TMDL Action Planning: A Menu-Based Approach

The new generation of MS4 permits is requiring localities to develop TMDL action plans to address local water quality impairments. Given the need to control costs, MS4 managers are likely to ask “What is the most affordable TMDL action planning approach that will meet regulatory requirements”, and “What enhancements to the basic approach would help address our challenges in specific watersheds?” This paper describes the manner in which the City of Columbia, South Carolina addressed the problem by developing a menu-based TMDL action planning methodology. This methodology identifies each of the key components of TMDL including pollutant source characterization, modeling, BMP selection, and stakeholder engagement. The methodology identifies the key decision criteria that can be used to select the appropriate level of effort for each watershed. Because planning is a continuous, iterative process, lower-level efforts can be followed by higher level efforts into the future based on better technology, data, budgets, or stakeholder involvement.