Potable water suppliers strive to maintain high quality raw water sources. Protecting raw water quality can reduce treatment costs and may postpone or avoid the need to develop new supplies. An important first step in maintaining a high quality raw water supply is to assess the presence of potential groundwater contamination sources in the area of water supply wells. This is particularly important in a dispersed wellfield system, where several wells may be linked together in an urban setting consisting of various land uses, specifically commercial and industrial uses. Tampa Bay Water recognizes the importance of protecting the raw groundwater supply from adverse environmental conditions, including contamination from historic or ongoing land use practices in the area of its supply wells. Tampa Bay Water's proactive dispersed wellfield monitoring program is key to the ongoing effort to protect this valuable resource. This monitoring program can be considered a comprehensive evaluation which can be used by other water suppliers to develop their own monitoring programs. Includes figure.