A New Approach to Adaptive Implementation in the TMDL Program

An expert panel was convened to explore the use of adaptive implementation in the TMDL program, following a 2001 National Research Council report recommendation. This paper summarizes the panel’s report suggesting an adaptive implementation process for water quality management. In current practice, what the panel calls standard implementation, a plan for reducing pollutant loads to meet water quality standards, is established when a TMDL is completed, and that TMDL and plan are not intentionally revisited. Adaptive implementation (AI) by contrast means that the TMDL and the implementation plan are continually updated and revised based on an intentional and well-resourced process to secure new information to reduce technical uncertainties. This paper identifies situations warranting an adaptive implementation approach, describes in concept adaptive implementation, and identifies key regulatory and technical challenges.