The UN's GEMStat project provides "scientifically sound data" on freshwater quality around the world. The data portal allows visitors to explore and download results from water samples from thousands of stations in over 80 countries. The information available for each sample varies, but may include chemical, biological and physical properties. Note: Not all locations have been sampled recently, and data downloads are limited to 500 stations at a time and for non-commercial purposes only. The World Bank's "The Invisible Water Crisis" report used GEMStat data.