Implementation of DVGW Guideline W 1001 at a RheinEnergie Waterworks (Cologne)

Abstract

This article describes the implementation of the DVGW Guideline W 1001 “Safe and secure drinking water supply – risk management under normal operating conditions” at a waterworks operated by the RheinEnergie AG, Cologne. This guideline integrates the WHO Water Safety Plan-approach (WSP) into the German DVGW Schedule Technical Standards. The supply chain components catchment area, water abstraction and water treatment were examined. After describing the water supply system the possible hazards were identified. The risks were assessed based upon severity (extent of damage) and likelihood of a hazardous event to occur. For the GIS-supported evaluation of the catchment area the initial risk was modified depending on the protectiveness of all strata between surface and groundwater level as well as on the risk-mitigating effect of the passage through the saturated zone to the water abstraction. For the assessment of the processes of water abstraction and water treatment all measures of risk control already taken were assumed to mitigate the initial risk. Apart from very few exceptions the resulting risks were low or very low. The RheinEnergie (RE) - Technologiezentrum Wasser (TZW) project shows the suitability of the approach to implement W 1001 as well as possible benefits of risk management.