Currently, the water supply in Costa Rica is good as large municipal systems that are part of state run systems obtain high water quality through extraction from deep wells. Conversely, small communities that are grouped into ASADAs find it challenging to obtain good water with limited funding. While quality drinking water is generally obtainable, the sanitation of that water is less certain. Much of the country relies on septic systems with grey water from general household use (kitchen, showers and sinks) flowing directly from households often down city streets or directly into neighboring streams. Students involved in this project will study rivers and beaches for contamination. We will look at extent of contamination and correlate findings to known and presumed sources of pollution. These findings will be presented to local and community leaders to work toward the betterment of water quality in the region and Costa Rica.