Influence of river and groundwater mixing on corrosion potential and drinking water quality stability in distribution networks

Corrosion and calcium carbonate (CaCO₃) scaling can occur during the transport of drinking water through the pipelines of a water distribution system, potentially leading to degradation of water quality and operational issues within the network. These processes are influenced by several factors, including pH value, temperature, alkalinity, hardness, total dissolved solids (TDS), and concentrations of chloride (Cl⁻), sulfate (SO₄²⁻), carbonate (CO₃²⁻), and bicarbonate (HCO₃⁻) ions. To predict the likelihood of corrosion and scaling, various empirical indices are used, such as the Langelier Saturation Index (LSI), Ryznar Stability Index (RSI), Puckorius Scaling Index (PSI), Larson-Skold Index (LR), and the Aggressiveness Index (AI), all of which rely on the physicochemical characteristics of water. This paper examines changes in corrosion and aggressiveness indices as a function of mixing ratios between two different sources of drinking water within a distribution network, with a focus on monitoring resulting changes in water quality.