Table 3. Results of chemical analysis for raw water and finished packaged sachet water (PSW) samples.
Mean (range), % compliant with WHO guidelines, (n).
| Parameter | National Standard (SLSB, 2010) | WHO Guideline [26] | Raw water | Finished PSW (PWMF) | Finished PSW (POS) | HH Water for Consumption |
|---|---|---|---|---|---|---|
| n = 47 | n = 47 | n = 46 | n = 60 | |||
| pH | 6.5–8.5 | 6.5–8.5 | 6.58 (5.14–7.64)66% (31) | 6.57 (5.01–7.81) 64% (30) | 6.31 (4.84–7.75) 48% (22) | 5.64 (3.95–6.90) 3% (2) |
| Total hardness | 500 mg/L | 500 mg/L | 5 (2–10) 100% (46) | 5 (2–10) 100% (46) | 6 (2–14) 100% (46) | 11 (2–40) 100% (60) |
| TDS | 1000 mg/L | 1000 mg/L | 6 (2–9) 100% (47) | 6 (2–9) 100% (47) | 7 (0–13) 100% (46) | 24 (5–132) 100% (60) |
| Free chlorine | N/A) | 0.5 mg/L | 0.1 (0.1–0.2) 100% (47) | 0.1 (0.1–0.2) 100% (47) | 0.1 (0.1) 100% (46) | 0.1 (0–0.1) 100% (60) |
| Turbidity | 5 NTU | 5 NTU | 1.12 (0.16–7.91) 98% (47) | 0.50 (0.11–3.12) 100% (46) | 0.54 (0.17–0.96) 100% (46) | 1.14 (0.17–3.64) 100% (60) |
| Fluoride | 1.5 mg/L | 1.5 mg/L | ND a 100% (47) | ND 100% (47) | ND 100% (46) | 0.025 (0–0.3) 100% (60) |
| Iron | 300 μg/L | 300 μg/L | 12.1 (8.2–17.3) 100% (47) | 12.0 (7.2–19.7) 100% (47) | 10.7 (1.4–16.4) 100% (46) | 20.0 (13.5–32.8) 100% (60) |
| Manganese | 400 μg/L | 400 μg/L | 463 (240–590) 6% (5) | 450 (5–651) 10% (3) | 418 (43–590) 26% (11) | 451 (327–600) 27% (16) |
| Arsenic | 10 μg/L | 10 μg/L | ND 100% (47) | ND 100% (47) | ND 100% (46) | ND 100% (60) |
| Nitrate | 50 mg/L | 50 mg/L | 5 (3–7) 100% (47) | 4 (2–6) 100% (47) | 4 (2–6) 100% (46) | 3 (2–5) 100% (60) |
a ND—not detect.