Huron County Health Unit, Beach Testing 2006

E.coli bacteria per 100 mL of water

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.

Summary statistics

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.

	Amberley Beach	Ashfield Park	Camp Kintail	Port Albert	Bogies Beach	Sunset Beach
days/samples	19/95	25/125	19/95	21/105	14/70	16/80
minimum, all samples	10	10	10	10	10	10
geo.mean of daily geo.means	77	40	89	52	25	27
geo.mean of daily maximums	115	73	126	83	44	41
average, all samples	412	96	271	107	55	56
maximum, all samples	6400	830	1800	500	470	330
Blue Flag % of samples >100	44%	31%	46%	42%	10%	4%

Compiled 2007-06-16 by Roger Watt, ACLA Steering Committee. We gratefully acknowledge the cooperation of HCHU in providing the daily data so that we could compute these summary statistics. Last updated 2007-08-13.