Table 2.
Water quality: comparison of field testing results to the eThekwini Water and Sanitation (EWS) Unit's requirements for the use of recycled water. MPN: most probable number.
| Parameter | Unit | EWS requirements | Field-testing results |
|---|---|---|---|
| Chemical oxygen demand (COD) | mg/L | 50 (avg) 150 (max) |
9.1 (avg, n = 17) 36 (max) |
| pH | – | 6–9 | 7.1–8.3 (n = 15) |
| Residual chlorine | mg/L | >0.5 (avg) | 1.9 (avg, n = 24) |
| E. coli | MPN/100 mL | 1 (avg) 10 (max) |
<1 (avg, n = 18) <1 (max) |
| Turbidity | NTU | 5 (avg) 10 (max) |
0.44 (avg, n = 14) 0.83 (max) |
| Total suspended solids (TSS) | mg/L | 10 (avg) 30 (max) |
0.4 (avg, n = 1) 0.4 (max) |