Residential Septic Systems
When considering potential risks regarding your water source it is important to remember that what you see on the surface is not always what is going on under the ground. A septic system is out of site, and therefore quite often forgotten. As a major component of a country home’s wastewater system, it  has the potential to impact the water quality for the home and the surrounding area. Properly installed septic systems are designed to prevent the leaching of chemicals and bacteria. Older systems and systems with improper leaching beds or holding tanks can result in septic effluent contaminating  the ground or even a neighbouring water supply. 

This risk can be amplified when rural houses are in close proximity to each other in small communities without municipal water and sewer services. If the soil depth beneath your leaching bed is plentiful, the level of absorption increases and the chances of contamination decreases. . Alternatively, the opposite is true when the bedrock is close to the surface and soil is scarce.  

As systems age, the effluent can work its way through this shallow depth and enter directly into fissures in the bedrock. This process can be naturally occurring as the leaching bed weeps, or it could be the result of improper care and maintenance of the septic system.

Soil Depth Plays an Important Role in Contaminant Leaching

Once inside the bedrock, the effluent becomes vastly more mobile, as it can travel wherever the water supply takes it. In areas with highly fissured bedrock, this effluent can travel for kilometres underground. It is common for the  septic effluent to enter a  household’s well or contaminate neighbouring properties and/or surface water supplies if present.

In 2020, a study published by Dr. Heather Murphy from Temple University concluded definitively that ”septic systems can represent an important source of contamination in private well water supplies.”1 This same study identified U.S. EPA44 regulation as one of particular interest, specifying that “areas with >40 septic systems per square mile are areas at high risk of groundwater contamination and that septic system density is a major contributor to the vulnerability of groundwater supplies due to human sewage.”2 This regulation speaks to the widespread nature of effluent and its adverse effects on groundwater sources. 

Septic Systems can be a Source of Water Contamination

In Canada, a septic system is privately owned, and by law you are responsible 
for its safe operation, maintenance and repair.

Things to Know about a Septic System
It is important to know the location of the septic tank and have the tank pumped out every 2-5 years depending on the usage. Pump outs will allow for inspection of the tank and identify if there are any cracks or holes that would allow effluent to leak directly into the surrounding soil. Pumping out the septic tank prevents solids, oils and grease from making their way into the leaching bed. Regular maintenance of the septic tank also prevents  costly backups of sewage into the home and helps you to avoid costly repairs or replacement of the entire system.

Test Your Water
Have the water tested with the local Health Unit for Coliform or e-Coli bacteria. This should be done a minimum of 3 or 4 times a year. Do not assume that one good test result determines the water quality for the other 364 days in the year. Often people will have the first test and never test the water again. In the country, water is a private responsibility that can have personal and public ramifications. Pumping out the septic tank and testing the water for bacteria on a routine basis is crucial to maintain safe water for both yourself and those around you. This practice will identify potential problems and allow you to make an educated decision on a solution. 

Best Practice Recommendation
Consult a water treatment professional for recommendations on the proper equipment to treat the water within your home. With proper septic care and the right treatment equipment, the water can be safe to drink, wash, bath and cook 365 days a year.

Volume 6 - Issue 4 Wahl H2O - Water Awareness
Copyright 2022 Jeff Wahl – Wahl Water | All Rights Reserved
Contact Jeff via email [email protected]


Amy Saunders

Date 9/12/2022

Anna Collins

Date 11/18/2022


Date 3/23/2023

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