Sampling

• Samplings have been taken at 13 sites representing all parts of the lake.

• Two samplings were taken at each site, one close to the shore, at a depth of about 50 cm. and a second at about 40 m. from the shore, at a depth of about 3 to 4 m.

• Two samplings were also taken from the Petite-Nation River, at a depth of 50 cm.

• The pH measurement is from a sampling taken in the middle of the lake, at a depth of 50 cm.

• Three samplings were taken from the following sites, at a depth of 50 cm., to measure the phosphorus content:

  - south of the public landing, close to the shore
  - in front of Poliquin's campground, about 60 m from the shore
  - downstream from the narrowing of the Petite-Nation River

• The number closest to the shore indicates the number of coliforms per 100 ml. in the sampling taken close to the shore. The number further to the shore represents the results from the sampling taken further away, in deeper water, where some take their drinking water.

• Two samplings were taken near the shore at the south beach, while two were taken near the surface where the depth was at shoulder height.

Results

• The water is always of excellent quality for swimming at lake Gagnon.

• There is no faecal coliform in more than half the samplings, i.e. 17 out of 28.

• South Beach: results are not dependant on depth but are somewhat  worse near the beach entrance, where many people were swimming on the previous day, the day of the mechoui.
  



• Beside two exceptions, there is no faecal coliform in any sampling taken in the deeper water, where people sometime take their drinking water.
  

• The two exceptions are near the mouths of the Ernest Creek and Petite-Nation River.  These results are worse at large than close to the shore, maybe due to the swirl at these locations.

• The worse reading, 9 faecal coliforms, was obtained close to the shore, while the reading is perfect in depth waters, within a few meters from the shore, at the same location.

• The water is rather acid in the lake.  A pH reading of 7 indicates a neutral water.  The lower the reading, the higher is the acidity.  Normal readings would be between 6.3 and 8.3 units of pH (5% and 95% ). Our pH reading stands at 6.4. In July 2000 the pH reading was 7.5 at the public landing and 7.1 at the south beach.

• There is no sign of phosphorus in any of the three sampligs. All readings are lower than 0,03 mg/l P, which is the lowest reading that can be identified by the instruments.