This study investigates the optimization of free chlorine-based disinfectant dosage for controlling the dissolution of lead (Pb) while limiting disinfection by-products (DBPs) formation in water distribution networks. A dynamic optimization framework is developed in this study to account for the impact of spatial and temporal variations of network hydraulics and water chemistry on dissolved lead concentrations. Accordingly, a dynamic schedule of disinfectant dosage is proposed to minimize water lead levels and two-point chlorine residual violations in the network. The results suggest that optimization of water chemistry parameters such as pH and orthophosphate dosage provide an additional degree of freedom to be explored in the problem of optimizing disinfectant dosage for compliance with conflicting mandates regulating lead levels and DBPs concentration in drinking water. © 2020, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.