ELR Citation: ELR 20203
No(s). 00-6232 (2d Cir. Oct 11, 2001)

The court affirms a district court holding that the Clean Water Act (CWA) does not require the state of New York to express its total maximum daily loads (TMDLs) for phosphorous in terms of daily loads but remands the case to the U.S. Environmental Protection Agency (EPA) to explain why New York's use of annual loads for phosphorous is appropriate. New York City's drinking water reservoirs have suffered increasing phosphorous pollution leading to eutrophication. After an environmental group sought to compel EPA to promulgate TMDLs for the reservoirs, New York established TMDLs based on the annual load of phosphorous in the reservoirs. The environmental group challenged the TMDLs. The district court upheld the TMDLs, and the group appealed. The court first holds that although the CWA calls for the establishment of daily loads, the term "TMDL" is susceptible to a broader range of meanings. The CWA contemplates the use of TMDLs in order to effectively regulate a pollutant, but because harmful effects of any pollutant may not be immediately present, close daily regulation for such pollutants may not be appropriate. Thus, EPA can utilize its expertise to determine that a TMDL may be expressed by another means of mass per time, where such an alternative measure best serves the purpose of effective regulation of pollutant levels in water bodies. Nevertheless, the court next holds that while the record makes clear why EPA or the state might not opt to measure loads on a daily basis, it remains unclear why an annual measurement of loads would be more appropriate since phosphorous concentrations vary within a water body on a seasonal basis. Therefore, the court remands to EPA to justify how the annual period of measurement takes seasonal variations into account. The court further holds that EPA's determination that the state can formulate its TMDLs for phosphorous in the drinking water reservoirs using an aesthetic criterion is not arbitrary and capricious. In the absence of national criterion for phosphorous, EPA relied on certain scientific evidence that the aesthetic value was sufficient to protect drinking water. Although there is conflicting scientific evidence, the court must defer to the agency's expertise. The court finally holds that EPA could reasonably conclude based on the close calibration of a model of phosphorous concentrations that a 10% margin of safety in the TMDL was sufficient.

Counsel for Plaintiffs
Mark A. Izeman
Natural Resources Defense Council
40 W. 20th St., New York NY 10011
(212) 727-2700

Counsel for Defendants
Andrew W. Schilling, Ass't U.S. Attorney
U.S. Attorney's Office
One St. Andrew's Plaza
100 Church St., New York NY 10007
(212) 637-2200

Pooler, J. Before Winter and McLaughlin, JJ.