From the Livingston Avenue bridge you can watch ice run on the Hudson in February, plates of it turning slowly downriver where the tide still reaches. Erno Enterprises Inc. takes Albany through both ends of that river year: snow plowing, walkway clearing and ice treatment in the cold months, then mowing, trimming and cleanups once the banks green up. Winter work is measured in cleared blacktop before sunrise; summer work is measured in a straight edge along a sidewalk. Neither is complicated, and both are easy to do badly. Doing them well is the whole trade.