the effluent enters into a mixture of rocks, sand and soil which filters the water as it passes through each layer. In properly functioning system the water will be clean and filtered before entering into ground water.

Click here to view an interactive model on how septic systems work!

How do I know if I have a septic system?

If you are not receiving municipal water (do not have a water meter and are not receiving a water bill) then you are likely on a septic system. You can also take a look at your property survey (you usually receive this when purchasing a property) or have one conducted. This will show you the property line as well as the exact location of the septic system.

Septic system maintenance:

Septic systems require regular maintenance to stay in working condition. Effluent filters should be checked and cleaned multiple times a year to ensure that there is no excessive build up of waste preventing the filter from doing its job. Septic tanks need to be emptied periodically, at least every 3-5 years for the average residence of 3-4 people, but this can vary depending on the amount of use (for example more people = more use= needs to be emptied more often).

If tanks are not periodically emptied it will result in a system failure. This can cause untreated sewage to enter the leaching field and may lead to groundwater and lake contamination.

Failure can result from a number of additional reasons including:

Harmful chemicals (like poison, draino, bleach etc) have been poured down the drain. These chemicals can kill the filtering bacteria that live in the septic tank which prevents the breakdown of solid waste and leads to the tank filling faster than expected. If chemicals are absolutely necessary, use the biodegradable option. If no such alternative is available use the conventional chemical as sparingly as possible.
Garbage has been put down the drain. Non-biodegradable garbage is not digested by bacteria and will remain in tank until removed. If there is a build up of garbage this can cause the tank to fill faster than expected. Putting garbage down the drain can also result in clogged pipes and water backup. All garbage should be put in trash bins and disposed of appropriately.
Cars are parked, buildings are built or heavy equipment is on the septic tank or leaching field. This can cause damage to septic infrastructure and result in failure. If you have an issue with unsolicited parking on your septic system consider installing a “no parking” sign.
Too much water is entering the system (the amount of water entering the tank is greater than its capacity). High influxes of water prevents solids from settling on the bottom of the tank and can again result it sewage seeping into the leaching field. Thus, it is important to minimize the amount of water entering the system and efforts should be made to ensure water conservation inside the residence.
Trees or shrubs are too close to the septic tank and/or leaching field. Roots from these plants can cause extensive damage to the underground infrastructure. All proximate trees or shrubs should be planted as far away from the septic system as their height at maturity, meaning that a tree which will grow up to 5 meters should be at least 5 meters away from your system.

How do I know if my septic system is failing?

A system failure can be very pricey, sometimes costing up to $25,000! By doing the best practices previously mentioned you can increase your chances of avoiding a costly failure. Keep an eye (or nose) out for the symptoms of failure listed below, if discovered, search for the cause of the problem and fix the system as soon as possible.

1. Foul smell outside/around the septic system, or inside from the drains

2. Soggy grass or unusually green grass over leaching field even during dry weather

3. Pooling of water on leaching field

4. Drain gurgling

5. Water backup, re-entering the residence

6. Sinks and showers are draining slowly

7. Toilet will not flush, but plunger is not fixing it

8. Contamination found in well water

9. New algal blooms at your waterfront