The first step in any source water protection or assessment activity isexamination of the current water quality for a given source. This involves notonly spatial, but also temporal analysis of water quality data to identifycurrent or future contaminants of concern and identify their sources. However,not all water utilities have the luxury of extensive water quality monitoringnetworks and analyses. Therefore, it is important to know where to find waterquality data and how to decipher it into something usable and accurate. There area number of sources of water quality data out there. This paper identifiesnational data sources and internet sources as well as local and regional waterquality data sources. Data availability and other issues and pitfalls arediscussed. Includes table.