2022 Water Quality report - Claire Vandervoort
2022 Sampling Program
Sampling continued in the same schedule as with our past Director, Ian Mackenzie. This involved DO / temp readings approx. monthly and collecting chemistry sampling in mid to late August. See the section LWCA Water Monitoring Program further down this page for more information.
Detailed graphs outlining the dissolved oxygen and temperature readings for June to August of 2022 can be
found in the final report. (Scroll down to find the .pdf) Notably, there has been an increase in water temperatures closer to the surface depths across the majority of sites compared to previous years (Appendix H).
Both phosphorous and E.coli results have been relatively stable over recent years, with a downward trend this
year. The results this year are well below this range, there is no health concern for swimming in Lake Weslemkoon. It should be noted that the South end inflow typically has the highest levels of E. coli (30 cfu/100mL) (Appendix J of the report), likely to its densely populated nature.
High Coliforms
The results for total coliforms for this sampling season were very high as you can see in the chart to the right. Total coliforms are bacteria that are found naturally in an environment through soil, surface water and animals. Total coliforms are not always bacteria that can make an individual sick, instead E. coli, a fecal coliform is used to determine sanitary conditions of a waterbody. In the case of Weslemkoon, E. coli levels were extremely low and did not indicate any health concern for cottage owners. Since E. coli is used to determine sanitary conditions, PWQO recommends against using total coliforms as a sanitary measure, but indicated 1000 cfu/100 mL is acceptable in freshwater systems.
There are a number of reasons that the results for total coliforms were so high this year, it could be due to temperature increases within the upper column of the lake (Appendix H), rainfall or storm events (there were several significant ones this year), which allow soil erosion into the lake, or even upstream events which we are unaware of. Most importantly, these high results are not an immediate health concern. These results will need to be compared to next year’s results to gather more sufficient information.
What you can do to help
- Maintain a properly functioning septic system. Have your septic system pumped every 3-5 years to remove the build-up of solids and scum, and take this opportunity to have the system checked for any required maintenance. If you are converting a cottage into a permanent dwelling be sure to check the capacity of your septic system. Exceeding the capacity of your septic could result in the remobilization of phosphorus in the soil.
- Reduce your water use at the cottage. Excessive water use is the most common cause of septic failure. Cut down on the amount of water entering your septic by installing low flow toilets and showerheads, and taking laundry home.
- Implement septic inspections. Arrange for an inspector to come inspect your current septic system to ensure it is operating properly.
- Naturalize your shorelines (e.g., vegetated buffer strips, wetlands) to help control soil erosion and the runoff of nutrients to the lake and nearby rivers and streams.
- Limit the amount of impervious surfaces, including roofs, parking areas, and patios, to reduce runoff to nearby waterbodies.
WATER QUALITY REPORT FROM DIRECTOR IAN MACKENZIE
2020 Water Quality Update
Maintaining the high quality of our Weslemkoon water is the highest priority of the LWCA. Key values being safety for swimming, visual/clarity of water, and the health of fish populations.
At left Liam and Will earn volunteer hours while they assist with water sampling.
How Lake Weslemkoon Works
Nutrients (nitrogen and phosphorus) originate from sources such as erosion, poor sewage treatment, fertilizer, detergents, or natural sources, and enter the lake in runoff. Nitrogen can also reach the lake from atmospheric deposition.
Nutrients and light allow the growth of microscopic algae, which supports the food web, including small fish that are eaten by trout. When algae die they sink to the bottom of the lake where they decay (are broken down by bacteria). The decay process uses oxygen, which leads to low levels of dissolved oxygen in the bottom of the lake in summer and fall.
If nutrient concentrations are too high, excessive growth of algae can occur, leading to the layer of low dissolved oxygen taking up more of the lower levels of the lake. Solar radiation and arm air warm the surface of the lake, while the deeper waters stay cool throughout the summer. If solar radiation levels and air temperatures are too high, more of the surface waters of the lake may become too warm for lake trout.
Note that bass are more tolerant than trout of warm water temperatures and lower dissolved oxygen levels.
This image shows the ideal zone where fish thrive. We need to maintain this zone for our lake trout!
The chart is representative of what we find when deep water sampling. The "blue zone" between about 10 meters and 36 meters deep represents a 'sweet spot' for lake trout, where temperature and oxygen meet their requirements. The crosshatched area below 36 meters contains too little oxygen to sustain fish.