Delayed pipe replacement halves environmental impacts but quadruples water loss

Abstract

Scheduling pipe replacement is critical for water distribution systems (WDSs) when managing finances and water loss. WDS replacements are often delayed due to high immediate costs without considering long-term environmental consequences. This study is the first to examine a real-world WDS using a novel workflow transferrable to other WDSs that integrates GIS, hydraulic modeling, breakage prediction, and life cycle analysis to evaluate environmental impacts and water loss of five replacement schedules (25-, 50-, 75-, 100-, 150-year intervals). Environmental impacts were reduced by half when replacement interval changed from 25 year to 150 years, yet volume of water leaked from the system quadrupled. Benefits plateaued beyond 50–75-year replacement while water loss steadily increased. Lowering water loss through break management enabled one-sixth pipe replacement without exceeding original leakage at 25-year replacement. Results were robust to uncertainty parameters and assert the importance of equilibrating environmental impacts and water loss when designing pipe replacement frequency.