This project was started in 1994 by the Directorate: Geohydrology (Dr. Milo Simonic) to ascertain the influence of rainfall on the groundwater quality and to determine the time series and spatial trends in the groundwater quality on the national scale.

A total of 391 monitoring Geosites are to be sampled twice a year before and after the rainfall season (October and April). The sampling itself is undertaken in most of the provinces of South Africa by qualified personnel of the Department. The spatial distribution of the monitoring Geosites is also available.

During the monitoring Geosite (borehole/spring) selection process as much information as possible was gathered, which was later stored in the National Groundwater Archive (NGA). These Geosites are also registered on the Water Management System (WMS), referred to as ZQM-Stations.

Routine sampling usually covers macro-elements.  The samples are analysed by the Directorate: Resource Quality Information Services (RQIS) at Department’s Roodeplaat Dam laboratory. The chemical analyses are captured on the WMS.

Due to the well-established National/Regional infrastructure of the monitoring programme, several other hydro-chemical constituents are covered from time to time, i.e.

• Trace Elements (metallic determinants in groundwater),

• Environmental Isotopes (Stable and Radiogenic) and

• Radioactivity (gross alpha/beta and chemical uranium content).

External laboratories are also contracted to perform special analyses, i.e.

• Council For Scientific and Industrial Research (CSIR):
  • Quaternary Laboratory (stable isotope in rainwater and radio-carbon in groundwater)
  • Atmospheric Laboratory (Low level Chemistry in rainwater)
    
    
• Nuclear Energy Corporation of South Africa (Necsa):
  • Radio Analysis Nuclear Services (radioactivity in groundwater)
    
    
• iThemba LABS Johannesburg (all radiogenic isotopes, stable isotopes and radio-carbon in groundwater).

Results will be used as a supporting tool to determine the changes in time / space in ambient water quality in South Africa.

In addition, this data is required to update the Groundwater Resource Assessment (GRA II) data sets. A geostatistical assessment of the groundwater quality data was performed in 2002, from where some changes in the monitoring programme was recommended.

A project under Directorate: National Hydrological Services namely “Review, Evaluation and Optimisation of the Water Resources Monitoring Network Project” (envisaged completion date end February 2017) will be looking for optimizing National Groundwater Quality Monitoring Network.

One special off-shoot from this monitor programme, which has now been completed in two time slots (1999 - 2000 and 2007 - 2008), is the hydro-chemistry sampling/analysis of the National Dolomitic Eyes of South Africa. This sampling exercise is performed under contract with the CSIR-Pretoria and covers above-mentioned analytical package, as well as CFC’s (chloro-fluro-carbon) from selected eyes. Chloro-Fluro-Carbons have been suggested as a replacement for the now “outdated” 3Hydrogen (Tritium) tracer for groundwater flow assessments.

Data from the NGwQMP is currently available on the Department’s WMS system and subsequently the environmental isotope data will be uploaded to the WMS as well.

It is, however, recommended that when WMS data is to be used for groundwater investigation, the Directorate: National Hydrological Services, Groundwater Resource Assessment & Monitoring (GRAM) office is notified accordingly.  This is due to the fact that some of the samples have been sampled under different conditions, which may have caused a variation in the hydro-chemical character of the groundwater samples.

For any further information please contact Mr. Ramusiya Fhedzisani.