Here Come the TMDLs?

Rivers, lakes, and other water bodies across the country – including those that provide our drinking water – are contaminated with an eclectic cocktail of pharmaceuticals, fertilizers, and nutrients.  Genetic mutations thought to exist only in the realm of science fiction are now readily observed in fish and other aquatic species.  Overall, the EPA estimates that only 12 percent of the nation’s waters have been surveyed, and of that small percentage more than half can no longer be used for at least one designated use.

A recent article in Inside EPA (subscription required) details plans inside the Environmental Protection Agency to strengthen the protection of water by reviving a much-discussed but ill-fated rule to regulate water pollution from non-point sources. 

The Clean Water Act differentiates between point source (PS) pollution, which enters water through a discrete point of discharge, and non-point source (NPS) pollution, which enters water as indiscrete runoff.  Point source pollution is regulated through a discharge permit system, but EPA has no authority to regulate non-point source pollution.  Pollution from non-point sources, including agriculture and forestry operations, urban runoff, and natural erosion, is a complicated and controversial issue (CPR Member Scholar Robert Adler has also written a CPR Perspective on non-point source pollution, available here).  One aspect is clear: while PS pollution has decreased significantly under the Clean Water Act, that progress is negated by a corresponding increase in NPS pollution. 

Section 303(d) of the CWA establishes the “total maximum daily load” (TMDL) program, which requires states to identify water bodies that remain polluted after implementing point source controls and to set a numeric TMDL for specified pollutants, such as nitrogen or phosphorous, so that the water body will meet water quality standards.  If a state fails to set a TMDL, the EPA can intervene.  However, this action may be for naught since the EPA has no authority – and the states have no obligation – to implement the TMDL, relegating the process to an exercise in data collection. 

A TMDL is both a planning process for attaining water quality standards and a quantitative assessment of pollution problems, sources, and reductions needed to restore a water body.  As a quantitative assessment of pollution sources, a TMDL is a pollution budget that addresses all pollution sources – point sources, non-point sources, and natural sources.  Where an effective permit system has reduced point source pollution as much as possible, the idea is that the TMDL implementation program will turn to reducing non-point sources to meet the budget.

The article in Inside EPA gives a brief history of the EPA’s prior attempt to regulate NPS pollution.  Under the Clinton Administration, the EPA issued a final rule in July 2000 for the TMDL program that required comprehensive identification of impaired waters, implementation plans based on TMDLs, and new opportunities for public participation.  More importantly, the July 2000 rule required states to provide “reasonable assurance” that the TMDL program would be implemented, implicitly requiring states to address and control NPS pollution.  Naturally, the potentially affected groups – namely agriculture and forestry operations, which contribute significantly to NPS pollution – vehemently opposed the rule, even though the final rule was already less stringent than proposed.  Eventually these groups persuaded the Bush Administration to first delay and then withdraw the rule in 2003.

If, as the article suggests, the EPA does revive the rule and strengthen TMDL program, it would be great news for the nation’s waters.  Developing a TMDL is a resource-intensive process with many unknowns, but it is necessary.  Polluters that are responsible for the dismal state of the nation’s water should not respond to attempts to control water pollution by crying foul play because of uncertainties in the science.  For states facing severe budget deficits, a revived TMDL rule may cause a collective groan across governors’ mansions.  But the waters that are so crucial to social, cultural, and economic development should not be a casualty of short-sighted present interests or political paralysis.