Our goal is to establish and maintain environmental conditions that will, over time, result in the attainment of water quality standards and restoration of beneficial uses in the Guadalupe Watershed. In order to meet this goal, we must first clarify the problem statement by involving the Santa Clara Basin Watershed Management Initiative (SCBWMI) in reviewing the problem. If the revised problem statement still supports a traditional TMDL approach, we must develop a conceptual model for mercury fate and transport in the Guadalupe Watershed. In order to develop this model, we must understand the sources and sinks of mercury and the processes that act on the mercury to transform it into the bioavailable form, methylmercury. At the same time we do source analysis, we must begin to identify control measures that may be implemented. After we develop and apply the conceptual model, we should be able to compare the results of the model to the list of potential control measures and determine if further traditional TMDL steps (e.g., develop numerical targets, load allocations, etc.) are necessary to control the problem. If we determine that further traditional TMDL steps are necessary, we may need to develop a more quantitative model of mercury in the system. If we determine that the sources and processes identified in the conceptual model are adequately addressed by the control measures, we can exit the traditional TMDL process at this point and work on implementing, and monitoring the implementation of, the identified control measures through regulatory and stakeholder mechanisms.