AWWA WQTC57169

Both aluminum solids and chlorine are often present in potable water systems, but their effect on copper corrosion and pitting is not well understood. Circumstantial evidence from one system with copper pitting problems suggested that high chlorine residuals and aluminum solids might be contributing factors. To test this hypothesis, a series of experiments were conducted to examine their effect on copper corrosion under stagnant conditions. Although chlorine alone impacted copper corrosion, a synergistic reaction was discovered between chlorine and aluminum solids when exposed to copper. Evidence for this effect was seen in increased chlorine decay rates, increased non-uniform copper corrosion, and rising corrosion potentials during exposure. Includes 29 references, tables, figures.