La Conception, Quebec, 2002

APEL Trois Montagnes 5 Mk04

Year: 2002

11″ x 8.5″

Media: Canon® Pro Platinum High Gloss Photo Paper

Printers: Canon® PIXMA


Art: Photo

Artist: Luc Paquin

Lac des Trois Montagnes, La Conception, Quebec

APEL des Trois Montagnes

Water Quality

The long term trend regarding the lake water transparency measurements remained stable between 2004 and 2009. To top things off, in 2010, the quality of bathing water index was also excellent!

The mean of this summer measurements of our lake water transparency, taken between 10 am and 3 pm with the Secchi disk, was 7.8 meters. The MRC has also tested it, obtaining similar results. These results categorize our lake at an aging stage between ultra-oligotrophic and oligotrophic.

As for the bathing water quality, 53 water samples were taken in 2008 at various locations on the lake and the results are excellent by MDDEP established standards (less than 20 CFU per 100 ml): they were at 2 CFU or less per 100 ml in 35 cases, and were all above 20 CFU per 100 ml in the remaining samples. We have also obtained excellent results for levels of phosphorus in the water.

We hope to integrate shortly the water measurements historical data in our website, so everyone can clearly see the trends over the years.


The time of sunset is defined in astronomy as the moment when the trailing edge of the Sun’s disk disappears below the horizon. The ray path of light from the setting Sun is highly distorted near the horizon because of atmospheric refraction, making the sunset appear to occur when the Sun’s disk is already about one diameter below the horizon. Sunset is distinct from dusk, which is the time at which the sky becomes completely dark, which occurs when the Sun is approximately eighteen degrees below the horizon. The period between sunset and dusk is called twilight.


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