septicAn Overflowing Septic Tank Photo credit: Rob Davis, EcoEthic Inc.

As part of our “Ask An Expert Webinar Series,” we heard from Rob Davis of EcoEthic Inc., last week on how septic systems work, how to watch for signs of failure, a few myths and lots of great tips for preventing bigger problems before they happen. I was so impressed with the information, I thought it was important to share it because I know there are a lot of septic system owners out there and these systems don’t always come with a user manual.

It was interesting to find out that septic systems were first invented in France about 260 years ago, but were intended only to handle black water (i.e. human waste), not the typical things we let go down the drain like bathing and laundry soap. The systems incorporate not only physical treatment (sinking and floating of material) but, more importantly, biological treatment as well (digestion of waste by bacteria). More microbes in the system equate to better treatment and fewer nutrients exiting the system.

Although your system is underground and you can’t see it, there are some telltale signs to watch out for that indicate your system may not be functioning properly: a strange odour, tile bed damp spots, green stripes on the grass above the system, breakout of effluent, slow drains throughout the house/camp, gurgling toilets and needing frequent pump-outs. These issues can arise if the system was installed poorly, if it has been improperly maintained over the years, if the baffles are missing or damaged, if too much water has been allowed to enter the system, if you use water softeners, iron filters or garburetors (these are all no-no’s) and if you allow harsh chemicals, paint or chlorinated cleansers to enter the system. It is important to have both sides of your system pumped out every three to five years (depending on use), have the baffles checked and the effluent filter cleaned regularly; equally important is the need to educate family and friends of what can and can’t go down the drain.

It’s important to remember not to drive on your septic field and don’t allow woody rooted plants, bushes or trees to grow within five metres (15 feet); don’t allow solvents, fats, oils or chemicals down the drain and a great alternative to regular toilets is a low flow or dual flush versions to reduce water flow into the system. While it’s a myth to add in rotten protein, road-kill, yogurt, yeast or extra water, it is a good idea to add in a good quality digestive bacteria mix.

There are lots of good reasons to be sure your system is working at its optimum- it will extend the life of your system and it will properly treat waste so that water quality impacts are reduced. The escape of nutrients, bacteria, pathogens and viruses from improperly maintained septic systems is a definite threat to our nearby water bodies.

If you are interested in watching the presentation by Rob Davis or registering for any of the remaining webinar series talks, please go to:

This series is provided as part of the International Watershed Coordination Program of the Lake of the Woods Water Sustainability Foundation (

Kelli Saunders, M.Sc., is the International Watershed Coordinator with the Lake of the Woods Water Sustainability Foundation.