Table 3.
Correlation of turbidity, conductivity, and total dissolved solids (TDS) with Cryptosporidium and Giardia detection in source water samplesa
| Source water sample | No. of samples | Turbidity (NTUb) (mean ± SD) | P valuec | Conductivity (μS/cm) (mean ± SD) | P value | TDS (mg/liter) (Mean ± SD) | P value |
|---|---|---|---|---|---|---|---|
| Cryptosporidium | |||||||
| Positive | 30 | 38.20 ± 25.63 | 0.71 | 965.23 ± 218.42 | 0.0001 | 509.33 ± 154.21 | 0.001 |
| Negative | 20 | 35.37 ± 26.31 | 759.60 ± 122.69 | 380.15 ± 62.02 | |||
| Giardia | |||||||
| Positive | 14 | 41.79 ± 34.52 | 0.42 | 879.71 ± 218.85 | 0.95 | 498.36 ± 204.02 | 0.20 |
| Negative | 36 | 35.24 ± 21.63 | 884.25 ± 210.72 | 441.83 ± 105.52 |
a
Correlation of turbidity, conductivity, and total dissolved solids (TDS) with Cryptosporidium and Giardia detection in source water samples that were positive by microscopy or PCR analysis of concentrates from filtration or CCF.
b
NTU, nephelometric turbidity unit.
c
The P values result from a comparison of the values (turbidity, conductivity, and TDS) for source water samples that are positive and negative for Cryptosporidium or Giardia.