Septic Systems

Water quality depends on good septics

Research shows that run-off from faulty septic systems is a major cause of pollution in our lakes.

Faulty systems release harmful bacteria into water, posing a threat to human health. And they leach nutrients into the lakes, “fertilizing” the growth of excessive algae and aquatic plants.

Based on the findings of re-inspection programs elsewhere, there’s no doubt that old and inadequate septic systems, holding tanks and privies are polluting our lakes.

This is why Environment Council continues to advocate for septic re-inspection by all of our surrounding townships. And why we are ramping up our efforts to inform waterfront owners about the importance of good septic system practices.

Faulty septics threaten human health

Failed or damaged septic systems can contaminate soil, groundwater, wells, streams and lakes.

Nitrates from faulty septics can leach into the surrounding soil and penetrate hundreds of feet into groundwater. This is a danger to human and animal health because nitrates can interfere with the body’s ability to carry oxygen.

Phosphorus and nitrogen from septics also cause excessive growth of aquatic plants and algae, including dangerous blue-green algae, which affects virtually all uses of lake water and can cause serious illness. To learn more about this, click on Algae on the menu bar under Water Quality.

Bacteria, such as E. coli, leaching from septics can cause a number of illnesses. Swimming or playing in contaminated lake water can result in eye infections, dysentery or hepatitis..

Research shows many septics need work 

Our septic task team has reviewed the results of many other re-inspection programs in cottage country.

These results show that about five percent of systems re-inspected need to

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have the septic tank and field replaced, and 20 to 30 percent need to be pumped and/or repaired.

Our lakes have many older and water access cottages, so many septic systems and holding tanks (not to mention privies) may be older than average. This means the proportion of faulty systems may be higher than in other locations.

Septic systems can falter or fail for many reasons:

  •  improper design or construction, or improper use and maintenance;
  • overloading, because they are too small or haven’t been pumped;

  • tanks may corrode and leak, have worn or missing baffles, become clogged with too much tissue or tree roots, or malfunction because foreign objects or chemicals have been put down the drain;

  • weeping tile fields may become blocked by tree roots or compacted by vehicles.

For quick tips on how to take care of your septic system, click on Septic Tips on the menu bar.

For more detailed information on septic systems, go to: or


Septic re-inspection is needed now

Environment Council has been advocating for municipal septic re-inspection programs for almost a decade.

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A few years ago, after extensive research and consultation, we shared our findings with our four local townships in a series of workshops.

Under the Ontario Building Code, municipalities are responsible for septic re-inspection, so we asked the townships to undertake programs, working with the public health unit.

North Kawartha launched its own program in 2014 and is re-inspecting all Ston(e)y Lake properties within its jurisdiction during spring and summer 2018. Trent Lakes began its program in co-operation with Peterborough Public Health in 2016.

Partly in response to urging from Environment Council, Selwyn and Douro-Dummer townships agreed in late 2016 to develop programs during 2017, with re-inspections to start in 2018.

Selwyn then delayed implementation by a year, announced that its proposed program would start in 2019, and eventually – after some opposition to the plan and its costs – invited community input. Eventually, Selwyn Council voted in September, 2018, to not approve the township’s proposed re-inspection program.

Douro-Dummer reversed its decision in early 2018, and currently has no plans to introduce re-inspection.

We will continue to press both townships to initiate thorough, viable re-inspection programs, because faulty septic systems pose a serious threat to human health, water quality and the recreational and economic value of our lakes.