TMDL Program: Are the State Standards Attainable?

Abstract

The restoration of impaired waters through the Total Maximum Daily Load (TMDL) program requires contributing pollutant sources to reduce their loads to a level that will result in the attainment of the water quality standard. In-stream numeric endpoints represent the water quality goals that are to be achieved by implementing the load reductions specified in the TMDL. To date, the TMDL allocation scenario is considered as the starting point for development of an implementation strategy. Modifications may be required if the necessary load reductions are not achieved or if the water quality goals are not met. The likelihood of a successful TMDL implementation depends on a feasible load a llocation among the polluters. A load allocation scenario developed for a given water quality criteria may not be feasible due to limitations on the effectiveness of the available control measures. The practicality of the load reduction levels when translated into the relevant control strategies should be investigated to better ascertain the attainability of a given water quality standard. If one considers the technical limitations of accomplishing the high level of reduction required by many sate TMDL programs, the question arises: “Are the state standards for the designated water uses attainable?”