mailmanDr. Larry Cathles writes (7/14) that Cargill’s Mine Shaft #4 project poses “no substantial risk of mine flooding,” and that any conceivable flooding would have “no societal impact.” Cathles’s conclusions, however, have been credibly rebutted by other experts, and the context Cathles proposes for DEC’s permit decision is incorrect:

DEC’s permit declarations are not based on how "substantial," "'special," or "compelling" an environmental risk or impact "will" be (Cathles’s words), but on whether any such risk "may be significant" (NYS SEQR law).

In risk analysis, “significance” is the combination of consequence and probability. A risk of very large potential consequence, even if deemed very rare, merits careful consideration of the sort DEC provides for in its Draft Environmental Impact Statement (DEIS) process. In such cases the “second-guessing” Dr. Cathles decries is not only desirable, it is required.

DEC may lack internal expertise on how catastrophic or rare a mine flood, a mine collapse, or the salinization of Cayuga Lake might be, but such risks fall well within the significance range for which DEC has required DEIS study.

In this case, the fact that well-trained, reasonable experts differ on risks of potentially very large consequence—however rare—argues for the release of all relevant data (such as seismic studies) and for public DEIS analysis.

Rob Mackenzie, MD, FACHE
Trumansburg, New York