N Range Minimum Maximum Mean Std. deviation Variance
  Statistic Statistic Statistic Statistic Statistic Std. error Statistic Statistic
pH 607 9.8 0 9.8 7.7551 0.03918 0.96528 0.932
BOD 607 252 98 350 268.8537 0.98483 24.26351 588.718
COD 607 263 167 430 301.2622 1.90044 46.82188 2192.289
TS 607 1021 979 2000 1626.496 5.0468 124.33995 15460.42
TDS 607 1935.92 340 2275.92 1606.269 9.32183 229.66549 52746.24
CHLORIDE 607 652 38 690 349.8151 3.06861 75.60242 5715.725
TSS 607 250 30 280 59.019 0.83601 20.59704 424.238
NITRATE 607 56 24 80 45.8425 0.44182 10.8853 118.49
Valid N (listwise) 607              
Table 1: Descriptive Statistics.