Table 2.
Summary of the microorganism concentrations and environmental parameters in water samples collected in this study.
| Variable | NumObs | % NDs | Meana | Std. deviation | Min | Kaplan-Meier Method |
||
|---|---|---|---|---|---|---|---|---|
| 90%ile | 95%ile | |||||||
| Fecal indicator bacteria |
E. coli (MPN/100 mL) | 231 | 7.3 | 111.7 | 31.7 | 0.5 | 9650 | 24707 |
|
Enterococcus (MPN/100 mL) |
234 |
8.6 |
40.7 |
22.4 |
0.5 |
3177 |
7760 |
|
| Coliphages |
Somatic coliphage (PFU/100 mL) | 227 | 23.2 | 14.8 | 16.2 | 0.5 | 500 | 1067 |
| F+ coliphage (PFU/100 mL) | 226 | 35.5 | 5.6 | 10.3 | 0.5 | 145.5 | 273.2 | |
| Total coliphage (PFU/100 mL) |
227 |
21.8 |
16.2 |
17.3 |
0.5 |
535.3 |
1781 |
|
| FRNA Genotypes |
FRNA G1 (GC/L) | 227 | 82.3 | 90.8 | 2.1 | 70 | 173.3 | 387.3 |
| FRNA G2 (GC/L) | 227 | 47.7 | 457.0 | 11.7 | 70 | 17411 | 34548 | |
| FRNA G3 (GC/L) | 227 | 95.0 | 81.6 | 2.2 | 70 | 70 | 72.98 | |
| FRNA G4 (GC/L) |
227 |
98.2 |
73.2 |
1.5 |
70 |
70 |
70 |
|
| Human specific markers |
B. theta (GC/100 mL) | 226 | 65.9 | 66.3 | 5.0 | 30 | 754.9 | 2346 |
| M. smithii (GC/100 mL) | 227 | 96.4 | 32.3 | 1.6 | 30 | 30 | 30 | |
| HPyVs (GC/100 mL) |
227 |
90.5 |
16.0 |
2.7 |
12 |
12 |
214.2 |
|
| Bacterial pathogens |
Salmonella (GC/100 mL) | 226 | 81.8 | 16.5 | 2.2 | 12 | 56.8 | 86.05 |
| P.aeruginosa (GC/100 mL) | 226 | 33.6 | 126.2 | 10.4 | 12 | 4205 | 8462 | |
| Pseudalert (MPN/100 mL) |
231 |
8.2 |
96.8 |
26.0 |
0.5 |
6268 |
18378 |
|
| Enteric viruses |
Adenovirus (GC/L) | 227 | 87.3 | 29.0 | 3.1 | 20 | 82.45 | 470.8 |
| Norovirus GI (GC/L) | 227 | 60.0 | 173.5 | 3.5 | 80 | 905.6 | 2628 | |
| Norovirus GII (GC/L) | 227 | 48.2 | 921.7 | 13.1 | 80 | 25213 | 36264 | |
| Rotavirus (GC/L) | 227 | 98.2 | 83.4 | 1.4 | 80 | 80 | 80 | |
| Astrovirus (GC/L) | 227 | 35.5 | 384.6 | 4.3 | 80 | 3105 | 4367 | |
| Enterovirus (GC/L) | 227 | 84.6 | 98.8 | 2.0 | 80 | 148.3 | 296.6 | |
| Hepatitis A virus (GC/L) | 227 | 60.9 | 33.4 | 2.2 | 20 | 96.7 | 141.2 | |
| Hepatitis E virus (GC/L) | 227 | 86.4 | 104.0 | 2.3 | 80 | 185.7 | 644.8 | |
| Aichi virus (GC/L) | 227 | 75.9 | 142.3 | 3.8 | 80 | 1141 | 4123 | |
| Sapovirus (GC/L) | 227 | 95.9 | 88.5 | 2.0 | 80 | 80 | 80 | |
| Influenza A virus (GC/L) |
227 |
34.6 |
352.4 |
3.8 |
80 |
1910 |
2512 |
|
| Plant virus |
PMMoV (GC/L) |
227 |
29.6 |
2027.1 |
19.5 |
80 |
125837 |
336514 |
| Environmental parameters | Temperature (°C) | 177 | – | 29.17 | 1.36 | 23.87 | ||
| pH | 230 | – | 7.56 | 0.97 | 3.85 | |||
| EC (μS/cm) | 221 | – | 295.07 | 155.12 | 3 | |||
| Salinity (psu) | 223 | – | 0.14 | 0.08 | 0 | |||
| DO (ppm) | 209 | – | 6.04 | 2.00 | 1.04 | |||
| Turbidity (FNU) | 220 | – | 16.24 | 27.42 | 0 | |||
| Daily rainfall (mm) | 224 | – | 7.53 | 13.58 | 0 | |||
| Antecedent dry period (d) | 224 | – | 1.66 | 2.84 | 0 | |||
Abbreviation: NumObs – Total number of observed samples; % NDs – Percentage of nondetects; Min – Minimum value; MPN – Most probable number; GC – Gene copy; PFU – Plaque forming unit; EC – Electrical conductivity; DO – Dissolved oxygen.
a
Geometric mean was calculated for microorganisms while arithmetic mean was calculated for environmental parameters.