Bulletins

Get the latest on our lake stewardship findings, two new events held in 2025, updates from our Mayor and Councillors, Loon news, wake-boating, Short-Term Rentals, creative writing and more.

The results are in from the 4 sites tested for 50 different contaminants in our lake water. One sample of raw lake water was taken from the boat launch on Little Otter Lake as a control (in green below). Filtered tap water from 3 volunteer Otter Lake properties was also taken from 3 diverse areas on the lake (in blue below).

According to the Near North Laboratories Analysis Interpretation Guide – 50 Parameter, the above data shows only a few areas of concern.

Alkalinity and pH are low. For Alkalinity, less than 30 mg/l as CaCO3 will corrode plumbing and may cause Iron to dissolve. For pH below 6.5 there is also the potential for corrosion of pipes.

Chloride is low in the filtered water samples. Ideal levels are being between 5 – 20 mg/l.

Bacterial Contamination: The main concern detected by this study was bacterial contamination in 2 of the 3 filtered drinking water locations, much to the surprise of the 2 affected households.

Significant bacteria levels are expected in raw lake water as contaminants wash into our lakes, especially during heavy rains. Hence, the Health Unit tests beaches for e-coli contamination and will close a beach if the count gets too high. But treated drinking water should have zero coliforms and e-coli to be safe. 2 of our 3 test sites were deemed to need increased filtration and/or sterilization to reduce their bacterial counts to zero.

Since all three filtered water test sites were using a combination of filters followed by a UV light for bacterial sterilization, it is clear that such a system is not infallible and all of us can learn from this. Bacteria can slip through filters and when they do, the UV light has to reach them all to have safe, potable water.

However, particles that slip through clogged filters can provide a shield for bacteria from the UV light. Also, if the sheath of the UV light becomes dirty or the light’s life expires, not all bacteria will be UV irradiated and may then cause illness. (It is worth noting that no illnesses were reported at any of our three volunteer sites.)

As an example, the 3 filters currently being used at the Long Arm location are for 30, 10 and lastly 5 micron size particles followed by a Trojan UV light.

The good news is that the North Bay Parry Sound Health Unit will test your filtered drinking water for bacteria for free and it is recommended to test regularly.

In summary, of the 50 parameters, our water samples showed no concerns for contaminants aside from bacteria which are treatable with a well maintained drinking water filtration system. Thank you to all the volunteers who made this project possible! And thanks go to the OLRA Board for funding it for our collective good.