Predicting Water Quality Impact After District Metered Area Implementation in a Full‐Scale Drinking Water Distribution System

Abstract

Pressure management using district metered areas (DMAs) can reduce leakage and break frequencies and extend the service life of pipes in drinking water networks. Valves must be closed, creating DMAs, resulting in hydraulic changes and increasing the number of dead ends. A field study of five pilot DMAs was conducted using an enhanced sampling program. Water quality was measured at different locations inside and outside DMA boundaries before and after implementation. Overall water quality did not change following DMA implementation. However, water quality (chlorine residuals, turbidity, and metals) was degraded at locations with elevated water residence times such as created dead ends, sites outside DMA boundaries, and extremities. An approach based on the combination of hydraulic modeling and water quality was developed to predict trihalomethane concentrations in the DMA using measurements only from an inlet site. Utilities can use a combination of hydraulic modeling and targeted monitoring to predict water quality changes after DMA implementation.