Table 5.
Water sample exceedances of E. coli culture method water quality standard, theoretical site-specific Method C threshold values, and an example, theoretical multi-site Method C threshold value.
| Site ID | N | E. coli culture method exceed | Site-Specific Method C exceed | TPa | FPb | FNc | TNd | FPRe | FNRf | Multi-site Method C exceed | TP | FP | FN | TN | FPR | FNR |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ross | 87 | 28.74% | 25.29% | 18 | 4 | 7 | 58 | 6% | 28% | 17.24% | 14 | 1 | 11 | 61 | 2% | 44% |
| Singing Bridge | 91 | 29.67% | 29.67% | 18 | 9 | 9 | 55 | 14% | 33% | 3.30% | 3 | 0 | 24 | 64 | 0% | 89% |
| Orchard | 45 | 2.22% | 2.22% | 1 | 0 | 0 | 44 | 0% | 0% | 0.00% | 0 | 0 | 1 | 44 | 0% | 100% |
| Hoffmaster Campground | 68 | 5.88% | 4.41% | 3 | 0 | 1 | 64 | 0% | 25% | 4.41% | 3 | 0 | 1 | 64 | 0% | 25% |
| Meinert | 98 | 5.10% | 7.14% | 5 | 2 | 0 | 91 | 2% | 0% | 4.08% | 4 | 0 | 1 | 93 | 0% | 20% |
| New Buffalo | 73 | 8.22% | 9.59% | 3 | 4 | 3 | 63 | 6% | 50% | 1.37% | 1 | 0 | 5 | 67 | 0% | 83% |
| Warren | 71 | 14.08% | 19.72% | 8 | 6 | 2 | 55 | 10% | 20% | 11.27% | 6 | 2 | 4 | 59 | 3% | 40% |
| Brimley | 51 | 15.69% | 17.65% | 7 | 2 | 1 | 41 | 5% | 13% | 9.80% | 5 | 0 | 3 | 43 | 0% | 38% |
| Sherman | 48 | 6.25% | 6.25% | 3 | 0 | 0 | 45 | 0% | 0% | 6.25% | 3 | 0 | 0 | 45 | 0% | 0% |
| 1 | 60 | 3.33% | 8.33% | 2 | 3 | 0 | 55 | 5% | 0% | 13.33% | 2 | 6 | 0 | 52 | 10% | 0% |
| 11 | 93 | 5.38% | 9.68% | 4 | 5 | 1 | 83 | 6% | 20% | 27.96% | 5 | 21 | 0 | 67 | 24% | 0% |
| 114 | 93 | 8.60% | 10.75% | 6 | 4 | 2 | 81 | 5% | 25% | 12.90% | 7 | 5 | 1 | 80 | 6% | 13% |
| 131 | 90 | 4.44% | 4.44% | 4 | 0 | 0 | 86 | 0% | 0% | 4.44% | 4 | 0 | 0 | 86 | 0% | 0% |
| 137 | 100 | 9.00% | 18.00% | 6 | 12 | 3 | 79 | 13% | 33% | 18.00% | 6 | 12 | 3 | 79 | 13% | 33% |
| 140 | 93 | 1.08% | 4.30% | 0 | 4 | 1 | 88 | 4% | 100% | 8.60% | 0 | 8 | 1 | 84 | 9% | 100% |
| 167 | 86 | 3.49% | 8.14% | 3 | 4 | 0 | 79 | 5% | 0% | 10.47% | 3 | 6 | 0 | 77 | 7% | 0% |
| 169 | 88 | 2.27% | 3.41% | 2 | 1 | 0 | 85 | 1% | 0% | 3.41% | 2 | 1 | 0 | 85 | 1% | 0% |
| 190 | 81 | 3.70% | 3.70% | 3 | 0 | 0 | 78 | 0% | 0% | 4.94% | 3 | 1 | 0 | 77 | 1% | 0% |
| 207 | 93 | 1.08% | 3.23% | 0 | 3 | 1 | 89 | 3% | 100% | 1.08% | 0 | 1 | 1 | 91 | 1% | 100% |
| 209 | 92 | 9.78% | 20.65% | 9 | 10 | 0 | 73 | 12% | 0% | 23.91% | 9 | 13 | 0 | 70 | 16% | 0% |
| 214 | 223 | 30.94% | 34.53% | 52 | 25 | 17 | 129 | 16% | 25% | 43.50% | 58 | 39 | 11 | 115 | 25% | 16% |
| 268 | 93 | 10.75% | 18.28% | 8 | 9 | 2 | 74 | 11% | 20% | 34.41% | 10 | 22 | 0 | 61 | 27% | 0% |
| 291 | 158 | 25.95% | 27.22% | 31 | 12 | 10 | 105 | 10% | 24% | 35.44% | 37 | 19 | 4 | 98 | 16% | 10% |
| 339 | 86 | 4.65% | 6.98% | 3 | 3 | 1 | 79 | 4% | 25% | 8.14% | 3 | 4 | 1 | 78 | 5% | 25% |
| 38 | 84 | 3.57% | 3.57% | 3 | 0 | 0 | 81 | 0% | 0% | 7.14% | 3 | 3 | 0 | 78 | 4% | 0% |
| 64 | 90 | 3.33% | 8.89% | 3 | 5 | 0 | 82 | 6% | 0% | 10.00% | 3 | 6 | 0 | 81 | 7% | 0% |
| 74 | 83 | 2.41% | 8.43% | 2 | 5 | 0 | 76 | 6% | 0% | 18.07% | 2 | 13 | 0 | 68 | 16% | 0% |
| 87 | 86 | 1.16% | 6.98% | 1 | 5 | 0 | 80 | 6% | 0% | 6.98% | 1 | 5 | 0 | 80 | 6% | 0% |
| Holland | 60 | 5.00% | 10.00% | 3 | 3 | 0 | 54 | 5% | 0% | 6.67% | 2 | 2 | 1 | 55 | 4% | 33% |
| Memorial | 70 | 25.71% | 28.57% | 15 | 5 | 3 | 47 | 10% | 17% | 11.43% | 7 | 1 | 11 | 51 | 2% | 61% |
| Metro | 69 | 15.94% | 24.64% | 9 | 8 | 2 | 50 | 14% | 18% | 20.29% | 8 | 6 | 3 | 52 | 10% | 27% |
| New Baltimore | 77 | 6.49% | 9.09% | 4 | 3 | 1 | 69 | 4% | 20% | 2.60% | 2 | 0 | 3 | 72 | 0% | 60% |
| Bay City | 61 | 8.20% | 11.48% | 4 | 3 | 1 | 53 | 5% | 20% | 16.39% | 5 | 5 | 0 | 51 | 9% | 0% |
| Bird Creek | 68 | 14.71% | 19.12% | 8 | 5 | 2 | 53 | 9% | 20% | 16.18% | 8 | 3 | 2 | 55 | 5% | 20% |
| Brissette | 63 | 6.35% | 7.94% | 4 | 1 | 0 | 58 | 2% | 0% | 4.76% | 3 | 0 | 1 | 59 | 0% | 25% |
| East Tawas | 30 | 3.33% | 3.33% | 1 | 0 | 0 | 29 | 0% | 0% | 3.33% | 1 | 0 | 0 | 29 | 0% | 0% |
| Gateway | 58 | 5.17% | 5.17% | 1 | 2 | 2 | 53 | 4% | 67% | 0.00% | 0 | 0 | 3 | 55 | 0% | 100% |
| Linwood | 85 | 8.24% | 12.94% | 6 | 5 | 1 | 73 | 6% | 14% | 8.24% | 5 | 2 | 2 | 76 | 3% | 29% |
| Van Ettan | 28 | 17.86% | 10.71% | 3 | 0 | 2 | 23 | 0% | 40% | 7.14% | 2 | 0 | 3 | 23 | 0% | 60% |
| All 39 sites | 3,173 | 10.75% | 13.80% | 266 | 172 | 75 | 2,660 | 6% | 22% | 14.09% | 240 | 207 | 101 | 2,625 | 7% | 30% |
| All 101 Sites | 6,679 | 6.65% | 11.39% | 318 | 443 | 126 | 5,772 | 7% | 28% |
a
# of culture exceedances identified as exceedances by Method C
b
# of culture non-exceedances identified as exceedances by Method C
c
# of culture exceedances identified as non-exceedances by Method C
d
# of culture non-exceedances identified as non-exceedances by Method C
e
False Positive rate (FPR): FP/(FP + TN) * 100
f
False Negative rate (FNR): FN/(FN + TP) * 100