In accordance with Province of Ontario standards, samples are taken at five different spots at a beach, and the geometric mean of those five samples is computed. The Province considers that a geometric mean of 100 or less for the day's five samples is acceptable.
Note: The geometic mean (the nth root of the product of n values) minimizes the effect of large values that are present in the data. One of the international Blue Flag beach criteria is that no more than 20% of the samples may be above 100.
Note: Camp Kintail and Bogies Beach are not public beaches. HCHU has historically sampled Bogies Beach so that it can compare its data to the samples taken by the Provincial Park.
Compared to recent years, the summer of 2007 experienced much less rainfall. Therefore, the run-off from farmland was less, and thus the lower statistics.
Amberley Beach |
Ashfield Park |
Camp Kintail |
Port Albert |
Bogies Beach |
Sunset Beach |
|
---|---|---|---|---|---|---|
days/samples | 24/120 | 24/120 | 10/50 | 23/115 | 14/70 | 14/70 |
minimum, all samples | 10 | 10 | 10 | 10 | 10 | 10 |
geo.mean of daily geo.means | 19 | 37 | 47 | 53 | 17 | 15 |
geo.mean of daily maximums | 25 | 73 | 66 | 88 | 25 | 20 |
average, all samples | 80 | 135 | 135 | 102 | 34 | 39 |
maximum, all samples | 2000 | 1100 | 590 | 470 | 270 | 440 |
Blue Flag % of samples >100 | 10% | 22% | 32% | 33% | 11% | 7% |