3 October 2004 CPR Expands Water Testing Calgary - Recent groundwater checks in the city's southeast for a dangerous chemical have prompted railway officials to expand precautionary testing to about 100 Riverbend homes. "The overall picture continues to be quite encouraging... we're now cautiously optimistic we've reached the outer limits of the TCE migration from the original site," said Ed Greenberg, a spokesman for Canadian Pacific Railway, adding most of 30 recent water tests in Riverbend showed only trace levels at most.   "But there were a couple that had slightly elevated levels just above trace."   CPR regularly used trichloroethylene - a degreaser that in high doses may cause liver disease or cancer - in its Ogden shops during the 1950s, but stopped using it decades ago.