A Waste Water Treatment Works (WWTW) is being constructed at Pearly Beach. A geohydrological assessment was conducted to assess the potential discharge of treated effluent above and below the subsurface calcrete layers. A hydrocensus has been completed of the area to confirm there is no use of groundwater down-gradient of the WWTW and there is no likely impact on ecosystem functioning. Based on existing boreholes, infiltration above the calcrete layer in the vadose zone was found to be more efficient.

The Department of Water and Sanitation reviewed and re-designed (optimised) the national water resources monitoring networks. During the re-design, monitoring objectives were formulated and prioritised. The highest priority, i.e. to make available data and information related to quantity and quality of present and future water resources is through planned infrastructure development and other interventions.

Monitored natural attenuation (MNA) is becoming a commonly employed sustainable site remediation strategy for sites with petroleum hydrocarbon groundwater impacts. Natural attenuation is essentially the reduction in contaminant concentration, mass or mobility due to naturally occurring processes within the environment. Aromatic compounds such as benzene, toluene, ethylbenzene, and xylenes (BTEX) are common compounds of concern in the context of petroleum hydrocarbon related investigations because of their relative mobility and toxicity characteristics.

The Department of Water Affairs and Sanitation is the custodian of the Water Resources in South Africa. The Western Cape Provincial Office, Geotechnical Services (Geohydrology) Sub Directorate, is responsible for management of groundwater resources in two Water Management Areas (WMA), Berg Olifants and Breede- Gouritz. Thirty-eight monitoring routes comprising 700 sites in total are monitored across the Western Cape Province. The purpose of this paper is to show the use of GIS as a management tool for groundwater monitoring in the Western Cape.

Monitored Natural Attenuation (MNA) refers to the monitoring of naturally occurring physical, chemical and biological processes. Three lines of evidence are commonly used to evaluate if MNA is occurring, and this paper focusses on the second line of evidence: The geochemical indicators of naturally occurring degradation processes and the site-specific estimation of attenuation rates.