Impact of Corrosion Inhibitors on Lead Release and Biofilm Development in Simulated Partial Lead Service Lines

Partial lead service line replacements intended to decrease lead in drinking water but found to potentially increase lead release by galvanic corrosion. This study investigated the effects of corrosion inhibitors on lead release in simulate partial lead service lines. The performance of orthophosphate, zinc orthophosphate, and sodium silicate were compared under different water quality conditions (CSMR, conductivity, chlorination). Both orthophosphate and zinc orthophosphate immediately decreased lead release in all conditions, while sodium silicate seemed to slowly decrease lead release over time. Biofilm is a potential reservoir of lead in distribution systems, and the detachment of biofilm containing lead particles can cause health risk in drinking water. The effect of corrosion control on biofilm development was also examined under stagnant and flow-through conditions. Chlorination significantly decreased biofilm and was effective both under stagnant and flow-through conditions. The densities of ATP and lead in biofilm were typically consistent.M.A.S