Using mastery learning as a conceptual framework, two courses were developed teaching sustainability and life-cycle principles. Course descriptions, student learning outcomes, and details of modules are provided in this case report. The results of teaching 5605: Environmental Systems Modeling over five semesters and the results of teaching 5619: Environmental Engineering Design over two semesters are summarized, including responses of students to end-of-term assessments of teaching effectiveness. Based on student performance and feedback, modified mastery learning is a valid approach to meeting the goal of teaching sustainability and life-cycle principles as part of modeling and design for environmental engineers in ABET-accredited degree programs. Future efforts should include replication with diverse student populations at additional institutions.