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. 2013 Oct;79(19):5799–5813. doi: 10.1128/AEM.00870-13

Table 1.

Enumeration of fecal indicator bacteria at study sites between 2007 and 2010

Site na %Hub 90th percentile (CFU/100 ml)
 Maximum (CFU/100 ml)
Total coliforms E. coli Enterococci Clostridia Total coliforms E. coli Enterococci Clostridia
WTP (influent)
    WTP1 103 19 119 5 6 15 320 112c 143 89
    WTP2 91 3 35 0 2 4 10,000 40 32 200
    WTP3 104 2 180 7 8 10 4,170 20 41 130
WTP (bottom)
    WTP1 45 7 332 9 13 4 850 26 40 241
    WTP2 67 6 525 7 17 4 1,900 27 65 10
    WTP3 68 6 556 18 26 4 5,000 58 210 15
WTP (surface)
    WTP1 49 8 334 13 34 6 679 70 118 23
    WTP2 71 6 812 19 17 9 1,620 222 400 71
    WTP3 72 10 480 14 11 4 1,690 86 52 11
Credit River
    River 90 31 100,000 1,883 1,122 218 430,000 8,400 4,160 540
    Surface 67 5 2,832 177 190 30 78,000 1,080 624 91
    Bottom 64 8 2,750 83 53 13 24,000 179 198 42
Humber River
    River 85 47 210,000 2,942 1,754 314 1,190,000 7,270 4,200 820
    Surface 43 69 3,840 378 98 256 22,800 648 200 376
    Bottom 41 63 7,200 154 66 173 12,400 1,600 516 248
STP
    Effluent 102 74 39,020 251 246 1,183 640,000 2,960 1,220 16,000
    Surface 62 19 1,336 68 15 60 8,900 288 300 132
    Bottom 58 16 1,804 29 80 36 8,400 74 210 110
10 km
    Surface 29 7 390 2 11 1 690 6 29 1
    Bottom 24 0 4,692 4 79 18 7,360 24 160 26
a

n, number of water samples analyzed for E. coli (slightly fewer samples were analyzed for the other indicator bacteria).

b

%Hu, percent positive for the HF183 human Bacteroidales DNA marker.

c

A concentration of 112 E. coli CFU/100 ml was measured on 14 March 2011. Otherwise, the maximum E. coli concentration measured during the 2007 to 2010 study period was 66 E. coli CFU/100 ml.