Economic and Environmental Analysis of Sanitation Technologies (EEAST) is an excel model developed at the Sustainability Engineering Lab of the University of Toledo for comparing alternative water and sanitation systems of buildings. EEAST compares the use of harvested rainwater to flush toilets to standard potable water flushed toilets and waterless composting toilets. EEAST can also model high efficiency toilets (less than 1.6 gal per flush) and the use of harvested rainwater versus potable water for irrigation purposes. With these capabilities, EEAST can model the most important water uses in a typical building.

EEAST first sizes the system based on user input data. Then, the sized system is used to calculate and output life cycle cost, energy, and greenhouse gas emissions of each design scenario so that an informed decision can be made on which design or technology is most suitable for that building. EEAST also calculates payback periods and the Net Present Value (NPV).

EEAST was developed because there currently exists no other tool for evaluating the economic and environmental pros and cons of alternative water and sanitation technologies in buildings.

EEAST is free to use.

Please contact Dr. Defne Apul if you have any questions or feedback on EEAST. To stay abreast of EEAST developments, please sign up for our EEAST LinkedIN group.