Obama's and Biden's promises to end coal-fired electrical generation may spell doom for Pittsburgh's Three Rivers as we know them today. Consider: These rivers, the Allegheny, Monongahela and the headwaters of the Ohio are maintained in a navigable (i.e. boat-able) condition for commercial tow traffic. Not for the benefit of recreational boaters, nor for supplying water to municipal water systems, or for hydrolectric power generation. These are but incidental benefits. According to the Port of Pittsburgh Commission, from 1998 through 2006, an average of 47.5 milion tons of commodities were moved annually on the Three Rivers. An average of 35.2...