Table 3.
Summary statistics of the water quality variables from the eight data sets.
| Variable | Min | 25th percentile | Median | 75th percentile | Max | Mean | Valid n |
|---|---|---|---|---|---|---|---|
| Sp cond (μS/cm) | 9.4 | 84.0 | 217 | 430 | 4,000 | 328 | 3,277 |
| Hardness (mg/L) | 0.00 | 20.0 | 42.0 | 118 | 772 | 83.4 | 1,488 |
| Alkalinity (μeq/L) | 6.28 | 983 | 1,960 | 3,160 | 7,670 | 2,120 | 995 |
| HCO3− (μeq/L) | 0.00 | 887 | 1,910 | 3,120 | 7,680 | 2,060 | 1,014 |
| SO42− (μeq/L) | 44.4 | 365 | 1,000 | 3,160 | 52,900 | 3,240 | 1,014 |
| Ca2+ (μeq/L) | 29.9 | 1,100 | 2,150 | 3,660 | 18,300 | 2,900 | 1,029 |
| Mg2+ (μeq/L) | 28.8 | 637 | 1,150 | 1,970 | 21,600 | 1,810 | 917 |
| Na+ (μeq/L) | 4.35 | 223 | 478 | 1,070 | 27,900 | 1,160 | 877 |
| K+ (μeq/L) | 6.39 | 51.2 | 76.7 | 102 | 1,240 | 87.0 | 872 |
| Cl− (μeq/L) | 0.726 | 139 | 310 | 673 | 8,610 | 587 | 1,035 |
| Total Fe (μg/L) | 1.00 | 10.0 | 36.3 | 110 | 2,690 | 143 | 369 |
| NO3− (μg/L) | 6.00 | 125 | 298 | 794 | 875,000 | 2,270 | 1,099 |
| Total N (μg/L) | 45.0 | 210 | 436 | 860 | 875,000 | 2,400 | 956 |
| Total Al (μg/L) | 1.00 | 6.00 | 16.0 | 31.0 | 1,060 | 52.8 | 360 |
| Total Mn (μg/L) | 1.10 | 10.0 | 20.0 | 82.0 | 2,090 | 82.6 | 367 |
| Total P (μg/L) | 1.0 | 6.0 | 13.0 | 24.0 | 971 | 28.1 | 532 |
| Total Se (μg/L) | 1.0 | 1.0 | 2.0 | 3.0 | 1,300 | 98.9 | 85 |
| Dissolved O2 (mg/L) | 1.2 | 7.3 | 8.6 | 9.6 | 18.6 | 8.5 | 822 |
| pH | 6.00 | 6.90 | 7.31 | 7.80 | 9.50 | 7.36 | 3,190 |
| Water temperature (°C) | 0.4 | 14.0 | 17.0 | 19.7 | 31.0 | 16.7 | 2,601 |
| RBP habitat score | 38 | 75 | 114 | 139 | 191 | 111 | 801 |
| Catchment area (km2) | 0.111 | 11.47 | 28.79 | 88.70 | 18,640 | 272 | 1,280 |
Sp cond = specific conductivity, RBP = Rapid Bioassessment Protocol [31]