Professor Mathisen's teaching and research concentrate in the areas of water resources and environmental engineering. He enjoys challenging himself to learn new ideas and concepts, which he can then apply to solve problems that can make a difference for other people. WPI's curriculum and projects program provide the perfect environment for fostering these opportunities. Professor Mathisen especially enjoys advising projects and working with students, since these activities always provide excellent opportunities to learn, solve problems, and make a difference. Some of the key challenges in water resources and environmental engineering include providing sufficient clean drinking water, protecting water quality and ecosystem health, and developing plans to address some of the long-term effects of development and climate change. By combining hands-on work in the laboratory and field with modeling techniques, and working in collaboration with a number of colleagues and a variety of organizations, Professor Mathisen’s teaching and research programs are addressing these challenges.