5.4 Water Quality

The dominant water types in the coastal aquifers are NaCl and CaHCO3 (Figure 22). There is a marked difference in salinity between the upper and lower aquifer units. In the lower aquifer unit, the electrical conductivity is commonly less than 120 mS/m, whilst in the upper aquifer unit it is generally > 250 mS/m and often exceeds 500 mS/m near the Berg River and the Saldanha Bay.

Tri-linear piper plot for West Coast water samples collected in 2017/2018.

Figure 22  Tri-linear piper plot for West Coast water samples collected in 2017/2018. LRAS is the Langebaan Regional Aquifer System and EAS is the Elandsfontyn Regional Aquifer System (Jovanovic et al., 2018).

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Managed Aquifer Recharge: Southern Africa Copyright © 2021 by Eberhard Braune and Sumaya Israel. All Rights Reserved.