Multi-objective optimization framework for prioritizing lead service line replacement in water distribution systems.

Area of Science:

• Environmental Engineering
• Public Health
• Water Resource Management

Background:

• Lead service line (LSL) replacement is crucial for reducing lead in drinking water.
• U.S. Lead and Copper Rule mandates LSL replacement within 10 years, prioritizing vulnerable populations.
• Water utilities face challenges in balancing diverse replacement priorities and regulatory compliance.

Purpose of the Study:

• To propose a multi-objective optimization decision framework for developing compliant LSL replacement plans.
• To incorporate utility-specific objectives alongside regulatory requirements.
• To enable evaluation of trade-offs among competing priorities like lead levels, socioeconomic vulnerability, and geography.

Main Methods:

• Developed a multi-objective optimization decision framework.
• Generated a set of strategies for evaluating trade-offs.
• Applied the framework using publicly available data from Flint, MI.

Main Results:

• The framework produces a set of strategies for LSL replacement.
• It allows for comparison of trade-offs between different replacement priorities.
• Demonstrated application using data from Flint, MI.

Conclusions:

• The proposed framework is general, flexible, and adaptable for utility-specific conditions.
• It supports the development of compliant and tailored LSL replacement strategies.
• Offers a foundation for data-driven tools to aid water utilities facing regulatory pressures.