 Train noise could be the largest impact to the environment should the merger between Canadian Pacific and Kansas City Southern come to fruition, according to a draft environmental impact statement EIS released by the Surface Transportation Board. STBs Office of Environmental Analysis OEA, which conducted the study, has concluded that, apart from train noise, which could result in adverse impacts at some locations, the potential adverse impacts of the proposed acquisition would be negligible, minor andor temporary, according to the draft EIS released Friday. 