The purpose of the CGPS monitoring program is to ascertain the water quality in the Great Salt Pond by gathering information to determine the distribution and concentrations of contaminants in the water that are of concern. The results are used to track where the pollution is occurring and find ways to remedy it, as well as how to plan for the future. The results are also used to track changes in the water body over a span of time. Contaminants come from many different sources. On the pond, pollution comes from boats in the form of black water (raw sewage), grey water (water from washing boats, showers, dishes etc), and fuel leakage. From upland areas, sources include agriculture, failed septic and sewer systems, runoff from yards, and wildlife.