Table 1 Statistical summary of the physicochemical parameters of borewell water samples collected from the study area
From: Investigating aquifer contamination and groundwater quality in eastern Terai region of Nepal
Parameters | Range | Mean | Standard deviation | Median | WHO guidelines | NDWQS guidelines | Samples not within limit | |
|---|---|---|---|---|---|---|---|---|
Number | % | |||||||
Borewell (N = 135) | ||||||||
 pH | 5.00–8.36 | 6.946 | 0.574 | 7 | 6.5–8.5 | 6.5–8.5 | 25 | 18.52 |
 Temp (°C) | 17.8–34.8 | 28.064 | 4.229 | 28.7 | – | – | – | – |
 EC (µS/cm) | 14.8–1192.0 | 433.797 | 233.926 | 433 | – | 1500 | 0 | 0 |
 Turbidity (NTU) | 0.00–93.00 | 13.508 | 20.929 | 3.44 | 5 | 5 | 63 | 46.67 |
 Color (Hazen) | 0.01–4.10 | 0.235 | 0.513 | 0.11 | 15 | 5 | 0 | 0 |
 TDS (mg/L) | 7.50–596.00 | 223.690 | 115.611 | 219.5 | 1000 | 1000 | 0 | 0 |
 F− (mg/L) | 0.02–1.04 | 0.232 | 0.193 | 0.18 | 1.5 | 0.5–1.5 | 0 (119) | 0 (88.15) |
 NH3 (mg/L) | 0.05–2.53 | 0.479 | 0.407 | 0.38 | 1.5 | 1.5 | 5 | 3.70 |
 NO3− (mg/L) | 0.05–2.83 | 0.187 | 0.408 | 0.05 | 50 | 50 | 0 | 0 |
 Cl− (mg/L) | 0.50–145.45 | 13.424 | 24.223 | 3 | 250 | 250 | 0 | 0 |
 TH (mg/L) | 1.11–510.00 | 190.875 | 87.955 | 205.35 | – | 500 | 1 | 0.74 |
 CH (mg/L) | 1.00–412.62 | 119.419 | 66.504 | 117.89 | – | – | – | – |
 TA (mg/L) | 2.36–512.40 | 196.491 | 90.848 | 209.72 | 500 | – | 1 | 0.74 |
 Fe (mg/L) | 0.05–23.10 | 2.030 | 3.945 | 0.59 | 0.3 | 0.3 | 87 | 64.44 |
 Mn (mg/L) | 0.05–3.10 | 0.356 | 0.463 | 0.22 | – | 0.2 | 70 | 51.85 |
 As (mg/L) | 0.005–0.050 | 0.005 | 0.004 | 0.005 | 0.01 | 0.05 | 1 (0) | 0.74 (0) |
 Ca2+ (mg/L) | 0.00–165.05 | 45.598 | 26.418 | 42.708 | – | 200 | 0 | 0 |
 Mg2+ (mg/L) | 0.00–57.07 | 18.118 | 12.255 | 16.53 | – | – | – | – |
Tubewell (N = 40) |  | |||||||
 pH | 5.27–8.59 | 6.978 | 0.669 | 6.965 | 6.5–8.5 | 6.5–8.5 | 9 | 22.5 |
 Temp (°C) | 17.0–35.9 | 26.563 | 5.603 | 28.5 | – | – | – | – |
 EC (µS/cm) | 32.2–1898.0 | 484.998 | 350.855 | 461.5 | – | 1500 | (1) | (2.5) |
 Turbidity (NTU) | 0.00–149.00 | 10.100 | 24.444 | 1.915 | 5 | 5 | 15 | 37.5 |
 Color (Hazen) | 0.01–1.03 | 0.164 | 0.202 | 0.125 | 15 | 5 | 0 | 0 |
 TDS (mg/L) | 42.00–949.0 | 255.820 | 164.383 | 235.0 | 1000 | 1000 | 0 | 0 |
 F− (mg/L) | 0.04–1.10 | 0.245 | 0.283 | 0.14 | 1.5 | 0.5–1.5 | 0 (33) | 0 (82.5) |
 NH3 (mg/L) | 0.05–3.36 | 0.472 | 0.545 | 0.38 | 1.5 | 1.5 | 1 | 2.5 |
 NO3 (mg/L) | 0.05–3.38 | 0.536 | 0.879 | 0.11 | 50 | 50 | 0 | 0 |
 Cl− (mg/L) | 0.50–161.80 | 29.118 | 40.772 | 8.0 | 250 | 250 | 0 | 0 |
 TH (mg/L) | 35.00–349.0 | 194.241 | 88.628 | 204.5 | – | 500 | 0 | 0 |
 CH (mg/L) | 13.35–270.26 | 116.957 | 65.504 | 107.045 | – | – | – | – |
 TA (mg/L) | 36.4–368.88 | 201.681 | 87.762 | 215.67 | 500 | – | 0 | 0 |
 Fe (mg/L) | 0.05–10.81 | 1.184 | 2.271 | 0.315 | 0.3 | 0.3 | 20 | 50 |
 Mn (mg/L) | 0.05–2.75 | 0.402 | 0.564 | 0.15 | – | 0.2 | (18) | (45) |
 As (mg/L) | 0.005–0.005 | 0.005 | 0.000 | 0.005 | 0.01 | 0.05 | 0 | 0 |
 Ca2+ (mg/L) | 5.34–108.10 | 43.580 | 25.797 | 40.079 | – | 200 | 0 | 0 |
 Mg2+ (mg/L) | 1.46–61.49 | 19.889 | 13.907 | 15.556 | – | – | – | – |