TMDLs: Expeditious or Implementable?

The development of total maximum daily loads (TMDLs) for watersheds with nonpoint source problems has been traditionally hindered by a lack of data. Recent legal decisions have accelerated TMDL development, although the same paucity of information that hindered earlier understanding still largely exists. The mandate to develop TMDLs in the absence of data can lead to two outcomes with a high probability of undesirable consequences relative to the implementation of TMDLs:Postponement of TMDL implementation until additional data can be collected: This outcome will further delay the attainment of water quality standards.Development of TMDLs based on very sparse data: This outcome will often lead to requirements for unnecessary controls, especially if the Margin of Safety component of the TMDL is given a literal interpretation.Both of these outcomes can be expected to lead to litigation, with the first outcome prompting litigation from the environmental community and the second outcome prompting litigation from the regulated community. Phased TMDLs, with immediate implementation of obviously necessary controls, followed by adaptive management may provide an acceptable middle ground at some sites. The only long-term solution to this problem is increased monitoring efforts; however, these monitoring efforts must be specifically designed to consider TMDL development needs.